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parquet/arrow/arrow_writer/
mod.rs

1// Licensed to the Apache Software Foundation (ASF) under one
2// or more contributor license agreements.  See the NOTICE file
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4// regarding copyright ownership.  The ASF licenses this file
5// to you under the Apache License, Version 2.0 (the
6// "License"); you may not use this file except in compliance
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8//
9//   http://www.apache.org/licenses/LICENSE-2.0
10//
11// Unless required by applicable law or agreed to in writing,
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14// KIND, either express or implied.  See the License for the
15// specific language governing permissions and limitations
16// under the License.
17
18//! Contains writer which writes arrow data into parquet data.
19
20use crate::column::chunker::ContentDefinedChunker;
21
22use bytes::Bytes;
23use std::io::Write;
24use std::slice::Iter;
25use std::sync::{Arc, Mutex};
26use std::vec::IntoIter;
27
28use arrow_array::cast::AsArray;
29use arrow_array::{ArrayRef, Int32Array, RecordBatch, RecordBatchWriter};
30use arrow_array::{PrimitiveArray, types::*};
31use arrow_schema::{
32    ArrowError, DataType as ArrowDataType, Field, IntervalUnit, SchemaRef, TimeUnit,
33};
34
35use super::schema::{add_encoded_arrow_schema_to_metadata, decimal_length_from_precision};
36
37use crate::arrow::ArrowSchemaConverter;
38use crate::arrow::arrow_writer::byte_array::ByteArrayEncoder;
39use crate::basic::PageType;
40use crate::column::page::{CompressedPage, PageWriteSpec, PageWriter};
41use crate::column::page_encryption::PageEncryptor;
42use crate::column::writer::encoder::ColumnValueEncoder;
43use crate::column::writer::{
44    ColumnCloseResult, ColumnWriter, GenericColumnWriter, get_column_writer,
45};
46use crate::data_type::{ByteArray, FixedLenByteArray};
47use std::collections::HashSet;
48type DistinctValuesSet = HashSet<u64>;
49#[cfg(feature = "encryption")]
50use crate::encryption::encrypt::FileEncryptor;
51use crate::errors::{ParquetError, Result};
52use crate::file::metadata::{KeyValue, ParquetMetaData, RowGroupMetaData};
53use crate::file::properties::{WriterProperties, WriterPropertiesPtr};
54use crate::file::writer::{SerializedFileWriter, SerializedRowGroupWriter};
55use crate::parquet_thrift::{ThriftCompactOutputProtocol, WriteThrift};
56use crate::schema::types::{ColumnDescPtr, SchemaDescPtr, SchemaDescriptor};
57use levels::{ArrayLevels, calculate_array_levels};
58
59mod byte_array;
60mod levels;
61
62#[doc(inline)]
63pub use crate::column::page_store::{
64    InMemoryPageStore, InMemoryPageStoreFactory, PageKey, PageStore, PageStoreArgs,
65    PageStoreFactory,
66};
67
68/// Encodes [`RecordBatch`] to parquet
69///
70/// Writes Arrow `RecordBatch`es to a Parquet writer. Multiple [`RecordBatch`] will be encoded
71/// to the same row group, up to `max_row_group_size` rows. Any remaining rows will be
72/// flushed on close, leading the final row group in the output file to potentially
73/// contain fewer than `max_row_group_size` rows
74///
75/// # Example: Writing `RecordBatch`es
76/// ```
77/// # use std::sync::Arc;
78/// # use bytes::Bytes;
79/// # use arrow_array::{ArrayRef, Int64Array};
80/// # use arrow_array::RecordBatch;
81/// # use parquet::arrow::arrow_writer::ArrowWriter;
82/// # use parquet::arrow::arrow_reader::ParquetRecordBatchReader;
83/// let col = Arc::new(Int64Array::from_iter_values([1, 2, 3])) as ArrayRef;
84/// let to_write = RecordBatch::try_from_iter([("col", col)]).unwrap();
85///
86/// let mut buffer = Vec::new();
87/// let mut writer = ArrowWriter::try_new(&mut buffer, to_write.schema(), None).unwrap();
88/// writer.write(&to_write).unwrap();
89/// writer.close().unwrap();
90///
91/// let mut reader = ParquetRecordBatchReader::try_new(Bytes::from(buffer), 1024).unwrap();
92/// let read = reader.next().unwrap().unwrap();
93///
94/// assert_eq!(to_write, read);
95/// ```
96///
97/// # Memory Usage and Limiting
98///
99/// The nature of Parquet requires buffering of an entire row group before it can
100/// be flushed to the underlying writer. Data is mostly buffered in its encoded
101/// form, reducing memory usage. However, some data such as dictionary keys,
102/// large strings or very nested data may still result in non-trivial memory
103/// usage.
104///
105/// See Also:
106/// * [`ArrowWriter::memory_size`]: the current memory usage of the writer.
107/// * [`ArrowWriter::in_progress_size`]: Estimated size of the buffered row group,
108///
109/// Call [`Self::flush`] to trigger an early flush of a row group based on a
110/// memory threshold and/or global memory pressure. However,  smaller row groups
111/// result in higher metadata overheads, and thus may worsen compression ratios
112/// and query performance.
113///
114/// ```no_run
115/// # use std::io::Write;
116/// # use arrow_array::RecordBatch;
117/// # use parquet::arrow::ArrowWriter;
118/// # let mut writer: ArrowWriter<Vec<u8>> = todo!();
119/// # let batch: RecordBatch = todo!();
120/// writer.write(&batch).unwrap();
121/// // Trigger an early flush if anticipated size exceeds 1_000_000
122/// if writer.in_progress_size() > 1_000_000 {
123///     writer.flush().unwrap();
124/// }
125/// ```
126///
127/// ## Type Support
128///
129/// The writer supports writing all Arrow [`DataType`]s that have a direct mapping to
130/// Parquet types including  [`StructArray`] and [`ListArray`].
131///
132/// The following are not supported:
133///
134/// * [`IntervalMonthDayNanoArray`]: Parquet does not [support nanosecond intervals].
135///
136/// [`DataType`]: https://docs.rs/arrow/latest/arrow/datatypes/enum.DataType.html
137/// [`StructArray`]: https://docs.rs/arrow/latest/arrow/array/struct.StructArray.html
138/// [`ListArray`]: https://docs.rs/arrow/latest/arrow/array/type.ListArray.html
139/// [`IntervalMonthDayNanoArray`]: https://docs.rs/arrow/latest/arrow/array/type.IntervalMonthDayNanoArray.html
140/// [support nanosecond intervals]: https://github.com/apache/parquet-format/blob/master/LogicalTypes.md#interval
141///
142/// ## Type Compatibility
143/// The writer can write Arrow [`RecordBatch`]s that are logically equivalent. This means that for
144/// a  given column, the writer can accept multiple Arrow [`DataType`]s that contain the same
145/// value type.
146///
147/// For example, the following [`DataType`]s are all logically equivalent and can be written
148/// to the same column:
149/// * String, LargeString, StringView
150/// * Binary, LargeBinary, BinaryView
151///
152/// The writer can will also accept both native and dictionary encoded arrays if the dictionaries
153/// contain compatible values.
154/// ```
155/// # use std::sync::Arc;
156/// # use arrow_array::{DictionaryArray, LargeStringArray, RecordBatch, StringArray, UInt8Array};
157/// # use arrow_schema::{DataType, Field, Schema};
158/// # use parquet::arrow::arrow_writer::ArrowWriter;
159/// let record_batch1 = RecordBatch::try_new(
160///    Arc::new(Schema::new(vec![Field::new("col", DataType::LargeUtf8, false)])),
161///    vec![Arc::new(LargeStringArray::from_iter_values(vec!["a", "b"]))]
162///  )
163/// .unwrap();
164///
165/// let mut buffer = Vec::new();
166/// let mut writer = ArrowWriter::try_new(&mut buffer, record_batch1.schema(), None).unwrap();
167/// writer.write(&record_batch1).unwrap();
168///
169/// let record_batch2 = RecordBatch::try_new(
170///     Arc::new(Schema::new(vec![Field::new(
171///         "col",
172///         DataType::Dictionary(Box::new(DataType::UInt8), Box::new(DataType::Utf8)),
173///          false,
174///     )])),
175///     vec![Arc::new(DictionaryArray::new(
176///          UInt8Array::from_iter_values(vec![0, 1]),
177///          Arc::new(StringArray::from_iter_values(vec!["b", "c"])),
178///      ))],
179///  )
180///  .unwrap();
181///  writer.write(&record_batch2).unwrap();
182///  writer.close();
183/// ```
184pub struct ArrowWriter<W: Write> {
185    /// Underlying Parquet writer
186    writer: SerializedFileWriter<W>,
187
188    /// The in-progress row group if any
189    in_progress: Option<ArrowRowGroupWriter>,
190
191    /// A copy of the Arrow schema.
192    ///
193    /// The schema is used to verify that each record batch written has the correct schema
194    arrow_schema: SchemaRef,
195
196    /// Creates new [`ArrowRowGroupWriter`] instances as required
197    row_group_writer_factory: ArrowRowGroupWriterFactory,
198
199    /// The maximum number of rows to write to each row group, or None for unlimited
200    max_row_group_row_count: Option<usize>,
201
202    /// The maximum size in bytes for a row group, or None for unlimited
203    max_row_group_bytes: Option<usize>,
204
205    /// CDC chunkers persisted across row groups (one per leaf column).
206    cdc_chunkers: Option<Vec<ContentDefinedChunker>>,
207}
208
209impl<W: Write + Send> std::fmt::Debug for ArrowWriter<W> {
210    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
211        let buffered_memory = self.in_progress_size();
212        f.debug_struct("ArrowWriter")
213            .field("writer", &self.writer)
214            .field("in_progress_size", &format_args!("{buffered_memory} bytes"))
215            .field("in_progress_rows", &self.in_progress_rows())
216            .field("arrow_schema", &self.arrow_schema)
217            .field("max_row_group_row_count", &self.max_row_group_row_count)
218            .field("max_row_group_bytes", &self.max_row_group_bytes)
219            .finish()
220    }
221}
222
223impl<W: Write + Send> ArrowWriter<W> {
224    /// Try to create a new Arrow writer
225    ///
226    /// The writer will fail if:
227    ///  * a `SerializedFileWriter` cannot be created from the ParquetWriter
228    ///  * the Arrow schema contains unsupported datatypes such as Unions
229    pub fn try_new(
230        writer: W,
231        arrow_schema: SchemaRef,
232        props: Option<WriterProperties>,
233    ) -> Result<Self> {
234        let options = ArrowWriterOptions::new().with_properties(props.unwrap_or_default());
235        Self::try_new_with_options(writer, arrow_schema, options)
236    }
237
238    /// Try to create a new Arrow writer with [`ArrowWriterOptions`].
239    ///
240    /// The writer will fail if:
241    ///  * a `SerializedFileWriter` cannot be created from the ParquetWriter
242    ///  * the Arrow schema contains unsupported datatypes such as Unions
243    pub fn try_new_with_options(
244        writer: W,
245        arrow_schema: SchemaRef,
246        options: ArrowWriterOptions,
247    ) -> Result<Self> {
248        let mut props = options.properties;
249
250        let schema = if let Some(parquet_schema) = options.schema_descr {
251            parquet_schema.clone()
252        } else {
253            let mut converter = ArrowSchemaConverter::new().with_coerce_types(props.coerce_types());
254            if let Some(schema_root) = &options.schema_root {
255                converter = converter.schema_root(schema_root);
256            }
257
258            converter.convert(&arrow_schema)?
259        };
260
261        if !options.skip_arrow_metadata {
262            // add serialized arrow schema
263            add_encoded_arrow_schema_to_metadata(&arrow_schema, &mut props);
264        }
265
266        let max_row_group_row_count = props.max_row_group_row_count();
267        let max_row_group_bytes = props.max_row_group_bytes();
268
269        let props_ptr = Arc::new(props);
270        let file_writer =
271            SerializedFileWriter::new(writer, schema.root_schema_ptr(), Arc::clone(&props_ptr))?;
272
273        let mut row_group_writer_factory =
274            ArrowRowGroupWriterFactory::new(&file_writer, arrow_schema.clone());
275        if let Some(page_store_factory) = options.page_store_factory {
276            row_group_writer_factory =
277                row_group_writer_factory.with_page_store_factory(page_store_factory);
278        }
279
280        let cdc_chunkers = props_ptr
281            .content_defined_chunking()
282            .map(|opts| {
283                file_writer
284                    .schema_descr()
285                    .columns()
286                    .iter()
287                    .map(|desc| ContentDefinedChunker::new(desc, opts))
288                    .collect::<Result<Vec<_>>>()
289            })
290            .transpose()?;
291
292        Ok(Self {
293            writer: file_writer,
294            in_progress: None,
295            arrow_schema,
296            row_group_writer_factory,
297            max_row_group_row_count,
298            max_row_group_bytes,
299            cdc_chunkers,
300        })
301    }
302
303    /// Returns metadata for any flushed row groups
304    pub fn flushed_row_groups(&self) -> &[RowGroupMetaData] {
305        self.writer.flushed_row_groups()
306    }
307
308    /// Estimated memory usage, in bytes, of this `ArrowWriter`
309    ///
310    /// This estimate is formed bu summing the values of
311    /// [`ArrowColumnWriter::memory_size`] all in progress columns.
312    pub fn memory_size(&self) -> usize {
313        match &self.in_progress {
314            Some(in_progress) => in_progress.writers.iter().map(|x| x.memory_size()).sum(),
315            None => 0,
316        }
317    }
318
319    /// Anticipated encoded size of the in progress row group.
320    ///
321    /// This estimate the row group size after being completely encoded is,
322    /// formed by summing the values of
323    /// [`ArrowColumnWriter::get_estimated_total_bytes`] for all in progress
324    /// columns.
325    pub fn in_progress_size(&self) -> usize {
326        match &self.in_progress {
327            Some(in_progress) => in_progress
328                .writers
329                .iter()
330                .map(|x| x.get_estimated_total_bytes())
331                .sum(),
332            None => 0,
333        }
334    }
335
336    /// Returns the number of rows buffered in the in progress row group
337    pub fn in_progress_rows(&self) -> usize {
338        self.in_progress
339            .as_ref()
340            .map(|x| x.buffered_rows)
341            .unwrap_or_default()
342    }
343
344    /// Returns the number of bytes written by this instance
345    pub fn bytes_written(&self) -> usize {
346        self.writer.bytes_written()
347    }
348
349    /// Encodes the provided [`RecordBatch`]
350    ///
351    /// If this would cause the current row group to exceed [`WriterProperties::max_row_group_row_count`]
352    /// rows or [`WriterProperties::max_row_group_bytes`] bytes, the contents of `batch` will be
353    /// written to one or more row groups such that limits are respected.
354    ///
355    /// If both limits are `None`, all data is written to a single row group.
356    /// If one limit is set, that limit is respected.
357    /// If both limits are set, the lower bound (whichever triggers first) is respected.
358    ///
359    /// This will fail if the `batch`'s schema does not match the writer's schema.
360    pub fn write(&mut self, batch: &RecordBatch) -> Result<()> {
361        if batch.num_rows() == 0 {
362            return Ok(());
363        }
364
365        let in_progress = match &mut self.in_progress {
366            Some(in_progress) => in_progress,
367            x => x.insert(
368                self.row_group_writer_factory
369                    .create_row_group_writer(self.writer.flushed_row_groups().len())?,
370            ),
371        };
372
373        if let Some(max_rows) = self.max_row_group_row_count
374            && in_progress.buffered_rows + batch.num_rows() > max_rows
375        {
376            let to_write = max_rows - in_progress.buffered_rows;
377            let a = batch.slice(0, to_write);
378            let b = batch.slice(to_write, batch.num_rows() - to_write);
379            self.write(&a)?;
380            return self.write(&b);
381        }
382
383        // Check byte limit: if we have buffered data, use measured average row size
384        // to split batch proactively before exceeding byte limit
385        if let Some(max_bytes) = self.max_row_group_bytes
386            && in_progress.buffered_rows > 0
387        {
388            let current_bytes = in_progress.get_estimated_total_bytes();
389
390            if current_bytes >= max_bytes {
391                self.flush()?;
392                return self.write(batch);
393            }
394
395            if let Some(avg_row_bytes) = current_bytes
396                .checked_div(in_progress.buffered_rows)
397                .filter(|avg_row_bytes| *avg_row_bytes > 0)
398            {
399                // At this point, `current_bytes < max_bytes` (checked above)
400                let remaining_bytes = max_bytes - current_bytes;
401                let rows_that_fit = remaining_bytes.checked_div(avg_row_bytes).unwrap_or(0);
402
403                if batch.num_rows() > rows_that_fit {
404                    if rows_that_fit > 0 {
405                        let a = batch.slice(0, rows_that_fit);
406                        let b = batch.slice(rows_that_fit, batch.num_rows() - rows_that_fit);
407                        self.write(&a)?;
408                        return self.write(&b);
409                    } else {
410                        self.flush()?;
411                        return self.write(batch);
412                    }
413                }
414            }
415        }
416
417        match self.cdc_chunkers.as_mut() {
418            Some(chunkers) => in_progress.write_with_chunkers(batch, chunkers)?,
419            None => in_progress.write(batch)?,
420        }
421
422        let should_flush = self
423            .max_row_group_row_count
424            .is_some_and(|max| in_progress.buffered_rows >= max)
425            || self
426                .max_row_group_bytes
427                .is_some_and(|max| in_progress.get_estimated_total_bytes() >= max);
428
429        if should_flush {
430            self.flush()?
431        }
432        Ok(())
433    }
434
435    /// Writes the given buf bytes to the internal buffer.
436    ///
437    /// It's safe to use this method to write data to the underlying writer,
438    /// because it will ensure that the buffering and byte‐counting layers are used.
439    pub fn write_all(&mut self, buf: &[u8]) -> std::io::Result<()> {
440        self.writer.write_all(buf)
441    }
442
443    /// Flushes underlying writer
444    pub fn sync(&mut self) -> std::io::Result<()> {
445        self.writer.flush()
446    }
447
448    /// Flushes all buffered rows into a new row group
449    ///
450    /// Note the underlying writer is not flushed with this call.
451    /// If this is a desired behavior, please call [`ArrowWriter::sync`].
452    pub fn flush(&mut self) -> Result<()> {
453        let Some(in_progress) = self.in_progress.take() else {
454            return Ok(());
455        };
456
457        let mut row_group_writer = self.writer.next_row_group()?;
458        for chunk in in_progress.close()? {
459            chunk.append_to_row_group(&mut row_group_writer)?;
460        }
461        row_group_writer.close()?;
462        Ok(())
463    }
464
465    /// Additional [`KeyValue`] metadata to be written in addition to those from [`WriterProperties`]
466    ///
467    /// This method provide a way to append kv_metadata after write RecordBatch
468    pub fn append_key_value_metadata(&mut self, kv_metadata: KeyValue) {
469        self.writer.append_key_value_metadata(kv_metadata)
470    }
471
472    /// Returns a reference to the underlying writer.
473    pub fn inner(&self) -> &W {
474        self.writer.inner()
475    }
476
477    /// Returns a mutable reference to the underlying writer.
478    ///
479    /// **Warning**: if you write directly to this writer, you will skip
480    /// the `TrackedWrite` buffering and byte‐counting layers. That’ll cause
481    /// the file footer’s recorded offsets and sizes to diverge from reality,
482    /// resulting in an unreadable or corrupted Parquet file.
483    ///
484    /// If you want to write safely to the underlying writer, use [`Self::write_all`].
485    pub fn inner_mut(&mut self) -> &mut W {
486        self.writer.inner_mut()
487    }
488
489    /// Flushes any outstanding data and returns the underlying writer.
490    pub fn into_inner(mut self) -> Result<W> {
491        self.flush()?;
492        self.writer.into_inner()
493    }
494
495    /// Close and finalize the underlying Parquet writer
496    ///
497    /// Unlike [`Self::close`] this does not consume self
498    ///
499    /// Attempting to write after calling finish will result in an error
500    pub fn finish(&mut self) -> Result<ParquetMetaData> {
501        self.flush()?;
502        self.writer.finish()
503    }
504
505    /// Close and finalize the underlying Parquet writer
506    pub fn close(mut self) -> Result<ParquetMetaData> {
507        self.finish()
508    }
509
510    /// Converts this writer into a lower-level [`SerializedFileWriter`] and [`ArrowRowGroupWriterFactory`].
511    ///
512    /// Flushes any outstanding data before returning.
513    ///
514    /// This can be useful to provide more control over how files are written, for example
515    /// to write columns in parallel. See the example on [`ArrowColumnWriter`].
516    pub fn into_serialized_writer(
517        mut self,
518    ) -> Result<(SerializedFileWriter<W>, ArrowRowGroupWriterFactory)> {
519        self.flush()?;
520        Ok((self.writer, self.row_group_writer_factory))
521    }
522}
523
524impl<W: Write + Send> RecordBatchWriter for ArrowWriter<W> {
525    fn write(&mut self, batch: &RecordBatch) -> Result<(), ArrowError> {
526        self.write(batch).map_err(|e| e.into())
527    }
528
529    fn close(self) -> std::result::Result<(), ArrowError> {
530        self.close()?;
531        Ok(())
532    }
533}
534
535/// Arrow-specific configuration settings for writing parquet files.
536///
537/// See [`ArrowWriter`] for how to configure the writer.
538#[derive(Debug, Clone, Default)]
539pub struct ArrowWriterOptions {
540    properties: WriterProperties,
541    skip_arrow_metadata: bool,
542    schema_root: Option<String>,
543    schema_descr: Option<SchemaDescriptor>,
544    page_store_factory: Option<Arc<dyn PageStoreFactory>>,
545}
546
547impl ArrowWriterOptions {
548    /// Creates a new [`ArrowWriterOptions`] with the default settings.
549    pub fn new() -> Self {
550        Self::default()
551    }
552
553    /// Sets the [`WriterProperties`] for writing parquet files.
554    pub fn with_properties(self, properties: WriterProperties) -> Self {
555        Self { properties, ..self }
556    }
557
558    /// Sets the [`PageStoreFactory`] used to buffer completed pages while a row
559    /// group is being written.
560    ///
561    /// The default implementation ([`InMemoryPageStore`]) buffers all completed
562    /// pages on the heap until the row group is flushed, so peak write memory
563    /// grows with the row group size. Using this API, pages can be spilled to a
564    /// file or object storage instead, reducing peak write memory substantially
565    /// at the expense of an extra write to and read from secondary storage.
566    ///
567    /// # Example: spilling pages to a temp file
568    ///
569    /// A simple spilling backend uses one temp file per column chunk; `put`
570    /// appends the page and `take` reads it back.
571    ///
572    /// ```
573    /// # use std::fs::File;
574    /// # use std::io::{Read, Seek, SeekFrom, Write};
575    /// # use std::sync::Arc;
576    /// # use bytes::Bytes;
577    /// # use arrow_array::{ArrayRef, Int64Array, RecordBatch};
578    /// # use parquet::arrow::arrow_writer::{
579    /// #     ArrowWriter, ArrowWriterOptions, PageKey, PageStore, PageStoreArgs, PageStoreFactory,
580    /// # };
581    /// # use parquet::arrow::arrow_reader::ParquetRecordBatchReader;
582    /// # use parquet::errors::Result;
583    /// struct TempFilePageStore {
584    ///     file: File,
585    ///     /// Total size of the file
586    ///     end: u64,
587    ///     /// Location of pages: (offset, len)
588    ///     locs: Vec<(u64, usize)>,
589    /// }
590    ///
591    /// impl PageStore for TempFilePageStore {
592    ///     fn put(&mut self, value: Bytes) -> Result<PageKey> {
593    ///         // Append to the end of the file
594    ///         self.file.seek(SeekFrom::Start(self.end))?;
595    ///         self.file.write_all(&value)?;
596    ///         let key = PageKey::new(self.locs.len() as u64);
597    ///         self.locs.push((self.end, value.len()));
598    ///         self.end += value.len() as u64;
599    ///         Ok(key)
600    ///     }
601    ///
602    ///     fn take(&mut self, key: PageKey) -> Result<Bytes> {
603    ///         let (offset, len) = self.locs[key.get() as usize];
604    ///         let mut buf = vec![0u8; len];
605    ///         self.file.seek(SeekFrom::Start(offset))?;
606    ///         self.file.read_exact(&mut buf)?;
607    ///         Ok(Bytes::from(buf))
608    ///     }
609    /// }
610    ///
611    /// /// Factory for creating [`TempFilePageStore`]
612    /// #[derive(Debug)]
613    /// struct TempFilePageStoreFactory;
614    ///
615    /// impl PageStoreFactory for TempFilePageStoreFactory {
616    ///     fn create(&self, args: &PageStoreArgs<'_>) -> Result<Box<dyn PageStore>> {
617    ///         // `args` exposes the column index and descriptor (physical/logical
618    ///         // type, path), so a real backend might choose to spill only large columns.
619    ///         let _ = (args.column_index(), args.column_descriptor());
620    ///         Ok(Box::new(TempFilePageStore {
621    ///             file: tempfile::tempfile()?, // temp file is cleaned on drop
622    ///             end: 0,
623    ///             locs: Vec::new(),
624    ///         }))
625    ///     }
626    /// }
627    /// // write 1000 integers
628    /// let col = Arc::new(Int64Array::from_iter_values(0..1000)) as ArrayRef;
629    /// let to_write = RecordBatch::try_from_iter([("col", col)]).unwrap();
630    ///
631    /// let options =
632    ///     ArrowWriterOptions::new().with_page_store_factory(Arc::new(TempFilePageStoreFactory));
633    /// let mut buffer = Vec::new();
634    /// let mut writer =
635    ///     ArrowWriter::try_new_with_options(&mut buffer, to_write.schema(), options).unwrap();
636    /// writer.write(&to_write).unwrap();
637    /// writer.close().unwrap();
638    ///
639    /// // buffer now holds valid Parquet data, which can be read as normal:
640    /// let mut reader = ParquetRecordBatchReader::try_new(Bytes::from(buffer), 1024).unwrap();
641    /// assert_eq!(to_write, reader.next().unwrap().unwrap());
642    /// ```
643    pub fn with_page_store_factory(self, page_store_factory: Arc<dyn PageStoreFactory>) -> Self {
644        Self {
645            page_store_factory: Some(page_store_factory),
646            ..self
647        }
648    }
649
650    /// Skip encoding the embedded arrow metadata (defaults to `false`)
651    ///
652    /// Parquet files generated by the [`ArrowWriter`] contain embedded arrow schema
653    /// by default.
654    ///
655    /// Set `skip_arrow_metadata` to true, to skip encoding the embedded metadata.
656    pub fn with_skip_arrow_metadata(self, skip_arrow_metadata: bool) -> Self {
657        Self {
658            skip_arrow_metadata,
659            ..self
660        }
661    }
662
663    /// Set the name of the root parquet schema element (defaults to `"arrow_schema"`)
664    pub fn with_schema_root(self, schema_root: String) -> Self {
665        Self {
666            schema_root: Some(schema_root),
667            ..self
668        }
669    }
670
671    /// Explicitly specify the Parquet schema to be used
672    ///
673    /// If omitted (the default), the [`ArrowSchemaConverter`] is used to compute the
674    /// Parquet [`SchemaDescriptor`]. This may be used When the [`SchemaDescriptor`] is
675    /// already known or must be calculated using custom logic.
676    pub fn with_parquet_schema(self, schema_descr: SchemaDescriptor) -> Self {
677        Self {
678            schema_descr: Some(schema_descr),
679            ..self
680        }
681    }
682}
683
684/// A single column chunk produced by [`ArrowColumnWriter`].
685///
686/// Holds the serialized page blobs (each page's header ‖ compressed data, in
687/// write order) in a [`PageStore`], plus the handles needed to read them back,
688/// in order, when the chunk is spliced into the output file.
689struct ArrowColumnChunkData {
690    length: usize,
691    store: Box<dyn PageStore>,
692    keys: Vec<PageKey>,
693    /// Handles to the dictionary page's blobs (header then data) in the store.
694    ///
695    /// A dictionary page is produced at most once and bounded by
696    /// `dict_page_size_limit`, but it must be written *first* in the chunk even
697    /// though the data pages reach the writer before it (see
698    /// [`PageWriter::defers_dictionary_ordering`]). Its header and data are `put`
699    /// into the store like any other page — which keeps the store uniform, and
700    /// lets an oversized dictionary page spill — and their handles are held apart
701    /// so they can be emitted ahead of the data pages at splice.
702    /// Empty for non-dictionary columns.
703    dictionary_keys: Vec<PageKey>,
704    /// Serialized length of the dictionary page (0 if there is none), recorded
705    /// so the data pages can be shifted past it when offsets are rewritten to a
706    /// dictionary-first layout at splice.
707    dictionary_len: usize,
708}
709
710impl ArrowColumnChunkData {
711    fn new(store: Box<dyn PageStore>) -> Self {
712        Self {
713            length: 0,
714            store,
715            keys: Vec::new(),
716            dictionary_keys: Vec::new(),
717            dictionary_len: 0,
718        }
719    }
720
721    /// Append a data-page blob to the store, recording its handle in write
722    /// order.
723    fn push(&mut self, value: Bytes) -> Result<()> {
724        let key = self.store.put(value)?;
725        self.keys.push(key);
726        Ok(())
727    }
728
729    /// Store a dictionary-page blob (header or data) in the page store,
730    /// recording its handle (emitted first at splice) and accumulating its
731    /// serialized length.
732    fn push_dictionary(&mut self, value: Bytes) -> Result<()> {
733        self.dictionary_len += value.len();
734        let key = self.store.put(value)?;
735        self.dictionary_keys.push(key);
736        Ok(())
737    }
738
739    /// Bytes this chunk currently holds on the heap: whatever the store keeps
740    /// resident (zero for a spilling backend).
741    fn memory_size(&self) -> usize {
742        self.store.memory_size()
743    }
744}
745
746/// A streaming iterator over one column chunk's buffered page blobs, in final
747/// file order: the dictionary page (if any) first, then the data pages.
748///
749/// Each blob is taken back out of the [`PageStore`] *as it is
750/// consumed* and released immediately afterwards, so splicing a chunk into the
751/// output file never materializes more than a single page in memory at a time.
752/// This is what keeps the splice phase within the memory bound for a spilling
753/// backend (an in-memory store already holds the bytes, so it is unaffected).
754struct StreamingColumnChunkPages {
755    store: Box<dyn PageStore>,
756    /// Page handles in final file order: the dictionary page first (if any),
757    /// then the data pages.
758    keys: IntoIter<PageKey>,
759}
760
761impl StreamingColumnChunkPages {
762    fn new(data: ArrowColumnChunkData) -> Self {
763        // The dictionary page must be emitted first, ahead of the data pages,
764        // even though it was the last page produced.
765        let keys = if data.dictionary_keys.is_empty() {
766            data.keys
767        } else {
768            let mut keys = Vec::with_capacity(data.dictionary_keys.len() + data.keys.len());
769            keys.extend(data.dictionary_keys);
770            keys.extend(data.keys);
771            keys
772        };
773        Self {
774            store: data.store,
775            keys: keys.into_iter(),
776        }
777    }
778}
779
780impl Iterator for StreamingColumnChunkPages {
781    type Item = Result<Bytes>;
782
783    fn next(&mut self) -> Option<Self::Item> {
784        let key = self.keys.next()?;
785        Some(self.store.take(key))
786    }
787}
788
789/// A shared [`ArrowColumnChunkData`]
790///
791/// This allows it to be owned by [`ArrowPageWriter`] whilst allowing access via
792/// [`ArrowRowGroupWriter`] on flush, without requiring self-referential borrows
793type SharedColumnChunk = Arc<Mutex<ArrowColumnChunkData>>;
794
795struct ArrowPageWriter {
796    buffer: SharedColumnChunk,
797    #[cfg(feature = "encryption")]
798    page_encryptor: Option<PageEncryptor>,
799}
800
801impl ArrowPageWriter {
802    /// Create a page writer that buffers completed pages in `store`.
803    fn new(store: Box<dyn PageStore>) -> Self {
804        Self {
805            buffer: Arc::new(Mutex::new(ArrowColumnChunkData::new(store))),
806            #[cfg(feature = "encryption")]
807            page_encryptor: None,
808        }
809    }
810
811    #[cfg(feature = "encryption")]
812    pub fn with_encryptor(mut self, page_encryptor: Option<PageEncryptor>) -> Self {
813        self.page_encryptor = page_encryptor;
814        self
815    }
816
817    #[cfg(feature = "encryption")]
818    fn page_encryptor_mut(&mut self) -> Option<&mut PageEncryptor> {
819        self.page_encryptor.as_mut()
820    }
821
822    // Mirrors the signature of the encryption-enabled version above, so that the
823    // callers do not need a `cfg` of their own.
824    #[cfg(not(feature = "encryption"))]
825    #[expect(
826        clippy::needless_pass_by_ref_mut,
827        reason = "mirrors the encryption-enabled signature"
828    )]
829    fn page_encryptor_mut(&mut self) -> Option<&mut PageEncryptor> {
830        None
831    }
832}
833
834impl PageWriter for ArrowPageWriter {
835    fn write_page(&mut self, page: CompressedPage) -> Result<PageWriteSpec> {
836        let page = match self.page_encryptor_mut() {
837            Some(page_encryptor) => page_encryptor.encrypt_compressed_page(page)?,
838            None => page,
839        };
840
841        let page_header = page.to_thrift_header()?;
842        let header = {
843            let mut header = Vec::with_capacity(1024);
844
845            match self.page_encryptor_mut() {
846                Some(page_encryptor) => {
847                    page_encryptor.encrypt_page_header(&page_header, &mut header)?;
848                    if page.compressed_page().is_data_page() {
849                        page_encryptor.increment_page();
850                    }
851                }
852                None => {
853                    let mut protocol = ThriftCompactOutputProtocol::new(&mut header);
854                    page_header.write_thrift(&mut protocol)?;
855                }
856            }
857
858            Bytes::from(header)
859        };
860
861        let mut buf = self.buffer.try_lock().unwrap();
862
863        let data = page.compressed_page().buffer().clone();
864        let compressed_size = data.len() + header.len();
865
866        let mut spec = PageWriteSpec::new();
867        spec.page_type = page.page_type();
868        spec.num_values = page.num_values();
869        spec.uncompressed_size = page.uncompressed_size() + header.len();
870        spec.offset = buf.length as u64;
871        spec.compressed_size = compressed_size;
872        spec.bytes_written = compressed_size as u64;
873
874        buf.length += compressed_size;
875        if spec.page_type == PageType::DICTIONARY_PAGE {
876            // Recorded apart from the data pages so it is emitted first at
877            // splice — see `ArrowColumnChunkData::dictionary_keys`.
878            buf.push_dictionary(header)?;
879            buf.push_dictionary(data)?;
880        } else {
881            buf.push(header)?;
882            buf.push(data)?;
883        }
884
885        Ok(spec)
886    }
887
888    fn defers_dictionary_ordering(&self) -> bool {
889        // The Arrow chunk is buffered in full and spliced at row-group flush, so
890        // data pages may be accepted before the dictionary page and reordered
891        // then. This lets `GenericColumnWriter` stream dictionary-column data
892        // pages straight through instead of buffering them in memory.
893        true
894    }
895
896    fn buffered_memory_size(&self) -> usize {
897        // Only what is actually resident: a spilling store reports ~0 here even
898        // though the chunk's bytes have all passed through it.
899        self.buffer.try_lock().unwrap().memory_size()
900    }
901
902    fn close(&mut self) -> Result<()> {
903        Ok(())
904    }
905}
906
907/// A leaf column that can be encoded by [`ArrowColumnWriter`]
908#[derive(Debug)]
909pub struct ArrowLeafColumn(ArrayLevels);
910
911/// Computes the [`ArrowLeafColumn`] for a potentially nested [`ArrayRef`]
912///
913/// This function can be used to encode individual columns in parallel.
914/// See example on [`ArrowColumnWriter`]
915pub fn compute_leaves(field: &Field, array: &ArrayRef) -> Result<Vec<ArrowLeafColumn>> {
916    let levels = calculate_array_levels(array, field)?;
917    Ok(levels.into_iter().map(ArrowLeafColumn).collect())
918}
919
920/// The data for a single column chunk, see [`ArrowColumnWriter`]
921pub struct ArrowColumnChunk {
922    data: ArrowColumnChunkData,
923    close: ColumnCloseResult,
924}
925
926impl std::fmt::Debug for ArrowColumnChunk {
927    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
928        f.debug_struct("ArrowColumnChunk")
929            .field("length", &self.data.length)
930            .finish_non_exhaustive()
931    }
932}
933
934impl ArrowColumnChunk {
935    /// Returns the [`ColumnCloseResult`] produced when the chunk was closed.
936    ///
937    /// Exposes encoding information, collected statistics, and the optional
938    /// [`ColumnIndexMetaData`](crate::file::page_index::column_index::ColumnIndexMetaData)
939    /// / [`OffsetIndexMetaData`](crate::file::page_index::offset_index::OffsetIndexMetaData)
940    /// gathered for the column chunk.
941    pub fn close(&self) -> &ColumnCloseResult {
942        &self.close
943    }
944
945    /// Returns a mutable reference to the [`ColumnCloseResult`].
946    ///
947    /// This allows callers to mutate the close result before the chunk is
948    /// appended to a row group — for example, clearing `column_index` or
949    /// `bloom_filter` based on a dynamic rule that inspects the encodings and
950    /// collected page statistics.
951    pub fn close_mut(&mut self) -> &mut ColumnCloseResult {
952        &mut self.close
953    }
954
955    /// Splices this column's buffered pages into the row group, streaming them
956    /// back out of the [`PageStore`] one page at a time.
957    pub fn append_to_row_group<W: Write + Send>(
958        self,
959        writer: &mut SerializedRowGroupWriter<'_, W>,
960    ) -> Result<()> {
961        let ArrowColumnChunk { data, close } = self;
962
963        // The dictionary page is produced *after* the data pages on this path (so
964        // they can stream straight through) but must be written *first*, so move
965        // it ahead of the data pages in the recorded offsets before the splice.
966        let close = close.update_dictionary_location(data.dictionary_len)?;
967
968        let pages = StreamingColumnChunkPages::new(data);
969        writer.append_column_from_pages(pages, close)
970    }
971}
972
973/// Encodes [`ArrowLeafColumn`] to [`ArrowColumnChunk`]
974///
975/// `ArrowColumnWriter` instances can be created using an [`ArrowRowGroupWriterFactory`];
976///
977/// Note: This is a low-level interface for applications that require
978/// fine-grained control of encoding (e.g. encoding using multiple threads),
979/// see [`ArrowWriter`] for a higher-level interface
980///
981/// # Example: Encoding two Arrow Array's in Parallel
982/// ```
983/// // The arrow schema
984/// # use std::sync::Arc;
985/// # use arrow_array::*;
986/// # use arrow_schema::*;
987/// # use parquet::arrow::ArrowSchemaConverter;
988/// # use parquet::arrow::arrow_writer::{compute_leaves, ArrowColumnChunk, ArrowLeafColumn, ArrowRowGroupWriterFactory};
989/// # use parquet::file::properties::WriterProperties;
990/// # use parquet::file::writer::{SerializedFileWriter, SerializedRowGroupWriter};
991/// #
992/// let schema = Arc::new(Schema::new(vec![
993///     Field::new("i32", DataType::Int32, false),
994///     Field::new("f32", DataType::Float32, false),
995/// ]));
996///
997/// // Compute the parquet schema
998/// let props = Arc::new(WriterProperties::default());
999/// let parquet_schema = ArrowSchemaConverter::new()
1000///   .with_coerce_types(props.coerce_types())
1001///   .convert(&schema)
1002///   .unwrap();
1003///
1004/// // Create parquet writer
1005/// let root_schema = parquet_schema.root_schema_ptr();
1006/// // write to memory in the example, but this could be a File
1007/// let mut out = Vec::with_capacity(1024);
1008/// let mut writer = SerializedFileWriter::new(&mut out, root_schema, props.clone())
1009///   .unwrap();
1010///
1011/// // Create a factory for building Arrow column writers
1012/// let row_group_factory = ArrowRowGroupWriterFactory::new(&writer, Arc::clone(&schema));
1013/// // Create column writers for the 0th row group
1014/// let col_writers = row_group_factory.create_column_writers(0).unwrap();
1015///
1016/// // Spawn a worker thread for each column
1017/// //
1018/// // Note: This is for demonstration purposes, a thread-pool e.g. rayon or tokio, would be better.
1019/// // The `map` produces an iterator of type `tuple of (thread handle, send channel)`.
1020/// let mut workers: Vec<_> = col_writers
1021///     .into_iter()
1022///     .map(|mut col_writer| {
1023///         let (send, recv) = std::sync::mpsc::channel::<ArrowLeafColumn>();
1024///         let handle = std::thread::spawn(move || {
1025///             // receive Arrays to encode via the channel
1026///             for col in recv {
1027///                 col_writer.write(&col)?;
1028///             }
1029///             // once the input is complete, close the writer
1030///             // to return the newly created ArrowColumnChunk
1031///             col_writer.close()
1032///         });
1033///         (handle, send)
1034///     })
1035///     .collect();
1036///
1037/// // Start row group
1038/// let mut row_group_writer: SerializedRowGroupWriter<'_, _> = writer
1039///   .next_row_group()
1040///   .unwrap();
1041///
1042/// // Create some example input columns to encode
1043/// let to_write = vec![
1044///     Arc::new(Int32Array::from_iter_values([1, 2, 3])) as _,
1045///     Arc::new(Float32Array::from_iter_values([1., 45., -1.])) as _,
1046/// ];
1047///
1048/// // Send the input columns to the workers
1049/// let mut worker_iter = workers.iter_mut();
1050/// for (arr, field) in to_write.iter().zip(&schema.fields) {
1051///     for leaves in compute_leaves(field, arr).unwrap() {
1052///         worker_iter.next().unwrap().1.send(leaves).unwrap();
1053///     }
1054/// }
1055///
1056/// // Wait for the workers to complete encoding, and append
1057/// // the resulting column chunks to the row group (and the file)
1058/// for (handle, send) in workers {
1059///     drop(send); // Drop send side to signal termination
1060///     // wait for the worker to send the completed chunk
1061///     let chunk: ArrowColumnChunk = handle.join().unwrap().unwrap();
1062///     chunk.append_to_row_group(&mut row_group_writer).unwrap();
1063/// }
1064/// // Close the row group which writes to the underlying file
1065/// row_group_writer.close().unwrap();
1066///
1067/// let metadata = writer.close().unwrap();
1068/// assert_eq!(metadata.file_metadata().num_rows(), 3);
1069/// ```
1070pub struct ArrowColumnWriter {
1071    writer: ArrowColumnWriterImpl,
1072    chunk: SharedColumnChunk,
1073    /// Non-null value hashes accumulated across all writes for this column's row group.
1074    /// `None` when tracking is disabled via [`WriterProperties::write_row_group_number_distinct_values`].
1075    distinct_values_seen: Option<DistinctValuesSet>,
1076}
1077
1078impl std::fmt::Debug for ArrowColumnWriter {
1079    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
1080        f.debug_struct("ArrowColumnWriter").finish_non_exhaustive()
1081    }
1082}
1083
1084enum ArrowColumnWriterImpl {
1085    ByteArray(GenericColumnWriter<'static, ByteArrayEncoder>),
1086    Column(ColumnWriter<'static>),
1087}
1088
1089impl ArrowColumnWriter {
1090    /// Write an [`ArrowLeafColumn`]
1091    pub fn write(&mut self, col: &ArrowLeafColumn) -> Result<()> {
1092        self.write_internal(&col.0)
1093    }
1094
1095    /// Write with content-defined chunking, inserting page flushes at chunk boundaries.
1096    fn write_with_chunker(
1097        &mut self,
1098        col: &ArrowLeafColumn,
1099        chunker: &mut ContentDefinedChunker,
1100    ) -> Result<()> {
1101        let levels = &col.0;
1102        let chunks = chunker.get_arrow_chunks(
1103            levels.def_level_data().as_ref(),
1104            levels.rep_level_data().as_ref(),
1105            levels.array(),
1106        )?;
1107
1108        let num_chunks = chunks.len();
1109        for (i, chunk) in chunks.iter().enumerate() {
1110            let chunk_levels = levels.slice_for_chunk(chunk);
1111            self.write_internal(&chunk_levels)?;
1112
1113            // Add a page break after each chunk except the last
1114            if i + 1 < num_chunks {
1115                match &mut self.writer {
1116                    ArrowColumnWriterImpl::Column(c) => c.add_data_page()?,
1117                    ArrowColumnWriterImpl::ByteArray(c) => c.add_data_page()?,
1118                }
1119            }
1120        }
1121        Ok(())
1122    }
1123
1124    fn write_internal(&mut self, levels: &ArrayLevels) -> Result<()> {
1125        if let Some(seen) = &mut self.distinct_values_seen {
1126            let array = levels.array();
1127            let non_null = levels.non_null_indices();
1128            match array.as_any_dictionary_opt() {
1129                Some(dict) => {
1130                    // For dictionary arrays, hash the integer keys rather than the actual values.
1131                    // Key cardinality equals value cardinality, so distinct-value counting stays
1132                    // correct while avoiding the cost of hashing arbitrary-length values.
1133                    let keys = dict.keys();
1134                    let key_data = keys.to_data();
1135                    let offset = key_data.offset();
1136                    let width = arrow_key_byte_width(keys.data_type());
1137                    if width > 0 {
1138                        let buffer = key_data.buffers()[0].as_slice();
1139                        // Only visit non-null rows to avoid counting nulls as a distinct value.
1140                        for &row in non_null {
1141                            let pos = (offset + row) * width;
1142                            seen.insert(hash_bytes(&buffer[pos..pos + width]));
1143                        }
1144                    }
1145                }
1146                // For plain arrays, hash the actual values directly.
1147                None => update_distinct_values_seen(array.as_ref(), non_null, seen),
1148            }
1149        }
1150
1151        match &mut self.writer {
1152            ArrowColumnWriterImpl::Column(c) => {
1153                let leaf = levels.array();
1154                match leaf.as_any_dictionary_opt() {
1155                    Some(dictionary) => {
1156                        let materialized =
1157                            arrow_select::take::take(dictionary.values(), dictionary.keys(), None)?;
1158                        write_leaf(c, &materialized, levels)?
1159                    }
1160                    None => write_leaf(c, leaf, levels)?,
1161                };
1162            }
1163            ArrowColumnWriterImpl::ByteArray(c) => {
1164                write_primitive(c, levels.array().as_ref(), levels)?;
1165            }
1166        }
1167        Ok(())
1168    }
1169
1170    /// Close this column returning the written [`ArrowColumnChunk`]
1171    pub fn close(self) -> Result<ArrowColumnChunk> {
1172        let distinct_count = self
1173            .distinct_values_seen
1174            .as_ref()
1175            .filter(|s| !s.is_empty())
1176            .map(|s| s.len() as u64);
1177        let close = match self.writer {
1178            ArrowColumnWriterImpl::ByteArray(mut c) => {
1179                if let Some(count) = distinct_count {
1180                    c.set_distinct_count_override(count);
1181                }
1182                c.close()?
1183            }
1184            ArrowColumnWriterImpl::Column(mut c) => {
1185                if let Some(count) = distinct_count {
1186                    c.set_distinct_count_override(count);
1187                }
1188                c.close()?
1189            }
1190        };
1191        let chunk = Arc::try_unwrap(self.chunk).ok().unwrap();
1192        let data = chunk.into_inner().unwrap();
1193        Ok(ArrowColumnChunk { data, close })
1194    }
1195
1196    /// Returns the estimated total memory usage by the writer.
1197    ///
1198    /// This  [`Self::get_estimated_total_bytes`] this is an estimate
1199    /// of the current memory usage and not it's anticipated encoded size.
1200    ///
1201    /// This includes:
1202    /// 1. Data buffered in encoded form
1203    /// 2. Data buffered in un-encoded form (e.g. `usize` dictionary keys)
1204    ///
1205    /// This value should be greater than or equal to [`Self::get_estimated_total_bytes`]
1206    pub fn memory_size(&self) -> usize {
1207        match &self.writer {
1208            ArrowColumnWriterImpl::ByteArray(c) => c.memory_size(),
1209            ArrowColumnWriterImpl::Column(c) => c.memory_size(),
1210        }
1211    }
1212
1213    /// Returns the estimated total encoded bytes for this column writer.
1214    ///
1215    /// This includes:
1216    /// 1. Data buffered in encoded form
1217    /// 2. An estimate of how large the data buffered in un-encoded form would be once encoded
1218    ///
1219    /// This value should be less than or equal to [`Self::memory_size`]
1220    pub fn get_estimated_total_bytes(&self) -> usize {
1221        match &self.writer {
1222            ArrowColumnWriterImpl::ByteArray(c) => c.get_estimated_total_bytes() as _,
1223            ArrowColumnWriterImpl::Column(c) => c.get_estimated_total_bytes() as _,
1224        }
1225    }
1226}
1227
1228/// Encodes [`RecordBatch`] to a parquet row group
1229///
1230/// Note: this structure is created by [`ArrowRowGroupWriterFactory`] internally used to
1231/// create [`ArrowRowGroupWriter`]s, but it is not exposed publicly.
1232///
1233/// See the example on [`ArrowColumnWriter`] for how to encode columns in parallel
1234#[derive(Debug)]
1235struct ArrowRowGroupWriter {
1236    writers: Vec<ArrowColumnWriter>,
1237    schema: SchemaRef,
1238    buffered_rows: usize,
1239}
1240
1241impl ArrowRowGroupWriter {
1242    fn new(writers: Vec<ArrowColumnWriter>, arrow: &SchemaRef) -> Self {
1243        Self {
1244            writers,
1245            schema: arrow.clone(),
1246            buffered_rows: 0,
1247        }
1248    }
1249
1250    fn write(&mut self, batch: &RecordBatch) -> Result<()> {
1251        self.buffered_rows += batch.num_rows();
1252        let mut writers = self.writers.iter_mut();
1253        for (field, column) in self.schema.fields().iter().zip(batch.columns()) {
1254            for leaf in compute_leaves(field.as_ref(), column)? {
1255                writers.next().unwrap().write(&leaf)?;
1256            }
1257        }
1258        Ok(())
1259    }
1260
1261    fn write_with_chunkers(
1262        &mut self,
1263        batch: &RecordBatch,
1264        chunkers: &mut [ContentDefinedChunker],
1265    ) -> Result<()> {
1266        self.buffered_rows += batch.num_rows();
1267        let mut writers = self.writers.iter_mut();
1268        let mut chunkers = chunkers.iter_mut();
1269        for (field, column) in self.schema.fields().iter().zip(batch.columns()) {
1270            for leaf in compute_leaves(field.as_ref(), column)? {
1271                writers
1272                    .next()
1273                    .unwrap()
1274                    .write_with_chunker(&leaf, chunkers.next().unwrap())?;
1275            }
1276        }
1277        Ok(())
1278    }
1279
1280    /// Returns the estimated total encoded bytes for this row group
1281    fn get_estimated_total_bytes(&self) -> usize {
1282        self.writers
1283            .iter()
1284            .map(|x| x.get_estimated_total_bytes())
1285            .sum()
1286    }
1287
1288    fn close(self) -> Result<Vec<ArrowColumnChunk>> {
1289        self.writers
1290            .into_iter()
1291            .map(|writer| writer.close())
1292            .collect()
1293    }
1294}
1295
1296/// Factory that creates new column writers for each row group in the Parquet file.
1297///
1298/// You can create this structure via an [`ArrowWriter::into_serialized_writer`].
1299/// See the example on [`ArrowColumnWriter`] for how to encode columns in parallel
1300#[derive(Debug)]
1301pub struct ArrowRowGroupWriterFactory {
1302    schema: SchemaDescPtr,
1303    arrow_schema: SchemaRef,
1304    props: WriterPropertiesPtr,
1305    page_store_factory: Arc<dyn PageStoreFactory>,
1306    #[cfg(feature = "encryption")]
1307    file_encryptor: Option<Arc<FileEncryptor>>,
1308}
1309
1310impl ArrowRowGroupWriterFactory {
1311    /// Create a new [`ArrowRowGroupWriterFactory`] for the provided file writer and Arrow schema
1312    pub fn new<W: Write + Send>(
1313        file_writer: &SerializedFileWriter<W>,
1314        arrow_schema: SchemaRef,
1315    ) -> Self {
1316        let schema = Arc::clone(file_writer.schema_descr_ptr());
1317        let props = Arc::clone(file_writer.properties());
1318        Self {
1319            schema,
1320            arrow_schema,
1321            props,
1322            page_store_factory: Arc::new(InMemoryPageStoreFactory),
1323            #[cfg(feature = "encryption")]
1324            file_encryptor: file_writer.file_encryptor(),
1325        }
1326    }
1327
1328    /// Set the [`PageStoreFactory`] used to allocate the buffer for each column
1329    /// chunk, e.g. to spill completed pages to a temp file or object storage
1330    /// instead of the heap. Defaults to [`InMemoryPageStoreFactory`].
1331    pub fn with_page_store_factory(
1332        mut self,
1333        page_store_factory: Arc<dyn PageStoreFactory>,
1334    ) -> Self {
1335        self.page_store_factory = page_store_factory;
1336        self
1337    }
1338
1339    fn create_row_group_writer(&self, row_group_index: usize) -> Result<ArrowRowGroupWriter> {
1340        let writers = self.create_column_writers(row_group_index)?;
1341        Ok(ArrowRowGroupWriter::new(writers, &self.arrow_schema))
1342    }
1343
1344    /// Create column writers for a new row group, with the given row group index
1345    pub fn create_column_writers(&self, row_group_index: usize) -> Result<Vec<ArrowColumnWriter>> {
1346        let mut writers = Vec::with_capacity(self.arrow_schema.fields.len());
1347        let mut leaves = self.schema.columns().iter();
1348        let column_factory = self.column_writer_factory(row_group_index);
1349        for field in &self.arrow_schema.fields {
1350            column_factory.get_arrow_column_writer(
1351                field.data_type(),
1352                &self.props,
1353                &mut leaves,
1354                &mut writers,
1355            )?;
1356        }
1357        Ok(writers)
1358    }
1359
1360    #[cfg(feature = "encryption")]
1361    fn column_writer_factory(&self, row_group_idx: usize) -> ArrowColumnWriterFactory {
1362        ArrowColumnWriterFactory::new()
1363            .with_page_store_factory(self.page_store_factory.clone())
1364            .with_file_encryptor(row_group_idx, self.file_encryptor.clone())
1365    }
1366
1367    #[cfg(not(feature = "encryption"))]
1368    fn column_writer_factory(&self, _row_group_idx: usize) -> ArrowColumnWriterFactory {
1369        ArrowColumnWriterFactory::new().with_page_store_factory(self.page_store_factory.clone())
1370    }
1371}
1372
1373/// Creates [`ArrowColumnWriter`] instances
1374struct ArrowColumnWriterFactory {
1375    /// Allocates the per-column-chunk [`PageStore`] backing each page writer.
1376    page_store_factory: Arc<dyn PageStoreFactory>,
1377    #[cfg(feature = "encryption")]
1378    row_group_index: usize,
1379    #[cfg(feature = "encryption")]
1380    file_encryptor: Option<Arc<FileEncryptor>>,
1381}
1382
1383impl ArrowColumnWriterFactory {
1384    pub fn new() -> Self {
1385        Self {
1386            page_store_factory: Arc::new(InMemoryPageStoreFactory),
1387            #[cfg(feature = "encryption")]
1388            row_group_index: 0,
1389            #[cfg(feature = "encryption")]
1390            file_encryptor: None,
1391        }
1392    }
1393
1394    /// Use `page_store_factory` to allocate the buffer for each column chunk.
1395    pub fn with_page_store_factory(
1396        mut self,
1397        page_store_factory: Arc<dyn PageStoreFactory>,
1398    ) -> Self {
1399        self.page_store_factory = page_store_factory;
1400        self
1401    }
1402
1403    #[cfg(feature = "encryption")]
1404    pub fn with_file_encryptor(
1405        mut self,
1406        row_group_index: usize,
1407        file_encryptor: Option<Arc<FileEncryptor>>,
1408    ) -> Self {
1409        self.row_group_index = row_group_index;
1410        self.file_encryptor = file_encryptor;
1411        self
1412    }
1413
1414    #[cfg(feature = "encryption")]
1415    fn create_page_writer(
1416        &self,
1417        column_descriptor: &ColumnDescPtr,
1418        column_index: usize,
1419    ) -> Result<Box<ArrowPageWriter>> {
1420        let column_path = column_descriptor.path().string();
1421        let page_encryptor = PageEncryptor::create_if_column_encrypted(
1422            self.file_encryptor.as_ref(),
1423            self.row_group_index,
1424            column_index,
1425            &column_path,
1426        )?;
1427        let args = PageStoreArgs::new(column_index, column_descriptor);
1428        let store = self.page_store_factory.create(&args)?;
1429        Ok(Box::new(
1430            ArrowPageWriter::new(store).with_encryptor(page_encryptor),
1431        ))
1432    }
1433
1434    #[cfg(not(feature = "encryption"))]
1435    fn create_page_writer(
1436        &self,
1437        column_descriptor: &ColumnDescPtr,
1438        column_index: usize,
1439    ) -> Result<Box<ArrowPageWriter>> {
1440        let args = PageStoreArgs::new(column_index, column_descriptor);
1441        let store = self.page_store_factory.create(&args)?;
1442        Ok(Box::new(ArrowPageWriter::new(store)))
1443    }
1444
1445    /// Gets an [`ArrowColumnWriter`] for the given `data_type`, appending the
1446    /// output ColumnDesc to `leaves` and the column writers to `out`
1447    fn get_arrow_column_writer(
1448        &self,
1449        data_type: &ArrowDataType,
1450        props: &WriterPropertiesPtr,
1451        leaves: &mut Iter<'_, ColumnDescPtr>,
1452        out: &mut Vec<ArrowColumnWriter>,
1453    ) -> Result<()> {
1454        let write_distinct_values = props.write_row_group_number_distinct_values();
1455
1456        // Instantiate writers for normal columns
1457        let col = |desc: &ColumnDescPtr| -> Result<ArrowColumnWriter> {
1458            let page_writer = self.create_page_writer(desc, out.len())?;
1459            let chunk = page_writer.buffer.clone();
1460            let writer = get_column_writer(desc.clone(), props.clone(), page_writer);
1461            Ok(ArrowColumnWriter {
1462                chunk,
1463                writer: ArrowColumnWriterImpl::Column(writer),
1464                distinct_values_seen: write_distinct_values.then(HashSet::new),
1465            })
1466        };
1467
1468        // Instantiate writers for byte arrays (e.g. Utf8,  Binary, etc)
1469        let bytes = |desc: &ColumnDescPtr| -> Result<ArrowColumnWriter> {
1470            let page_writer = self.create_page_writer(desc, out.len())?;
1471            let chunk = page_writer.buffer.clone();
1472            let writer = GenericColumnWriter::new(desc.clone(), props.clone(), page_writer);
1473            Ok(ArrowColumnWriter {
1474                chunk,
1475                writer: ArrowColumnWriterImpl::ByteArray(writer),
1476                distinct_values_seen: write_distinct_values.then(HashSet::new),
1477            })
1478        };
1479
1480        match data_type {
1481            _ if data_type.is_primitive() => out.push(col(leaves.next().unwrap())?),
1482            ArrowDataType::FixedSizeBinary(_) | ArrowDataType::Boolean | ArrowDataType::Null => {
1483                out.push(col(leaves.next().unwrap())?)
1484            }
1485            ArrowDataType::LargeBinary
1486            | ArrowDataType::Binary
1487            | ArrowDataType::Utf8
1488            | ArrowDataType::LargeUtf8
1489            | ArrowDataType::BinaryView
1490            | ArrowDataType::Utf8View => out.push(bytes(leaves.next().unwrap())?),
1491            ArrowDataType::List(f)
1492            | ArrowDataType::LargeList(f)
1493            | ArrowDataType::FixedSizeList(f, _)
1494            | ArrowDataType::ListView(f)
1495            | ArrowDataType::LargeListView(f) => {
1496                self.get_arrow_column_writer(f.data_type(), props, leaves, out)?
1497            }
1498            ArrowDataType::Struct(fields) => {
1499                for field in fields {
1500                    self.get_arrow_column_writer(field.data_type(), props, leaves, out)?
1501                }
1502            }
1503            ArrowDataType::Map(f, _) => match f.data_type() {
1504                ArrowDataType::Struct(f) => {
1505                    self.get_arrow_column_writer(f[0].data_type(), props, leaves, out)?;
1506                    self.get_arrow_column_writer(f[1].data_type(), props, leaves, out)?
1507                }
1508                _ => unreachable!("invalid map type"),
1509            },
1510            ArrowDataType::Dictionary(_, value_type) => match value_type.as_ref() {
1511                ArrowDataType::Utf8
1512                | ArrowDataType::LargeUtf8
1513                | ArrowDataType::Binary
1514                | ArrowDataType::LargeBinary => out.push(bytes(leaves.next().unwrap())?),
1515                ArrowDataType::Utf8View | ArrowDataType::BinaryView => {
1516                    out.push(bytes(leaves.next().unwrap())?)
1517                }
1518                ArrowDataType::FixedSizeBinary(_) => out.push(bytes(leaves.next().unwrap())?),
1519                _ => out.push(col(leaves.next().unwrap())?),
1520            },
1521            ArrowDataType::RunEndEncoded(_, value_field) => {
1522                self.get_arrow_column_writer(value_field.data_type(), props, leaves, out)?
1523            }
1524            _ => {
1525                return Err(ParquetError::NYI(format!(
1526                    "Attempting to write an Arrow type {data_type} to parquet that is not yet implemented"
1527                )));
1528            }
1529        }
1530        Ok(())
1531    }
1532}
1533
1534fn write_leaf(
1535    writer: &mut ColumnWriter<'_>,
1536    column: &dyn arrow_array::Array,
1537    levels: &ArrayLevels,
1538) -> Result<usize> {
1539    let indices = levels.non_null_indices();
1540
1541    match writer {
1542        // Note: this should match the contents of arrow_to_parquet_type
1543        ColumnWriter::Int32ColumnWriter(typed) => {
1544            match column.data_type() {
1545                ArrowDataType::Null => {
1546                    let array = Int32Array::new_null(column.len());
1547                    write_primitive(typed, array.values(), levels)
1548                }
1549                ArrowDataType::Int8 => {
1550                    let array: Int32Array = column.as_primitive::<Int8Type>().unary(|x| x as i32);
1551                    write_primitive(typed, array.values(), levels)
1552                }
1553                ArrowDataType::Int16 => {
1554                    let array: Int32Array = column.as_primitive::<Int16Type>().unary(|x| x as i32);
1555                    write_primitive(typed, array.values(), levels)
1556                }
1557                ArrowDataType::Int32 => {
1558                    write_primitive(typed, column.as_primitive::<Int32Type>().values(), levels)
1559                }
1560                ArrowDataType::UInt8 => {
1561                    let array: Int32Array = column.as_primitive::<UInt8Type>().unary(|x| x as i32);
1562                    write_primitive(typed, array.values(), levels)
1563                }
1564                ArrowDataType::UInt16 => {
1565                    let array: Int32Array = column.as_primitive::<UInt16Type>().unary(|x| x as i32);
1566                    write_primitive(typed, array.values(), levels)
1567                }
1568                ArrowDataType::UInt32 => {
1569                    // follow C++ implementation and use overflow/reinterpret cast from  u32 to i32 which will map
1570                    // `(i32::MAX as u32)..u32::MAX` to `i32::MIN..0`
1571                    let array = column.as_primitive::<UInt32Type>();
1572                    write_primitive(typed, array.values().inner().typed_data(), levels)
1573                }
1574                ArrowDataType::Date32 => {
1575                    let array = column.as_primitive::<Date32Type>();
1576                    write_primitive(typed, array.values(), levels)
1577                }
1578                ArrowDataType::Time32(TimeUnit::Second) => {
1579                    let array = column.as_primitive::<Time32SecondType>();
1580                    write_primitive(typed, array.values(), levels)
1581                }
1582                ArrowDataType::Time32(TimeUnit::Millisecond) => {
1583                    let array = column.as_primitive::<Time32MillisecondType>();
1584                    write_primitive(typed, array.values(), levels)
1585                }
1586                ArrowDataType::Date64 => {
1587                    // If the column is a Date64, we truncate it
1588                    let array: Int32Array = column
1589                        .as_primitive::<Date64Type>()
1590                        .unary(|x| (x / 86_400_000) as _);
1591
1592                    write_primitive(typed, array.values(), levels)
1593                }
1594                ArrowDataType::Decimal32(_, _) => {
1595                    let array = column
1596                        .as_primitive::<Decimal32Type>()
1597                        .unary::<_, Int32Type>(|v| v);
1598                    write_primitive(typed, array.values(), levels)
1599                }
1600                ArrowDataType::Decimal64(_, _) => {
1601                    // use the int32 to represent the decimal with low precision
1602                    let array = column
1603                        .as_primitive::<Decimal64Type>()
1604                        .unary::<_, Int32Type>(|v| v as i32);
1605                    write_primitive(typed, array.values(), levels)
1606                }
1607                ArrowDataType::Decimal128(_, _) => {
1608                    // use the int32 to represent the decimal with low precision
1609                    let array = column
1610                        .as_primitive::<Decimal128Type>()
1611                        .unary::<_, Int32Type>(|v| v as i32);
1612                    write_primitive(typed, array.values(), levels)
1613                }
1614                ArrowDataType::Decimal256(_, _) => {
1615                    // use the int32 to represent the decimal with low precision
1616                    let array = column
1617                        .as_primitive::<Decimal256Type>()
1618                        .unary::<_, Int32Type>(|v| v.as_i128() as i32);
1619                    write_primitive(typed, array.values(), levels)
1620                }
1621                d => Err(ParquetError::General(format!("Cannot coerce {d} to I32"))),
1622            }
1623        }
1624        ColumnWriter::BoolColumnWriter(typed) => {
1625            let array = column.as_boolean();
1626            let values = get_bool_array_slice(array, indices.iter().copied());
1627            typed.write_batch_internal(
1628                values.as_slice(),
1629                None,
1630                levels.def_level_data().as_ref(),
1631                levels.rep_level_data().as_ref(),
1632                None,
1633                None,
1634                None,
1635            )
1636        }
1637        ColumnWriter::Int64ColumnWriter(typed) => {
1638            match column.data_type() {
1639                ArrowDataType::Date64 => {
1640                    let array = column
1641                        .as_primitive::<Date64Type>()
1642                        .reinterpret_cast::<Int64Type>();
1643
1644                    write_primitive(typed, array.values(), levels)
1645                }
1646                ArrowDataType::Int64 => {
1647                    let array = column.as_primitive::<Int64Type>();
1648                    write_primitive(typed, array.values(), levels)
1649                }
1650                ArrowDataType::UInt64 => {
1651                    let values = column.as_primitive::<UInt64Type>().values();
1652                    // follow C++ implementation and use overflow/reinterpret cast from  u64 to i64 which will map
1653                    // `(i64::MAX as u64)..u64::MAX` to `i64::MIN..0`
1654                    let array = values.inner().typed_data::<i64>();
1655                    write_primitive(typed, array, levels)
1656                }
1657                ArrowDataType::Time64(TimeUnit::Microsecond) => {
1658                    let array = column.as_primitive::<Time64MicrosecondType>();
1659                    write_primitive(typed, array.values(), levels)
1660                }
1661                ArrowDataType::Time64(TimeUnit::Nanosecond) => {
1662                    let array = column.as_primitive::<Time64NanosecondType>();
1663                    write_primitive(typed, array.values(), levels)
1664                }
1665                ArrowDataType::Timestamp(unit, _) => match unit {
1666                    TimeUnit::Second => {
1667                        let array = column.as_primitive::<TimestampSecondType>();
1668                        write_primitive(typed, array.values(), levels)
1669                    }
1670                    TimeUnit::Millisecond => {
1671                        let array = column.as_primitive::<TimestampMillisecondType>();
1672                        write_primitive(typed, array.values(), levels)
1673                    }
1674                    TimeUnit::Microsecond => {
1675                        let array = column.as_primitive::<TimestampMicrosecondType>();
1676                        write_primitive(typed, array.values(), levels)
1677                    }
1678                    TimeUnit::Nanosecond => {
1679                        let array = column.as_primitive::<TimestampNanosecondType>();
1680                        write_primitive(typed, array.values(), levels)
1681                    }
1682                },
1683                ArrowDataType::Duration(unit) => match unit {
1684                    TimeUnit::Second => {
1685                        let array = column.as_primitive::<DurationSecondType>();
1686                        write_primitive(typed, array.values(), levels)
1687                    }
1688                    TimeUnit::Millisecond => {
1689                        let array = column.as_primitive::<DurationMillisecondType>();
1690                        write_primitive(typed, array.values(), levels)
1691                    }
1692                    TimeUnit::Microsecond => {
1693                        let array = column.as_primitive::<DurationMicrosecondType>();
1694                        write_primitive(typed, array.values(), levels)
1695                    }
1696                    TimeUnit::Nanosecond => {
1697                        let array = column.as_primitive::<DurationNanosecondType>();
1698                        write_primitive(typed, array.values(), levels)
1699                    }
1700                },
1701                ArrowDataType::Decimal64(_, _) => {
1702                    let array = column
1703                        .as_primitive::<Decimal64Type>()
1704                        .reinterpret_cast::<Int64Type>();
1705                    write_primitive(typed, array.values(), levels)
1706                }
1707                ArrowDataType::Decimal128(_, _) => {
1708                    // use the int64 to represent the decimal with low precision
1709                    let array = column
1710                        .as_primitive::<Decimal128Type>()
1711                        .unary::<_, Int64Type>(|v| v as i64);
1712                    write_primitive(typed, array.values(), levels)
1713                }
1714                ArrowDataType::Decimal256(_, _) => {
1715                    // use the int64 to represent the decimal with low precision
1716                    let array = column
1717                        .as_primitive::<Decimal256Type>()
1718                        .unary::<_, Int64Type>(|v| v.as_i128() as i64);
1719                    write_primitive(typed, array.values(), levels)
1720                }
1721                d => Err(ParquetError::General(format!("Cannot coerce {d} to I64"))),
1722            }
1723        }
1724        ColumnWriter::Int96ColumnWriter(_typed) => {
1725            unreachable!("Currently unreachable because data type not supported")
1726        }
1727        ColumnWriter::FloatColumnWriter(typed) => {
1728            let array = column.as_primitive::<Float32Type>();
1729            write_primitive(typed, array.values(), levels)
1730        }
1731        ColumnWriter::DoubleColumnWriter(typed) => {
1732            let array = column.as_primitive::<Float64Type>();
1733            write_primitive(typed, array.values(), levels)
1734        }
1735        ColumnWriter::ByteArrayColumnWriter(_) => {
1736            unreachable!("should use ByteArrayWriter")
1737        }
1738        ColumnWriter::FixedLenByteArrayColumnWriter(typed) => {
1739            let bytes = match column.data_type() {
1740                ArrowDataType::Interval(interval_unit) => match interval_unit {
1741                    IntervalUnit::YearMonth => {
1742                        let array = column.as_primitive::<IntervalYearMonthType>();
1743                        get_interval_ym_array_slice(array, indices.iter().copied())
1744                    }
1745                    IntervalUnit::DayTime => {
1746                        let array = column.as_primitive::<IntervalDayTimeType>();
1747                        get_interval_dt_array_slice(array, indices.iter().copied())
1748                    }
1749                    IntervalUnit::MonthDayNano => {
1750                        return Err(ParquetError::NYI(format!(
1751                            "Attempting to write an Arrow interval type {interval_unit:?} to parquet that is not yet implemented"
1752                        )));
1753                    }
1754                },
1755                ArrowDataType::FixedSizeBinary(_) => {
1756                    let array = column.as_fixed_size_binary();
1757                    get_fsb_array_slice(array, indices.iter().copied())
1758                }
1759                ArrowDataType::Decimal32(_, _) => {
1760                    let array = column.as_primitive::<Decimal32Type>();
1761                    get_decimal_array_slice(array, indices.iter().copied())
1762                }
1763                ArrowDataType::Decimal64(_, _) => {
1764                    let array = column.as_primitive::<Decimal64Type>();
1765                    get_decimal_array_slice(array, indices.iter().copied())
1766                }
1767                ArrowDataType::Decimal128(_, _) => {
1768                    let array = column.as_primitive::<Decimal128Type>();
1769                    get_decimal_array_slice(array, indices.iter().copied())
1770                }
1771                ArrowDataType::Decimal256(_, _) => {
1772                    let array = column.as_primitive::<Decimal256Type>();
1773                    get_decimal_array_slice(array, indices.iter().copied())
1774                }
1775                ArrowDataType::Float16 => {
1776                    let array = column.as_primitive::<Float16Type>();
1777                    get_float_16_array_slice(array, indices.iter().copied())
1778                }
1779                _ => {
1780                    return Err(ParquetError::NYI(
1781                        "Attempting to write an Arrow type that is not yet implemented".to_string(),
1782                    ));
1783                }
1784            };
1785            typed.write_batch_internal(
1786                bytes.as_slice(),
1787                None,
1788                levels.def_level_data().as_ref(),
1789                levels.rep_level_data().as_ref(),
1790                None,
1791                None,
1792                None,
1793            )
1794        }
1795    }
1796}
1797
1798fn write_primitive<E: ColumnValueEncoder>(
1799    writer: &mut GenericColumnWriter<E>,
1800    values: &E::Values,
1801    levels: &ArrayLevels,
1802) -> Result<usize> {
1803    writer.write_batch_internal(
1804        values,
1805        Some(levels.non_null_indices()),
1806        levels.def_level_data().as_ref(),
1807        levels.rep_level_data().as_ref(),
1808        None,
1809        None,
1810        None,
1811    )
1812}
1813
1814fn get_bool_array_slice(
1815    array: &arrow_array::BooleanArray,
1816    indices: impl ExactSizeIterator<Item = usize>,
1817) -> Vec<bool> {
1818    let mut values = Vec::with_capacity(indices.len());
1819    for i in indices {
1820        values.push(array.value(i))
1821    }
1822    values
1823}
1824
1825/// Returns 12-byte values representing 3 values of months, days and milliseconds (4-bytes each).
1826/// An Arrow YearMonth interval only stores months, thus only the first 4 bytes are populated.
1827fn get_interval_ym_array_slice(
1828    array: &arrow_array::IntervalYearMonthArray,
1829    indices: impl ExactSizeIterator<Item = usize>,
1830) -> Vec<FixedLenByteArray> {
1831    chunk_array_slice(12, indices, move |i, chunk| {
1832        let value = array.value(i);
1833        chunk[0..4].copy_from_slice(&value.to_le_bytes());
1834    })
1835}
1836
1837/// Returns 12-byte values representing 3 values of months, days and milliseconds (4-bytes each).
1838/// An Arrow DayTime interval only stores days and millis, thus the first 4 bytes are not populated.
1839fn get_interval_dt_array_slice(
1840    array: &arrow_array::IntervalDayTimeArray,
1841    indices: impl ExactSizeIterator<Item = usize>,
1842) -> Vec<FixedLenByteArray> {
1843    chunk_array_slice(12, indices, move |i, chunk| {
1844        let value = array.value(i);
1845        chunk[4..8].copy_from_slice(&value.days.to_le_bytes());
1846        chunk[8..12].copy_from_slice(&value.milliseconds.to_le_bytes());
1847    })
1848}
1849
1850trait NativeDecimalType: DecimalType {
1851    type NativeBytes: AsRef<[u8]>;
1852
1853    fn to_be_bytes(value: Self::Native) -> Self::NativeBytes;
1854}
1855impl NativeDecimalType for Decimal32Type {
1856    type NativeBytes = [u8; Self::BYTE_LENGTH];
1857
1858    fn to_be_bytes(value: Self::Native) -> Self::NativeBytes {
1859        value.to_be_bytes()
1860    }
1861}
1862impl NativeDecimalType for Decimal64Type {
1863    type NativeBytes = [u8; Self::BYTE_LENGTH];
1864
1865    fn to_be_bytes(value: Self::Native) -> Self::NativeBytes {
1866        value.to_be_bytes()
1867    }
1868}
1869impl NativeDecimalType for Decimal128Type {
1870    type NativeBytes = [u8; Self::BYTE_LENGTH];
1871
1872    fn to_be_bytes(value: Self::Native) -> Self::NativeBytes {
1873        value.to_be_bytes()
1874    }
1875}
1876impl NativeDecimalType for Decimal256Type {
1877    type NativeBytes = [u8; Self::BYTE_LENGTH];
1878
1879    fn to_be_bytes(value: Self::Native) -> Self::NativeBytes {
1880        value.to_be_bytes()
1881    }
1882}
1883
1884fn get_decimal_array_slice<T: NativeDecimalType>(
1885    array: &PrimitiveArray<T>,
1886    indices: impl ExactSizeIterator<Item = usize>,
1887) -> Vec<FixedLenByteArray> {
1888    let chunk_size = decimal_length_from_precision(array.precision());
1889    assert!(chunk_size <= T::BYTE_LENGTH);
1890
1891    if chunk_size == T::BYTE_LENGTH {
1892        // Special-case that allows inlining memcpy.
1893        chunk_array_slice(chunk_size, indices, move |i, chunk| {
1894            let as_be_bytes = T::to_be_bytes(array.value(i));
1895            chunk.copy_from_slice(as_be_bytes.as_ref());
1896        })
1897    } else {
1898        chunk_array_slice(chunk_size, indices, move |i, chunk| {
1899            let as_be_bytes = T::to_be_bytes(array.value(i));
1900            let resized_value = &as_be_bytes.as_ref()[(T::BYTE_LENGTH - chunk.len())..];
1901            chunk.copy_from_slice(resized_value);
1902        })
1903    }
1904}
1905
1906fn get_float_16_array_slice(
1907    array: &arrow_array::Float16Array,
1908    indices: impl ExactSizeIterator<Item = usize>,
1909) -> Vec<FixedLenByteArray> {
1910    chunk_array_slice(2, indices, move |i, chunk| {
1911        let value = array.value(i).to_le_bytes();
1912        chunk.copy_from_slice(&value);
1913    })
1914}
1915
1916fn get_fsb_array_slice(
1917    array: &arrow_array::FixedSizeBinaryArray,
1918    indices: impl ExactSizeIterator<Item = usize>,
1919) -> Vec<FixedLenByteArray> {
1920    chunk_array_slice(array.value_size(), indices, move |i, chunk| {
1921        let value = array.value(i);
1922        chunk.copy_from_slice(value);
1923    })
1924}
1925
1926#[inline]
1927fn chunk_array_slice(
1928    chunk_size: usize,
1929    indices: impl ExactSizeIterator<Item = usize>,
1930    writer: impl Fn(usize, &mut [u8]),
1931) -> Vec<FixedLenByteArray> {
1932    let capacity = indices.len() * chunk_size;
1933    // TODO: This could be done with Vec::spare_capacity_mut,
1934    //       but [MaybeUninit]::write_copy_of_slice is gated behind MSRV 1.93
1935    let mut arena = vec![0; capacity];
1936    for (i, chunk) in indices.zip(arena.chunks_exact_mut(chunk_size)) {
1937        writer(i, chunk);
1938    }
1939    chunk_contiguous_vec(arena, chunk_size)
1940}
1941
1942fn chunk_contiguous_vec(arena: Vec<u8>, chunk_size: usize) -> Vec<FixedLenByteArray> {
1943    let mut values = Vec::with_capacity(arena.len() / chunk_size);
1944    let mut arena = Bytes::from(arena);
1945    while arena.len() >= chunk_size {
1946        let slice = arena.split_to(chunk_size);
1947        values.push(FixedLenByteArray::from(ByteArray::from(slice)));
1948    }
1949    values
1950}
1951
1952/// Hash a byte slice to a u64 for NDV tracking.
1953#[inline]
1954fn hash_bytes(bytes: &[u8]) -> u64 {
1955    twox_hash::XxHash64::oneshot(0, bytes)
1956}
1957
1958/// Returns the byte width of an Arrow dictionary key type, or 0 if unsupported.
1959fn arrow_key_byte_width(dt: &ArrowDataType) -> usize {
1960    match dt {
1961        ArrowDataType::Int8 | ArrowDataType::UInt8 => 1,
1962        ArrowDataType::Int16 | ArrowDataType::UInt16 => 2,
1963        ArrowDataType::Int32 | ArrowDataType::UInt32 => 4,
1964        ArrowDataType::Int64 | ArrowDataType::UInt64 => 8,
1965        _ => 0,
1966    }
1967}
1968
1969/// Returns the fixed byte width for primitive Arrow types, or `None` for variable-length types.
1970fn fixed_byte_width(dt: &ArrowDataType) -> Option<usize> {
1971    use ArrowDataType::*;
1972    match dt {
1973        Int8 | UInt8 => Some(1),
1974        Int16 | UInt16 | Float16 => Some(2),
1975        Int32 | UInt32 | Float32 | Date32 | Time32(_) | Decimal32(_, _) => Some(4),
1976        Int64
1977        | UInt64
1978        | Float64
1979        | Date64
1980        | Time64(_)
1981        | Timestamp(_, _)
1982        | Duration(_)
1983        | Decimal64(_, _) => Some(8),
1984        Interval(IntervalUnit::YearMonth) => Some(4),
1985        Interval(IntervalUnit::DayTime) => Some(8),
1986        Interval(IntervalUnit::MonthDayNano) => Some(16),
1987        Decimal128(_, _) => Some(16),
1988        Decimal256(_, _) => Some(32),
1989        _ => None,
1990    }
1991}
1992
1993/// Hash the non-null values in `array` (at `non_null_indices`) into `seen`.
1994///
1995/// Handles primitive, boolean, fixed-size-binary, and variable-length (Utf8/Binary)
1996/// arrays. Unsupported types are silently skipped, leaving `seen` unchanged for
1997/// those values (NDV is best-effort).
1998fn update_distinct_values_seen(
1999    array: &dyn arrow_array::Array,
2000    non_null_indices: &[usize],
2001    seen: &mut DistinctValuesSet,
2002) {
2003    let data = array.to_data();
2004    let offset = data.offset();
2005
2006    match array.data_type() {
2007        ArrowDataType::Boolean => {
2008            let arr = array
2009                .as_any()
2010                .downcast_ref::<arrow_array::BooleanArray>()
2011                .unwrap();
2012            for &row in non_null_indices {
2013                seen.insert(arr.value(row) as u64);
2014            }
2015        }
2016        ArrowDataType::Utf8 | ArrowDataType::Binary => {
2017            let offsets = data.buffers()[0].typed_data::<i32>();
2018            let values = data.buffers()[1].as_slice();
2019            for &row in non_null_indices {
2020                let start = offsets[offset + row] as usize;
2021                let end = offsets[offset + row + 1] as usize;
2022                seen.insert(hash_bytes(&values[start..end]));
2023            }
2024        }
2025        ArrowDataType::LargeUtf8 | ArrowDataType::LargeBinary => {
2026            let offsets = data.buffers()[0].typed_data::<i64>();
2027            let values = data.buffers()[1].as_slice();
2028            for &row in non_null_indices {
2029                let start = offsets[offset + row] as usize;
2030                let end = offsets[offset + row + 1] as usize;
2031                seen.insert(hash_bytes(&values[start..end]));
2032            }
2033        }
2034        ArrowDataType::FixedSizeBinary(byte_width) => {
2035            let byte_width = *byte_width as usize;
2036            let buffer = data.buffers()[0].as_slice();
2037            for &row in non_null_indices {
2038                let start = (offset + row) * byte_width;
2039                seen.insert(hash_bytes(&buffer[start..start + byte_width]));
2040            }
2041        }
2042        data_type => {
2043            if let Some(width) = fixed_byte_width(data_type) {
2044                let buffer = data.buffers()[0].as_slice();
2045                for &row in non_null_indices {
2046                    let pos = (offset + row) * width;
2047                    seen.insert(hash_bytes(&buffer[pos..pos + width]));
2048                }
2049            }
2050            // Utf8View, BinaryView, nested types: skip
2051        }
2052    }
2053}
2054
2055#[cfg(test)]
2056mod tests {
2057    use super::*;
2058    use std::cmp::Ordering;
2059    use std::collections::HashMap;
2060
2061    use std::fs::File;
2062
2063    use crate::arrow::arrow_reader::{ParquetRecordBatchReader, ParquetRecordBatchReaderBuilder};
2064    use crate::arrow::{ARROW_SCHEMA_META_KEY, PARQUET_FIELD_ID_META_KEY};
2065    use crate::column::page::{Page, PageReader};
2066    use crate::file::metadata::thrift::PageHeader;
2067    use crate::file::page_index::column_index::ColumnIndexMetaData;
2068    use crate::file::reader::SerializedPageReader;
2069    use crate::parquet_thrift::{ReadThrift, ThriftSliceInputProtocol};
2070    use crate::schema::types::ColumnPath;
2071    use arrow::datatypes::ToByteSlice;
2072    use arrow::datatypes::{DataType, Schema};
2073    use arrow::error::Result as ArrowResult;
2074    use arrow::util::data_gen::create_random_array;
2075    use arrow::util::pretty::pretty_format_batches;
2076    use arrow::{array::*, buffer::Buffer};
2077    use arrow_buffer::{IntervalDayTime, IntervalMonthDayNano, NullBuffer, OffsetBuffer, i256};
2078    use arrow_schema::Fields;
2079    use half::f16;
2080    use num_traits::{FromPrimitive, ToPrimitive};
2081    use tempfile::tempfile;
2082
2083    use crate::basic::Encoding;
2084    use crate::data_type::AsBytes;
2085    use crate::file::metadata::{ColumnChunkMetaData, ParquetMetaData, ParquetMetaDataReader};
2086    use crate::file::properties::{
2087        BloomFilterPosition, EnabledStatistics, ReaderProperties, WriterVersion,
2088    };
2089    use crate::file::serialized_reader::ReadOptionsBuilder;
2090    use crate::file::{
2091        reader::{FileReader, SerializedFileReader},
2092        statistics::Statistics,
2093    };
2094
2095    /// A [`PageStore`] that allocates *sparse, non-contiguous* handles and keeps
2096    /// blobs in a `HashMap` — nothing like the default `Vec<Bytes>`. Used to
2097    /// prove the writer relies only on the opaque-handle contract and never on
2098    /// handles being dense `Vec` indices. Records how many blobs were stored.
2099    #[derive(Debug, Default)]
2100    struct RecordingPageStore {
2101        next: u64,
2102        blobs: HashMap<u64, Bytes>,
2103        puts: Arc<std::sync::atomic::AtomicUsize>,
2104    }
2105
2106    impl PageStore for RecordingPageStore {
2107        fn put(&mut self, value: Bytes) -> Result<PageKey> {
2108            // Deliberately non-sequential, never-zero handles.
2109            let id = 100 + self.next * 7;
2110            self.next += 1;
2111            self.puts.fetch_add(1, std::sync::atomic::Ordering::Relaxed);
2112            self.blobs.insert(id, value);
2113            Ok(PageKey::new(id))
2114        }
2115
2116        fn take(&mut self, key: PageKey) -> Result<Bytes> {
2117            self.blobs
2118                .remove(&key.get())
2119                .ok_or_else(|| ParquetError::General(format!("missing key {}", key.get())))
2120        }
2121    }
2122
2123    #[derive(Debug)]
2124    struct RecordingPageStoreFactory {
2125        puts: Arc<std::sync::atomic::AtomicUsize>,
2126    }
2127
2128    impl PageStoreFactory for RecordingPageStoreFactory {
2129        fn create(&self, _args: &PageStoreArgs<'_>) -> Result<Box<dyn PageStore>> {
2130            Ok(Box::new(RecordingPageStore {
2131                puts: self.puts.clone(),
2132                ..Default::default()
2133            }))
2134        }
2135    }
2136
2137    /// A custom [`PageStore`] must produce byte-identical files to the in-memory
2138    /// default, across dictionary and non-dictionary columns and multiple row
2139    /// groups (so multiple store instances are exercised).
2140    #[test]
2141    fn custom_page_store_is_byte_identical_to_default() {
2142        let schema = Arc::new(Schema::new(vec![
2143            Field::new("i", DataType::Int32, true),
2144            // A low-cardinality string column to exercise the dictionary path.
2145            Field::new("s", DataType::Utf8, true),
2146        ]));
2147        let i = Int32Array::from(vec![Some(1), None, Some(3), Some(4), Some(5), Some(6)]);
2148        let s = StringArray::from(vec![
2149            Some("a"),
2150            Some("bb"),
2151            Some("a"),
2152            None,
2153            Some("bb"),
2154            Some("ccc"),
2155        ]);
2156        let batch = RecordBatch::try_new(schema.clone(), vec![Arc::new(i), Arc::new(s)]).unwrap();
2157
2158        // Small row groups so multiple column chunks (hence multiple store
2159        // instances) are produced.
2160        let props = WriterProperties::builder()
2161            .set_max_row_group_row_count(Some(3))
2162            .build();
2163
2164        let write = |factory: Option<Arc<dyn PageStoreFactory>>| {
2165            let mut buffer = Vec::new();
2166            let mut opts = ArrowWriterOptions::new().with_properties(props.clone());
2167            if let Some(factory) = factory {
2168                opts = opts.with_page_store_factory(factory);
2169            }
2170            let mut writer =
2171                ArrowWriter::try_new_with_options(&mut buffer, schema.clone(), opts).unwrap();
2172            writer.write(&batch).unwrap();
2173            writer.close().unwrap();
2174            buffer
2175        };
2176
2177        let default_bytes = write(None);
2178
2179        let puts = Arc::new(std::sync::atomic::AtomicUsize::new(0));
2180        let custom_bytes = write(Some(Arc::new(RecordingPageStoreFactory {
2181            puts: puts.clone(),
2182        })));
2183
2184        assert!(
2185            puts.load(std::sync::atomic::Ordering::Relaxed) > 0,
2186            "custom PageStore was never written to"
2187        );
2188        assert_eq!(
2189            default_bytes, custom_bytes,
2190            "a custom PageStore must produce byte-identical output to the default"
2191        );
2192    }
2193
2194    /// A dictionary-encoded column written through the deferred-ordering Arrow
2195    /// path must round-trip correctly even with the offset index disabled, when
2196    /// only the chunk-level dictionary/data page offsets are rewritten (there is
2197    /// no offset index to rebuild). Spans multiple data pages so the
2198    /// dictionary-first reordering is exercised.
2199    #[test]
2200    fn dictionary_column_round_trips_with_offset_index_disabled() {
2201        let schema = Arc::new(Schema::new(vec![Field::new("k", DataType::Int32, true)]));
2202
2203        // Low cardinality so the column stays dictionary-encoded; enough rows to
2204        // span several data pages within a single row group.
2205        let values: Vec<Option<i32>> = (0..50_000).map(|i| Some(i % 8)).collect();
2206        let array = Int32Array::from(values.clone());
2207        let batch = RecordBatch::try_new(schema.clone(), vec![Arc::new(array)]).unwrap();
2208
2209        let props = WriterProperties::builder()
2210            .set_offset_index_disabled(true)
2211            .set_data_page_row_count_limit(4096)
2212            .build();
2213        let opts = ArrowWriterOptions::new().with_properties(props);
2214
2215        let mut buffer = Vec::new();
2216        let mut writer =
2217            ArrowWriter::try_new_with_options(&mut buffer, schema.clone(), opts).unwrap();
2218        writer.write(&batch).unwrap();
2219        writer.close().unwrap();
2220
2221        let reader = ParquetRecordBatchReader::try_new(Bytes::from(buffer), values.len()).unwrap();
2222        let read: Vec<RecordBatch> = reader.collect::<ArrowResult<_>>().unwrap();
2223        let read_values: Vec<Option<i32>> = read
2224            .iter()
2225            .flat_map(|b| b.column(0).as_primitive::<Int32Type>().iter())
2226            .collect();
2227        assert_eq!(read_values, values);
2228    }
2229
2230    /// The dictionary page is routed through the [`PageStore`] like any other
2231    /// page rather than held resident in memory, so a dictionary column chunk's
2232    /// *entire* serialized size — dictionary page included — passes through the
2233    /// store.
2234    #[test]
2235    fn dictionary_page_is_routed_through_the_store() {
2236        /// A store that sums the bytes handed to `put`.
2237        #[derive(Debug, Default)]
2238        struct SizeRecordingPageStore {
2239            blobs: Vec<Bytes>,
2240            bytes_put: Arc<std::sync::atomic::AtomicUsize>,
2241        }
2242        impl PageStore for SizeRecordingPageStore {
2243            fn put(&mut self, value: Bytes) -> Result<PageKey> {
2244                self.bytes_put
2245                    .fetch_add(value.len(), std::sync::atomic::Ordering::Relaxed);
2246                let key = PageKey::new(self.blobs.len() as u64);
2247                self.blobs.push(value);
2248                Ok(key)
2249            }
2250            fn take(&mut self, key: PageKey) -> Result<Bytes> {
2251                Ok(std::mem::take(&mut self.blobs[key.get() as usize]))
2252            }
2253        }
2254        #[derive(Debug)]
2255        struct Factory {
2256            bytes_put: Arc<std::sync::atomic::AtomicUsize>,
2257        }
2258        impl PageStoreFactory for Factory {
2259            fn create(&self, _args: &PageStoreArgs<'_>) -> Result<Box<dyn PageStore>> {
2260                Ok(Box::new(SizeRecordingPageStore {
2261                    bytes_put: self.bytes_put.clone(),
2262                    ..Default::default()
2263                }))
2264            }
2265        }
2266
2267        let schema = Arc::new(Schema::new(vec![Field::new("s", DataType::Utf8, false)]));
2268        // Low cardinality keeps the column dictionary-encoded with a real,
2269        // non-empty dictionary page.
2270        let values: Vec<&str> = (0..2048)
2271            .map(|i| ["alpha", "beta", "gamma", "delta"][i % 4])
2272            .collect();
2273        let batch = RecordBatch::try_new(schema.clone(), vec![Arc::new(StringArray::from(values))])
2274            .unwrap();
2275
2276        let bytes_put = Arc::new(std::sync::atomic::AtomicUsize::new(0));
2277        let opts = ArrowWriterOptions::new().with_page_store_factory(Arc::new(Factory {
2278            bytes_put: bytes_put.clone(),
2279        }));
2280
2281        // A single batch / single column means exactly one row group and one
2282        // store instance, so the bytes it saw map to one column chunk.
2283        let mut buffer = Vec::new();
2284        let mut writer =
2285            ArrowWriter::try_new_with_options(&mut buffer, schema.clone(), opts).unwrap();
2286        writer.write(&batch).unwrap();
2287        writer.close().unwrap();
2288
2289        let reader = SerializedFileReader::new(Bytes::from(buffer)).unwrap();
2290        let column = reader.metadata().row_group(0).column(0);
2291        assert!(
2292            column.dictionary_page_offset().is_some(),
2293            "expected the column to be dictionary-encoded"
2294        );
2295
2296        // The bytes the store was handed must account for the whole chunk,
2297        // dictionary page included. Holding the dictionary page apart from the
2298        // store would make this fall short by the dictionary page's size.
2299        assert_eq!(
2300            bytes_put.load(std::sync::atomic::Ordering::Relaxed) as i64,
2301            column.compressed_size(),
2302            "the dictionary page must pass through the store like any other page"
2303        );
2304    }
2305
2306    #[test]
2307    fn arrow_writer() {
2308        // define schema
2309        let schema = Schema::new(vec![
2310            Field::new("a", DataType::Int32, false),
2311            Field::new("b", DataType::Int32, true),
2312        ]);
2313
2314        // create some data
2315        let a = Int32Array::from(vec![1, 2, 3, 4, 5]);
2316        let b = Int32Array::from(vec![Some(1), None, None, Some(4), Some(5)]);
2317
2318        // build a record batch
2319        let batch = RecordBatch::try_new(Arc::new(schema), vec![Arc::new(a), Arc::new(b)]).unwrap();
2320
2321        roundtrip(batch, Some(SMALL_SIZE / 2));
2322    }
2323
2324    fn get_bytes_after_close(schema: SchemaRef, expected_batch: &RecordBatch) -> Vec<u8> {
2325        let mut buffer = vec![];
2326
2327        let mut writer = ArrowWriter::try_new(&mut buffer, schema, None).unwrap();
2328        writer.write(expected_batch).unwrap();
2329        writer.close().unwrap();
2330
2331        buffer
2332    }
2333
2334    fn get_bytes_by_into_inner(schema: SchemaRef, expected_batch: &RecordBatch) -> Vec<u8> {
2335        let mut writer = ArrowWriter::try_new(Vec::new(), schema, None).unwrap();
2336        writer.write(expected_batch).unwrap();
2337        writer.into_inner().unwrap()
2338    }
2339
2340    #[test]
2341    fn roundtrip_bytes() {
2342        // define schema
2343        let schema = Arc::new(Schema::new(vec![
2344            Field::new("a", DataType::Int32, false),
2345            Field::new("b", DataType::Int32, true),
2346        ]));
2347
2348        // create some data
2349        let a = Int32Array::from(vec![1, 2, 3, 4, 5]);
2350        let b = Int32Array::from(vec![Some(1), None, None, Some(4), Some(5)]);
2351
2352        // build a record batch
2353        let expected_batch =
2354            RecordBatch::try_new(schema.clone(), vec![Arc::new(a), Arc::new(b)]).unwrap();
2355
2356        for buffer in [
2357            get_bytes_after_close(schema.clone(), &expected_batch),
2358            get_bytes_by_into_inner(schema, &expected_batch),
2359        ] {
2360            let cursor = Bytes::from(buffer);
2361            let mut record_batch_reader = ParquetRecordBatchReader::try_new(cursor, 1024).unwrap();
2362
2363            let actual_batch = record_batch_reader
2364                .next()
2365                .expect("No batch found")
2366                .expect("Unable to get batch");
2367
2368            assert_eq!(expected_batch.schema(), actual_batch.schema());
2369            assert_eq!(expected_batch.num_columns(), actual_batch.num_columns());
2370            assert_eq!(expected_batch.num_rows(), actual_batch.num_rows());
2371            for i in 0..expected_batch.num_columns() {
2372                let expected_data = expected_batch.column(i).to_data();
2373                let actual_data = actual_batch.column(i).to_data();
2374
2375                assert_eq!(expected_data, actual_data);
2376            }
2377        }
2378    }
2379
2380    #[test]
2381    fn arrow_writer_non_null() {
2382        let schema = Schema::new(vec![Field::new("a", DataType::Int32, false)]);
2383        let a = Int32Array::from(vec![1, 2, 3, 4, 5]);
2384
2385        RoundTripTest::new(Arc::new(a))
2386            .with_schema(Arc::new(schema))
2387            .run();
2388    }
2389
2390    #[test]
2391    fn arrow_writer_list() {
2392        // define schema
2393        let schema = Schema::new(vec![Field::new(
2394            "a",
2395            DataType::List(Arc::new(Field::new_list_field(DataType::Int32, false))),
2396            true,
2397        )]);
2398
2399        // create some data
2400        let a_values = Int32Array::from(vec![1, 2, 3, 4, 5, 6, 7, 8, 9, 10]);
2401
2402        // Construct a buffer for value offsets, for the nested array:
2403        //  [[1], [2, 3], null, [4, 5, 6], [7, 8, 9, 10]]
2404        let a_value_offsets = arrow::buffer::Buffer::from([0, 1, 3, 3, 6, 10].to_byte_slice());
2405
2406        // Construct a list array from the above two
2407        let a_list_data = ArrayData::builder(DataType::List(Arc::new(Field::new_list_field(
2408            DataType::Int32,
2409            false,
2410        ))))
2411        .len(5)
2412        .add_buffer(a_value_offsets)
2413        .add_child_data(a_values.into_data())
2414        .null_bit_buffer(Some(Buffer::from([0b00011011])))
2415        .build()
2416        .unwrap();
2417        let a = ListArray::from(a_list_data);
2418        assert_eq!(a.null_count(), 1);
2419
2420        RoundTripTest::new(Arc::new(a))
2421            .with_schema(Arc::new(schema))
2422            .run();
2423    }
2424
2425    #[test]
2426    fn arrow_writer_list_non_null() {
2427        // define schema
2428        let schema = Schema::new(vec![Field::new(
2429            "a",
2430            DataType::List(Arc::new(Field::new_list_field(DataType::Int32, false))),
2431            false,
2432        )]);
2433
2434        // create some data
2435        let a_values = Int32Array::from(vec![1, 2, 3, 4, 5, 6, 7, 8, 9, 10]);
2436
2437        // Construct a buffer for value offsets, for the nested array:
2438        //  [[1], [2, 3], [], [4, 5, 6], [7, 8, 9, 10]]
2439        let a_value_offsets = arrow::buffer::Buffer::from([0, 1, 3, 3, 6, 10].to_byte_slice());
2440
2441        // Construct a list array from the above two
2442        let a_list_data = ArrayData::builder(DataType::List(Arc::new(Field::new_list_field(
2443            DataType::Int32,
2444            false,
2445        ))))
2446        .len(5)
2447        .add_buffer(a_value_offsets)
2448        .add_child_data(a_values.into_data())
2449        .build()
2450        .unwrap();
2451        let a = ListArray::from(a_list_data);
2452        assert_eq!(a.null_count(), 0);
2453
2454        RoundTripTest::new(Arc::new(a))
2455            .with_schema(Arc::new(schema))
2456            .run();
2457    }
2458
2459    #[test]
2460    fn arrow_writer_list_view() {
2461        let list_field = Arc::new(Field::new_list_field(DataType::Int32, false));
2462        let schema = Schema::new(vec![Field::new(
2463            "a",
2464            DataType::ListView(list_field.clone()),
2465            true,
2466        )]);
2467
2468        //  [[1], [2, 3], null, [4, 5, 6], [7, 8, 9, 10]]
2469        let a = ListViewArray::new(
2470            list_field,
2471            vec![0, 1, 0, 3, 6].into(),
2472            vec![1, 2, 0, 3, 4].into(),
2473            Arc::new(Int32Array::from(vec![1, 2, 3, 4, 5, 6, 7, 8, 9, 10])),
2474            Some(vec![true, true, false, true, true].into()),
2475        );
2476        assert_eq!(a.null_count(), 1);
2477
2478        RoundTripTest::new(Arc::new(a))
2479            .with_schema(Arc::new(schema))
2480            .run();
2481    }
2482
2483    #[test]
2484    fn arrow_writer_list_view_non_null() {
2485        let list_field = Arc::new(Field::new_list_field(DataType::Int32, false));
2486        let schema = Schema::new(vec![Field::new(
2487            "a",
2488            DataType::ListView(list_field.clone()),
2489            false,
2490        )]);
2491
2492        //  [[1], [2, 3], [], [4, 5, 6], [7, 8, 9, 10]]
2493        let a = ListViewArray::new(
2494            list_field,
2495            vec![0, 1, 0, 3, 6].into(),
2496            vec![1, 2, 0, 3, 4].into(),
2497            Arc::new(Int32Array::from(vec![1, 2, 3, 4, 5, 6, 7, 8, 9, 10])),
2498            None,
2499        );
2500        assert_eq!(a.null_count(), 0);
2501
2502        RoundTripTest::new(Arc::new(a))
2503            .with_schema(Arc::new(schema))
2504            .run();
2505    }
2506
2507    #[test]
2508    fn arrow_writer_list_view_out_of_order() {
2509        let list_field = Arc::new(Field::new_list_field(DataType::Int32, false));
2510        let schema = Schema::new(vec![Field::new(
2511            "a",
2512            DataType::ListView(list_field.clone()),
2513            false,
2514        )]);
2515
2516        // [[1], [2, 3], [], [7, 8, 9, 10], [4, 5, 6]] - out of order offsets
2517        let a = ListViewArray::new(
2518            list_field,
2519            vec![0, 1, 0, 6, 3].into(),
2520            vec![1, 2, 0, 4, 3].into(),
2521            Arc::new(Int32Array::from(vec![1, 2, 3, 4, 5, 6, 7, 8, 9, 10])),
2522            None,
2523        );
2524        assert_eq!(a.null_count(), 0);
2525
2526        RoundTripTest::new(Arc::new(a))
2527            .with_schema(Arc::new(schema))
2528            .run();
2529    }
2530
2531    #[test]
2532    fn arrow_writer_large_list_view() {
2533        let list_field = Arc::new(Field::new_list_field(DataType::Int32, false));
2534        let schema = Schema::new(vec![Field::new(
2535            "a",
2536            DataType::LargeListView(list_field.clone()),
2537            true,
2538        )]);
2539
2540        //  [[1], [2, 3], null, [4, 5, 6], [7, 8, 9, 10]]
2541        let a = LargeListViewArray::new(
2542            list_field,
2543            vec![0i64, 1, 0, 3, 6].into(),
2544            vec![1i64, 2, 0, 3, 4].into(),
2545            Arc::new(Int32Array::from(vec![1, 2, 3, 4, 5, 6, 7, 8, 9, 10])),
2546            Some(vec![true, true, false, true, true].into()),
2547        );
2548        assert_eq!(a.null_count(), 1);
2549
2550        RoundTripTest::new(Arc::new(a))
2551            .with_schema(Arc::new(schema))
2552            .run();
2553    }
2554
2555    #[test]
2556    fn arrow_writer_list_view_with_struct() {
2557        // Test ListView containing Struct: ListView<Struct<Int32, Utf8>>
2558        let struct_fields = Fields::from(vec![
2559            Field::new("id", DataType::Int32, false),
2560            Field::new("name", DataType::Utf8, false),
2561        ]);
2562        let struct_type = DataType::Struct(struct_fields.clone());
2563        let list_field = Arc::new(Field::new("item", struct_type.clone(), false));
2564
2565        let schema = Schema::new(vec![Field::new(
2566            "a",
2567            DataType::ListView(list_field.clone()),
2568            true,
2569        )]);
2570
2571        // Create struct values
2572        let id_array = Int32Array::from(vec![1, 2, 3, 4, 5]);
2573        let name_array = StringArray::from(vec!["a", "b", "c", "d", "e"]);
2574        let struct_array = StructArray::new(
2575            struct_fields,
2576            vec![Arc::new(id_array), Arc::new(name_array)],
2577            None,
2578        );
2579
2580        // Create ListView: [{1, "a"}, {2, "b"}], null, [{3, "c"}, {4, "d"}, {5, "e"}]
2581        let list_view = ListViewArray::new(
2582            list_field,
2583            vec![0, 2, 2].into(), // offsets
2584            vec![2, 0, 3].into(), // sizes
2585            Arc::new(struct_array),
2586            Some(vec![true, false, true].into()),
2587        );
2588        assert_eq!(list_view.null_count(), 1);
2589
2590        RoundTripTest::new(Arc::new(list_view))
2591            .with_schema(Arc::new(schema))
2592            .run();
2593    }
2594
2595    #[test]
2596    fn arrow_writer_binary() {
2597        let raw_string_values = vec!["foo", "bar", "baz", "quux"];
2598        let raw_binary_values = [
2599            b"foo".to_vec(),
2600            b"bar".to_vec(),
2601            b"baz".to_vec(),
2602            b"quux".to_vec(),
2603        ];
2604        let raw_binary_value_refs = raw_binary_values
2605            .iter()
2606            .map(|x| x.as_slice())
2607            .collect::<Vec<_>>();
2608
2609        let string_values = StringArray::from(raw_string_values.clone());
2610        let binary_values = BinaryArray::from(raw_binary_value_refs);
2611        assert_eq!(string_values.null_count(), 0);
2612        assert_eq!(binary_values.null_count(), 0);
2613
2614        RoundTripTest::new(Arc::new(string_values)).run();
2615        RoundTripTest::new(Arc::new(binary_values)).run();
2616    }
2617
2618    #[test]
2619    fn arrow_writer_binary_view() {
2620        let raw_string_values = vec!["foo", "bar", "large payload over 12 bytes", "lulu"];
2621        let raw_binary_values = vec![
2622            b"foo".to_vec(),
2623            b"bar".to_vec(),
2624            b"large payload over 12 bytes".to_vec(),
2625            b"lulu".to_vec(),
2626        ];
2627        let nullable_string_values =
2628            vec![Some("foo"), None, Some("large payload over 12 bytes"), None];
2629
2630        let string_view_values = StringViewArray::from(raw_string_values);
2631        let binary_view_values = BinaryViewArray::from_iter_values(raw_binary_values);
2632        let nullable_string_view_values = StringViewArray::from(nullable_string_values);
2633
2634        RoundTripTest::new(Arc::new(string_view_values)).run();
2635        RoundTripTest::new(Arc::new(binary_view_values)).run();
2636        RoundTripTest::new(Arc::new(nullable_string_view_values)).run();
2637    }
2638
2639    #[test]
2640    fn arrow_writer_binary_view_long_value() {
2641        // There is special case validation for long values (greater than 128)
2642        // 128 encodes as 0x80 0x00 0x00 0x00 in little endian, which should
2643        // trigger the long-string UTF-8 validation branch in the plain decoder.
2644        let long = "a".repeat(128);
2645        let raw_string_values = vec!["foo", long.as_str(), "bar"];
2646        let raw_binary_values = vec![b"foo".to_vec(), long.as_bytes().to_vec(), b"bar".to_vec()];
2647
2648        let string_view_values: ArrayRef = Arc::new(StringViewArray::from(raw_string_values));
2649        let binary_view_values: ArrayRef =
2650            Arc::new(BinaryViewArray::from_iter_values(raw_binary_values));
2651
2652        RoundTripTest::new(Arc::clone(&string_view_values))
2653            .with_nullable(false)
2654            .run();
2655        RoundTripTest::new(Arc::clone(&binary_view_values))
2656            .with_nullable(false)
2657            .run();
2658    }
2659
2660    fn get_decimal_batch(precision: u8, scale: i8) -> RecordBatch {
2661        let decimal_field = Field::new("a", DataType::Decimal128(precision, scale), false);
2662        let schema = Schema::new(vec![decimal_field]);
2663
2664        let decimal_values = vec![10_000, 50_000, 0, -100]
2665            .into_iter()
2666            .map(Some)
2667            .collect::<Decimal128Array>()
2668            .with_precision_and_scale(precision, scale)
2669            .unwrap();
2670
2671        RecordBatch::try_new(Arc::new(schema), vec![Arc::new(decimal_values)]).unwrap()
2672    }
2673
2674    #[test]
2675    fn arrow_writer_decimal() {
2676        // int32 to store the decimal value
2677        let batch_int32_decimal = get_decimal_batch(5, 2);
2678        roundtrip(batch_int32_decimal, Some(SMALL_SIZE / 2));
2679        // int64 to store the decimal value
2680        let batch_int64_decimal = get_decimal_batch(12, 2);
2681        roundtrip(batch_int64_decimal, Some(SMALL_SIZE / 2));
2682        // fixed_length_byte_array to store the decimal value
2683        let batch_fixed_len_byte_array_decimal = get_decimal_batch(30, 2);
2684        roundtrip(batch_fixed_len_byte_array_decimal, Some(SMALL_SIZE / 2));
2685    }
2686
2687    #[test]
2688    fn arrow_writer_complex() {
2689        // define schema
2690        let struct_field_d = Arc::new(Field::new("d", DataType::Float64, true));
2691        let struct_field_f = Arc::new(Field::new("f", DataType::Float32, true));
2692        let struct_field_g = Arc::new(Field::new_list(
2693            "g",
2694            Field::new_list_field(DataType::Int16, true),
2695            false,
2696        ));
2697        let struct_field_h = Arc::new(Field::new_list(
2698            "h",
2699            Field::new_list_field(DataType::Int16, false),
2700            true,
2701        ));
2702        let struct_field_e = Arc::new(Field::new_struct(
2703            "e",
2704            vec![
2705                struct_field_f.clone(),
2706                struct_field_g.clone(),
2707                struct_field_h.clone(),
2708            ],
2709            false,
2710        ));
2711        let schema = Schema::new(vec![
2712            Field::new("a", DataType::Int32, false),
2713            Field::new("b", DataType::Int32, true),
2714            Field::new_struct(
2715                "c",
2716                vec![struct_field_d.clone(), struct_field_e.clone()],
2717                false,
2718            ),
2719        ]);
2720
2721        // create some data
2722        let a = Int32Array::from(vec![1, 2, 3, 4, 5]);
2723        let b = Int32Array::from(vec![Some(1), None, None, Some(4), Some(5)]);
2724        let d = Float64Array::from(vec![None, None, None, Some(1.0), None]);
2725        let f = Float32Array::from(vec![Some(0.0), None, Some(333.3), None, Some(5.25)]);
2726
2727        let g_value = Int16Array::from(vec![1, 2, 3, 4, 5, 6, 7, 8, 9, 10]);
2728
2729        // Construct a buffer for value offsets, for the nested array:
2730        //  [[1], [2, 3], [], [4, 5, 6], [7, 8, 9, 10]]
2731        let g_value_offsets = arrow::buffer::Buffer::from([0, 1, 3, 3, 6, 10].to_byte_slice());
2732
2733        // Construct a list array from the above two
2734        let g_list_data = ArrayData::builder(struct_field_g.data_type().clone())
2735            .len(5)
2736            .add_buffer(g_value_offsets.clone())
2737            .add_child_data(g_value.to_data())
2738            .build()
2739            .unwrap();
2740        let g = ListArray::from(g_list_data);
2741        // The difference between g and h is that h has a null bitmap
2742        let h_list_data = ArrayData::builder(struct_field_h.data_type().clone())
2743            .len(5)
2744            .add_buffer(g_value_offsets)
2745            .add_child_data(g_value.to_data())
2746            .null_bit_buffer(Some(Buffer::from([0b00011011])))
2747            .build()
2748            .unwrap();
2749        let h = ListArray::from(h_list_data);
2750
2751        let e = StructArray::from(vec![
2752            (struct_field_f, Arc::new(f) as ArrayRef),
2753            (struct_field_g, Arc::new(g) as ArrayRef),
2754            (struct_field_h, Arc::new(h) as ArrayRef),
2755        ]);
2756
2757        let c = StructArray::from(vec![
2758            (struct_field_d, Arc::new(d) as ArrayRef),
2759            (struct_field_e, Arc::new(e) as ArrayRef),
2760        ]);
2761
2762        // build a record batch
2763        let batch = RecordBatch::try_new(
2764            Arc::new(schema),
2765            vec![Arc::new(a), Arc::new(b), Arc::new(c)],
2766        )
2767        .unwrap();
2768
2769        roundtrip(batch.clone(), Some(SMALL_SIZE / 2));
2770        roundtrip(batch, Some(SMALL_SIZE / 3));
2771    }
2772
2773    #[test]
2774    fn arrow_writer_complex_mixed() {
2775        // This test was added while investigating https://github.com/apache/arrow-rs/issues/244.
2776        // It was subsequently fixed while investigating https://github.com/apache/arrow-rs/issues/245.
2777
2778        // define schema
2779        let offset_field = Arc::new(Field::new("offset", DataType::Int32, false));
2780        let partition_field = Arc::new(Field::new("partition", DataType::Int64, true));
2781        let topic_field = Arc::new(Field::new("topic", DataType::Utf8, true));
2782        let schema = Schema::new(vec![Field::new(
2783            "some_nested_object",
2784            DataType::Struct(Fields::from(vec![
2785                offset_field.clone(),
2786                partition_field.clone(),
2787                topic_field.clone(),
2788            ])),
2789            false,
2790        )]);
2791
2792        // create some data
2793        let offset = Int32Array::from(vec![1, 2, 3, 4, 5]);
2794        let partition = Int64Array::from(vec![Some(1), None, None, Some(4), Some(5)]);
2795        let topic = StringArray::from(vec![Some("A"), None, Some("A"), Some(""), None]);
2796
2797        let some_nested_object = StructArray::from(vec![
2798            (offset_field, Arc::new(offset) as ArrayRef),
2799            (partition_field, Arc::new(partition) as ArrayRef),
2800            (topic_field, Arc::new(topic) as ArrayRef),
2801        ]);
2802
2803        // build a record batch
2804        let batch =
2805            RecordBatch::try_new(Arc::new(schema), vec![Arc::new(some_nested_object)]).unwrap();
2806
2807        roundtrip(batch, Some(SMALL_SIZE / 2));
2808    }
2809
2810    #[test]
2811    fn arrow_writer_map() {
2812        // Note: we are using the JSON Arrow reader for brevity
2813        let json_content = r#"
2814        {"stocks":{"long": "$AAA", "short": "$BBB"}}
2815        {"stocks":{"long": null, "long": "$CCC", "short": null}}
2816        {"stocks":{"hedged": "$YYY", "long": null, "short": "$D"}}
2817        "#;
2818        let entries_struct_type = DataType::Struct(Fields::from(vec![
2819            Field::new(Field::MAP_KEY_FIELD_DEFAULT_NAME, DataType::Utf8, false),
2820            Field::new(Field::MAP_VALUE_FIELD_DEFAULT_NAME, DataType::Utf8, true),
2821        ]));
2822        let stocks_field = Field::new(
2823            "stocks",
2824            DataType::Map(
2825                Arc::new(Field::new(
2826                    Field::MAP_ENTRIES_FIELD_DEFAULT_NAME,
2827                    entries_struct_type,
2828                    false,
2829                )),
2830                false,
2831            ),
2832            true,
2833        );
2834        let schema = Arc::new(Schema::new(vec![stocks_field]));
2835        let builder = arrow::json::ReaderBuilder::new(schema).with_batch_size(64);
2836        let mut reader = builder.build(std::io::Cursor::new(json_content)).unwrap();
2837
2838        let batch = reader.next().unwrap().unwrap();
2839        roundtrip(batch, None);
2840    }
2841
2842    #[test]
2843    fn arrow_writer_2_level_struct() {
2844        // tests writing <struct<struct<primitive>>
2845        let field_c = Field::new("c", DataType::Int32, true);
2846        let field_b = Field::new("b", DataType::Struct(vec![field_c].into()), true);
2847        let type_a = DataType::Struct(vec![field_b.clone()].into());
2848        let field_a = Field::new("a", type_a, true);
2849        let schema = Schema::new(vec![field_a.clone()]);
2850
2851        // create data
2852        let c = Int32Array::from(vec![Some(1), None, Some(3), None, None, Some(6)]);
2853        let b_data = ArrayDataBuilder::new(field_b.data_type().clone())
2854            .len(6)
2855            .null_bit_buffer(Some(Buffer::from([0b00100111])))
2856            .add_child_data(c.into_data())
2857            .build()
2858            .unwrap();
2859        let b = StructArray::from(b_data);
2860        let a_data = ArrayDataBuilder::new(field_a.data_type().clone())
2861            .len(6)
2862            .null_bit_buffer(Some(Buffer::from([0b00101111])))
2863            .add_child_data(b.into_data())
2864            .build()
2865            .unwrap();
2866        let a = StructArray::from(a_data);
2867
2868        assert_eq!(a.null_count(), 1);
2869        assert_eq!(a.column(0).null_count(), 2);
2870
2871        // build a racord batch
2872        let batch = RecordBatch::try_new(Arc::new(schema), vec![Arc::new(a)]).unwrap();
2873
2874        roundtrip(batch, Some(SMALL_SIZE / 2));
2875    }
2876
2877    #[test]
2878    fn arrow_writer_2_level_struct_non_null() {
2879        // tests writing <struct<struct<primitive>>
2880        let field_c = Field::new("c", DataType::Int32, false);
2881        let type_b = DataType::Struct(vec![field_c].into());
2882        let field_b = Field::new("b", type_b.clone(), false);
2883        let type_a = DataType::Struct(vec![field_b].into());
2884        let field_a = Field::new("a", type_a.clone(), false);
2885        let schema = Schema::new(vec![field_a]);
2886
2887        // create data
2888        let c = Int32Array::from(vec![1, 2, 3, 4, 5, 6]);
2889        let b_data = ArrayDataBuilder::new(type_b)
2890            .len(6)
2891            .add_child_data(c.into_data())
2892            .build()
2893            .unwrap();
2894        let b = StructArray::from(b_data);
2895        let a_data = ArrayDataBuilder::new(type_a)
2896            .len(6)
2897            .add_child_data(b.into_data())
2898            .build()
2899            .unwrap();
2900        let a = StructArray::from(a_data);
2901
2902        assert_eq!(a.null_count(), 0);
2903        assert_eq!(a.column(0).null_count(), 0);
2904
2905        // build a racord batch
2906        let batch = RecordBatch::try_new(Arc::new(schema), vec![Arc::new(a)]).unwrap();
2907
2908        roundtrip(batch, Some(SMALL_SIZE / 2));
2909    }
2910
2911    #[test]
2912    fn arrow_writer_2_level_struct_mixed_null() {
2913        // tests writing <struct<struct<primitive>>
2914        let field_c = Field::new("c", DataType::Int32, false);
2915        let type_b = DataType::Struct(vec![field_c].into());
2916        let field_b = Field::new("b", type_b.clone(), true);
2917        let type_a = DataType::Struct(vec![field_b].into());
2918        let field_a = Field::new("a", type_a.clone(), false);
2919        let schema = Schema::new(vec![field_a]);
2920
2921        // create data
2922        let c = Int32Array::from(vec![1, 2, 3, 4, 5, 6]);
2923        let b_data = ArrayDataBuilder::new(type_b)
2924            .len(6)
2925            .null_bit_buffer(Some(Buffer::from([0b00100111])))
2926            .add_child_data(c.into_data())
2927            .build()
2928            .unwrap();
2929        let b = StructArray::from(b_data);
2930        // a intentionally has no null buffer, to test that this is handled correctly
2931        let a_data = ArrayDataBuilder::new(type_a)
2932            .len(6)
2933            .add_child_data(b.into_data())
2934            .build()
2935            .unwrap();
2936        let a = StructArray::from(a_data);
2937
2938        assert_eq!(a.null_count(), 0);
2939        assert_eq!(a.column(0).null_count(), 2);
2940
2941        // build a racord batch
2942        let batch = RecordBatch::try_new(Arc::new(schema), vec![Arc::new(a)]).unwrap();
2943
2944        roundtrip(batch, Some(SMALL_SIZE / 2));
2945    }
2946
2947    #[test]
2948    fn arrow_writer_2_level_struct_mixed_null_2() {
2949        // tests writing <struct<struct<primitive>>, where the primitive columns are non-null.
2950        let field_c = Field::new("c", DataType::Int32, false);
2951        let field_d = Field::new("d", DataType::FixedSizeBinary(4), false);
2952        let field_e = Field::new(
2953            "e",
2954            DataType::Dictionary(Box::new(DataType::Int32), Box::new(DataType::Utf8)),
2955            false,
2956        );
2957
2958        let field_b = Field::new(
2959            "b",
2960            DataType::Struct(vec![field_c, field_d, field_e].into()),
2961            false,
2962        );
2963        let type_a = DataType::Struct(vec![field_b.clone()].into());
2964        let field_a = Field::new("a", type_a, true);
2965        let schema = Schema::new(vec![field_a.clone()]);
2966
2967        // create data
2968        let c = Int32Array::from_iter_values(0..6);
2969        let d = FixedSizeBinaryArray::try_from_iter(
2970            ["aaaa", "bbbb", "cccc", "dddd", "eeee", "ffff"].into_iter(),
2971        )
2972        .expect("four byte values");
2973        let e = Int32DictionaryArray::from_iter(["one", "two", "three", "four", "five", "one"]);
2974        let b_data = ArrayDataBuilder::new(field_b.data_type().clone())
2975            .len(6)
2976            .add_child_data(c.into_data())
2977            .add_child_data(d.into_data())
2978            .add_child_data(e.into_data())
2979            .build()
2980            .unwrap();
2981        let b = StructArray::from(b_data);
2982        let a_data = ArrayDataBuilder::new(field_a.data_type().clone())
2983            .len(6)
2984            .null_bit_buffer(Some(Buffer::from([0b00100101])))
2985            .add_child_data(b.into_data())
2986            .build()
2987            .unwrap();
2988        let a = StructArray::from(a_data);
2989
2990        assert_eq!(a.null_count(), 3);
2991        assert_eq!(a.column(0).null_count(), 0);
2992
2993        // build a record batch
2994        let batch = RecordBatch::try_new(Arc::new(schema), vec![Arc::new(a)]).unwrap();
2995
2996        roundtrip(batch, Some(SMALL_SIZE / 2));
2997    }
2998
2999    #[test]
3000    fn test_fixed_size_binary_in_dict() {
3001        fn test_fixed_size_binary_in_dict_inner<K>()
3002        where
3003            K: ArrowDictionaryKeyType,
3004            K::Native: FromPrimitive + ToPrimitive + TryFrom<u8>,
3005            <<K as arrow_array::ArrowPrimitiveType>::Native as TryFrom<u8>>::Error: std::fmt::Debug,
3006        {
3007            let field = Field::new(
3008                "a",
3009                DataType::Dictionary(
3010                    Box::new(K::DATA_TYPE),
3011                    Box::new(DataType::FixedSizeBinary(4)),
3012                ),
3013                false,
3014            );
3015            let schema = Schema::new(vec![field]);
3016
3017            let keys: Vec<K::Native> = vec![
3018                K::Native::try_from(0u8).unwrap(),
3019                K::Native::try_from(0u8).unwrap(),
3020                K::Native::try_from(1u8).unwrap(),
3021            ];
3022            let keys = PrimitiveArray::<K>::from_iter_values(keys);
3023            let values = FixedSizeBinaryArray::try_from_iter(
3024                vec![vec![0, 0, 0, 0], vec![1, 1, 1, 1]].into_iter(),
3025            )
3026            .unwrap();
3027
3028            let data = DictionaryArray::<K>::new(keys, Arc::new(values));
3029            let batch = RecordBatch::try_new(Arc::new(schema), vec![Arc::new(data)]).unwrap();
3030            roundtrip(batch, None);
3031        }
3032
3033        test_fixed_size_binary_in_dict_inner::<UInt8Type>();
3034        test_fixed_size_binary_in_dict_inner::<UInt16Type>();
3035        test_fixed_size_binary_in_dict_inner::<UInt32Type>();
3036        test_fixed_size_binary_in_dict_inner::<UInt16Type>();
3037        test_fixed_size_binary_in_dict_inner::<Int8Type>();
3038        test_fixed_size_binary_in_dict_inner::<Int16Type>();
3039        test_fixed_size_binary_in_dict_inner::<Int32Type>();
3040        test_fixed_size_binary_in_dict_inner::<Int64Type>();
3041    }
3042
3043    #[test]
3044    fn test_empty_dict() {
3045        let struct_fields = Fields::from(vec![Field::new(
3046            "dict",
3047            DataType::Dictionary(Box::new(DataType::Int32), Box::new(DataType::Utf8)),
3048            false,
3049        )]);
3050
3051        let schema = Schema::new(vec![Field::new_struct(
3052            "struct",
3053            struct_fields.clone(),
3054            true,
3055        )]);
3056        let dictionary = Arc::new(DictionaryArray::new(
3057            Int32Array::new_null(5),
3058            Arc::new(StringArray::new_null(0)),
3059        ));
3060
3061        let s = StructArray::new(
3062            struct_fields,
3063            vec![dictionary],
3064            Some(NullBuffer::new_null(5)),
3065        );
3066
3067        let batch = RecordBatch::try_new(Arc::new(schema), vec![Arc::new(s)]).unwrap();
3068        roundtrip(batch, None);
3069    }
3070    #[test]
3071    fn arrow_writer_page_size() {
3072        let schema = Arc::new(Schema::new(vec![Field::new("col", DataType::Utf8, false)]));
3073
3074        let mut builder = StringBuilder::with_capacity(100, 329 * 10_000);
3075
3076        // Generate an array of 10 unique 10 character string
3077        for i in 0..10 {
3078            let value = i
3079                .to_string()
3080                .repeat(10)
3081                .chars()
3082                .take(10)
3083                .collect::<String>();
3084
3085            builder.append_value(value);
3086        }
3087
3088        let array = Arc::new(builder.finish());
3089
3090        let batch = RecordBatch::try_new(schema, vec![array]).unwrap();
3091
3092        let file = tempfile::tempfile().unwrap();
3093
3094        // Set everything very low so we fallback to PLAIN encoding after the first row
3095        let props = WriterProperties::builder()
3096            .set_data_page_size_limit(1)
3097            .set_dictionary_page_size_limit(1)
3098            .set_write_batch_size(1)
3099            .build();
3100
3101        let mut writer =
3102            ArrowWriter::try_new(file.try_clone().unwrap(), batch.schema(), Some(props))
3103                .expect("Unable to write file");
3104        writer.write(&batch).unwrap();
3105        writer.close().unwrap();
3106
3107        let options = ReadOptionsBuilder::new().with_page_index().build();
3108        let reader =
3109            SerializedFileReader::new_with_options(file.try_clone().unwrap(), options).unwrap();
3110
3111        let column = reader.metadata().row_group(0).columns();
3112
3113        assert_eq!(column.len(), 1);
3114
3115        // We should write one row before falling back to PLAIN encoding so there should still be a
3116        // dictionary page.
3117        assert!(
3118            column[0].dictionary_page_offset().is_some(),
3119            "Expected a dictionary page"
3120        );
3121
3122        let page_index = reader
3123            .metadata()
3124            .page_index()
3125            .expect("page index should be present");
3126        let page_locations = page_index
3127            .page_locations(0, 0)
3128            .expect("page locations should exist");
3129
3130        // We should fallback to PLAIN encoding after the first row and our max page size is 1 bytes
3131        // so we expect one dictionary encoded page and then a page per row thereafter.
3132        assert_eq!(
3133            page_locations.len(),
3134            10,
3135            "Expected 10 pages but got {page_locations:#?}"
3136        );
3137    }
3138
3139    #[test]
3140    fn arrow_writer_float_nans() {
3141        let f16_field = Field::new("a", DataType::Float16, false);
3142        let f32_field = Field::new("b", DataType::Float32, false);
3143        let f64_field = Field::new("c", DataType::Float64, false);
3144        let schema = Schema::new(vec![f16_field, f32_field, f64_field]);
3145
3146        let f16_values = (0..MEDIUM_SIZE)
3147            .map(|i| {
3148                Some(if i % 2 == 0 {
3149                    f16::NAN
3150                } else {
3151                    f16::from_f32(i as f32)
3152                })
3153            })
3154            .collect::<Float16Array>();
3155
3156        let f32_values = (0..MEDIUM_SIZE)
3157            .map(|i| Some(if i % 2 == 0 { f32::NAN } else { i as f32 }))
3158            .collect::<Float32Array>();
3159
3160        let f64_values = (0..MEDIUM_SIZE)
3161            .map(|i| Some(if i % 2 == 0 { f64::NAN } else { i as f64 }))
3162            .collect::<Float64Array>();
3163
3164        let batch = RecordBatch::try_new(
3165            Arc::new(schema),
3166            vec![
3167                Arc::new(f16_values),
3168                Arc::new(f32_values),
3169                Arc::new(f64_values),
3170            ],
3171        )
3172        .unwrap();
3173
3174        roundtrip(batch, None);
3175    }
3176
3177    const SMALL_SIZE: usize = 7;
3178    const MEDIUM_SIZE: usize = 63;
3179
3180    // Write the batch to parquet and read it back out, ensuring
3181    // that what comes out is the same as what was written in
3182    fn roundtrip(expected_batch: RecordBatch, max_row_group_size: Option<usize>) -> Vec<Bytes> {
3183        let mut files = vec![];
3184        for version in [WriterVersion::PARQUET_1_0, WriterVersion::PARQUET_2_0] {
3185            let mut props = WriterProperties::builder().set_writer_version(version);
3186
3187            if let Some(size) = max_row_group_size {
3188                props = props.set_max_row_group_row_count(Some(size))
3189            }
3190
3191            let props = props.build();
3192            files.push(roundtrip_opts(&expected_batch, props))
3193        }
3194        files
3195    }
3196
3197    // Round trip the specified record batch with the specified writer properties,
3198    // to an in-memory file, and validate the arrays using the specified function.
3199    // Returns the in-memory file.
3200    fn roundtrip_opts_with_array_validation<F>(
3201        expected_batch: &RecordBatch,
3202        props: WriterProperties,
3203        validate: F,
3204    ) -> Bytes
3205    where
3206        F: Fn(&ArrayData, &ArrayData),
3207    {
3208        let mut file = vec![];
3209
3210        let mut writer = ArrowWriter::try_new(&mut file, expected_batch.schema(), Some(props))
3211            .expect("Unable to write file");
3212        writer.write(expected_batch).unwrap();
3213        writer.close().unwrap();
3214
3215        let file = Bytes::from(file);
3216        let mut record_batch_reader =
3217            ParquetRecordBatchReader::try_new(file.clone(), 1024).unwrap();
3218
3219        let actual_batch = record_batch_reader
3220            .next()
3221            .expect("No batch found")
3222            .expect("Unable to get batch");
3223
3224        assert_eq!(expected_batch.schema(), actual_batch.schema());
3225        assert_eq!(expected_batch.num_columns(), actual_batch.num_columns());
3226        assert_eq!(expected_batch.num_rows(), actual_batch.num_rows());
3227        for i in 0..expected_batch.num_columns() {
3228            let expected_data = expected_batch.column(i).to_data();
3229            let actual_data = actual_batch.column(i).to_data();
3230            validate(&expected_data, &actual_data);
3231        }
3232
3233        file
3234    }
3235
3236    fn roundtrip_opts(expected_batch: &RecordBatch, props: WriterProperties) -> Bytes {
3237        roundtrip_opts_with_array_validation(expected_batch, props, |a, b| {
3238            a.validate_full().expect("valid expected data");
3239            b.validate_full().expect("valid actual data");
3240            assert_eq!(a, b)
3241        })
3242    }
3243
3244    /// Round trip testing fixture:
3245    ///
3246    /// Tests based on this fixture write data to parquet and then read it back.
3247    struct RoundTripTest {
3248        values: ArrayRef,
3249        /// Optionally supplied schema
3250        schema: Option<SchemaRef>,
3251        /// If the created schema should be nullable. Defaults to true. Ignored
3252        /// if schema is set to Some.
3253        nullable: bool,
3254        bloom_filter: bool,
3255        bloom_filter_ndv: Option<u64>,
3256        bloom_filter_position: BloomFilterPosition,
3257    }
3258
3259    impl RoundTripTest {
3260        /// Create a test for round tripping values with a nullable schema
3261        fn new(values: ArrayRef) -> Self {
3262            Self {
3263                values,
3264                schema: None,
3265                nullable: true,
3266                bloom_filter: false,
3267                bloom_filter_ndv: None,
3268                bloom_filter_position: BloomFilterPosition::AfterRowGroup,
3269            }
3270        }
3271
3272        /// Set the schema
3273        fn with_schema(mut self, schema: SchemaRef) -> Self {
3274            self.schema = Some(schema);
3275            self
3276        }
3277
3278        /// Set the nullable flag
3279        fn with_nullable(mut self, nullable: bool) -> Self {
3280            self.nullable = nullable;
3281            self
3282        }
3283
3284        /// Set bloom filter
3285        fn with_bloom_filter(mut self, bloom_filter: bool) -> Self {
3286            self.bloom_filter = bloom_filter;
3287            self
3288        }
3289
3290        /// Set bloom filter max ndv
3291        fn with_bloom_filter_ndv(mut self, bloom_filter_ndv: u64) -> Self {
3292            self.bloom_filter_ndv = Some(bloom_filter_ndv);
3293            self
3294        }
3295
3296        /// Set bloom filter position
3297        fn with_bloom_filter_position(
3298            mut self,
3299            bloom_filter_position: BloomFilterPosition,
3300        ) -> Self {
3301            self.bloom_filter_position = bloom_filter_position;
3302            self
3303        }
3304
3305        /// Run the test specified by the options, returning the encoded Parquet bytes
3306        fn run(self) -> Vec<Bytes> {
3307            let RoundTripTest {
3308                values,
3309                schema,
3310                nullable,
3311                bloom_filter,
3312                bloom_filter_ndv,
3313                bloom_filter_position,
3314            } = self;
3315
3316            let schema = schema.unwrap_or_else(|| {
3317                let data_type = values.data_type().clone();
3318                Arc::new(Schema::new(vec![Field::new("col", data_type, nullable)]))
3319            });
3320
3321            let encodings = match values.data_type() {
3322                DataType::Utf8 | DataType::LargeUtf8 | DataType::Binary | DataType::LargeBinary => {
3323                    vec![
3324                        Encoding::PLAIN,
3325                        Encoding::DELTA_BYTE_ARRAY,
3326                        Encoding::DELTA_LENGTH_BYTE_ARRAY,
3327                    ]
3328                }
3329                DataType::Int64
3330                | DataType::Int32
3331                | DataType::Int16
3332                | DataType::Int8
3333                | DataType::UInt64
3334                | DataType::UInt32
3335                | DataType::UInt16
3336                | DataType::UInt8 => vec![
3337                    Encoding::PLAIN,
3338                    Encoding::DELTA_BINARY_PACKED,
3339                    Encoding::BYTE_STREAM_SPLIT,
3340                ],
3341                DataType::Float32 | DataType::Float64 => {
3342                    vec![Encoding::PLAIN, Encoding::BYTE_STREAM_SPLIT]
3343                }
3344                _ => vec![Encoding::PLAIN],
3345            };
3346
3347            let expected_batch = RecordBatch::try_new(schema, vec![values]).unwrap();
3348
3349            let row_group_sizes = [1024, SMALL_SIZE, SMALL_SIZE / 2, SMALL_SIZE / 2 + 1, 10];
3350
3351            let mut files = vec![];
3352            for dictionary_size in [0, 1, 1024] {
3353                for encoding in &encodings {
3354                    for version in [WriterVersion::PARQUET_1_0, WriterVersion::PARQUET_2_0] {
3355                        for row_group_size in row_group_sizes {
3356                            let mut builder = WriterProperties::builder()
3357                                .set_writer_version(version)
3358                                .set_max_row_group_row_count(Some(row_group_size))
3359                                .set_dictionary_enabled(dictionary_size != 0)
3360                                .set_dictionary_page_size_limit(dictionary_size.max(1))
3361                                .set_encoding(*encoding)
3362                                .set_bloom_filter_enabled(bloom_filter)
3363                                .set_bloom_filter_position(bloom_filter_position);
3364                            if let Some(ndv) = bloom_filter_ndv {
3365                                builder = builder.set_bloom_filter_max_ndv(ndv);
3366                            }
3367                            let props = builder.build();
3368
3369                            files.push(roundtrip_opts(&expected_batch, props))
3370                        }
3371                    }
3372                }
3373            }
3374            files
3375        }
3376    }
3377
3378    fn values_required<A, I>(iter: I) -> Vec<Bytes>
3379    where
3380        A: From<Vec<I::Item>> + Array + 'static,
3381        I: IntoIterator,
3382    {
3383        let raw_values: Vec<_> = iter.into_iter().collect();
3384        let values = Arc::new(A::from(raw_values));
3385        RoundTripTest::new(values).with_nullable(false).run()
3386    }
3387
3388    fn values_optional<A, I>(iter: I) -> Vec<Bytes>
3389    where
3390        A: From<Vec<Option<I::Item>>> + Array + 'static,
3391        I: IntoIterator,
3392    {
3393        let optional_raw_values: Vec<_> = iter
3394            .into_iter()
3395            .enumerate()
3396            .map(|(i, v)| if i % 2 == 0 { None } else { Some(v) })
3397            .collect();
3398        let optional_values = Arc::new(A::from(optional_raw_values));
3399        RoundTripTest::new(optional_values).run()
3400    }
3401
3402    fn required_and_optional<A, I>(iter: I)
3403    where
3404        A: From<Vec<I::Item>> + From<Vec<Option<I::Item>>> + Array + 'static,
3405        I: IntoIterator + Clone,
3406    {
3407        values_required::<A, I>(iter.clone());
3408        values_optional::<A, I>(iter);
3409    }
3410
3411    fn check_bloom_filter<T: AsBytes>(
3412        files: Vec<Bytes>,
3413        file_column: String,
3414        positive_values: Vec<T>,
3415        negative_values: Vec<T>,
3416    ) {
3417        files.into_iter().take(1).for_each(|file| {
3418            let file_reader = SerializedFileReader::new_with_options(
3419                file,
3420                ReadOptionsBuilder::new()
3421                    .with_reader_properties(
3422                        ReaderProperties::builder()
3423                            .set_read_bloom_filter(true)
3424                            .build(),
3425                    )
3426                    .build(),
3427            )
3428            .expect("Unable to open file as Parquet");
3429            let metadata = file_reader.metadata();
3430
3431            // Gets bloom filters from all row groups.
3432            let mut bloom_filters: Vec<_> = vec![];
3433            for (ri, row_group) in metadata.row_groups().iter().enumerate() {
3434                if let Some((column_index, _)) = row_group
3435                    .columns()
3436                    .iter()
3437                    .enumerate()
3438                    .find(|(_, column)| column.column_path().string() == file_column)
3439                {
3440                    let row_group_reader = file_reader
3441                        .get_row_group(ri)
3442                        .expect("Unable to read row group");
3443                    if let Some(sbbf) = row_group_reader.get_column_bloom_filter(column_index) {
3444                        bloom_filters.push(sbbf.clone());
3445                    } else {
3446                        panic!("No bloom filter for column named {file_column} found");
3447                    }
3448                } else {
3449                    panic!("No column named {file_column} found");
3450                }
3451            }
3452
3453            positive_values.iter().for_each(|value| {
3454                let found = bloom_filters.iter().find(|sbbf| sbbf.check(value));
3455                assert!(
3456                    found.is_some(),
3457                    "{}",
3458                    format!("Value {:?} should be in bloom filter", value.as_bytes())
3459                );
3460            });
3461
3462            negative_values.iter().for_each(|value| {
3463                let found = bloom_filters.iter().find(|sbbf| sbbf.check(value));
3464                assert!(
3465                    found.is_none(),
3466                    "{}",
3467                    format!("Value {:?} should not be in bloom filter", value.as_bytes())
3468                );
3469            });
3470        });
3471    }
3472
3473    #[test]
3474    fn all_null_primitive_single_column() {
3475        let values = Arc::new(Int32Array::from(vec![None; SMALL_SIZE]));
3476        RoundTripTest::new(values).run();
3477    }
3478    #[test]
3479    fn null_single_column() {
3480        let values = Arc::new(NullArray::new(SMALL_SIZE));
3481        RoundTripTest::new(values).run();
3482        // null arrays are always nullable, a test with non-nullable nulls fails
3483    }
3484
3485    #[test]
3486    fn bool_single_column() {
3487        required_and_optional::<BooleanArray, _>(
3488            [true, false].iter().cycle().copied().take(SMALL_SIZE),
3489        );
3490    }
3491
3492    #[test]
3493    fn bool_large_single_column() {
3494        let values = Arc::new(
3495            [None, Some(true), Some(false)]
3496                .iter()
3497                .cycle()
3498                .copied()
3499                .take(200_000)
3500                .collect::<BooleanArray>(),
3501        );
3502        let schema = Schema::new(vec![Field::new("col", values.data_type().clone(), true)]);
3503        let expected_batch = RecordBatch::try_new(Arc::new(schema), vec![values]).unwrap();
3504        let file = tempfile::tempfile().unwrap();
3505
3506        let mut writer =
3507            ArrowWriter::try_new(file.try_clone().unwrap(), expected_batch.schema(), None)
3508                .expect("Unable to write file");
3509        writer.write(&expected_batch).unwrap();
3510        writer.close().unwrap();
3511    }
3512
3513    #[test]
3514    fn check_page_offset_index_with_nan() {
3515        let values = Arc::new(Float64Array::from(vec![f64::NAN; 10]));
3516        let schema = Schema::new(vec![Field::new("col", DataType::Float64, true)]);
3517        let batch = RecordBatch::try_new(Arc::new(schema), vec![values]).unwrap();
3518
3519        let mut out = Vec::with_capacity(1024);
3520        let mut writer =
3521            ArrowWriter::try_new(&mut out, batch.schema(), None).expect("Unable to write file");
3522        writer.write(&batch).unwrap();
3523        let file_meta_data = writer.close().unwrap();
3524        for row_group in file_meta_data.row_groups() {
3525            for column in row_group.columns() {
3526                assert!(column.offset_index_offset().is_some());
3527                assert!(column.offset_index_length().is_some());
3528                assert!(column.column_index_offset().is_some());
3529                assert!(column.column_index_length().is_some());
3530            }
3531        }
3532        if let Some(page_index) = file_meta_data.page_index() {
3533            for rg in 0..file_meta_data.num_row_groups() {
3534                for col in 0..file_meta_data.row_group(rg).num_columns() {
3535                    let idx = page_index
3536                        .column_index(rg, col)
3537                        .expect("column index should exist");
3538                    assert!(idx.nan_counts().is_some());
3539                    let ColumnIndexMetaData::DOUBLE(float_idx) = idx else {
3540                        panic!("expected double statistics")
3541                    };
3542                    for i in 0..idx.num_pages() as usize {
3543                        assert_eq!(float_idx.nan_count(i), Some(10));
3544                        assert_eq!(
3545                            f64::NAN.total_cmp(float_idx.min_value(i).unwrap()),
3546                            Ordering::Equal
3547                        );
3548                        assert_eq!(
3549                            f64::NAN.total_cmp(float_idx.max_value(i).unwrap()),
3550                            Ordering::Equal
3551                        );
3552                    }
3553                }
3554            }
3555        } else {
3556            panic!("page index should be present");
3557        }
3558    }
3559
3560    #[test]
3561    fn check_page_offset_index_with_mixed_nan() {
3562        let schema = Arc::new(Schema::new(vec![Field::new(
3563            "col",
3564            DataType::Float64,
3565            true,
3566        )]));
3567
3568        let mut out = Vec::with_capacity(1024);
3569        let props = WriterProperties::builder()
3570            .set_data_page_row_count_limit(10)
3571            .build();
3572        let mut writer = ArrowWriter::try_new(&mut out, schema.clone(), Some(props))
3573            .expect("Unable to write file");
3574
3575        // write a page of all NaN (since batch min and max are NaN, global min/max are NaN)
3576        let values = Arc::new(Float64Array::from(vec![f64::NAN; 10]));
3577        let batch = RecordBatch::try_new(schema.clone(), vec![values]).unwrap();
3578        writer.write(&batch).unwrap();
3579
3580        // write a page of all -NaN (batch min/max is -NaN, should update global min to -NaN)
3581        let values = Arc::new(Float64Array::from(vec![-f64::NAN; 10]));
3582        let batch = RecordBatch::try_new(schema.clone(), vec![values]).unwrap();
3583        writer.write(&batch).unwrap();
3584
3585        // write a page of all 0 (non-NaN should override global min/max, now 0/0)
3586        let values = Arc::new(Float64Array::from(vec![0_f64; 10]));
3587        let batch = RecordBatch::try_new(schema.clone(), vec![values]).unwrap();
3588        writer.write(&batch).unwrap();
3589
3590        // write a mixed page (should now have min -1, max 1)
3591        let values = Arc::new(Float64Array::from(vec![
3592            -1.0,
3593            0.0,
3594            f64::NAN,
3595            -f64::NAN,
3596            1.0,
3597        ]));
3598        let batch = RecordBatch::try_new(schema.clone(), vec![values]).unwrap();
3599        writer.write(&batch).unwrap();
3600
3601        let file_meta_data = writer.close().unwrap();
3602
3603        // check the column chunk stats are correct
3604        let col_stats = file_meta_data
3605            .row_group(0)
3606            .column(0)
3607            .statistics()
3608            .expect("missing column chunk statistics");
3609
3610        assert_eq!(col_stats.nan_count_opt(), Some(22));
3611        assert_eq!(col_stats.min_bytes_opt(), Some((-1.0f64).as_bytes()));
3612        assert_eq!(col_stats.max_bytes_opt(), Some(1.0f64.as_bytes()));
3613
3614        assert!(file_meta_data.page_index().is_some());
3615        let col_idx = &file_meta_data.page_index().unwrap().column_index(0, 0);
3616        assert_eq!(col_idx.as_ref().unwrap().num_pages(), 4);
3617
3618        // test each page
3619        let Some(ColumnIndexMetaData::DOUBLE(float_idx)) = col_idx else {
3620            panic!("expected double statistics")
3621        };
3622
3623        assert_eq!(float_idx.nan_counts, Some(vec![10, 10, 0, 2]));
3624        assert_eq!(
3625            f64::NAN.total_cmp(float_idx.min_value(0).unwrap()),
3626            Ordering::Equal
3627        );
3628        assert_eq!(
3629            f64::NAN.total_cmp(float_idx.max_value(0).unwrap()),
3630            Ordering::Equal
3631        );
3632        assert_eq!(
3633            (-f64::NAN).total_cmp(float_idx.min_value(1).unwrap()),
3634            Ordering::Equal
3635        );
3636        assert_eq!(
3637            (-f64::NAN).total_cmp(float_idx.max_value(1).unwrap()),
3638            Ordering::Equal
3639        );
3640        assert_eq!(float_idx.min_value(2), Some(&0.0));
3641        assert_eq!(float_idx.max_value(2), Some(&0.0));
3642        assert_eq!(float_idx.min_value(3), Some(&-1.0));
3643        assert_eq!(float_idx.max_value(3), Some(&1.0));
3644    }
3645
3646    #[test]
3647    fn i8_single_column() {
3648        required_and_optional::<Int8Array, _>(0..SMALL_SIZE as i8);
3649    }
3650
3651    #[test]
3652    fn i16_single_column() {
3653        required_and_optional::<Int16Array, _>(0..SMALL_SIZE as i16);
3654    }
3655
3656    #[test]
3657    fn i32_single_column() {
3658        required_and_optional::<Int32Array, _>(0..SMALL_SIZE as i32);
3659    }
3660
3661    #[test]
3662    fn i64_single_column() {
3663        required_and_optional::<Int64Array, _>(0..SMALL_SIZE as i64);
3664    }
3665
3666    #[test]
3667    fn u8_single_column() {
3668        required_and_optional::<UInt8Array, _>(0..SMALL_SIZE as u8);
3669    }
3670
3671    #[test]
3672    fn u16_single_column() {
3673        required_and_optional::<UInt16Array, _>(0..SMALL_SIZE as u16);
3674    }
3675
3676    #[test]
3677    fn u32_single_column() {
3678        required_and_optional::<UInt32Array, _>(0..SMALL_SIZE as u32);
3679    }
3680
3681    #[test]
3682    fn u64_single_column() {
3683        required_and_optional::<UInt64Array, _>(0..SMALL_SIZE as u64);
3684    }
3685
3686    #[test]
3687    fn f32_single_column() {
3688        required_and_optional::<Float32Array, _>((0..SMALL_SIZE).map(|i| i as f32));
3689    }
3690
3691    #[test]
3692    fn f64_single_column() {
3693        required_and_optional::<Float64Array, _>((0..SMALL_SIZE).map(|i| i as f64));
3694    }
3695
3696    // The timestamp array types don't implement From<Vec<T>> because they need the timezone
3697    // argument, and they also doesn't support building from a Vec<Option<T>>, so call
3698    // RoundTripTest manually instead of calling required_and_optional for these tests.
3699
3700    #[test]
3701    fn timestamp_second_single_column() {
3702        let raw_values: Vec<_> = (0..SMALL_SIZE as i64).collect();
3703        let values = Arc::new(TimestampSecondArray::from(raw_values));
3704
3705        RoundTripTest::new(values).with_nullable(false).run();
3706    }
3707
3708    #[test]
3709    fn timestamp_millisecond_single_column() {
3710        let raw_values: Vec<_> = (0..SMALL_SIZE as i64).collect();
3711        let values = Arc::new(TimestampMillisecondArray::from(raw_values));
3712
3713        RoundTripTest::new(values).with_nullable(false).run();
3714    }
3715
3716    #[test]
3717    fn timestamp_microsecond_single_column() {
3718        let raw_values: Vec<_> = (0..SMALL_SIZE as i64).collect();
3719        let values = Arc::new(TimestampMicrosecondArray::from(raw_values));
3720
3721        RoundTripTest::new(values).with_nullable(false).run();
3722    }
3723
3724    #[test]
3725    fn timestamp_nanosecond_single_column() {
3726        let raw_values: Vec<_> = (0..SMALL_SIZE as i64).collect();
3727        let values = Arc::new(TimestampNanosecondArray::from(raw_values));
3728
3729        RoundTripTest::new(values).with_nullable(false).run();
3730    }
3731
3732    #[test]
3733    fn date32_single_column() {
3734        required_and_optional::<Date32Array, _>(0..SMALL_SIZE as i32);
3735    }
3736
3737    #[test]
3738    fn date64_single_column() {
3739        // Date64 must be a multiple of 86400000, see ARROW-10925
3740        required_and_optional::<Date64Array, _>(
3741            (0..(SMALL_SIZE as i64 * 86400000)).step_by(86400000),
3742        );
3743    }
3744
3745    #[test]
3746    fn time32_second_single_column() {
3747        required_and_optional::<Time32SecondArray, _>(0..SMALL_SIZE as i32);
3748    }
3749
3750    #[test]
3751    fn time32_millisecond_single_column() {
3752        required_and_optional::<Time32MillisecondArray, _>(0..SMALL_SIZE as i32);
3753    }
3754
3755    #[test]
3756    fn time64_microsecond_single_column() {
3757        required_and_optional::<Time64MicrosecondArray, _>(0..SMALL_SIZE as i64);
3758    }
3759
3760    #[test]
3761    fn time64_nanosecond_single_column() {
3762        required_and_optional::<Time64NanosecondArray, _>(0..SMALL_SIZE as i64);
3763    }
3764
3765    #[test]
3766    fn duration_second_single_column() {
3767        required_and_optional::<DurationSecondArray, _>(0..SMALL_SIZE as i64);
3768    }
3769
3770    #[test]
3771    fn duration_millisecond_single_column() {
3772        required_and_optional::<DurationMillisecondArray, _>(0..SMALL_SIZE as i64);
3773    }
3774
3775    #[test]
3776    fn duration_microsecond_single_column() {
3777        required_and_optional::<DurationMicrosecondArray, _>(0..SMALL_SIZE as i64);
3778    }
3779
3780    #[test]
3781    fn duration_nanosecond_single_column() {
3782        required_and_optional::<DurationNanosecondArray, _>(0..SMALL_SIZE as i64);
3783    }
3784
3785    #[test]
3786    fn interval_year_month_single_column() {
3787        required_and_optional::<IntervalYearMonthArray, _>(0..SMALL_SIZE as i32);
3788    }
3789
3790    #[test]
3791    fn interval_day_time_single_column() {
3792        required_and_optional::<IntervalDayTimeArray, _>(vec![
3793            IntervalDayTime::new(0, 1),
3794            IntervalDayTime::new(0, 3),
3795            IntervalDayTime::new(3, -2),
3796            IntervalDayTime::new(-200, 4),
3797        ]);
3798    }
3799
3800    #[test]
3801    #[should_panic(
3802        expected = "Attempting to write an Arrow interval type MonthDayNano to parquet that is not yet implemented"
3803    )]
3804    fn interval_month_day_nano_single_column() {
3805        required_and_optional::<IntervalMonthDayNanoArray, _>(vec![
3806            IntervalMonthDayNano::new(0, 1, 5),
3807            IntervalMonthDayNano::new(0, 3, 2),
3808            IntervalMonthDayNano::new(3, -2, -5),
3809            IntervalMonthDayNano::new(-200, 4, -1),
3810        ]);
3811    }
3812
3813    #[test]
3814    fn binary_single_column() {
3815        let one_vec: Vec<u8> = (0..SMALL_SIZE as u8).collect();
3816        let many_vecs: Vec<_> = std::iter::repeat_n(one_vec, SMALL_SIZE).collect();
3817        let many_vecs_iter = many_vecs.iter().map(|v| v.as_slice());
3818
3819        // BinaryArrays can't be built from Vec<Option<&str>>, so only call `values_required`
3820        values_required::<BinaryArray, _>(many_vecs_iter);
3821    }
3822
3823    #[test]
3824    fn binary_view_single_column() {
3825        let one_vec: Vec<u8> = (0..SMALL_SIZE as u8).collect();
3826        let many_vecs: Vec<_> = std::iter::repeat_n(one_vec, SMALL_SIZE).collect();
3827        let many_vecs_iter = many_vecs.iter().map(|v| v.as_slice());
3828
3829        // BinaryArrays can't be built from Vec<Option<&str>>, so only call `values_required`
3830        values_required::<BinaryViewArray, _>(many_vecs_iter);
3831    }
3832
3833    #[test]
3834    fn i32_column_bloom_filter_at_end() {
3835        let array = Arc::new(Int32Array::from_iter(0..SMALL_SIZE as i32));
3836        let files = RoundTripTest::new(array)
3837            .with_nullable(false)
3838            .with_bloom_filter(true)
3839            .with_bloom_filter_position(BloomFilterPosition::End)
3840            .run();
3841
3842        check_bloom_filter(
3843            files,
3844            "col".to_string(),
3845            (0..SMALL_SIZE as i32).collect(),
3846            (SMALL_SIZE as i32 + 1..SMALL_SIZE as i32 + 10).collect(),
3847        );
3848    }
3849
3850    #[test]
3851    fn i32_column_bloom_filter() {
3852        let array = Arc::new(Int32Array::from_iter(0..SMALL_SIZE as i32));
3853        let files = RoundTripTest::new(array)
3854            .with_nullable(false)
3855            .with_bloom_filter(true)
3856            .run();
3857
3858        check_bloom_filter(
3859            files,
3860            "col".to_string(),
3861            (0..SMALL_SIZE as i32).collect(),
3862            (SMALL_SIZE as i32 + 1..SMALL_SIZE as i32 + 10).collect(),
3863        );
3864    }
3865
3866    /// Test that bloom filter folding produces correct results even when
3867    /// the configured NDV differs significantly from actual NDV.
3868    /// A large NDV means a larger initial filter that gets folded down;
3869    /// a small NDV means a smaller initial filter.
3870    #[test]
3871    fn i32_column_bloom_filter_fixed_ndv() {
3872        let array = Arc::new(Int32Array::from_iter(0..SMALL_SIZE as i32));
3873
3874        // NDV much larger than actual distinct values — tests folding a large filter down
3875        let files = RoundTripTest::new(array.clone())
3876            .with_nullable(false)
3877            .with_bloom_filter(true)
3878            .with_bloom_filter_ndv(1_000_000)
3879            .run();
3880
3881        check_bloom_filter(
3882            files,
3883            "col".to_string(),
3884            (0..SMALL_SIZE as i32).collect(),
3885            (SMALL_SIZE as i32 + 1..SMALL_SIZE as i32 + 10).collect(),
3886        );
3887
3888        // NDV smaller than actual distinct values — tests the underestimate path
3889        let files = RoundTripTest::new(array)
3890            .with_nullable(false)
3891            .with_bloom_filter(true)
3892            .with_bloom_filter_ndv(3)
3893            .run();
3894
3895        check_bloom_filter(
3896            files,
3897            "col".to_string(),
3898            (0..SMALL_SIZE as i32).collect(),
3899            (SMALL_SIZE as i32 + 1..SMALL_SIZE as i32 + 10).collect(),
3900        );
3901    }
3902
3903    #[test]
3904    fn binary_column_bloom_filter() {
3905        let one_vec: Vec<u8> = (0..SMALL_SIZE as u8).collect();
3906        let many_vecs: Vec<_> = std::iter::repeat_n(one_vec, SMALL_SIZE).collect();
3907        let many_vecs_iter = many_vecs.iter().map(|v| v.as_slice());
3908
3909        let array = Arc::new(BinaryArray::from_iter_values(many_vecs_iter));
3910        let files = RoundTripTest::new(array)
3911            .with_nullable(false)
3912            .with_bloom_filter(true)
3913            .run();
3914
3915        check_bloom_filter(
3916            files,
3917            "col".to_string(),
3918            many_vecs,
3919            vec![vec![(SMALL_SIZE + 1) as u8]],
3920        );
3921    }
3922
3923    #[test]
3924    fn empty_string_null_column_bloom_filter() {
3925        let raw_values: Vec<_> = (0..SMALL_SIZE).map(|i| i.to_string()).collect();
3926        let raw_strs = raw_values.iter().map(|s| s.as_str());
3927
3928        let array = Arc::new(StringArray::from_iter_values(raw_strs));
3929        let files = RoundTripTest::new(array)
3930            .with_nullable(false)
3931            .with_bloom_filter(true)
3932            .run();
3933
3934        let optional_raw_values: Vec<_> = raw_values
3935            .iter()
3936            .enumerate()
3937            .filter_map(|(i, v)| if i % 2 == 0 { None } else { Some(v.as_str()) })
3938            .collect();
3939        // For null slots, empty string should not be in bloom filter.
3940        check_bloom_filter(files, "col".to_string(), optional_raw_values, vec![""]);
3941    }
3942
3943    #[test]
3944    fn large_binary_single_column() {
3945        let one_vec: Vec<u8> = (0..SMALL_SIZE as u8).collect();
3946        let many_vecs: Vec<_> = std::iter::repeat_n(one_vec, SMALL_SIZE).collect();
3947        let many_vecs_iter = many_vecs.iter().map(|v| v.as_slice());
3948
3949        // LargeBinaryArrays can't be built from Vec<Option<&str>>, so only call `values_required`
3950        values_required::<LargeBinaryArray, _>(many_vecs_iter);
3951    }
3952
3953    #[test]
3954    fn fixed_size_binary_single_column() {
3955        let mut builder = FixedSizeBinaryBuilder::new(4);
3956        builder.append_value(b"0123").unwrap();
3957        builder.append_null();
3958        builder.append_value(b"8910").unwrap();
3959        builder.append_value(b"1112").unwrap();
3960        let array = Arc::new(builder.finish());
3961
3962        RoundTripTest::new(array).run();
3963    }
3964
3965    #[test]
3966    fn string_single_column() {
3967        let raw_values: Vec<_> = (0..SMALL_SIZE).map(|i| i.to_string()).collect();
3968        let raw_strs = raw_values.iter().map(|s| s.as_str());
3969
3970        required_and_optional::<StringArray, _>(raw_strs);
3971    }
3972
3973    #[test]
3974    fn large_string_single_column() {
3975        let raw_values: Vec<_> = (0..SMALL_SIZE).map(|i| i.to_string()).collect();
3976        let raw_strs = raw_values.iter().map(|s| s.as_str());
3977
3978        required_and_optional::<LargeStringArray, _>(raw_strs);
3979    }
3980
3981    #[test]
3982    fn string_view_single_column() {
3983        let raw_values: Vec<_> = (0..SMALL_SIZE).map(|i| i.to_string()).collect();
3984        let raw_strs = raw_values.iter().map(|s| s.as_str());
3985
3986        required_and_optional::<StringViewArray, _>(raw_strs);
3987    }
3988
3989    #[test]
3990    fn null_list_single_column() {
3991        let null_field = Field::new_list_field(DataType::Null, true);
3992        let list_field = Field::new("emptylist", DataType::List(Arc::new(null_field)), true);
3993
3994        let schema = Schema::new(vec![list_field]);
3995
3996        // Build [[], null, [null, null]]
3997        let a_values = NullArray::new(2);
3998        let a_value_offsets = arrow::buffer::Buffer::from([0, 0, 0, 2].to_byte_slice());
3999        let a_list_data = ArrayData::builder(DataType::List(Arc::new(Field::new_list_field(
4000            DataType::Null,
4001            true,
4002        ))))
4003        .len(3)
4004        .add_buffer(a_value_offsets)
4005        .null_bit_buffer(Some(Buffer::from([0b00000101])))
4006        .add_child_data(a_values.into_data())
4007        .build()
4008        .unwrap();
4009
4010        let a = ListArray::from(a_list_data);
4011
4012        assert!(a.is_valid(0));
4013        assert!(!a.is_valid(1));
4014        assert!(a.is_valid(2));
4015
4016        assert_eq!(a.value(0).len(), 0);
4017        assert_eq!(a.value(2).len(), 2);
4018        assert_eq!(a.value(2).logical_nulls().unwrap().null_count(), 2);
4019
4020        let batch = RecordBatch::try_new(Arc::new(schema), vec![Arc::new(a)]).unwrap();
4021        roundtrip(batch, None);
4022    }
4023
4024    #[test]
4025    fn list_single_column() {
4026        let a_values = Int32Array::from(vec![1, 2, 3, 4, 5, 6, 7, 8, 9, 10]);
4027        let a_value_offsets = arrow::buffer::Buffer::from([0, 1, 3, 3, 6, 10].to_byte_slice());
4028        let a_list_data = ArrayData::builder(DataType::List(Arc::new(Field::new_list_field(
4029            DataType::Int32,
4030            false,
4031        ))))
4032        .len(5)
4033        .add_buffer(a_value_offsets)
4034        .null_bit_buffer(Some(Buffer::from([0b00011011])))
4035        .add_child_data(a_values.into_data())
4036        .build()
4037        .unwrap();
4038
4039        assert_eq!(a_list_data.null_count(), 1);
4040
4041        let a = ListArray::from(a_list_data);
4042        let values = Arc::new(a);
4043
4044        RoundTripTest::new(values).run();
4045    }
4046
4047    #[test]
4048    fn large_list_single_column() {
4049        let a_values = Int32Array::from(vec![1, 2, 3, 4, 5, 6, 7, 8, 9, 10]);
4050        let a_value_offsets = arrow::buffer::Buffer::from([0i64, 1, 3, 3, 6, 10].to_byte_slice());
4051        let a_list_data = ArrayData::builder(DataType::LargeList(Arc::new(Field::new(
4052            "large_item",
4053            DataType::Int32,
4054            true,
4055        ))))
4056        .len(5)
4057        .add_buffer(a_value_offsets)
4058        .add_child_data(a_values.into_data())
4059        .null_bit_buffer(Some(Buffer::from([0b00011011])))
4060        .build()
4061        .unwrap();
4062
4063        // I think this setup is incorrect because this should pass
4064        assert_eq!(a_list_data.null_count(), 1);
4065
4066        let a = LargeListArray::from(a_list_data);
4067        let values = Arc::new(a);
4068
4069        RoundTripTest::new(values).run();
4070    }
4071
4072    #[test]
4073    fn list_nested_nulls() {
4074        use arrow::datatypes::Int32Type;
4075        let data = vec![
4076            Some(vec![Some(1)]),
4077            Some(vec![Some(2), Some(3)]),
4078            None,
4079            Some(vec![Some(4), Some(5), None]),
4080            Some(vec![None]),
4081            Some(vec![Some(6), Some(7)]),
4082        ];
4083
4084        let list = ListArray::from_iter_primitive::<Int32Type, _, _>(data.clone());
4085        RoundTripTest::new(Arc::new(list)).run();
4086
4087        let list = LargeListArray::from_iter_primitive::<Int32Type, _, _>(data);
4088        RoundTripTest::new(Arc::new(list)).run();
4089    }
4090
4091    #[test]
4092    fn list_utf8_view_selective_padding_roundtrip() {
4093        let item = Arc::new(Field::new_list_field(DataType::Utf8View, true));
4094        let mut builder = ListBuilder::new(StringViewBuilder::new()).with_field(item);
4095        builder.values().append_value("a");
4096        builder.values().append_null();
4097        builder.append(true);
4098        // The null parent list covers selective padding dropping values below
4099        // the list definition level while preserving the preceding item null.
4100        builder.append(false);
4101        // The long string covers the non-inlined Utf8View buffer path.
4102        builder.values().append_value("large payload over 12 bytes");
4103        builder.append(true);
4104
4105        RoundTripTest::new(Arc::new(builder.finish())).run();
4106    }
4107
4108    #[test]
4109    fn struct_single_column() {
4110        let a_values = Int32Array::from(vec![1, 2, 3, 4, 5, 6, 7, 8, 9, 10]);
4111        let struct_field_a = Arc::new(Field::new("f", DataType::Int32, false));
4112        let s = StructArray::from(vec![(struct_field_a, Arc::new(a_values) as ArrayRef)]);
4113
4114        let values = Arc::new(s);
4115        RoundTripTest::new(values).with_nullable(false).run();
4116    }
4117
4118    #[test]
4119    fn list_and_map_coerced_names() {
4120        // Create map and list with non-Parquet naming
4121        let list_field =
4122            Field::new_list("my_list", Field::new("item", DataType::Int32, false), false);
4123        let map_field = Field::new_map(
4124            "my_map",
4125            "my_entries",
4126            Field::new("my_keys", DataType::Int32, false),
4127            Field::new("my_values", DataType::Int32, true),
4128            false,
4129            true,
4130        );
4131
4132        let list_array = create_random_array(&list_field, 100, 0.0, 0.0).unwrap();
4133        let map_array = create_random_array(&map_field, 100, 0.0, 0.0).unwrap();
4134
4135        let arrow_schema = Arc::new(Schema::new(vec![list_field, map_field]));
4136
4137        // Write data to Parquet but coerce names to match spec
4138        let props = Some(WriterProperties::builder().set_coerce_types(true).build());
4139        let file = tempfile::tempfile().unwrap();
4140        let mut writer =
4141            ArrowWriter::try_new(file.try_clone().unwrap(), arrow_schema.clone(), props).unwrap();
4142
4143        let batch = RecordBatch::try_new(arrow_schema, vec![list_array, map_array]).unwrap();
4144        writer.write(&batch).unwrap();
4145        let file_metadata = writer.close().unwrap();
4146
4147        let schema = file_metadata.file_metadata().schema();
4148        // Coerced name of "item" should be "element"
4149        let list_field = &schema.get_fields()[0].get_fields()[0];
4150        assert_eq!(list_field.get_fields()[0].name(), "element");
4151
4152        let map_field = &schema.get_fields()[1].get_fields()[0];
4153        // Coerced name of "entries" should be "key_value"
4154        assert_eq!(map_field.name(), "key_value");
4155        // Coerced name of "my_keys" should be "key"
4156        assert_eq!(map_field.get_fields()[0].name(), "key");
4157        // Coerced name of "my_values" should be "value"
4158        assert_eq!(map_field.get_fields()[1].name(), "value");
4159
4160        // Double check schema after reading from the file
4161        let reader = SerializedFileReader::new(file).unwrap();
4162        let file_schema = reader.metadata().file_metadata().schema();
4163        let fields = file_schema.get_fields();
4164        let list_field = &fields[0].get_fields()[0];
4165        assert_eq!(list_field.get_fields()[0].name(), "element");
4166        let map_field = &fields[1].get_fields()[0];
4167        assert_eq!(map_field.name(), "key_value");
4168        assert_eq!(map_field.get_fields()[0].name(), "key");
4169        assert_eq!(map_field.get_fields()[1].name(), "value");
4170    }
4171
4172    #[test]
4173    fn fallback_flush_data_page() {
4174        //tests if the Fallback::flush_data_page clears all buffers correctly
4175        let raw_values: Vec<_> = (0..MEDIUM_SIZE).map(|i| i.to_string()).collect();
4176        let values = Arc::new(StringArray::from(raw_values));
4177        let encodings = vec![
4178            Encoding::DELTA_BYTE_ARRAY,
4179            Encoding::DELTA_LENGTH_BYTE_ARRAY,
4180        ];
4181        let data_type = values.data_type().clone();
4182        let schema = Arc::new(Schema::new(vec![Field::new("col", data_type, false)]));
4183        let expected_batch = RecordBatch::try_new(schema, vec![values]).unwrap();
4184
4185        let row_group_sizes = [1024, SMALL_SIZE, SMALL_SIZE / 2, SMALL_SIZE / 2 + 1, 10];
4186        let data_page_size_limit: usize = 32;
4187        let write_batch_size: usize = 16;
4188
4189        for encoding in &encodings {
4190            for row_group_size in row_group_sizes {
4191                let props = WriterProperties::builder()
4192                    .set_writer_version(WriterVersion::PARQUET_2_0)
4193                    .set_max_row_group_row_count(Some(row_group_size))
4194                    .set_dictionary_enabled(false)
4195                    .set_encoding(*encoding)
4196                    .set_data_page_size_limit(data_page_size_limit)
4197                    .set_write_batch_size(write_batch_size)
4198                    .build();
4199
4200                roundtrip_opts_with_array_validation(&expected_batch, props, |a, b| {
4201                    let string_array_a = StringArray::from(a.clone());
4202                    let string_array_b = StringArray::from(b.clone());
4203                    let vec_a: Vec<&str> = string_array_a.iter().map(|v| v.unwrap()).collect();
4204                    let vec_b: Vec<&str> = string_array_b.iter().map(|v| v.unwrap()).collect();
4205                    assert_eq!(
4206                        vec_a, vec_b,
4207                        "failed for encoder: {encoding:?} and row_group_size: {row_group_size:?}"
4208                    );
4209                });
4210            }
4211        }
4212    }
4213
4214    #[test]
4215    fn arrow_writer_string_dictionary() {
4216        // define schema
4217        #[expect(deprecated)]
4218        let schema = Arc::new(Schema::new(vec![Field::new_dict(
4219            "dictionary",
4220            DataType::Dictionary(Box::new(DataType::Int32), Box::new(DataType::Utf8)),
4221            true,
4222            42,
4223            true,
4224        )]));
4225
4226        // create some data
4227        let d: Int32DictionaryArray = [Some("alpha"), None, Some("beta"), Some("alpha")]
4228            .iter()
4229            .copied()
4230            .collect();
4231
4232        // build a record batch
4233        RoundTripTest::new(Arc::new(d)).with_schema(schema).run();
4234    }
4235
4236    #[test]
4237    fn arrow_writer_test_type_compatibility() {
4238        fn ensure_compatible_write<T1, T2>(array1: T1, array2: T2, expected_result: T1)
4239        where
4240            T1: Array + 'static,
4241            T2: Array + 'static,
4242        {
4243            let schema1 = Arc::new(Schema::new(vec![Field::new(
4244                "a",
4245                array1.data_type().clone(),
4246                false,
4247            )]));
4248
4249            let file = tempfile().unwrap();
4250            let mut writer =
4251                ArrowWriter::try_new(file.try_clone().unwrap(), schema1.clone(), None).unwrap();
4252
4253            let rb1 = RecordBatch::try_new(schema1.clone(), vec![Arc::new(array1)]).unwrap();
4254            writer.write(&rb1).unwrap();
4255
4256            let schema2 = Arc::new(Schema::new(vec![Field::new(
4257                "a",
4258                array2.data_type().clone(),
4259                false,
4260            )]));
4261            let rb2 = RecordBatch::try_new(schema2, vec![Arc::new(array2)]).unwrap();
4262            writer.write(&rb2).unwrap();
4263
4264            writer.close().unwrap();
4265
4266            let mut record_batch_reader =
4267                ParquetRecordBatchReader::try_new(file.try_clone().unwrap(), 1024).unwrap();
4268            let actual_batch = record_batch_reader.next().unwrap().unwrap();
4269
4270            let expected_batch =
4271                RecordBatch::try_new(schema1, vec![Arc::new(expected_result)]).unwrap();
4272            assert_eq!(actual_batch, expected_batch);
4273        }
4274
4275        // check compatibility between native and dictionaries
4276
4277        ensure_compatible_write(
4278            DictionaryArray::new(
4279                UInt8Array::from_iter_values(vec![0]),
4280                Arc::new(StringArray::from_iter_values(vec!["parquet"])),
4281            ),
4282            StringArray::from_iter_values(vec!["barquet"]),
4283            DictionaryArray::new(
4284                UInt8Array::from_iter_values(vec![0, 1]),
4285                Arc::new(StringArray::from_iter_values(vec!["parquet", "barquet"])),
4286            ),
4287        );
4288
4289        ensure_compatible_write(
4290            StringArray::from_iter_values(vec!["parquet"]),
4291            DictionaryArray::new(
4292                UInt8Array::from_iter_values(vec![0]),
4293                Arc::new(StringArray::from_iter_values(vec!["barquet"])),
4294            ),
4295            StringArray::from_iter_values(vec!["parquet", "barquet"]),
4296        );
4297
4298        // check compatibility between dictionaries with different key types
4299
4300        ensure_compatible_write(
4301            DictionaryArray::new(
4302                UInt8Array::from_iter_values(vec![0]),
4303                Arc::new(StringArray::from_iter_values(vec!["parquet"])),
4304            ),
4305            DictionaryArray::new(
4306                UInt16Array::from_iter_values(vec![0]),
4307                Arc::new(StringArray::from_iter_values(vec!["barquet"])),
4308            ),
4309            DictionaryArray::new(
4310                UInt8Array::from_iter_values(vec![0, 1]),
4311                Arc::new(StringArray::from_iter_values(vec!["parquet", "barquet"])),
4312            ),
4313        );
4314
4315        // check compatibility between dictionaries with different value types
4316        ensure_compatible_write(
4317            DictionaryArray::new(
4318                UInt8Array::from_iter_values(vec![0]),
4319                Arc::new(StringArray::from_iter_values(vec!["parquet"])),
4320            ),
4321            DictionaryArray::new(
4322                UInt8Array::from_iter_values(vec![0]),
4323                Arc::new(LargeStringArray::from_iter_values(vec!["barquet"])),
4324            ),
4325            DictionaryArray::new(
4326                UInt8Array::from_iter_values(vec![0, 1]),
4327                Arc::new(StringArray::from_iter_values(vec!["parquet", "barquet"])),
4328            ),
4329        );
4330
4331        // check compatibility between a dictionary and a native array with a different type
4332        ensure_compatible_write(
4333            DictionaryArray::new(
4334                UInt8Array::from_iter_values(vec![0]),
4335                Arc::new(StringArray::from_iter_values(vec!["parquet"])),
4336            ),
4337            LargeStringArray::from_iter_values(vec!["barquet"]),
4338            DictionaryArray::new(
4339                UInt8Array::from_iter_values(vec![0, 1]),
4340                Arc::new(StringArray::from_iter_values(vec!["parquet", "barquet"])),
4341            ),
4342        );
4343
4344        // check compatibility for string types
4345
4346        ensure_compatible_write(
4347            StringArray::from_iter_values(vec!["parquet"]),
4348            LargeStringArray::from_iter_values(vec!["barquet"]),
4349            StringArray::from_iter_values(vec!["parquet", "barquet"]),
4350        );
4351
4352        ensure_compatible_write(
4353            LargeStringArray::from_iter_values(vec!["parquet"]),
4354            StringArray::from_iter_values(vec!["barquet"]),
4355            LargeStringArray::from_iter_values(vec!["parquet", "barquet"]),
4356        );
4357
4358        ensure_compatible_write(
4359            StringArray::from_iter_values(vec!["parquet"]),
4360            StringViewArray::from_iter_values(vec!["barquet"]),
4361            StringArray::from_iter_values(vec!["parquet", "barquet"]),
4362        );
4363
4364        ensure_compatible_write(
4365            StringViewArray::from_iter_values(vec!["parquet"]),
4366            StringArray::from_iter_values(vec!["barquet"]),
4367            StringViewArray::from_iter_values(vec!["parquet", "barquet"]),
4368        );
4369
4370        ensure_compatible_write(
4371            LargeStringArray::from_iter_values(vec!["parquet"]),
4372            StringViewArray::from_iter_values(vec!["barquet"]),
4373            LargeStringArray::from_iter_values(vec!["parquet", "barquet"]),
4374        );
4375
4376        ensure_compatible_write(
4377            StringViewArray::from_iter_values(vec!["parquet"]),
4378            LargeStringArray::from_iter_values(vec!["barquet"]),
4379            StringViewArray::from_iter_values(vec!["parquet", "barquet"]),
4380        );
4381
4382        // check compatibility for binary types
4383
4384        ensure_compatible_write(
4385            BinaryArray::from_iter_values(vec![b"parquet"]),
4386            LargeBinaryArray::from_iter_values(vec![b"barquet"]),
4387            BinaryArray::from_iter_values(vec![b"parquet", b"barquet"]),
4388        );
4389
4390        ensure_compatible_write(
4391            LargeBinaryArray::from_iter_values(vec![b"parquet"]),
4392            BinaryArray::from_iter_values(vec![b"barquet"]),
4393            LargeBinaryArray::from_iter_values(vec![b"parquet", b"barquet"]),
4394        );
4395
4396        ensure_compatible_write(
4397            BinaryArray::from_iter_values(vec![b"parquet"]),
4398            BinaryViewArray::from_iter_values(vec![b"barquet"]),
4399            BinaryArray::from_iter_values(vec![b"parquet", b"barquet"]),
4400        );
4401
4402        ensure_compatible_write(
4403            BinaryViewArray::from_iter_values(vec![b"parquet"]),
4404            BinaryArray::from_iter_values(vec![b"barquet"]),
4405            BinaryViewArray::from_iter_values(vec![b"parquet", b"barquet"]),
4406        );
4407
4408        ensure_compatible_write(
4409            BinaryViewArray::from_iter_values(vec![b"parquet"]),
4410            LargeBinaryArray::from_iter_values(vec![b"barquet"]),
4411            BinaryViewArray::from_iter_values(vec![b"parquet", b"barquet"]),
4412        );
4413
4414        ensure_compatible_write(
4415            LargeBinaryArray::from_iter_values(vec![b"parquet"]),
4416            BinaryViewArray::from_iter_values(vec![b"barquet"]),
4417            LargeBinaryArray::from_iter_values(vec![b"parquet", b"barquet"]),
4418        );
4419
4420        // check compatibility for list types
4421
4422        let list_field_metadata = HashMap::from_iter(vec![(
4423            PARQUET_FIELD_ID_META_KEY.to_string(),
4424            "1".to_string(),
4425        )]);
4426        let list_field = Field::new_list_field(DataType::Int32, false);
4427
4428        let values1 = Arc::new(Int32Array::from(vec![0, 1, 2, 3, 4]));
4429        let offsets1 = OffsetBuffer::new(vec![0, 2, 5].into());
4430
4431        let values2 = Arc::new(Int32Array::from(vec![5, 6, 7, 8, 9]));
4432        let offsets2 = OffsetBuffer::new(vec![0, 3, 5].into());
4433
4434        let values_expected = Arc::new(Int32Array::from(vec![0, 1, 2, 3, 4, 5, 6, 7, 8, 9]));
4435        let offsets_expected = OffsetBuffer::new(vec![0, 2, 5, 8, 10].into());
4436
4437        ensure_compatible_write(
4438            // when the initial schema has the metadata ...
4439            ListArray::try_new(
4440                Arc::new(
4441                    list_field
4442                        .clone()
4443                        .with_metadata(list_field_metadata.clone()),
4444                ),
4445                offsets1,
4446                values1,
4447                None,
4448            )
4449            .unwrap(),
4450            // ... and some intermediate schema doesn't have the metadata
4451            ListArray::try_new(Arc::new(list_field.clone()), offsets2, values2, None).unwrap(),
4452            // ... the write will still go through, and the resulting schema will inherit the initial metadata
4453            ListArray::try_new(
4454                Arc::new(
4455                    list_field
4456                        .clone()
4457                        .with_metadata(list_field_metadata.clone()),
4458                ),
4459                offsets_expected,
4460                values_expected,
4461                None,
4462            )
4463            .unwrap(),
4464        );
4465    }
4466
4467    #[test]
4468    fn arrow_writer_primitive_dictionary() {
4469        // define schema
4470        #[expect(deprecated)]
4471        let schema = Arc::new(Schema::new(vec![Field::new_dict(
4472            "dictionary",
4473            DataType::Dictionary(Box::new(DataType::UInt8), Box::new(DataType::UInt32)),
4474            true,
4475            42,
4476            true,
4477        )]));
4478
4479        // create some data
4480        let mut builder = PrimitiveDictionaryBuilder::<UInt8Type, UInt32Type>::new();
4481        builder.append(12345678).unwrap();
4482        builder.append_null();
4483        builder.append(22345678).unwrap();
4484        builder.append(12345678).unwrap();
4485        let d = builder.finish();
4486
4487        RoundTripTest::new(Arc::new(d)).with_schema(schema).run();
4488    }
4489
4490    #[test]
4491    fn arrow_writer_decimal32_dictionary() {
4492        let integers = vec![12345, 56789, 34567];
4493
4494        let keys = UInt8Array::from(vec![Some(0), None, Some(1), Some(2), Some(1)]);
4495
4496        let values = Decimal32Array::from(integers.clone())
4497            .with_precision_and_scale(5, 2)
4498            .unwrap();
4499
4500        let array = DictionaryArray::new(keys, Arc::new(values));
4501        RoundTripTest::new(Arc::new(array.clone())).run();
4502
4503        let values = Decimal32Array::from(integers)
4504            .with_precision_and_scale(9, 2)
4505            .unwrap();
4506
4507        let array = array.with_values(Arc::new(values));
4508        RoundTripTest::new(Arc::new(array)).run();
4509    }
4510
4511    #[test]
4512    fn arrow_writer_decimal64_dictionary() {
4513        let integers = vec![12345, 56789, 34567];
4514
4515        let keys = UInt8Array::from(vec![Some(0), None, Some(1), Some(2), Some(1)]);
4516
4517        let values = Decimal64Array::from(integers.clone())
4518            .with_precision_and_scale(5, 2)
4519            .unwrap();
4520
4521        let array = DictionaryArray::new(keys, Arc::new(values));
4522        RoundTripTest::new(Arc::new(array.clone())).run();
4523
4524        let values = Decimal64Array::from(integers)
4525            .with_precision_and_scale(12, 2)
4526            .unwrap();
4527
4528        let array = array.with_values(Arc::new(values));
4529        RoundTripTest::new(Arc::new(array)).run();
4530    }
4531
4532    #[test]
4533    fn arrow_writer_decimal128_dictionary() {
4534        let integers = vec![12345, 56789, 34567];
4535
4536        let keys = UInt8Array::from(vec![Some(0), None, Some(1), Some(2), Some(1)]);
4537
4538        let values = Decimal128Array::from(integers.clone())
4539            .with_precision_and_scale(5, 2)
4540            .unwrap();
4541
4542        let array = DictionaryArray::new(keys, Arc::new(values));
4543        RoundTripTest::new(Arc::new(array.clone())).run();
4544
4545        let values = Decimal128Array::from(integers)
4546            .with_precision_and_scale(12, 2)
4547            .unwrap();
4548
4549        let array = array.with_values(Arc::new(values));
4550        RoundTripTest::new(Arc::new(array)).run();
4551    }
4552
4553    #[test]
4554    fn arrow_writer_decimal256_dictionary() {
4555        let integers = vec![
4556            i256::from_i128(12345),
4557            i256::from_i128(56789),
4558            i256::from_i128(34567),
4559        ];
4560
4561        let keys = UInt8Array::from(vec![Some(0), None, Some(1), Some(2), Some(1)]);
4562
4563        let values = Decimal256Array::from(integers.clone())
4564            .with_precision_and_scale(5, 2)
4565            .unwrap();
4566
4567        let array = DictionaryArray::new(keys, Arc::new(values));
4568        RoundTripTest::new(Arc::new(array.clone())).run();
4569
4570        let values = Decimal256Array::from(integers)
4571            .with_precision_and_scale(12, 2)
4572            .unwrap();
4573
4574        let array = array.with_values(Arc::new(values));
4575        RoundTripTest::new(Arc::new(array)).run();
4576    }
4577
4578    #[test]
4579    fn arrow_writer_string_dictionary_unsigned_index() {
4580        // define schema
4581        #[expect(deprecated)]
4582        let schema = Arc::new(Schema::new(vec![Field::new_dict(
4583            "dictionary",
4584            DataType::Dictionary(Box::new(DataType::UInt8), Box::new(DataType::Utf8)),
4585            true,
4586            42,
4587            true,
4588        )]));
4589
4590        // create some data
4591        let d: UInt8DictionaryArray = [Some("alpha"), None, Some("beta"), Some("alpha")]
4592            .iter()
4593            .copied()
4594            .collect();
4595
4596        RoundTripTest::new(Arc::new(d)).with_schema(schema).run();
4597    }
4598
4599    #[test]
4600    fn u32_min_max() {
4601        // check values roundtrip through parquet
4602        let src = [
4603            u32::MIN,
4604            1,
4605            (i32::MAX as u32) - 1,
4606            i32::MAX as u32,
4607            (i32::MAX as u32) + 1,
4608            u32::MAX - 1,
4609            u32::MAX,
4610        ];
4611        let values = Arc::new(UInt32Array::from_iter_values(src.iter().copied()));
4612        let files = RoundTripTest::new(values).with_nullable(false).run();
4613
4614        for file in files {
4615            // check statistics are valid
4616            let reader = SerializedFileReader::new(file).unwrap();
4617            let metadata = reader.metadata();
4618
4619            let mut row_offset = 0;
4620            for row_group in metadata.row_groups() {
4621                assert_eq!(row_group.num_columns(), 1);
4622                let column = row_group.column(0);
4623
4624                let num_values = column.num_values() as usize;
4625                let src_slice = &src[row_offset..row_offset + num_values];
4626                row_offset += column.num_values() as usize;
4627
4628                let stats = column.statistics().unwrap();
4629                if let Statistics::Int32(stats) = stats {
4630                    assert_eq!(
4631                        *stats.min_opt().unwrap() as u32,
4632                        *src_slice.iter().min().unwrap()
4633                    );
4634                    assert_eq!(
4635                        *stats.max_opt().unwrap() as u32,
4636                        *src_slice.iter().max().unwrap()
4637                    );
4638                } else {
4639                    panic!("Statistics::Int32 missing")
4640                }
4641            }
4642        }
4643    }
4644
4645    #[test]
4646    fn u64_min_max() {
4647        // check values roundtrip through parquet
4648        let src = [
4649            u64::MIN,
4650            1,
4651            (i64::MAX as u64) - 1,
4652            i64::MAX as u64,
4653            (i64::MAX as u64) + 1,
4654            u64::MAX - 1,
4655            u64::MAX,
4656        ];
4657        let values = Arc::new(UInt64Array::from_iter_values(src.iter().copied()));
4658        let files = RoundTripTest::new(values).with_nullable(false).run();
4659
4660        for file in files {
4661            // check statistics are valid
4662            let reader = SerializedFileReader::new(file).unwrap();
4663            let metadata = reader.metadata();
4664
4665            let mut row_offset = 0;
4666            for row_group in metadata.row_groups() {
4667                assert_eq!(row_group.num_columns(), 1);
4668                let column = row_group.column(0);
4669
4670                let num_values = column.num_values() as usize;
4671                let src_slice = &src[row_offset..row_offset + num_values];
4672                row_offset += column.num_values() as usize;
4673
4674                let stats = column.statistics().unwrap();
4675                if let Statistics::Int64(stats) = stats {
4676                    assert_eq!(
4677                        *stats.min_opt().unwrap() as u64,
4678                        *src_slice.iter().min().unwrap()
4679                    );
4680                    assert_eq!(
4681                        *stats.max_opt().unwrap() as u64,
4682                        *src_slice.iter().max().unwrap()
4683                    );
4684                } else {
4685                    panic!("Statistics::Int64 missing")
4686                }
4687            }
4688        }
4689    }
4690
4691    #[test]
4692    fn statistics_null_counts_only_nulls() {
4693        // check that null-count statistics for "only NULL"-columns are correct
4694        let values = Arc::new(UInt64Array::from(vec![None, None]));
4695        let files = RoundTripTest::new(values).run();
4696
4697        for file in files {
4698            // check statistics are valid
4699            let reader = SerializedFileReader::new(file).unwrap();
4700            let metadata = reader.metadata();
4701            assert_eq!(metadata.num_row_groups(), 1);
4702            let row_group = metadata.row_group(0);
4703            assert_eq!(row_group.num_columns(), 1);
4704            let column = row_group.column(0);
4705            let stats = column.statistics().unwrap();
4706            assert_eq!(stats.null_count_opt(), Some(2));
4707        }
4708    }
4709
4710    #[test]
4711    fn test_list_of_struct_roundtrip() {
4712        // define schema
4713        let int_field = Field::new("a", DataType::Int32, true);
4714        let int_field2 = Field::new("b", DataType::Int32, true);
4715
4716        let int_builder = Int32Builder::with_capacity(10);
4717        let int_builder2 = Int32Builder::with_capacity(10);
4718
4719        let struct_builder = StructBuilder::new(
4720            vec![int_field, int_field2],
4721            vec![Box::new(int_builder), Box::new(int_builder2)],
4722        );
4723        let mut list_builder = ListBuilder::new(struct_builder);
4724
4725        // Construct the following array
4726        // [{a: 1, b: 2}], [], null, [null, null], [{a: null, b: 3}], [{a: 2, b: null}]
4727
4728        // [{a: 1, b: 2}]
4729        let values = list_builder.values();
4730        values
4731            .field_builder::<Int32Builder>(0)
4732            .unwrap()
4733            .append_value(1);
4734        values
4735            .field_builder::<Int32Builder>(1)
4736            .unwrap()
4737            .append_value(2);
4738        values.append(true);
4739        list_builder.append(true);
4740
4741        // []
4742        list_builder.append(true);
4743
4744        // null
4745        list_builder.append(false);
4746
4747        // [null, null]
4748        let values = list_builder.values();
4749        values
4750            .field_builder::<Int32Builder>(0)
4751            .unwrap()
4752            .append_null();
4753        values
4754            .field_builder::<Int32Builder>(1)
4755            .unwrap()
4756            .append_null();
4757        values.append(false);
4758        values
4759            .field_builder::<Int32Builder>(0)
4760            .unwrap()
4761            .append_null();
4762        values
4763            .field_builder::<Int32Builder>(1)
4764            .unwrap()
4765            .append_null();
4766        values.append(false);
4767        list_builder.append(true);
4768
4769        // [{a: null, b: 3}]
4770        let values = list_builder.values();
4771        values
4772            .field_builder::<Int32Builder>(0)
4773            .unwrap()
4774            .append_null();
4775        values
4776            .field_builder::<Int32Builder>(1)
4777            .unwrap()
4778            .append_value(3);
4779        values.append(true);
4780        list_builder.append(true);
4781
4782        // [{a: 2, b: null}]
4783        let values = list_builder.values();
4784        values
4785            .field_builder::<Int32Builder>(0)
4786            .unwrap()
4787            .append_value(2);
4788        values
4789            .field_builder::<Int32Builder>(1)
4790            .unwrap()
4791            .append_null();
4792        values.append(true);
4793        list_builder.append(true);
4794
4795        let array = Arc::new(list_builder.finish());
4796
4797        RoundTripTest::new(array).run();
4798    }
4799
4800    fn row_group_sizes(metadata: &ParquetMetaData) -> Vec<i64> {
4801        metadata.row_groups().iter().map(|x| x.num_rows()).collect()
4802    }
4803
4804    #[test]
4805    fn test_aggregates_records() {
4806        let arrays = [
4807            Int32Array::from((0..100).collect::<Vec<_>>()),
4808            Int32Array::from((0..50).collect::<Vec<_>>()),
4809            Int32Array::from((200..500).collect::<Vec<_>>()),
4810        ];
4811
4812        let schema = Arc::new(Schema::new(vec![Field::new(
4813            "int",
4814            ArrowDataType::Int32,
4815            false,
4816        )]));
4817
4818        let file = tempfile::tempfile().unwrap();
4819
4820        let props = WriterProperties::builder()
4821            .set_max_row_group_row_count(Some(200))
4822            .build();
4823
4824        let mut writer =
4825            ArrowWriter::try_new(file.try_clone().unwrap(), schema.clone(), Some(props)).unwrap();
4826
4827        for array in arrays {
4828            let batch = RecordBatch::try_new(schema.clone(), vec![Arc::new(array)]).unwrap();
4829            writer.write(&batch).unwrap();
4830        }
4831
4832        writer.close().unwrap();
4833
4834        let builder = ParquetRecordBatchReaderBuilder::try_new(file).unwrap();
4835        assert_eq!(&row_group_sizes(builder.metadata()), &[200, 200, 50]);
4836
4837        let batches = builder
4838            .with_batch_size(100)
4839            .build()
4840            .unwrap()
4841            .collect::<ArrowResult<Vec<_>>>()
4842            .unwrap();
4843
4844        assert_eq!(batches.len(), 5);
4845        assert!(batches.iter().all(|x| x.num_columns() == 1));
4846
4847        let batch_sizes: Vec<_> = batches.iter().map(|x| x.num_rows()).collect();
4848
4849        assert_eq!(&batch_sizes, &[100, 100, 100, 100, 50]);
4850
4851        let values: Vec<_> = batches
4852            .iter()
4853            .flat_map(|x| {
4854                x.column(0)
4855                    .as_any()
4856                    .downcast_ref::<Int32Array>()
4857                    .unwrap()
4858                    .values()
4859                    .iter()
4860                    .copied()
4861            })
4862            .collect();
4863
4864        let expected_values: Vec<_> = [0..100, 0..50, 200..500].into_iter().flatten().collect();
4865        assert_eq!(&values, &expected_values)
4866    }
4867
4868    #[test]
4869    fn complex_aggregate() {
4870        // Tests aggregating nested data
4871        let field_a = Arc::new(Field::new("leaf_a", DataType::Int32, false));
4872        let field_b = Arc::new(Field::new("leaf_b", DataType::Int32, true));
4873        let struct_a = Arc::new(Field::new(
4874            "struct_a",
4875            DataType::Struct(vec![field_a.clone(), field_b.clone()].into()),
4876            true,
4877        ));
4878
4879        let list_a = Arc::new(Field::new("list", DataType::List(struct_a), true));
4880        let struct_b = Arc::new(Field::new(
4881            "struct_b",
4882            DataType::Struct(vec![list_a.clone()].into()),
4883            false,
4884        ));
4885
4886        let schema = Arc::new(Schema::new(vec![struct_b]));
4887
4888        // create nested data
4889        let field_a_array = Int32Array::from(vec![1, 2, 3, 4, 5, 6]);
4890        let field_b_array =
4891            Int32Array::from_iter(vec![Some(1), None, Some(2), None, None, Some(6)]);
4892
4893        let struct_a_array = StructArray::from(vec![
4894            (field_a.clone(), Arc::new(field_a_array) as ArrayRef),
4895            (field_b.clone(), Arc::new(field_b_array) as ArrayRef),
4896        ]);
4897
4898        let list_data = ArrayDataBuilder::new(list_a.data_type().clone())
4899            .len(5)
4900            .add_buffer(Buffer::from_iter(vec![
4901                0_i32, 1_i32, 1_i32, 3_i32, 3_i32, 5_i32,
4902            ]))
4903            .null_bit_buffer(Some(Buffer::from_iter(vec![
4904                true, false, true, false, true,
4905            ])))
4906            .child_data(vec![struct_a_array.into_data()])
4907            .build()
4908            .unwrap();
4909
4910        let list_a_array = Arc::new(ListArray::from(list_data)) as ArrayRef;
4911        let struct_b_array = StructArray::from(vec![(list_a.clone(), list_a_array)]);
4912
4913        let batch1 =
4914            RecordBatch::try_from_iter(vec![("struct_b", Arc::new(struct_b_array) as ArrayRef)])
4915                .unwrap();
4916
4917        let field_a_array = Int32Array::from(vec![6, 7, 8, 9, 10]);
4918        let field_b_array = Int32Array::from_iter(vec![None, None, None, Some(1), None]);
4919
4920        let struct_a_array = StructArray::from(vec![
4921            (field_a, Arc::new(field_a_array) as ArrayRef),
4922            (field_b, Arc::new(field_b_array) as ArrayRef),
4923        ]);
4924
4925        let list_data = ArrayDataBuilder::new(list_a.data_type().clone())
4926            .len(2)
4927            .add_buffer(Buffer::from_iter(vec![0_i32, 4_i32, 5_i32]))
4928            .child_data(vec![struct_a_array.into_data()])
4929            .build()
4930            .unwrap();
4931
4932        let list_a_array = Arc::new(ListArray::from(list_data)) as ArrayRef;
4933        let struct_b_array = StructArray::from(vec![(list_a, list_a_array)]);
4934
4935        let batch2 =
4936            RecordBatch::try_from_iter(vec![("struct_b", Arc::new(struct_b_array) as ArrayRef)])
4937                .unwrap();
4938
4939        let batches = &[batch1, batch2];
4940
4941        // Verify data is as expected
4942
4943        let expected = r"
4944            +-------------------------------------------------------------------------------------------------------+
4945            | struct_b                                                                                              |
4946            +-------------------------------------------------------------------------------------------------------+
4947            | {list: [{leaf_a: 1, leaf_b: 1}]}                                                                      |
4948            | {list: }                                                                                              |
4949            | {list: [{leaf_a: 2, leaf_b: }, {leaf_a: 3, leaf_b: 2}]}                                               |
4950            | {list: }                                                                                              |
4951            | {list: [{leaf_a: 4, leaf_b: }, {leaf_a: 5, leaf_b: }]}                                                |
4952            | {list: [{leaf_a: 6, leaf_b: }, {leaf_a: 7, leaf_b: }, {leaf_a: 8, leaf_b: }, {leaf_a: 9, leaf_b: 1}]} |
4953            | {list: [{leaf_a: 10, leaf_b: }]}                                                                      |
4954            +-------------------------------------------------------------------------------------------------------+
4955        ".trim().split('\n').map(|x| x.trim()).collect::<Vec<_>>().join("\n");
4956
4957        let actual = pretty_format_batches(batches).unwrap().to_string();
4958        assert_eq!(actual, expected);
4959
4960        // Write data
4961        let file = tempfile::tempfile().unwrap();
4962        let props = WriterProperties::builder()
4963            .set_max_row_group_row_count(Some(6))
4964            .build();
4965
4966        let mut writer =
4967            ArrowWriter::try_new(file.try_clone().unwrap(), schema, Some(props)).unwrap();
4968
4969        for batch in batches {
4970            writer.write(batch).unwrap();
4971        }
4972        writer.close().unwrap();
4973
4974        // Read Data
4975        // Should have written entire first batch and first row of second to the first row group
4976        // leaving a single row in the second row group
4977
4978        let builder = ParquetRecordBatchReaderBuilder::try_new(file).unwrap();
4979        assert_eq!(&row_group_sizes(builder.metadata()), &[6, 1]);
4980
4981        let batches = builder
4982            .with_batch_size(2)
4983            .build()
4984            .unwrap()
4985            .collect::<ArrowResult<Vec<_>>>()
4986            .unwrap();
4987
4988        assert_eq!(batches.len(), 4);
4989        let batch_counts: Vec<_> = batches.iter().map(|x| x.num_rows()).collect();
4990        assert_eq!(&batch_counts, &[2, 2, 2, 1]);
4991
4992        let actual = pretty_format_batches(&batches).unwrap().to_string();
4993        assert_eq!(actual, expected);
4994    }
4995
4996    #[test]
4997    fn test_arrow_writer_metadata() {
4998        let batch_schema = Schema::new(vec![Field::new("int32", DataType::Int32, false)]);
4999        let file_schema = batch_schema.clone().with_metadata([("foo", "bar")]);
5000
5001        let batch = RecordBatch::try_new(
5002            Arc::new(batch_schema),
5003            vec![Arc::new(Int32Array::from(vec![1, 2, 3, 4])) as _],
5004        )
5005        .unwrap();
5006
5007        let mut buf = Vec::with_capacity(1024);
5008        let mut writer = ArrowWriter::try_new(&mut buf, Arc::new(file_schema), None).unwrap();
5009        writer.write(&batch).unwrap();
5010        writer.close().unwrap();
5011    }
5012
5013    #[test]
5014    fn test_arrow_writer_nullable() {
5015        let batch_schema = Schema::new(vec![Field::new("int32", DataType::Int32, false)]);
5016        let file_schema = Schema::new(vec![Field::new("int32", DataType::Int32, true)]);
5017        let file_schema = Arc::new(file_schema);
5018
5019        let batch = RecordBatch::try_new(
5020            Arc::new(batch_schema),
5021            vec![Arc::new(Int32Array::from(vec![1, 2, 3, 4])) as _],
5022        )
5023        .unwrap();
5024
5025        let mut buf = Vec::with_capacity(1024);
5026        let mut writer = ArrowWriter::try_new(&mut buf, file_schema.clone(), None).unwrap();
5027        writer.write(&batch).unwrap();
5028        writer.close().unwrap();
5029
5030        let mut read = ParquetRecordBatchReader::try_new(Bytes::from(buf), 1024).unwrap();
5031        let back = read.next().unwrap().unwrap();
5032        assert_eq!(back.schema(), file_schema);
5033        assert_ne!(back.schema(), batch.schema());
5034        assert_eq!(back.column(0).as_ref(), batch.column(0).as_ref());
5035    }
5036
5037    #[test]
5038    fn in_progress_accounting() {
5039        // define schema
5040        let schema = Schema::new(vec![Field::new("a", DataType::Int32, false)]);
5041
5042        // create some data
5043        let a = Int32Array::from(vec![1, 2, 3, 4, 5]);
5044
5045        // build a record batch
5046        let batch = RecordBatch::try_new(Arc::new(schema), vec![Arc::new(a)]).unwrap();
5047
5048        let mut writer = ArrowWriter::try_new(vec![], batch.schema(), None).unwrap();
5049
5050        // starts empty
5051        assert_eq!(writer.in_progress_size(), 0);
5052        assert_eq!(writer.in_progress_rows(), 0);
5053        assert_eq!(writer.memory_size(), 0);
5054        assert_eq!(writer.bytes_written(), 4); // Initial header
5055        writer.write(&batch).unwrap();
5056
5057        // updated on write
5058        let initial_size = writer.in_progress_size();
5059        assert!(initial_size > 0);
5060        assert_eq!(writer.in_progress_rows(), 5);
5061        let initial_memory = writer.memory_size();
5062        assert!(initial_memory > 0);
5063        // memory estimate is larger than estimated encoded size
5064        assert!(
5065            initial_size <= initial_memory,
5066            "{initial_size} <= {initial_memory}"
5067        );
5068
5069        // updated on second write
5070        writer.write(&batch).unwrap();
5071        assert!(writer.in_progress_size() > initial_size);
5072        assert_eq!(writer.in_progress_rows(), 10);
5073        assert!(writer.memory_size() > initial_memory);
5074        assert!(
5075            writer.in_progress_size() <= writer.memory_size(),
5076            "in_progress_size {} <= memory_size {}",
5077            writer.in_progress_size(),
5078            writer.memory_size()
5079        );
5080
5081        // in progress tracking is cleared, but the overall data written is updated
5082        let pre_flush_bytes_written = writer.bytes_written();
5083        writer.flush().unwrap();
5084        assert_eq!(writer.in_progress_size(), 0);
5085        assert_eq!(writer.memory_size(), 0);
5086        assert!(writer.bytes_written() > pre_flush_bytes_written);
5087
5088        writer.close().unwrap();
5089    }
5090
5091    #[test]
5092    fn test_writer_all_null() {
5093        let a = Int32Array::from(vec![1, 2, 3, 4, 5]);
5094        let b = Int32Array::new(vec![0; 5].into(), Some(NullBuffer::new_null(5)));
5095        let batch = RecordBatch::try_from_iter(vec![
5096            ("a", Arc::new(a) as ArrayRef),
5097            ("b", Arc::new(b) as ArrayRef),
5098        ])
5099        .unwrap();
5100
5101        let mut buf = Vec::with_capacity(1024);
5102        let mut writer = ArrowWriter::try_new(&mut buf, batch.schema(), None).unwrap();
5103        writer.write(&batch).unwrap();
5104        writer.close().unwrap();
5105
5106        let bytes = Bytes::from(buf);
5107        let options = ReadOptionsBuilder::new().with_page_index().build();
5108        let reader = SerializedFileReader::new_with_options(bytes, options).unwrap();
5109        let index = reader.metadata().page_index().unwrap();
5110
5111        assert_eq!(index.num_data_pages(0, 0), Some(1)); // 1 page
5112        assert_eq!(index.num_data_pages(0, 1), Some(1)); // 1 page
5113    }
5114
5115    #[test]
5116    fn test_disabled_statistics_with_page() {
5117        let file_schema = Schema::new(vec![
5118            Field::new("a", DataType::Utf8, true),
5119            Field::new("b", DataType::Utf8, true),
5120        ]);
5121        let file_schema = Arc::new(file_schema);
5122
5123        let batch = RecordBatch::try_new(
5124            file_schema.clone(),
5125            vec![
5126                Arc::new(StringArray::from(vec!["a", "b", "c", "d"])) as _,
5127                Arc::new(StringArray::from(vec!["w", "x", "y", "z"])) as _,
5128            ],
5129        )
5130        .unwrap();
5131
5132        let props = WriterProperties::builder()
5133            .set_statistics_enabled(EnabledStatistics::None)
5134            .set_column_statistics_enabled("a".into(), EnabledStatistics::Page)
5135            .build();
5136
5137        let mut buf = Vec::with_capacity(1024);
5138        let mut writer = ArrowWriter::try_new(&mut buf, file_schema.clone(), Some(props)).unwrap();
5139        writer.write(&batch).unwrap();
5140
5141        let metadata = writer.close().unwrap();
5142        assert_eq!(metadata.num_row_groups(), 1);
5143        let row_group = metadata.row_group(0);
5144        assert_eq!(row_group.num_columns(), 2);
5145        // Column "a" has both offset and column index, as requested
5146        assert!(row_group.column(0).offset_index_offset().is_some());
5147        assert!(row_group.column(0).column_index_offset().is_some());
5148        // Column "b" should only have offset index
5149        assert!(row_group.column(1).offset_index_offset().is_some());
5150        assert!(row_group.column(1).column_index_offset().is_none());
5151
5152        let options = ReadOptionsBuilder::new().with_page_index().build();
5153        let reader = SerializedFileReader::new_with_options(Bytes::from(buf), options).unwrap();
5154
5155        let row_group = reader.get_row_group(0).unwrap();
5156        let a_col = row_group.metadata().column(0);
5157        let b_col = row_group.metadata().column(1);
5158
5159        // Column chunk of column "a" should have chunk level statistics
5160        if let Statistics::ByteArray(byte_array_stats) = a_col.statistics().unwrap() {
5161            let min = byte_array_stats.min_opt().unwrap();
5162            let max = byte_array_stats.max_opt().unwrap();
5163
5164            assert_eq!(min.as_bytes(), b"a");
5165            assert_eq!(max.as_bytes(), b"d");
5166        } else {
5167            panic!("expecting Statistics::ByteArray");
5168        }
5169
5170        // The column chunk for column "b" shouldn't have statistics
5171        assert!(b_col.statistics().is_none());
5172
5173        let page_index = reader.metadata().page_index().unwrap();
5174
5175        let a_idx = page_index.column_index(0, 0);
5176        assert!(
5177            matches!(a_idx, Some(ColumnIndexMetaData::BYTE_ARRAY(_))),
5178            "{a_idx:?}"
5179        );
5180        let b_idx = page_index.column_index(0, 1);
5181        assert!(b_idx.is_none(), "{b_idx:?}");
5182    }
5183
5184    #[test]
5185    fn test_disabled_statistics_with_chunk() {
5186        let file_schema = Schema::new(vec![
5187            Field::new("a", DataType::Utf8, true),
5188            Field::new("b", DataType::Utf8, true),
5189        ]);
5190        let file_schema = Arc::new(file_schema);
5191
5192        let batch = RecordBatch::try_new(
5193            file_schema.clone(),
5194            vec![
5195                Arc::new(StringArray::from(vec!["a", "b", "c", "d"])) as _,
5196                Arc::new(StringArray::from(vec!["w", "x", "y", "z"])) as _,
5197            ],
5198        )
5199        .unwrap();
5200
5201        let props = WriterProperties::builder()
5202            .set_statistics_enabled(EnabledStatistics::None)
5203            .set_column_statistics_enabled("a".into(), EnabledStatistics::Chunk)
5204            .build();
5205
5206        let mut buf = Vec::with_capacity(1024);
5207        let mut writer = ArrowWriter::try_new(&mut buf, file_schema.clone(), Some(props)).unwrap();
5208        writer.write(&batch).unwrap();
5209
5210        let metadata = writer.close().unwrap();
5211        assert_eq!(metadata.num_row_groups(), 1);
5212        let row_group = metadata.row_group(0);
5213        assert_eq!(row_group.num_columns(), 2);
5214        // Column "a" should only have offset index
5215        assert!(row_group.column(0).offset_index_offset().is_some());
5216        assert!(row_group.column(0).column_index_offset().is_none());
5217        // Column "b" should only have offset index
5218        assert!(row_group.column(1).offset_index_offset().is_some());
5219        assert!(row_group.column(1).column_index_offset().is_none());
5220
5221        let options = ReadOptionsBuilder::new().with_page_index().build();
5222        let reader = SerializedFileReader::new_with_options(Bytes::from(buf), options).unwrap();
5223
5224        let row_group = reader.get_row_group(0).unwrap();
5225        let a_col = row_group.metadata().column(0);
5226        let b_col = row_group.metadata().column(1);
5227
5228        // Column chunk of column "a" should have chunk level statistics
5229        if let Statistics::ByteArray(byte_array_stats) = a_col.statistics().unwrap() {
5230            let min = byte_array_stats.min_opt().unwrap();
5231            let max = byte_array_stats.max_opt().unwrap();
5232
5233            assert_eq!(min.as_bytes(), b"a");
5234            assert_eq!(max.as_bytes(), b"d");
5235        } else {
5236            panic!("expecting Statistics::ByteArray");
5237        }
5238
5239        // The column chunk for column "b"  shouldn't have statistics
5240        assert!(b_col.statistics().is_none());
5241
5242        let page_index = reader.metadata().page_index().unwrap();
5243
5244        let a_idx = page_index.column_index(0, 0);
5245        assert!(a_idx.is_none(), "{a_idx:?}");
5246        let b_idx = page_index.column_index(0, 1);
5247        assert!(b_idx.is_none(), "{b_idx:?}");
5248    }
5249
5250    #[test]
5251    fn test_arrow_writer_skip_metadata() {
5252        let batch_schema = Schema::new(vec![Field::new("int32", DataType::Int32, false)]);
5253        let file_schema = Arc::new(batch_schema.clone());
5254
5255        let batch = RecordBatch::try_new(
5256            Arc::new(batch_schema),
5257            vec![Arc::new(Int32Array::from(vec![1, 2, 3, 4])) as _],
5258        )
5259        .unwrap();
5260        let skip_options = ArrowWriterOptions::new().with_skip_arrow_metadata(true);
5261
5262        let mut buf = Vec::with_capacity(1024);
5263        let mut writer =
5264            ArrowWriter::try_new_with_options(&mut buf, file_schema.clone(), skip_options).unwrap();
5265        writer.write(&batch).unwrap();
5266        writer.close().unwrap();
5267
5268        let bytes = Bytes::from(buf);
5269        let reader_builder = ParquetRecordBatchReaderBuilder::try_new(bytes).unwrap();
5270        assert_eq!(file_schema, *reader_builder.schema());
5271        if let Some(key_value_metadata) = reader_builder
5272            .metadata()
5273            .file_metadata()
5274            .key_value_metadata()
5275        {
5276            assert!(
5277                !key_value_metadata
5278                    .iter()
5279                    .any(|kv| kv.key.as_str() == ARROW_SCHEMA_META_KEY)
5280            );
5281        }
5282    }
5283
5284    #[test]
5285    fn test_arrow_writer_skip_path_in_schema() {
5286        let batch_schema = Schema::new(vec![Field::new("int32", DataType::Int32, false)]);
5287        let file_schema = Arc::new(batch_schema.clone());
5288
5289        let batch = RecordBatch::try_new(
5290            Arc::new(batch_schema),
5291            vec![Arc::new(Int32Array::from(vec![1, 2, 3, 4])) as _],
5292        )
5293        .unwrap();
5294
5295        // default options should still write path_in_schema
5296        let skip_options = ArrowWriterOptions::new();
5297
5298        let mut buf = Vec::with_capacity(1024);
5299        let mut writer =
5300            ArrowWriter::try_new_with_options(&mut buf, file_schema.clone(), skip_options).unwrap();
5301        writer.write(&batch).unwrap();
5302        writer.close().unwrap();
5303
5304        // override to not write path_in_schema
5305        let skip_options = ArrowWriterOptions::new().with_properties(
5306            WriterProperties::builder()
5307                .set_write_path_in_schema(false)
5308                .build(),
5309        );
5310
5311        let mut buf2 = Vec::with_capacity(1024);
5312        let mut writer =
5313            ArrowWriter::try_new_with_options(&mut buf2, file_schema.clone(), skip_options)
5314                .unwrap();
5315        writer.write(&batch).unwrap();
5316        writer.close().unwrap();
5317
5318        // buf2 should be a bit smaller due to lack of path_in_schema
5319        assert!(buf.len() > buf2.len());
5320    }
5321
5322    #[test]
5323    fn mismatched_schemas() {
5324        let batch_schema = Schema::new(vec![Field::new("count", DataType::Int32, false)]);
5325        let file_schema = Arc::new(Schema::new(vec![Field::new(
5326            "temperature",
5327            DataType::Float64,
5328            false,
5329        )]));
5330
5331        let batch = RecordBatch::try_new(
5332            Arc::new(batch_schema),
5333            vec![Arc::new(Int32Array::from(vec![1, 2, 3, 4])) as _],
5334        )
5335        .unwrap();
5336
5337        let mut buf = Vec::with_capacity(1024);
5338        let mut writer = ArrowWriter::try_new(&mut buf, file_schema.clone(), None).unwrap();
5339
5340        let err = writer.write(&batch).unwrap_err().to_string();
5341        assert_eq!(
5342            err,
5343            "Arrow: Incompatible type. Field 'temperature' has type Float64, array has type Int32"
5344        );
5345    }
5346
5347    #[test]
5348    // https://github.com/apache/arrow-rs/issues/6988
5349    fn test_roundtrip_empty_schema() {
5350        // create empty record batch with empty schema
5351        let empty_batch = RecordBatch::try_new_with_options(
5352            Arc::new(Schema::empty()),
5353            vec![],
5354            &RecordBatchOptions::default().with_row_count(Some(0)),
5355        )
5356        .unwrap();
5357
5358        // write to parquet
5359        let mut parquet_bytes: Vec<u8> = Vec::new();
5360        let mut writer =
5361            ArrowWriter::try_new(&mut parquet_bytes, empty_batch.schema(), None).unwrap();
5362        writer.write(&empty_batch).unwrap();
5363        writer.close().unwrap();
5364
5365        // read from parquet
5366        let bytes = Bytes::from(parquet_bytes);
5367        let reader = ParquetRecordBatchReaderBuilder::try_new(bytes).unwrap();
5368        assert_eq!(reader.schema(), &empty_batch.schema());
5369        let batches: Vec<_> = reader
5370            .build()
5371            .unwrap()
5372            .collect::<ArrowResult<Vec<_>>>()
5373            .unwrap();
5374        assert_eq!(batches.len(), 0);
5375    }
5376
5377    #[test]
5378    fn test_page_stats_not_written_by_default() {
5379        let string_field = Field::new("a", DataType::Utf8, false);
5380        let schema = Schema::new(vec![string_field]);
5381        let raw_string_values = vec!["Blart Versenwald III"];
5382        let string_values = StringArray::from(raw_string_values.clone());
5383        let batch = RecordBatch::try_new(Arc::new(schema), vec![Arc::new(string_values)]).unwrap();
5384
5385        let props = WriterProperties::builder()
5386            .set_statistics_enabled(EnabledStatistics::Page)
5387            .set_dictionary_enabled(false)
5388            .set_encoding(Encoding::PLAIN)
5389            .set_compression(crate::basic::Compression::UNCOMPRESSED)
5390            .build();
5391
5392        let file = roundtrip_opts(&batch, props);
5393
5394        // read file and decode page headers
5395        // Note: use the thrift API as there is no Rust API to access the statistics in the page headers
5396
5397        // decode first page header
5398        let first_page = &file[4..];
5399        let mut prot = ThriftSliceInputProtocol::new(first_page);
5400        let hdr = PageHeader::read_thrift(&mut prot).unwrap();
5401        let stats = hdr.data_page_header.unwrap().statistics;
5402
5403        assert!(stats.is_none());
5404    }
5405
5406    #[test]
5407    fn test_page_stats_when_enabled() {
5408        let string_field = Field::new("a", DataType::Utf8, false);
5409        let schema = Schema::new(vec![string_field]);
5410        let raw_string_values = vec!["Blart Versenwald III", "Andrew Lamb"];
5411        let string_values = StringArray::from(raw_string_values.clone());
5412        let batch = RecordBatch::try_new(Arc::new(schema), vec![Arc::new(string_values)]).unwrap();
5413
5414        let props = WriterProperties::builder()
5415            .set_statistics_enabled(EnabledStatistics::Page)
5416            .set_dictionary_enabled(false)
5417            .set_encoding(Encoding::PLAIN)
5418            .set_write_page_header_statistics(true)
5419            .set_compression(crate::basic::Compression::UNCOMPRESSED)
5420            .build();
5421
5422        let file = roundtrip_opts(&batch, props);
5423
5424        // read file and decode page headers
5425        // Note: use the thrift API as there is no Rust API to access the statistics in the page headers
5426
5427        // decode first page header
5428        let first_page = &file[4..];
5429        let mut prot = ThriftSliceInputProtocol::new(first_page);
5430        let hdr = PageHeader::read_thrift(&mut prot).unwrap();
5431        let stats = hdr.data_page_header.unwrap().statistics;
5432
5433        let stats = stats.unwrap();
5434        // check that min/max were actually written to the page
5435        assert!(stats.is_max_value_exact.unwrap());
5436        assert!(stats.is_min_value_exact.unwrap());
5437        assert_eq!(stats.max_value.unwrap(), b"Blart Versenwald III");
5438        assert_eq!(stats.min_value.unwrap(), b"Andrew Lamb");
5439    }
5440
5441    #[test]
5442    fn test_page_stats_truncation() {
5443        let string_field = Field::new("a", DataType::Utf8, false);
5444        let binary_field = Field::new("b", DataType::Binary, false);
5445        let schema = Schema::new(vec![string_field, binary_field]);
5446
5447        let raw_string_values = vec!["Blart Versenwald III"];
5448        let raw_binary_values = [b"Blart Versenwald III".to_vec()];
5449        let raw_binary_value_refs = raw_binary_values
5450            .iter()
5451            .map(|x| x.as_slice())
5452            .collect::<Vec<_>>();
5453
5454        let string_values = StringArray::from(raw_string_values.clone());
5455        let binary_values = BinaryArray::from(raw_binary_value_refs);
5456        let batch = RecordBatch::try_new(
5457            Arc::new(schema),
5458            vec![Arc::new(string_values), Arc::new(binary_values)],
5459        )
5460        .unwrap();
5461
5462        let props = WriterProperties::builder()
5463            .set_statistics_truncate_length(Some(2))
5464            .set_dictionary_enabled(false)
5465            .set_encoding(Encoding::PLAIN)
5466            .set_write_page_header_statistics(true)
5467            .set_compression(crate::basic::Compression::UNCOMPRESSED)
5468            .build();
5469
5470        let file = roundtrip_opts(&batch, props);
5471
5472        // read file and decode page headers
5473        // Note: use the thrift API as there is no Rust API to access the statistics in the page headers
5474
5475        // decode first page header
5476        let first_page = &file[4..];
5477        let mut prot = ThriftSliceInputProtocol::new(first_page);
5478        let hdr = PageHeader::read_thrift(&mut prot).unwrap();
5479        let stats = hdr.data_page_header.unwrap().statistics;
5480        assert!(stats.is_some());
5481        let stats = stats.unwrap();
5482        // check that min/max were properly truncated
5483        assert!(!stats.is_max_value_exact.unwrap());
5484        assert!(!stats.is_min_value_exact.unwrap());
5485        assert_eq!(stats.max_value.unwrap(), b"Bm");
5486        assert_eq!(stats.min_value.unwrap(), b"Bl");
5487
5488        // check second page now
5489        let second_page = &prot.as_slice()[hdr.compressed_page_size as usize..];
5490        let mut prot = ThriftSliceInputProtocol::new(second_page);
5491        let hdr = PageHeader::read_thrift(&mut prot).unwrap();
5492        let stats = hdr.data_page_header.unwrap().statistics;
5493        assert!(stats.is_some());
5494        let stats = stats.unwrap();
5495        // check that min/max were properly truncated
5496        assert!(!stats.is_max_value_exact.unwrap());
5497        assert!(!stats.is_min_value_exact.unwrap());
5498        assert_eq!(stats.max_value.unwrap(), b"Bm");
5499        assert_eq!(stats.min_value.unwrap(), b"Bl");
5500    }
5501
5502    #[test]
5503    fn test_page_encoding_statistics_roundtrip() {
5504        let batch_schema = Schema::new(vec![Field::new(
5505            "int32",
5506            arrow_schema::DataType::Int32,
5507            false,
5508        )]);
5509
5510        let batch = RecordBatch::try_new(
5511            Arc::new(batch_schema.clone()),
5512            vec![Arc::new(Int32Array::from(vec![1, 2, 3, 4])) as _],
5513        )
5514        .unwrap();
5515
5516        let mut file: File = tempfile::tempfile().unwrap();
5517        let mut writer = ArrowWriter::try_new(&mut file, Arc::new(batch_schema), None).unwrap();
5518        writer.write(&batch).unwrap();
5519        let file_metadata = writer.close().unwrap();
5520
5521        assert_eq!(file_metadata.num_row_groups(), 1);
5522        assert_eq!(file_metadata.row_group(0).num_columns(), 1);
5523        assert!(
5524            file_metadata
5525                .row_group(0)
5526                .column(0)
5527                .page_encoding_stats()
5528                .is_some()
5529        );
5530        let chunk_page_stats = file_metadata
5531            .row_group(0)
5532            .column(0)
5533            .page_encoding_stats()
5534            .unwrap();
5535
5536        // check that the read metadata is also correct
5537        let options = ReadOptionsBuilder::new()
5538            .with_page_index()
5539            .with_encoding_stats_as_mask(false)
5540            .build();
5541        let reader = SerializedFileReader::new_with_options(file, options).unwrap();
5542
5543        let rowgroup = reader.get_row_group(0).expect("row group missing");
5544        assert_eq!(rowgroup.num_columns(), 1);
5545        let column = rowgroup.metadata().column(0);
5546        assert!(column.page_encoding_stats().is_some());
5547        let file_page_stats = column.page_encoding_stats().unwrap();
5548        assert_eq!(chunk_page_stats, file_page_stats);
5549    }
5550
5551    #[test]
5552    fn test_different_dict_page_size_limit() {
5553        let array = Arc::new(Int64Array::from_iter(0..1024 * 1024));
5554        let schema = Arc::new(Schema::new(vec![
5555            Field::new("col0", arrow_schema::DataType::Int64, false),
5556            Field::new("col1", arrow_schema::DataType::Int64, false),
5557        ]));
5558        let batch =
5559            arrow_array::RecordBatch::try_new(schema.clone(), vec![array.clone(), array]).unwrap();
5560
5561        let props = WriterProperties::builder()
5562            .set_dictionary_page_size_limit(1024 * 1024)
5563            .set_column_dictionary_page_size_limit(ColumnPath::from("col1"), 1024 * 1024 * 4)
5564            .build();
5565        let mut writer = ArrowWriter::try_new(Vec::new(), schema, Some(props)).unwrap();
5566        writer.write(&batch).unwrap();
5567        let data = Bytes::from(writer.into_inner().unwrap());
5568
5569        let mut metadata = ParquetMetaDataReader::new();
5570        metadata.try_parse(&data).unwrap();
5571        let metadata = metadata.finish().unwrap();
5572        let col0_meta = metadata.row_group(0).column(0);
5573        let col1_meta = metadata.row_group(0).column(1);
5574
5575        let get_dict_page_size = move |meta: &ColumnChunkMetaData| {
5576            let mut reader =
5577                SerializedPageReader::new(Arc::new(data.clone()), meta, 0, None).unwrap();
5578            let page = reader.get_next_page().unwrap().unwrap();
5579            match page {
5580                Page::DictionaryPage { buf, .. } => buf.len(),
5581                _ => panic!("expected DictionaryPage"),
5582            }
5583        };
5584
5585        assert_eq!(get_dict_page_size(col0_meta), 1024 * 1024);
5586        assert_eq!(get_dict_page_size(col1_meta), 1024 * 1024 * 4);
5587    }
5588
5589    #[test]
5590    fn test_arrow_writer_granular_mode_roundtrip() {
5591        // Granular mode subdivides chunks and writes more pages than the
5592        // default batched path. Make sure the data we write back is
5593        // bit-identical to what went in — page-count assertions elsewhere
5594        // only prove pages were cut, not that the encoded data is correct.
5595        //
5596        // Mix value sizes so that the cumulative-byte-budget cutoff
5597        // lands mid-chunk, exercising both batched and granular paths
5598        // within the same `write_batch_internal` call.
5599        let small = "tiny".to_string();
5600        let big = "x".repeat(64 * 1024);
5601        let strings: Vec<String> = (0..256)
5602            .map(|i| {
5603                if i % 16 == 0 {
5604                    big.clone()
5605                } else {
5606                    small.clone()
5607                }
5608            })
5609            .collect();
5610
5611        let schema = Arc::new(Schema::new(vec![Field::new(
5612            "col",
5613            ArrowDataType::Utf8,
5614            false,
5615        )]));
5616        let batch = RecordBatch::try_new(
5617            schema.clone(),
5618            vec![Arc::new(StringArray::from(strings.clone())) as _],
5619        )
5620        .unwrap();
5621
5622        let props = WriterProperties::builder()
5623            .set_dictionary_enabled(false)
5624            .set_data_page_size_limit(16 * 1024)
5625            .build();
5626        let mut writer = ArrowWriter::try_new(Vec::new(), schema, Some(props)).unwrap();
5627        writer.write(&batch).unwrap();
5628        let data = Bytes::from(writer.into_inner().unwrap());
5629
5630        let mut reader = ParquetRecordBatchReader::try_new(data, 1024).unwrap();
5631        let read = reader.next().unwrap().unwrap();
5632        assert!(reader.next().is_none(), "expected one batch");
5633        let col = read
5634            .column(0)
5635            .as_any()
5636            .downcast_ref::<StringArray>()
5637            .unwrap();
5638        assert_eq!(col.len(), strings.len());
5639        for (i, expected) in strings.iter().enumerate() {
5640            assert_eq!(
5641                col.value(i),
5642                expected.as_str(),
5643                "value mismatch at index {i}"
5644            );
5645        }
5646    }
5647
5648    #[test]
5649    fn test_arrow_writer_all_null_string_column() {
5650        // The `LevelDataRef::value_count` Uniform branch with
5651        // `value != max_def` (entirely-null chunk) must return 0 so the
5652        // sub-batch sizer short-circuits to batch mode without trying
5653        // to estimate byte budgets for non-existent values.
5654        let num_rows = 1024;
5655        let schema = Arc::new(Schema::new(vec![Field::new(
5656            "col",
5657            ArrowDataType::Utf8,
5658            true,
5659        )]));
5660        let nulls: Vec<Option<&str>> = vec![None; num_rows];
5661        let batch = RecordBatch::try_new(
5662            schema.clone(),
5663            vec![Arc::new(StringArray::from(nulls)) as _],
5664        )
5665        .unwrap();
5666
5667        let props = WriterProperties::builder()
5668            .set_dictionary_enabled(false)
5669            .set_data_page_size_limit(16 * 1024)
5670            .build();
5671        let mut writer = ArrowWriter::try_new(Vec::new(), schema, Some(props)).unwrap();
5672        writer.write(&batch).unwrap();
5673        let data = Bytes::from(writer.into_inner().unwrap());
5674
5675        // Re-parse the file: row group has one column, every row is
5676        // null, all data pages report `num_rows / page_count` rows.
5677        let mut metadata = ParquetMetaDataReader::new();
5678        metadata.try_parse(&data).unwrap();
5679        let metadata = metadata.finish().unwrap();
5680        let row_group = metadata.row_group(0);
5681        let col_meta = row_group.column(0);
5682        assert_eq!(row_group.num_rows() as usize, num_rows);
5683        // Statistics record `null_count = num_rows` — proves every value
5684        // was written as null.
5685        if let Some(stats) = col_meta.statistics() {
5686            assert_eq!(
5687                stats.null_count_opt().unwrap_or(0) as usize,
5688                num_rows,
5689                "expected all-null column to report null_count = num_rows"
5690            );
5691        }
5692
5693        let mut reader =
5694            SerializedPageReader::new(Arc::new(data.clone()), col_meta, num_rows, None).unwrap();
5695        let mut total_values = 0u32;
5696        while let Some(page) = reader.get_next_page().unwrap() {
5697            if matches!(page, Page::DataPage { .. } | Page::DataPageV2 { .. }) {
5698                total_values += page.num_values();
5699            }
5700        }
5701        assert_eq!(
5702            total_values as usize, num_rows,
5703            "expected every level position to be represented in some page"
5704        );
5705    }
5706
5707    struct WriteBatchesShape {
5708        num_batches: usize,
5709        rows_per_batch: usize,
5710        row_size: usize,
5711    }
5712
5713    /// Helper function to write batches with the provided `WriteBatchesShape` into an `ArrowWriter`
5714    fn write_batches(
5715        WriteBatchesShape {
5716            num_batches,
5717            rows_per_batch,
5718            row_size,
5719        }: WriteBatchesShape,
5720        props: WriterProperties,
5721    ) -> ParquetRecordBatchReaderBuilder<File> {
5722        let schema = Arc::new(Schema::new(vec![Field::new(
5723            "str",
5724            ArrowDataType::Utf8,
5725            false,
5726        )]));
5727        let file = tempfile::tempfile().unwrap();
5728        let mut writer =
5729            ArrowWriter::try_new(file.try_clone().unwrap(), schema.clone(), Some(props)).unwrap();
5730
5731        for batch_idx in 0..num_batches {
5732            let strings: Vec<String> = (0..rows_per_batch)
5733                .map(|i| format!("{:0>width$}", batch_idx * 10 + i, width = row_size))
5734                .collect();
5735            let array = StringArray::from(strings);
5736            let batch = RecordBatch::try_new(schema.clone(), vec![Arc::new(array)]).unwrap();
5737            writer.write(&batch).unwrap();
5738        }
5739        writer.close().unwrap();
5740        ParquetRecordBatchReaderBuilder::try_new(file).unwrap()
5741    }
5742
5743    #[test]
5744    // When both limits are None, all data should go into a single row group
5745    fn test_row_group_limit_none_writes_single_row_group() {
5746        let props = WriterProperties::builder()
5747            .set_max_row_group_row_count(None)
5748            .set_max_row_group_bytes(None)
5749            .build();
5750
5751        let builder = write_batches(
5752            WriteBatchesShape {
5753                num_batches: 1,
5754                rows_per_batch: 1000,
5755                row_size: 4,
5756            },
5757            props,
5758        );
5759
5760        assert_eq!(
5761            &row_group_sizes(builder.metadata()),
5762            &[1000],
5763            "With no limits, all rows should be in a single row group"
5764        );
5765    }
5766
5767    #[test]
5768    // When only max_row_group_size is set, respect the row limit
5769    fn test_row_group_limit_rows_only() {
5770        let props = WriterProperties::builder()
5771            .set_max_row_group_row_count(Some(300))
5772            .set_max_row_group_bytes(None)
5773            .build();
5774
5775        let builder = write_batches(
5776            WriteBatchesShape {
5777                num_batches: 1,
5778                rows_per_batch: 1000,
5779                row_size: 4,
5780            },
5781            props,
5782        );
5783
5784        assert_eq!(
5785            &row_group_sizes(builder.metadata()),
5786            &[300, 300, 300, 100],
5787            "Row groups should be split by row count"
5788        );
5789    }
5790
5791    #[test]
5792    // When only max_row_group_bytes is set, respect the byte limit
5793    fn test_row_group_limit_bytes_only() {
5794        let props = WriterProperties::builder()
5795            .set_max_row_group_row_count(None)
5796            // Set byte limit to approximately fit ~30 rows worth of data (~100 bytes each)
5797            .set_max_row_group_bytes(Some(3500))
5798            .build();
5799
5800        let builder = write_batches(
5801            WriteBatchesShape {
5802                num_batches: 10,
5803                rows_per_batch: 10,
5804                row_size: 100,
5805            },
5806            props,
5807        );
5808
5809        let sizes = row_group_sizes(builder.metadata());
5810
5811        assert!(
5812            sizes.len() > 1,
5813            "Should have multiple row groups due to byte limit, got {sizes:?}",
5814        );
5815
5816        let total_rows: i64 = sizes.iter().sum();
5817        assert_eq!(total_rows, 100, "Total rows should be preserved");
5818    }
5819
5820    #[test]
5821    // If an in-progress row group is already oversized, it should be flushed before writing more.
5822    fn test_row_group_limit_bytes_flushes_when_current_group_already_too_large() {
5823        let schema = Arc::new(Schema::new(vec![Field::new(
5824            "str",
5825            ArrowDataType::Utf8,
5826            false,
5827        )]));
5828        let file = tempfile::tempfile().unwrap();
5829
5830        // Start with no byte limit so we can intentionally build an oversized in-progress row group.
5831        let props = WriterProperties::builder()
5832            .set_max_row_group_row_count(None)
5833            .set_max_row_group_bytes(None)
5834            .build();
5835        let mut writer =
5836            ArrowWriter::try_new(file.try_clone().unwrap(), schema.clone(), Some(props)).unwrap();
5837
5838        let first_array = StringArray::from(
5839            (0..10)
5840                .map(|i| format!("{i:0>100}"))
5841                .collect::<Vec<String>>(),
5842        );
5843        let first_batch =
5844            RecordBatch::try_new(schema.clone(), vec![Arc::new(first_array)]).unwrap();
5845        writer.write(&first_batch).unwrap();
5846        assert_eq!(writer.in_progress_rows(), 10);
5847
5848        // Tighten the limit below the current in-progress bytes to exercise:
5849        // `if current_bytes >= max_bytes { self.flush()?; ... }`
5850        writer.max_row_group_bytes = Some(1);
5851
5852        let second_array = StringArray::from(vec!["x".to_string()]);
5853        let second_batch =
5854            RecordBatch::try_new(schema.clone(), vec![Arc::new(second_array)]).unwrap();
5855        writer.write(&second_batch).unwrap();
5856        writer.close().unwrap();
5857        let builder = ParquetRecordBatchReaderBuilder::try_new(file).unwrap();
5858
5859        assert_eq!(
5860            &row_group_sizes(builder.metadata()),
5861            &[10, 1],
5862            "The second write should flush an oversized in-progress row group first",
5863        );
5864    }
5865
5866    #[test]
5867    // When both limits are set, the row limit triggers first
5868    fn test_row_group_limit_both_row_wins_single_batch() {
5869        let props = WriterProperties::builder()
5870            .set_max_row_group_row_count(Some(200)) // Will trigger at 200 rows
5871            .set_max_row_group_bytes(Some(1024 * 1024)) // 1MB - won't trigger for small int data
5872            .build();
5873
5874        let builder = write_batches(
5875            WriteBatchesShape {
5876                num_batches: 1,
5877                row_size: 4,
5878                rows_per_batch: 1000,
5879            },
5880            props,
5881        );
5882
5883        assert_eq!(
5884            &row_group_sizes(builder.metadata()),
5885            &[200, 200, 200, 200, 200],
5886            "Row limit should trigger before byte limit"
5887        );
5888    }
5889
5890    #[test]
5891    // When both limits are set, the row limit triggers first
5892    fn test_row_group_limit_both_row_wins_multiple_batches() {
5893        let props = WriterProperties::builder()
5894            .set_max_row_group_row_count(Some(5)) // Will trigger every 5 rows
5895            .set_max_row_group_bytes(Some(9999)) // Won't trigger
5896            .build();
5897
5898        let builder = write_batches(
5899            WriteBatchesShape {
5900                num_batches: 10,
5901                rows_per_batch: 10,
5902                row_size: 100,
5903            },
5904            props,
5905        );
5906
5907        assert_eq!(
5908            &row_group_sizes(builder.metadata()),
5909            &[5; 20],
5910            "Row limit should trigger before byte limit"
5911        );
5912    }
5913
5914    #[test]
5915    // When both limits are set, the byte limit triggers first
5916    fn test_row_group_limit_both_bytes_wins() {
5917        let props = WriterProperties::builder()
5918            .set_max_row_group_row_count(Some(1000)) // Won't trigger for 100 rows
5919            .set_max_row_group_bytes(Some(3500)) // Will trigger at ~30-35 rows
5920            .build();
5921
5922        let builder = write_batches(
5923            WriteBatchesShape {
5924                num_batches: 10,
5925                rows_per_batch: 10,
5926                row_size: 100,
5927            },
5928            props,
5929        );
5930
5931        let sizes = row_group_sizes(builder.metadata());
5932
5933        assert!(
5934            sizes.len() > 1,
5935            "Byte limit should trigger before row limit, got {sizes:?}",
5936        );
5937
5938        assert!(
5939            sizes.iter().all(|&s| s < 1000),
5940            "No row group should hit the row limit"
5941        );
5942
5943        let total_rows: i64 = sizes.iter().sum();
5944        assert_eq!(total_rows, 100, "Total rows should be preserved");
5945    }
5946
5947    #[test]
5948    fn arrow_column_chunk_close_mut_drops_column_index() {
5949        use crate::arrow::ArrowSchemaConverter;
5950        use crate::file::writer::SerializedFileWriter;
5951
5952        let schema = Arc::new(Schema::new(vec![Field::new("i", DataType::Int32, false)]));
5953        let props = Arc::new(
5954            WriterProperties::builder()
5955                .set_statistics_enabled(EnabledStatistics::Page)
5956                .build(),
5957        );
5958        let parquet_schema = ArrowSchemaConverter::new()
5959            .with_coerce_types(props.coerce_types())
5960            .convert(&schema)
5961            .unwrap();
5962
5963        let mut buf = Vec::with_capacity(1024);
5964        let mut writer =
5965            SerializedFileWriter::new(&mut buf, parquet_schema.root_schema_ptr(), props.clone())
5966                .unwrap();
5967
5968        let factory = ArrowRowGroupWriterFactory::new(&writer, Arc::clone(&schema));
5969        let mut col_writers = factory.create_column_writers(0).unwrap();
5970        let arr: ArrayRef = Arc::new(Int32Array::from_iter_values(0..64));
5971        for leaves in compute_leaves(schema.field(0), &arr).unwrap() {
5972            col_writers[0].write(&leaves).unwrap();
5973        }
5974        let mut chunk = col_writers.pop().unwrap().close().unwrap();
5975
5976        // Immutable accessor exposes the close result produced at close time.
5977        assert!(
5978            chunk.close().column_index.is_some(),
5979            "EnabledStatistics::Page should produce a column_index"
5980        );
5981
5982        // Mutable accessor lets callers drop the page-level index before append.
5983        chunk.close_mut().column_index = None;
5984        assert!(chunk.close().column_index.is_none());
5985
5986        let mut rg = writer.next_row_group().unwrap();
5987        chunk.append_to_row_group(&mut rg).unwrap();
5988        rg.close().unwrap();
5989        let file_meta = writer.close().unwrap();
5990
5991        // After dropping column_index, the resulting file records no column
5992        // index offset/length for this chunk.
5993        let cc = file_meta.row_group(0).column(0);
5994        assert!(cc.column_index_range().is_none());
5995    }
5996
5997    /// Writes a single-column RecordBatch to an in-memory Parquet buffer.
5998    fn write_column_to_bytes(array: ArrayRef) -> Bytes {
5999        let schema = Arc::new(Schema::new(vec![Field::new(
6000            "col",
6001            array.data_type().clone(),
6002            true,
6003        )]));
6004        let buf = get_bytes_after_close(
6005            schema.clone(),
6006            &RecordBatch::try_new(schema, vec![array]).unwrap(),
6007        );
6008        Bytes::from(buf)
6009    }
6010
6011    /// Reads column 0 from a single-row-group Parquet buffer, projecting it with the given schema.
6012    /// Passing a flat schema when the buffer was written from a REE array lets callers decode
6013    /// the physical values without the run-end encoding wrapper.
6014    fn read_column_with_schema(bytes: Bytes, schema: SchemaRef) -> ArrayRef {
6015        let opts = crate::arrow::arrow_reader::ArrowReaderOptions::new().with_schema(schema);
6016        ParquetRecordBatchReaderBuilder::try_new_with_options(bytes, opts)
6017            .unwrap()
6018            .build()
6019            .unwrap()
6020            .next()
6021            .unwrap()
6022            .unwrap()
6023            .column(0)
6024            .clone()
6025    }
6026
6027    fn ree_write_read_roundtrip(ree: ArrayRef, flat: ArrayRef) {
6028        let flat_schema = Arc::new(Schema::new(vec![Field::new(
6029            "col",
6030            flat.data_type().clone(),
6031            true,
6032        )]));
6033        let ree_bytes = write_column_to_bytes(ree);
6034        let flat_bytes = write_column_to_bytes(flat.clone());
6035        assert_eq!(
6036            ree_bytes, flat_bytes,
6037            "REE and flat bytes should be identical"
6038        );
6039
6040        let decoded_ree = read_column_with_schema(ree_bytes, flat_schema.clone());
6041        let decoded_flat = read_column_with_schema(flat_bytes, flat_schema);
6042
6043        assert_eq!(decoded_ree.as_ref(), flat.as_ref());
6044        assert_eq!(decoded_ree.as_ref(), decoded_flat.as_ref());
6045    }
6046
6047    #[test]
6048    fn ree_string() {
6049        let ree: ArrayRef = Arc::new(
6050            [Some("a"), Some("a"), None, Some("b"), Some("b")]
6051                .into_iter()
6052                .collect::<Int32RunArray>(),
6053        );
6054        let flat: ArrayRef = Arc::new(StringArray::from(vec![
6055            Some("a"),
6056            Some("a"),
6057            None,
6058            Some("b"),
6059            Some("b"),
6060        ]));
6061        ree_write_read_roundtrip(ree, flat);
6062    }
6063
6064    #[test]
6065    fn ree_int32() {
6066        let mut b = PrimitiveRunBuilder::<Int32Type, Int32Type>::new();
6067        for v in [Some(1), Some(1), None, Some(2), Some(2)] {
6068            b.append_option(v);
6069        }
6070        let ree: ArrayRef = Arc::new(b.finish());
6071        let flat: ArrayRef = Arc::new(Int32Array::from(vec![
6072            Some(1),
6073            Some(1),
6074            None,
6075            Some(2),
6076            Some(2),
6077        ]));
6078        ree_write_read_roundtrip(ree, flat);
6079    }
6080
6081    #[test]
6082    fn ree_bool() {
6083        // run_ends [3, 5, 7] → [T,T,T, null,null, F,F]
6084        let ree: ArrayRef = Arc::new(
6085            RunArray::try_new(
6086                &Int32Array::from(vec![3, 5, 7]),
6087                &BooleanArray::from(vec![Some(true), None, Some(false)]),
6088            )
6089            .unwrap(),
6090        );
6091        let flat: ArrayRef = Arc::new(BooleanArray::from(vec![
6092            Some(true),
6093            Some(true),
6094            Some(true),
6095            None,
6096            None,
6097            Some(false),
6098            Some(false),
6099        ]));
6100        ree_write_read_roundtrip(ree, flat);
6101    }
6102
6103    #[test]
6104    fn ree_fixed_size_binary() {
6105        let mk = |vals: &[Option<&[u8]>]| -> FixedSizeBinaryArray {
6106            let mut b = FixedSizeBinaryBuilder::new(2);
6107            for v in vals {
6108                match v {
6109                    Some(x) => b.append_value(x).unwrap(),
6110                    None => b.append_null(),
6111                }
6112            }
6113            b.finish()
6114        };
6115        // run_ends [2, 4, 6] → [aa,aa, null,null, bb,bb]
6116        let ree: ArrayRef = Arc::new(
6117            RunArray::try_new(
6118                &Int32Array::from(vec![2, 4, 6]),
6119                &mk(&[Some(b"aa"), None, Some(b"bb")]),
6120            )
6121            .unwrap(),
6122        );
6123        let flat: ArrayRef = Arc::new(mk(&[
6124            Some(b"aa"),
6125            Some(b"aa"),
6126            None,
6127            None,
6128            Some(b"bb"),
6129            Some(b"bb"),
6130        ]));
6131        ree_write_read_roundtrip(ree, flat);
6132    }
6133
6134    #[test]
6135    fn ree_single_run() {
6136        let ree: ArrayRef = Arc::new(["x", "x", "x"].into_iter().collect::<Int32RunArray>());
6137        let flat: ArrayRef = Arc::new(StringArray::from(vec!["x", "x", "x"]));
6138        ree_write_read_roundtrip(ree, flat);
6139    }
6140
6141    #[test]
6142    fn ree_float32() {
6143        // run_ends [2, 4, 5] → [1.0, 1.0, null, null, 2.5]
6144        let ree: ArrayRef = Arc::new(
6145            RunArray::try_new(
6146                &Int32Array::from(vec![2, 4, 5]),
6147                &Float32Array::from(vec![Some(1.0_f32), None, Some(2.5_f32)]),
6148            )
6149            .unwrap(),
6150        );
6151        let flat: ArrayRef = Arc::new(Float32Array::from(vec![
6152            Some(1.0_f32),
6153            Some(1.0_f32),
6154            None,
6155            None,
6156            Some(2.5_f32),
6157        ]));
6158        ree_write_read_roundtrip(ree, flat);
6159    }
6160
6161    #[test]
6162    fn ree_sliced() {
6163        // A sliced (non-zero offset) REE array: verify that get_physical_index
6164        // correctly accounts for the logical offset when expanding.
6165        // Full array: run_ends [3, 5, 7] → [a,a,a, b,b, c,c]
6166        // After slice(2, 5) the logical view is [a, b, b, c, c].
6167        let full: ArrayRef = Arc::new(
6168            RunArray::try_new(
6169                &Int32Array::from(vec![3, 5, 7]),
6170                &StringArray::from(vec!["a", "b", "c"]),
6171            )
6172            .unwrap(),
6173        );
6174        let sliced = full.slice(2, 5);
6175        let flat: ArrayRef = Arc::new(StringArray::from(vec!["a", "b", "b", "c", "c"]));
6176        ree_write_read_roundtrip(sliced, flat);
6177    }
6178
6179    #[test]
6180    fn test_number_distinct_values_exact_count() {
6181        // 50 distinct Int32 values repeated across 100k rows, with every 7th row null.
6182        // Nulls must not be counted as a distinct value.
6183        let cardinality = 50u32;
6184        let array: ArrayRef = Arc::new(Int32Array::from_iter((0..100_000u32).map(|i| {
6185            if i % 7 == 0 {
6186                None
6187            } else {
6188                Some((i % cardinality) as i32)
6189            }
6190        })));
6191        let schema = Arc::new(Schema::new(vec![Field::new("x", DataType::Int32, true)]));
6192        let batch = RecordBatch::try_new(schema, vec![array]).unwrap();
6193
6194        let props = WriterProperties::builder()
6195            .set_write_row_group_number_distinct_values(true)
6196            .build();
6197        let mut buf = Vec::new();
6198        let mut writer = ArrowWriter::try_new(&mut buf, batch.schema(), Some(props)).unwrap();
6199        writer.write(&batch).unwrap();
6200        let metadata = writer.close().unwrap();
6201
6202        let count = metadata
6203            .row_group(0)
6204            .column(0)
6205            .statistics()
6206            .and_then(|s| s.distinct_count_opt())
6207            .expect("distinct_count should be set");
6208        // Must equal cardinality exactly; nulls must not inflate the count.
6209        assert_eq!(count, cardinality as u64);
6210    }
6211
6212    #[test]
6213    fn test_number_distinct_values_not_written_by_default() {
6214        let array: ArrayRef = Arc::new(Int32Array::from_iter_values(0..100));
6215        let schema = Arc::new(Schema::new(vec![Field::new("x", DataType::Int32, false)]));
6216        let batch = RecordBatch::try_new(schema, vec![array]).unwrap();
6217
6218        let mut buf = Vec::new();
6219        let mut writer = ArrowWriter::try_new(&mut buf, batch.schema(), None).unwrap();
6220        writer.write(&batch).unwrap();
6221        let metadata = writer.close().unwrap();
6222
6223        let count = metadata
6224            .row_group(0)
6225            .column(0)
6226            .statistics()
6227            .and_then(|s| s.distinct_count_opt());
6228        assert!(count.is_none());
6229    }
6230
6231    #[test]
6232    fn ree_struct_with_ree_child() {
6233        // Struct with a REE string field and a REE int field — confirms
6234        // recursion visits every child and each collapses to the right leaf type.
6235        let run_ends = Int32Array::from(vec![2i32, 3, 5]);
6236
6237        let col_a: ArrayRef = Arc::new(
6238            RunArray::try_new(
6239                &run_ends,
6240                &StringArray::from(vec![Some("foo"), None, Some("bar")]),
6241            )
6242            .unwrap(),
6243        );
6244        let col_b: ArrayRef = Arc::new(
6245            RunArray::try_new(&run_ends, &Int32Array::from(vec![Some(1), None, Some(2)])).unwrap(),
6246        );
6247
6248        let struct_array: ArrayRef = Arc::new(StructArray::new(
6249            Fields::from(vec![
6250                Field::new("a", col_a.data_type().clone(), true),
6251                Field::new("b", col_b.data_type().clone(), true),
6252            ]),
6253            vec![col_a, col_b],
6254            None,
6255        ));
6256
6257        let schema = Arc::new(Schema::new(vec![Field::new(
6258            "row",
6259            struct_array.data_type().clone(),
6260            true,
6261        )]));
6262        let batch = RecordBatch::try_new(schema.clone(), vec![struct_array]).unwrap();
6263
6264        let mut buf = Vec::new();
6265        let mut writer = ArrowWriter::try_new(&mut buf, schema, None).unwrap();
6266        writer.write(&batch).unwrap();
6267        let metadata = writer.close().unwrap();
6268
6269        let parquet_schema = metadata.file_metadata().schema_descr();
6270        assert_eq!(parquet_schema.num_columns(), 2);
6271        assert_eq!(
6272            parquet_schema.column(0).physical_type(),
6273            crate::basic::Type::BYTE_ARRAY
6274        );
6275        assert_eq!(parquet_schema.column(0).path().string(), "row.a");
6276        assert_eq!(
6277            parquet_schema.column(1).physical_type(),
6278            crate::basic::Type::INT32
6279        );
6280        assert_eq!(parquet_schema.column(1).path().string(), "row.b");
6281    }
6282}