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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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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,
12// software distributed under the License is distributed on an
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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        // Rows not yet handed to a row group writer. Splitting iterates here instead of
366        // recursing, so a small row group limit over a large batch cannot exhaust the stack.
367        let mut remaining = batch.clone();
368
369        loop {
370            let in_progress = match &mut self.in_progress {
371                Some(in_progress) => in_progress,
372                x => x.insert(
373                    self.row_group_writer_factory
374                        .create_row_group_writer(self.writer.flushed_row_groups().len())?,
375                ),
376            };
377            let buffered_rows = in_progress.buffered_rows;
378
379            // Leading rows of `remaining` that still fit in the current row group, when the
380            // rest has to go to a later one.
381            let mut split_at = match self.max_row_group_row_count {
382                Some(max_rows) if buffered_rows + remaining.num_rows() > max_rows => {
383                    Some(max_rows - buffered_rows)
384                }
385                _ => None,
386            };
387
388            // Check byte limit: if we have buffered data, use measured average row size
389            // to split batch proactively before exceeding byte limit. Both limits apply to
390            // the same rows, so measure against whatever the row limit already trimmed
391            // `remaining` down to; otherwise the row limit would always win.
392            let candidate_rows = split_at.unwrap_or_else(|| remaining.num_rows());
393
394            if let Some(max_bytes) = self.max_row_group_bytes
395                && buffered_rows > 0
396            {
397                let current_bytes = in_progress.get_estimated_total_bytes();
398
399                if current_bytes >= max_bytes {
400                    self.flush()?;
401                    continue;
402                }
403
404                if let Some(avg_row_bytes) = current_bytes
405                    .checked_div(buffered_rows)
406                    .filter(|avg_row_bytes| *avg_row_bytes > 0)
407                {
408                    // At this point, `current_bytes < max_bytes` (checked above)
409                    let remaining_bytes = max_bytes - current_bytes;
410                    let rows_that_fit = remaining_bytes.checked_div(avg_row_bytes).unwrap_or(0);
411
412                    if candidate_rows > rows_that_fit {
413                        if rows_that_fit > 0 {
414                            split_at = Some(rows_that_fit);
415                        } else {
416                            self.flush()?;
417                            continue;
418                        }
419                    }
420                }
421            }
422
423            let rest = split_at.map(|to_write| {
424                let rest = remaining.slice(to_write, remaining.num_rows() - to_write);
425                remaining = remaining.slice(0, to_write);
426                rest
427            });
428
429            let in_progress = self.in_progress.as_mut().unwrap();
430            match self.cdc_chunkers.as_mut() {
431                Some(chunkers) => in_progress.write_with_chunkers(&remaining, chunkers)?,
432                None => in_progress.write(&remaining)?,
433            }
434
435            let should_flush = self
436                .max_row_group_row_count
437                .is_some_and(|max| in_progress.buffered_rows >= max)
438                || self
439                    .max_row_group_bytes
440                    .is_some_and(|max| in_progress.get_estimated_total_bytes() >= max);
441
442            if should_flush {
443                self.flush()?
444            }
445
446            match rest {
447                Some(rest) => remaining = rest,
448                None => return Ok(()),
449            }
450        }
451    }
452
453    /// Writes the given buf bytes to the internal buffer.
454    ///
455    /// It's safe to use this method to write data to the underlying writer,
456    /// because it will ensure that the buffering and byte‐counting layers are used.
457    pub fn write_all(&mut self, buf: &[u8]) -> std::io::Result<()> {
458        self.writer.write_all(buf)
459    }
460
461    /// Flushes underlying writer
462    pub fn sync(&mut self) -> std::io::Result<()> {
463        self.writer.flush()
464    }
465
466    /// Flushes all buffered rows into a new row group
467    ///
468    /// Note the underlying writer is not flushed with this call.
469    /// If this is a desired behavior, please call [`ArrowWriter::sync`].
470    pub fn flush(&mut self) -> Result<()> {
471        let Some(in_progress) = self.in_progress.take() else {
472            return Ok(());
473        };
474
475        let mut row_group_writer = self.writer.next_row_group()?;
476        for chunk in in_progress.close()? {
477            chunk.append_to_row_group(&mut row_group_writer)?;
478        }
479        row_group_writer.close()?;
480        Ok(())
481    }
482
483    /// Additional [`KeyValue`] metadata to be written in addition to those from [`WriterProperties`]
484    ///
485    /// This method provide a way to append kv_metadata after write RecordBatch
486    pub fn append_key_value_metadata(&mut self, kv_metadata: KeyValue) {
487        self.writer.append_key_value_metadata(kv_metadata)
488    }
489
490    /// Returns a reference to the underlying writer.
491    pub fn inner(&self) -> &W {
492        self.writer.inner()
493    }
494
495    /// Returns a mutable reference to the underlying writer.
496    ///
497    /// **Warning**: if you write directly to this writer, you will skip
498    /// the `TrackedWrite` buffering and byte‐counting layers. That’ll cause
499    /// the file footer’s recorded offsets and sizes to diverge from reality,
500    /// resulting in an unreadable or corrupted Parquet file.
501    ///
502    /// If you want to write safely to the underlying writer, use [`Self::write_all`].
503    pub fn inner_mut(&mut self) -> &mut W {
504        self.writer.inner_mut()
505    }
506
507    /// Flushes any outstanding data and returns the underlying writer.
508    pub fn into_inner(mut self) -> Result<W> {
509        self.flush()?;
510        self.writer.into_inner()
511    }
512
513    /// Close and finalize the underlying Parquet writer
514    ///
515    /// Unlike [`Self::close`] this does not consume self
516    ///
517    /// Attempting to write after calling finish will result in an error
518    pub fn finish(&mut self) -> Result<ParquetMetaData> {
519        self.flush()?;
520        self.writer.finish()
521    }
522
523    /// Close and finalize the underlying Parquet writer
524    pub fn close(mut self) -> Result<ParquetMetaData> {
525        self.finish()
526    }
527
528    /// Converts this writer into a lower-level [`SerializedFileWriter`] and [`ArrowRowGroupWriterFactory`].
529    ///
530    /// Flushes any outstanding data before returning.
531    ///
532    /// This can be useful to provide more control over how files are written, for example
533    /// to write columns in parallel. See the example on [`ArrowColumnWriter`].
534    pub fn into_serialized_writer(
535        mut self,
536    ) -> Result<(SerializedFileWriter<W>, ArrowRowGroupWriterFactory)> {
537        self.flush()?;
538        Ok((self.writer, self.row_group_writer_factory))
539    }
540}
541
542impl<W: Write + Send> RecordBatchWriter for ArrowWriter<W> {
543    fn write(&mut self, batch: &RecordBatch) -> Result<(), ArrowError> {
544        self.write(batch).map_err(|e| e.into())
545    }
546
547    fn close(self) -> std::result::Result<(), ArrowError> {
548        self.close()?;
549        Ok(())
550    }
551}
552
553/// Arrow-specific configuration settings for writing parquet files.
554///
555/// See [`ArrowWriter`] for how to configure the writer.
556#[derive(Debug, Clone, Default)]
557pub struct ArrowWriterOptions {
558    properties: WriterProperties,
559    skip_arrow_metadata: bool,
560    schema_root: Option<String>,
561    schema_descr: Option<SchemaDescriptor>,
562    page_store_factory: Option<Arc<dyn PageStoreFactory>>,
563}
564
565impl ArrowWriterOptions {
566    /// Creates a new [`ArrowWriterOptions`] with the default settings.
567    pub fn new() -> Self {
568        Self::default()
569    }
570
571    /// Sets the [`WriterProperties`] for writing parquet files.
572    pub fn with_properties(self, properties: WriterProperties) -> Self {
573        Self { properties, ..self }
574    }
575
576    /// Sets the [`PageStoreFactory`] used to buffer completed pages while a row
577    /// group is being written.
578    ///
579    /// The default implementation ([`InMemoryPageStore`]) buffers all completed
580    /// pages on the heap until the row group is flushed, so peak write memory
581    /// grows with the row group size. Using this API, pages can be spilled to a
582    /// file or object storage instead, reducing peak write memory substantially
583    /// at the expense of an extra write to and read from secondary storage.
584    ///
585    /// # Example: spilling pages to a temp file
586    ///
587    /// A simple spilling backend uses one temp file per column chunk; `put`
588    /// appends the page and `take` reads it back.
589    ///
590    /// ```
591    /// # use std::fs::File;
592    /// # use std::io::{Read, Seek, SeekFrom, Write};
593    /// # use std::sync::Arc;
594    /// # use bytes::Bytes;
595    /// # use arrow_array::{ArrayRef, Int64Array, RecordBatch};
596    /// # use parquet::arrow::arrow_writer::{
597    /// #     ArrowWriter, ArrowWriterOptions, PageKey, PageStore, PageStoreArgs, PageStoreFactory,
598    /// # };
599    /// # use parquet::arrow::arrow_reader::ParquetRecordBatchReader;
600    /// # use parquet::errors::Result;
601    /// struct TempFilePageStore {
602    ///     file: File,
603    ///     /// Total size of the file
604    ///     end: u64,
605    ///     /// Location of pages: (offset, len)
606    ///     locs: Vec<(u64, usize)>,
607    /// }
608    ///
609    /// impl PageStore for TempFilePageStore {
610    ///     fn put(&mut self, value: Bytes) -> Result<PageKey> {
611    ///         // Append to the end of the file
612    ///         self.file.seek(SeekFrom::Start(self.end))?;
613    ///         self.file.write_all(&value)?;
614    ///         let key = PageKey::new(self.locs.len() as u64);
615    ///         self.locs.push((self.end, value.len()));
616    ///         self.end += value.len() as u64;
617    ///         Ok(key)
618    ///     }
619    ///
620    ///     fn take(&mut self, key: PageKey) -> Result<Bytes> {
621    ///         let (offset, len) = self.locs[key.get() as usize];
622    ///         let mut buf = vec![0u8; len];
623    ///         self.file.seek(SeekFrom::Start(offset))?;
624    ///         self.file.read_exact(&mut buf)?;
625    ///         Ok(Bytes::from(buf))
626    ///     }
627    /// }
628    ///
629    /// /// Factory for creating [`TempFilePageStore`]
630    /// #[derive(Debug)]
631    /// struct TempFilePageStoreFactory;
632    ///
633    /// impl PageStoreFactory for TempFilePageStoreFactory {
634    ///     fn create(&self, args: &PageStoreArgs<'_>) -> Result<Box<dyn PageStore>> {
635    ///         // `args` exposes the column index and descriptor (physical/logical
636    ///         // type, path), so a real backend might choose to spill only large columns.
637    ///         let _ = (args.column_index(), args.column_descriptor());
638    ///         Ok(Box::new(TempFilePageStore {
639    ///             file: tempfile::tempfile()?, // temp file is cleaned on drop
640    ///             end: 0,
641    ///             locs: Vec::new(),
642    ///         }))
643    ///     }
644    /// }
645    /// // write 1000 integers
646    /// let col = Arc::new(Int64Array::from_iter_values(0..1000)) as ArrayRef;
647    /// let to_write = RecordBatch::try_from_iter([("col", col)]).unwrap();
648    ///
649    /// let options =
650    ///     ArrowWriterOptions::new().with_page_store_factory(Arc::new(TempFilePageStoreFactory));
651    /// let mut buffer = Vec::new();
652    /// let mut writer =
653    ///     ArrowWriter::try_new_with_options(&mut buffer, to_write.schema(), options).unwrap();
654    /// writer.write(&to_write).unwrap();
655    /// writer.close().unwrap();
656    ///
657    /// // buffer now holds valid Parquet data, which can be read as normal:
658    /// let mut reader = ParquetRecordBatchReader::try_new(Bytes::from(buffer), 1024).unwrap();
659    /// assert_eq!(to_write, reader.next().unwrap().unwrap());
660    /// ```
661    pub fn with_page_store_factory(self, page_store_factory: Arc<dyn PageStoreFactory>) -> Self {
662        Self {
663            page_store_factory: Some(page_store_factory),
664            ..self
665        }
666    }
667
668    /// Skip encoding the embedded arrow metadata (defaults to `false`)
669    ///
670    /// Parquet files generated by the [`ArrowWriter`] contain embedded arrow schema
671    /// by default.
672    ///
673    /// Set `skip_arrow_metadata` to true, to skip encoding the embedded metadata.
674    pub fn with_skip_arrow_metadata(self, skip_arrow_metadata: bool) -> Self {
675        Self {
676            skip_arrow_metadata,
677            ..self
678        }
679    }
680
681    /// Set the name of the root parquet schema element (defaults to `"arrow_schema"`)
682    pub fn with_schema_root(self, schema_root: String) -> Self {
683        Self {
684            schema_root: Some(schema_root),
685            ..self
686        }
687    }
688
689    /// Explicitly specify the Parquet schema to be used
690    ///
691    /// If omitted (the default), the [`ArrowSchemaConverter`] is used to compute the
692    /// Parquet [`SchemaDescriptor`]. This may be used When the [`SchemaDescriptor`] is
693    /// already known or must be calculated using custom logic.
694    pub fn with_parquet_schema(self, schema_descr: SchemaDescriptor) -> Self {
695        Self {
696            schema_descr: Some(schema_descr),
697            ..self
698        }
699    }
700}
701
702/// A single column chunk produced by [`ArrowColumnWriter`].
703///
704/// Holds the serialized page blobs (each page's header ‖ compressed data, in
705/// write order) in a [`PageStore`], plus the handles needed to read them back,
706/// in order, when the chunk is spliced into the output file.
707struct ArrowColumnChunkData {
708    length: usize,
709    store: Box<dyn PageStore>,
710    keys: Vec<PageKey>,
711    /// Handles to the dictionary page's blobs (header then data) in the store.
712    ///
713    /// A dictionary page is produced at most once and bounded by
714    /// `dict_page_size_limit`, but it must be written *first* in the chunk even
715    /// though the data pages reach the writer before it (see
716    /// [`PageWriter::defers_dictionary_ordering`]). Its header and data are `put`
717    /// into the store like any other page — which keeps the store uniform, and
718    /// lets an oversized dictionary page spill — and their handles are held apart
719    /// so they can be emitted ahead of the data pages at splice.
720    /// Empty for non-dictionary columns.
721    dictionary_keys: Vec<PageKey>,
722    /// Serialized length of the dictionary page (0 if there is none), recorded
723    /// so the data pages can be shifted past it when offsets are rewritten to a
724    /// dictionary-first layout at splice.
725    dictionary_len: usize,
726}
727
728impl ArrowColumnChunkData {
729    fn new(store: Box<dyn PageStore>) -> Self {
730        Self {
731            length: 0,
732            store,
733            keys: Vec::new(),
734            dictionary_keys: Vec::new(),
735            dictionary_len: 0,
736        }
737    }
738
739    /// Append a data-page blob to the store, recording its handle in write
740    /// order.
741    fn push(&mut self, value: Bytes) -> Result<()> {
742        let key = self.store.put(value)?;
743        self.keys.push(key);
744        Ok(())
745    }
746
747    /// Store a dictionary-page blob (header or data) in the page store,
748    /// recording its handle (emitted first at splice) and accumulating its
749    /// serialized length.
750    fn push_dictionary(&mut self, value: Bytes) -> Result<()> {
751        self.dictionary_len += value.len();
752        let key = self.store.put(value)?;
753        self.dictionary_keys.push(key);
754        Ok(())
755    }
756
757    /// Bytes this chunk currently holds on the heap: whatever the store keeps
758    /// resident (zero for a spilling backend).
759    fn memory_size(&self) -> usize {
760        self.store.memory_size()
761    }
762}
763
764/// A streaming iterator over one column chunk's buffered page blobs, in final
765/// file order: the dictionary page (if any) first, then the data pages.
766///
767/// Each blob is taken back out of the [`PageStore`] *as it is
768/// consumed* and released immediately afterwards, so splicing a chunk into the
769/// output file never materializes more than a single page in memory at a time.
770/// This is what keeps the splice phase within the memory bound for a spilling
771/// backend (an in-memory store already holds the bytes, so it is unaffected).
772struct StreamingColumnChunkPages {
773    store: Box<dyn PageStore>,
774    /// Page handles in final file order: the dictionary page first (if any),
775    /// then the data pages.
776    keys: IntoIter<PageKey>,
777}
778
779impl StreamingColumnChunkPages {
780    fn new(data: ArrowColumnChunkData) -> Self {
781        // The dictionary page must be emitted first, ahead of the data pages,
782        // even though it was the last page produced.
783        let keys = if data.dictionary_keys.is_empty() {
784            data.keys
785        } else {
786            let mut keys = Vec::with_capacity(data.dictionary_keys.len() + data.keys.len());
787            keys.extend(data.dictionary_keys);
788            keys.extend(data.keys);
789            keys
790        };
791        Self {
792            store: data.store,
793            keys: keys.into_iter(),
794        }
795    }
796}
797
798impl Iterator for StreamingColumnChunkPages {
799    type Item = Result<Bytes>;
800
801    fn next(&mut self) -> Option<Self::Item> {
802        let key = self.keys.next()?;
803        Some(self.store.take(key))
804    }
805}
806
807/// A shared [`ArrowColumnChunkData`]
808///
809/// This allows it to be owned by [`ArrowPageWriter`] whilst allowing access via
810/// [`ArrowRowGroupWriter`] on flush, without requiring self-referential borrows
811type SharedColumnChunk = Arc<Mutex<ArrowColumnChunkData>>;
812
813struct ArrowPageWriter {
814    buffer: SharedColumnChunk,
815    #[cfg(feature = "encryption")]
816    page_encryptor: Option<PageEncryptor>,
817}
818
819impl ArrowPageWriter {
820    /// Create a page writer that buffers completed pages in `store`.
821    fn new(store: Box<dyn PageStore>) -> Self {
822        Self {
823            buffer: Arc::new(Mutex::new(ArrowColumnChunkData::new(store))),
824            #[cfg(feature = "encryption")]
825            page_encryptor: None,
826        }
827    }
828
829    #[cfg(feature = "encryption")]
830    pub fn with_encryptor(mut self, page_encryptor: Option<PageEncryptor>) -> Self {
831        self.page_encryptor = page_encryptor;
832        self
833    }
834
835    #[cfg(feature = "encryption")]
836    fn page_encryptor_mut(&mut self) -> Option<&mut PageEncryptor> {
837        self.page_encryptor.as_mut()
838    }
839
840    // Mirrors the signature of the encryption-enabled version above, so that the
841    // callers do not need a `cfg` of their own.
842    #[cfg(not(feature = "encryption"))]
843    #[expect(
844        clippy::needless_pass_by_ref_mut,
845        reason = "mirrors the encryption-enabled signature"
846    )]
847    fn page_encryptor_mut(&mut self) -> Option<&mut PageEncryptor> {
848        None
849    }
850}
851
852impl PageWriter for ArrowPageWriter {
853    fn write_page(&mut self, page: CompressedPage) -> Result<PageWriteSpec> {
854        let page = match self.page_encryptor_mut() {
855            Some(page_encryptor) => page_encryptor.encrypt_compressed_page(page)?,
856            None => page,
857        };
858
859        let page_header = page.to_thrift_header()?;
860        let header = {
861            let mut header = Vec::with_capacity(1024);
862
863            match self.page_encryptor_mut() {
864                Some(page_encryptor) => {
865                    page_encryptor.encrypt_page_header(&page_header, &mut header)?;
866                    if page.compressed_page().is_data_page() {
867                        page_encryptor.increment_page();
868                    }
869                }
870                None => {
871                    let mut protocol = ThriftCompactOutputProtocol::new(&mut header);
872                    page_header.write_thrift(&mut protocol)?;
873                }
874            }
875
876            Bytes::from(header)
877        };
878
879        let mut buf = self.buffer.try_lock().unwrap();
880
881        let data = page.compressed_page().buffer().clone();
882        let compressed_size = data.len() + header.len();
883
884        let mut spec = PageWriteSpec::new();
885        spec.page_type = page.page_type();
886        spec.num_values = page.num_values();
887        spec.uncompressed_size = page.uncompressed_size() + header.len();
888        spec.offset = buf.length as u64;
889        spec.compressed_size = compressed_size;
890        spec.bytes_written = compressed_size as u64;
891
892        buf.length += compressed_size;
893        if spec.page_type == PageType::DICTIONARY_PAGE {
894            // Recorded apart from the data pages so it is emitted first at
895            // splice — see `ArrowColumnChunkData::dictionary_keys`.
896            buf.push_dictionary(header)?;
897            buf.push_dictionary(data)?;
898        } else {
899            buf.push(header)?;
900            buf.push(data)?;
901        }
902
903        Ok(spec)
904    }
905
906    fn defers_dictionary_ordering(&self) -> bool {
907        // The Arrow chunk is buffered in full and spliced at row-group flush, so
908        // data pages may be accepted before the dictionary page and reordered
909        // then. This lets `GenericColumnWriter` stream dictionary-column data
910        // pages straight through instead of buffering them in memory.
911        true
912    }
913
914    fn buffered_memory_size(&self) -> usize {
915        // Only what is actually resident: a spilling store reports ~0 here even
916        // though the chunk's bytes have all passed through it.
917        self.buffer.try_lock().unwrap().memory_size()
918    }
919
920    fn close(&mut self) -> Result<()> {
921        Ok(())
922    }
923}
924
925/// A leaf column that can be encoded by [`ArrowColumnWriter`]
926#[derive(Debug)]
927pub struct ArrowLeafColumn(ArrayLevels);
928
929/// Computes the [`ArrowLeafColumn`] for a potentially nested [`ArrayRef`]
930///
931/// This function can be used to encode individual columns in parallel.
932/// See example on [`ArrowColumnWriter`]
933pub fn compute_leaves(field: &Field, array: &ArrayRef) -> Result<Vec<ArrowLeafColumn>> {
934    let levels = calculate_array_levels(array, field)?;
935    Ok(levels.into_iter().map(ArrowLeafColumn).collect())
936}
937
938/// The data for a single column chunk, see [`ArrowColumnWriter`]
939pub struct ArrowColumnChunk {
940    data: ArrowColumnChunkData,
941    close: ColumnCloseResult,
942}
943
944impl std::fmt::Debug for ArrowColumnChunk {
945    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
946        f.debug_struct("ArrowColumnChunk")
947            .field("length", &self.data.length)
948            .finish_non_exhaustive()
949    }
950}
951
952impl ArrowColumnChunk {
953    /// Returns the [`ColumnCloseResult`] produced when the chunk was closed.
954    ///
955    /// Exposes encoding information, collected statistics, and the optional
956    /// [`ColumnIndexMetaData`](crate::file::page_index::column_index::ColumnIndexMetaData)
957    /// / [`OffsetIndexMetaData`](crate::file::page_index::offset_index::OffsetIndexMetaData)
958    /// gathered for the column chunk.
959    pub fn close(&self) -> &ColumnCloseResult {
960        &self.close
961    }
962
963    /// Returns a mutable reference to the [`ColumnCloseResult`].
964    ///
965    /// This allows callers to mutate the close result before the chunk is
966    /// appended to a row group — for example, clearing `column_index` or
967    /// `bloom_filter` based on a dynamic rule that inspects the encodings and
968    /// collected page statistics.
969    pub fn close_mut(&mut self) -> &mut ColumnCloseResult {
970        &mut self.close
971    }
972
973    /// Splices this column's buffered pages into the row group, streaming them
974    /// back out of the [`PageStore`] one page at a time.
975    pub fn append_to_row_group<W: Write + Send>(
976        self,
977        writer: &mut SerializedRowGroupWriter<'_, W>,
978    ) -> Result<()> {
979        let ArrowColumnChunk { data, close } = self;
980
981        // The dictionary page is produced *after* the data pages on this path (so
982        // they can stream straight through) but must be written *first*, so move
983        // it ahead of the data pages in the recorded offsets before the splice.
984        let close = close.update_dictionary_location(data.dictionary_len)?;
985
986        let pages = StreamingColumnChunkPages::new(data);
987        writer.append_column_from_pages(pages, close)
988    }
989}
990
991/// Encodes [`ArrowLeafColumn`] to [`ArrowColumnChunk`]
992///
993/// `ArrowColumnWriter` instances can be created using an [`ArrowRowGroupWriterFactory`];
994///
995/// Note: This is a low-level interface for applications that require
996/// fine-grained control of encoding (e.g. encoding using multiple threads),
997/// see [`ArrowWriter`] for a higher-level interface
998///
999/// # Example: Encoding two Arrow Array's in Parallel
1000/// ```
1001/// // The arrow schema
1002/// # use std::sync::Arc;
1003/// # use arrow_array::*;
1004/// # use arrow_schema::*;
1005/// # use parquet::arrow::ArrowSchemaConverter;
1006/// # use parquet::arrow::arrow_writer::{compute_leaves, ArrowColumnChunk, ArrowLeafColumn, ArrowRowGroupWriterFactory};
1007/// # use parquet::file::properties::WriterProperties;
1008/// # use parquet::file::writer::{SerializedFileWriter, SerializedRowGroupWriter};
1009/// #
1010/// let schema = Arc::new(Schema::new(vec![
1011///     Field::new("i32", DataType::Int32, false),
1012///     Field::new("f32", DataType::Float32, false),
1013/// ]));
1014///
1015/// // Compute the parquet schema
1016/// let props = Arc::new(WriterProperties::default());
1017/// let parquet_schema = ArrowSchemaConverter::new()
1018///   .with_coerce_types(props.coerce_types())
1019///   .convert(&schema)
1020///   .unwrap();
1021///
1022/// // Create parquet writer
1023/// let root_schema = parquet_schema.root_schema_ptr();
1024/// // write to memory in the example, but this could be a File
1025/// let mut out = Vec::with_capacity(1024);
1026/// let mut writer = SerializedFileWriter::new(&mut out, root_schema, props.clone())
1027///   .unwrap();
1028///
1029/// // Create a factory for building Arrow column writers
1030/// let row_group_factory = ArrowRowGroupWriterFactory::new(&writer, Arc::clone(&schema));
1031/// // Create column writers for the 0th row group
1032/// let col_writers = row_group_factory.create_column_writers(0).unwrap();
1033///
1034/// // Spawn a worker thread for each column
1035/// //
1036/// // Note: This is for demonstration purposes, a thread-pool e.g. rayon or tokio, would be better.
1037/// // The `map` produces an iterator of type `tuple of (thread handle, send channel)`.
1038/// let mut workers: Vec<_> = col_writers
1039///     .into_iter()
1040///     .map(|mut col_writer| {
1041///         let (send, recv) = std::sync::mpsc::channel::<ArrowLeafColumn>();
1042///         let handle = std::thread::spawn(move || {
1043///             // receive Arrays to encode via the channel
1044///             for col in recv {
1045///                 col_writer.write(&col)?;
1046///             }
1047///             // once the input is complete, close the writer
1048///             // to return the newly created ArrowColumnChunk
1049///             col_writer.close()
1050///         });
1051///         (handle, send)
1052///     })
1053///     .collect();
1054///
1055/// // Start row group
1056/// let mut row_group_writer: SerializedRowGroupWriter<'_, _> = writer
1057///   .next_row_group()
1058///   .unwrap();
1059///
1060/// // Create some example input columns to encode
1061/// let to_write = vec![
1062///     Arc::new(Int32Array::from_iter_values([1, 2, 3])) as _,
1063///     Arc::new(Float32Array::from_iter_values([1., 45., -1.])) as _,
1064/// ];
1065///
1066/// // Send the input columns to the workers
1067/// let mut worker_iter = workers.iter_mut();
1068/// for (arr, field) in to_write.iter().zip(&schema.fields) {
1069///     for leaves in compute_leaves(field, arr).unwrap() {
1070///         worker_iter.next().unwrap().1.send(leaves).unwrap();
1071///     }
1072/// }
1073///
1074/// // Wait for the workers to complete encoding, and append
1075/// // the resulting column chunks to the row group (and the file)
1076/// for (handle, send) in workers {
1077///     drop(send); // Drop send side to signal termination
1078///     // wait for the worker to send the completed chunk
1079///     let chunk: ArrowColumnChunk = handle.join().unwrap().unwrap();
1080///     chunk.append_to_row_group(&mut row_group_writer).unwrap();
1081/// }
1082/// // Close the row group which writes to the underlying file
1083/// row_group_writer.close().unwrap();
1084///
1085/// let metadata = writer.close().unwrap();
1086/// assert_eq!(metadata.file_metadata().num_rows(), 3);
1087/// ```
1088pub struct ArrowColumnWriter {
1089    writer: ArrowColumnWriterImpl,
1090    chunk: SharedColumnChunk,
1091    /// Non-null value hashes accumulated across all writes for this column's row group.
1092    /// `None` when tracking is disabled via [`WriterProperties::write_row_group_number_distinct_values`].
1093    distinct_values_seen: Option<DistinctValuesSet>,
1094}
1095
1096impl std::fmt::Debug for ArrowColumnWriter {
1097    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
1098        f.debug_struct("ArrowColumnWriter").finish_non_exhaustive()
1099    }
1100}
1101
1102enum ArrowColumnWriterImpl {
1103    ByteArray(GenericColumnWriter<'static, ByteArrayEncoder>),
1104    Column(ColumnWriter<'static>),
1105}
1106
1107impl ArrowColumnWriter {
1108    /// Write an [`ArrowLeafColumn`]
1109    pub fn write(&mut self, col: &ArrowLeafColumn) -> Result<()> {
1110        self.write_internal(&col.0)
1111    }
1112
1113    /// Write with content-defined chunking, inserting page flushes at chunk boundaries.
1114    fn write_with_chunker(
1115        &mut self,
1116        col: &ArrowLeafColumn,
1117        chunker: &mut ContentDefinedChunker,
1118    ) -> Result<()> {
1119        let levels = &col.0;
1120        let chunks = chunker.get_arrow_chunks(
1121            levels.def_level_data().as_ref(),
1122            levels.rep_level_data().as_ref(),
1123            levels.array(),
1124        )?;
1125
1126        let num_chunks = chunks.len();
1127        for (i, chunk) in chunks.iter().enumerate() {
1128            let chunk_levels = levels.slice_for_chunk(chunk);
1129            self.write_internal(&chunk_levels)?;
1130
1131            // Add a page break after each chunk except the last
1132            if i + 1 < num_chunks {
1133                match &mut self.writer {
1134                    ArrowColumnWriterImpl::Column(c) => c.add_data_page()?,
1135                    ArrowColumnWriterImpl::ByteArray(c) => c.add_data_page()?,
1136                }
1137            }
1138        }
1139        Ok(())
1140    }
1141
1142    fn write_internal(&mut self, levels: &ArrayLevels) -> Result<()> {
1143        if let Some(seen) = &mut self.distinct_values_seen {
1144            let array = levels.array();
1145            let non_null = levels.non_null_indices();
1146            match array.as_any_dictionary_opt() {
1147                Some(dict) => {
1148                    // Hash referenced values, not key indices: keys can map to different
1149                    // values across batches, and unreferenced values must not count toward NDV.
1150                    let values = dict.values();
1151                    let keys = dict.normalized_keys();
1152                    let referenced_value_indices: Vec<usize> = non_null
1153                        .iter()
1154                        .map(|&pos| keys[pos])
1155                        .filter(|&val_idx| values.is_valid(val_idx))
1156                        .collect();
1157                    update_distinct_values_seen(values.as_ref(), &referenced_value_indices, seen);
1158                }
1159                // For plain arrays, hash the actual values directly.
1160                None => update_distinct_values_seen(array.as_ref(), non_null, seen),
1161            }
1162        }
1163
1164        match &mut self.writer {
1165            ArrowColumnWriterImpl::Column(c) => {
1166                let leaf = levels.array();
1167                match leaf.as_any_dictionary_opt() {
1168                    Some(dictionary) => {
1169                        let materialized =
1170                            arrow_select::take::take(dictionary.values(), dictionary.keys(), None)?;
1171                        write_leaf(c, &materialized, levels)?
1172                    }
1173                    None => write_leaf(c, leaf, levels)?,
1174                };
1175            }
1176            ArrowColumnWriterImpl::ByteArray(c) => {
1177                write_primitive(c, levels.array().as_ref(), levels)?;
1178            }
1179        }
1180        Ok(())
1181    }
1182
1183    /// Close this column returning the written [`ArrowColumnChunk`]
1184    ///
1185    /// # Errors
1186    ///
1187    /// Returns an error if the column could not be finalised, or if another thread
1188    /// panicked while holding the column chunk. The caller cannot cause either.
1189    pub fn close(self) -> Result<ArrowColumnChunk> {
1190        let distinct_count = self
1191            .distinct_values_seen
1192            .as_ref()
1193            .filter(|s| !s.is_empty())
1194            .map(|s| s.len() as u64);
1195        let close = match self.writer {
1196            ArrowColumnWriterImpl::ByteArray(mut c) => {
1197                if let Some(count) = distinct_count {
1198                    c.set_distinct_count_override(count);
1199                }
1200                c.close()?
1201            }
1202            ArrowColumnWriterImpl::Column(mut c) => {
1203                if let Some(count) = distinct_count {
1204                    c.set_distinct_count_override(count);
1205                }
1206                c.close()?
1207            }
1208        };
1209        // Closing the writer above dropped the only other handle on the chunk.
1210        let chunk = Arc::try_unwrap(self.chunk)
1211            .map_err(|_| general_err!("Internal Error: the column chunk is still shared"))?;
1212        let data = chunk
1213            .into_inner()
1214            .map_err(|_| general_err!("The column chunk lock is poisoned"))?;
1215        Ok(ArrowColumnChunk { data, close })
1216    }
1217
1218    /// Returns the estimated total memory usage by the writer.
1219    ///
1220    /// This  [`Self::get_estimated_total_bytes`] this is an estimate
1221    /// of the current memory usage and not it's anticipated encoded size.
1222    ///
1223    /// This includes:
1224    /// 1. Data buffered in encoded form
1225    /// 2. Data buffered in un-encoded form (e.g. `usize` dictionary keys)
1226    ///
1227    /// This value should be greater than or equal to [`Self::get_estimated_total_bytes`]
1228    pub fn memory_size(&self) -> usize {
1229        match &self.writer {
1230            ArrowColumnWriterImpl::ByteArray(c) => c.memory_size(),
1231            ArrowColumnWriterImpl::Column(c) => c.memory_size(),
1232        }
1233    }
1234
1235    /// Returns the estimated total encoded bytes for this column writer.
1236    ///
1237    /// This includes:
1238    /// 1. Data buffered in encoded form
1239    /// 2. An estimate of how large the data buffered in un-encoded form would be once encoded
1240    ///
1241    /// This value should be less than or equal to [`Self::memory_size`]
1242    pub fn get_estimated_total_bytes(&self) -> usize {
1243        match &self.writer {
1244            ArrowColumnWriterImpl::ByteArray(c) => c.get_estimated_total_bytes() as _,
1245            ArrowColumnWriterImpl::Column(c) => c.get_estimated_total_bytes() as _,
1246        }
1247    }
1248}
1249
1250/// Encodes [`RecordBatch`] to a parquet row group
1251///
1252/// Note: this structure is created by [`ArrowRowGroupWriterFactory`] internally used to
1253/// create [`ArrowRowGroupWriter`]s, but it is not exposed publicly.
1254///
1255/// See the example on [`ArrowColumnWriter`] for how to encode columns in parallel
1256#[derive(Debug)]
1257struct ArrowRowGroupWriter {
1258    writers: Vec<ArrowColumnWriter>,
1259    schema: SchemaRef,
1260    buffered_rows: usize,
1261}
1262
1263impl ArrowRowGroupWriter {
1264    fn new(writers: Vec<ArrowColumnWriter>, arrow: &SchemaRef) -> Self {
1265        Self {
1266            writers,
1267            schema: arrow.clone(),
1268            buffered_rows: 0,
1269        }
1270    }
1271
1272    fn write(&mut self, batch: &RecordBatch) -> Result<()> {
1273        self.buffered_rows += batch.num_rows();
1274        let mut writers = self.writers.iter_mut();
1275        for (field, column) in self.schema.fields().iter().zip(batch.columns()) {
1276            for leaf in compute_leaves(field.as_ref(), column)? {
1277                writers.next().unwrap().write(&leaf)?;
1278            }
1279        }
1280        Ok(())
1281    }
1282
1283    fn write_with_chunkers(
1284        &mut self,
1285        batch: &RecordBatch,
1286        chunkers: &mut [ContentDefinedChunker],
1287    ) -> Result<()> {
1288        self.buffered_rows += batch.num_rows();
1289        let mut writers = self.writers.iter_mut();
1290        let mut chunkers = chunkers.iter_mut();
1291        for (field, column) in self.schema.fields().iter().zip(batch.columns()) {
1292            for leaf in compute_leaves(field.as_ref(), column)? {
1293                writers
1294                    .next()
1295                    .unwrap()
1296                    .write_with_chunker(&leaf, chunkers.next().unwrap())?;
1297            }
1298        }
1299        Ok(())
1300    }
1301
1302    /// Returns the estimated total encoded bytes for this row group
1303    fn get_estimated_total_bytes(&self) -> usize {
1304        self.writers
1305            .iter()
1306            .map(|x| x.get_estimated_total_bytes())
1307            .sum()
1308    }
1309
1310    fn close(self) -> Result<Vec<ArrowColumnChunk>> {
1311        self.writers
1312            .into_iter()
1313            .map(|writer| writer.close())
1314            .collect()
1315    }
1316}
1317
1318/// Factory that creates new column writers for each row group in the Parquet file.
1319///
1320/// You can create this structure via an [`ArrowWriter::into_serialized_writer`].
1321/// See the example on [`ArrowColumnWriter`] for how to encode columns in parallel
1322#[derive(Debug)]
1323pub struct ArrowRowGroupWriterFactory {
1324    schema: SchemaDescPtr,
1325    arrow_schema: SchemaRef,
1326    props: WriterPropertiesPtr,
1327    page_store_factory: Arc<dyn PageStoreFactory>,
1328    #[cfg(feature = "encryption")]
1329    file_encryptor: Option<Arc<FileEncryptor>>,
1330}
1331
1332impl ArrowRowGroupWriterFactory {
1333    /// Create a new [`ArrowRowGroupWriterFactory`] for the provided file writer and Arrow schema
1334    pub fn new<W: Write + Send>(
1335        file_writer: &SerializedFileWriter<W>,
1336        arrow_schema: SchemaRef,
1337    ) -> Self {
1338        let schema = Arc::clone(file_writer.schema_descr_ptr());
1339        let props = Arc::clone(file_writer.properties());
1340        Self {
1341            schema,
1342            arrow_schema,
1343            props,
1344            page_store_factory: Arc::new(InMemoryPageStoreFactory),
1345            #[cfg(feature = "encryption")]
1346            file_encryptor: file_writer.file_encryptor(),
1347        }
1348    }
1349
1350    /// Set the [`PageStoreFactory`] used to allocate the buffer for each column
1351    /// chunk, e.g. to spill completed pages to a temp file or object storage
1352    /// instead of the heap. Defaults to [`InMemoryPageStoreFactory`].
1353    pub fn with_page_store_factory(
1354        mut self,
1355        page_store_factory: Arc<dyn PageStoreFactory>,
1356    ) -> Self {
1357        self.page_store_factory = page_store_factory;
1358        self
1359    }
1360
1361    fn create_row_group_writer(&self, row_group_index: usize) -> Result<ArrowRowGroupWriter> {
1362        let writers = self.create_column_writers(row_group_index)?;
1363        Ok(ArrowRowGroupWriter::new(writers, &self.arrow_schema))
1364    }
1365
1366    /// Create column writers for a new row group, with the given row group index
1367    pub fn create_column_writers(&self, row_group_index: usize) -> Result<Vec<ArrowColumnWriter>> {
1368        let mut writers = Vec::with_capacity(self.arrow_schema.fields.len());
1369        let mut leaves = self.schema.columns().iter();
1370        let column_factory = self.column_writer_factory(row_group_index);
1371        for field in &self.arrow_schema.fields {
1372            column_factory.get_arrow_column_writer(
1373                field.data_type(),
1374                &self.props,
1375                &mut leaves,
1376                &mut writers,
1377            )?;
1378        }
1379        Ok(writers)
1380    }
1381
1382    #[cfg(feature = "encryption")]
1383    fn column_writer_factory(&self, row_group_idx: usize) -> ArrowColumnWriterFactory {
1384        ArrowColumnWriterFactory::new()
1385            .with_page_store_factory(self.page_store_factory.clone())
1386            .with_file_encryptor(row_group_idx, self.file_encryptor.clone())
1387    }
1388
1389    #[cfg(not(feature = "encryption"))]
1390    fn column_writer_factory(&self, _row_group_idx: usize) -> ArrowColumnWriterFactory {
1391        ArrowColumnWriterFactory::new().with_page_store_factory(self.page_store_factory.clone())
1392    }
1393}
1394
1395/// Creates [`ArrowColumnWriter`] instances
1396struct ArrowColumnWriterFactory {
1397    /// Allocates the per-column-chunk [`PageStore`] backing each page writer.
1398    page_store_factory: Arc<dyn PageStoreFactory>,
1399    #[cfg(feature = "encryption")]
1400    row_group_index: usize,
1401    #[cfg(feature = "encryption")]
1402    file_encryptor: Option<Arc<FileEncryptor>>,
1403}
1404
1405impl ArrowColumnWriterFactory {
1406    pub fn new() -> Self {
1407        Self {
1408            page_store_factory: Arc::new(InMemoryPageStoreFactory),
1409            #[cfg(feature = "encryption")]
1410            row_group_index: 0,
1411            #[cfg(feature = "encryption")]
1412            file_encryptor: None,
1413        }
1414    }
1415
1416    /// Use `page_store_factory` to allocate the buffer for each column chunk.
1417    pub fn with_page_store_factory(
1418        mut self,
1419        page_store_factory: Arc<dyn PageStoreFactory>,
1420    ) -> Self {
1421        self.page_store_factory = page_store_factory;
1422        self
1423    }
1424
1425    #[cfg(feature = "encryption")]
1426    pub fn with_file_encryptor(
1427        mut self,
1428        row_group_index: usize,
1429        file_encryptor: Option<Arc<FileEncryptor>>,
1430    ) -> Self {
1431        self.row_group_index = row_group_index;
1432        self.file_encryptor = file_encryptor;
1433        self
1434    }
1435
1436    #[cfg(feature = "encryption")]
1437    fn create_page_writer(
1438        &self,
1439        column_descriptor: &ColumnDescPtr,
1440        column_index: usize,
1441    ) -> Result<Box<ArrowPageWriter>> {
1442        let column_path = column_descriptor.path().string();
1443        let page_encryptor = PageEncryptor::create_if_column_encrypted(
1444            self.file_encryptor.as_ref(),
1445            self.row_group_index,
1446            column_index,
1447            &column_path,
1448        )?;
1449        let args = PageStoreArgs::new(column_index, column_descriptor);
1450        let store = self.page_store_factory.create(&args)?;
1451        Ok(Box::new(
1452            ArrowPageWriter::new(store).with_encryptor(page_encryptor),
1453        ))
1454    }
1455
1456    #[cfg(not(feature = "encryption"))]
1457    fn create_page_writer(
1458        &self,
1459        column_descriptor: &ColumnDescPtr,
1460        column_index: usize,
1461    ) -> Result<Box<ArrowPageWriter>> {
1462        let args = PageStoreArgs::new(column_index, column_descriptor);
1463        let store = self.page_store_factory.create(&args)?;
1464        Ok(Box::new(ArrowPageWriter::new(store)))
1465    }
1466
1467    /// Gets an [`ArrowColumnWriter`] for the given `data_type`, appending the
1468    /// output ColumnDesc to `leaves` and the column writers to `out`
1469    fn get_arrow_column_writer(
1470        &self,
1471        data_type: &ArrowDataType,
1472        props: &WriterPropertiesPtr,
1473        leaves: &mut Iter<'_, ColumnDescPtr>,
1474        out: &mut Vec<ArrowColumnWriter>,
1475    ) -> Result<()> {
1476        let write_distinct_values = props.write_row_group_number_distinct_values();
1477
1478        // Instantiate writers for normal columns
1479        let col = |desc: &ColumnDescPtr| -> Result<ArrowColumnWriter> {
1480            let page_writer = self.create_page_writer(desc, out.len())?;
1481            let chunk = page_writer.buffer.clone();
1482            let writer = get_column_writer(desc.clone(), props.clone(), page_writer);
1483            Ok(ArrowColumnWriter {
1484                chunk,
1485                writer: ArrowColumnWriterImpl::Column(writer),
1486                distinct_values_seen: write_distinct_values.then(HashSet::new),
1487            })
1488        };
1489
1490        // Instantiate writers for byte arrays (e.g. Utf8,  Binary, etc)
1491        let bytes = |desc: &ColumnDescPtr| -> Result<ArrowColumnWriter> {
1492            let page_writer = self.create_page_writer(desc, out.len())?;
1493            let chunk = page_writer.buffer.clone();
1494            let writer = GenericColumnWriter::new(desc.clone(), props.clone(), page_writer);
1495            Ok(ArrowColumnWriter {
1496                chunk,
1497                writer: ArrowColumnWriterImpl::ByteArray(writer),
1498                distinct_values_seen: write_distinct_values.then(HashSet::new),
1499            })
1500        };
1501
1502        match data_type {
1503            _ if data_type.is_primitive() => out.push(col(leaves.next().unwrap())?),
1504            ArrowDataType::FixedSizeBinary(_) | ArrowDataType::Boolean | ArrowDataType::Null => {
1505                out.push(col(leaves.next().unwrap())?)
1506            }
1507            ArrowDataType::LargeBinary
1508            | ArrowDataType::Binary
1509            | ArrowDataType::Utf8
1510            | ArrowDataType::LargeUtf8
1511            | ArrowDataType::BinaryView
1512            | ArrowDataType::Utf8View => out.push(bytes(leaves.next().unwrap())?),
1513            ArrowDataType::List(f)
1514            | ArrowDataType::LargeList(f)
1515            | ArrowDataType::FixedSizeList(f, _)
1516            | ArrowDataType::ListView(f)
1517            | ArrowDataType::LargeListView(f) => {
1518                self.get_arrow_column_writer(f.data_type(), props, leaves, out)?
1519            }
1520            ArrowDataType::Struct(fields) => {
1521                for field in fields {
1522                    self.get_arrow_column_writer(field.data_type(), props, leaves, out)?
1523                }
1524            }
1525            ArrowDataType::Map(f, _) => match f.data_type() {
1526                ArrowDataType::Struct(f) => {
1527                    self.get_arrow_column_writer(f[0].data_type(), props, leaves, out)?;
1528                    self.get_arrow_column_writer(f[1].data_type(), props, leaves, out)?
1529                }
1530                _ => unreachable!("invalid map type"),
1531            },
1532            ArrowDataType::Dictionary(_, value_type) => match value_type.as_ref() {
1533                ArrowDataType::Utf8
1534                | ArrowDataType::LargeUtf8
1535                | ArrowDataType::Binary
1536                | ArrowDataType::LargeBinary => out.push(bytes(leaves.next().unwrap())?),
1537                ArrowDataType::Utf8View | ArrowDataType::BinaryView => {
1538                    out.push(bytes(leaves.next().unwrap())?)
1539                }
1540                ArrowDataType::FixedSizeBinary(_) => out.push(bytes(leaves.next().unwrap())?),
1541                _ => out.push(col(leaves.next().unwrap())?),
1542            },
1543            ArrowDataType::RunEndEncoded(_, value_field) => {
1544                self.get_arrow_column_writer(value_field.data_type(), props, leaves, out)?
1545            }
1546            _ => {
1547                return Err(ParquetError::NYI(format!(
1548                    "Attempting to write an Arrow type {data_type} to parquet that is not yet implemented"
1549                )));
1550            }
1551        }
1552        Ok(())
1553    }
1554}
1555
1556fn write_leaf(
1557    writer: &mut ColumnWriter<'_>,
1558    column: &dyn arrow_array::Array,
1559    levels: &ArrayLevels,
1560) -> Result<usize> {
1561    let indices = levels.non_null_indices();
1562
1563    match writer {
1564        // Note: this should match the contents of arrow_to_parquet_type
1565        ColumnWriter::Int32ColumnWriter(typed) => {
1566            match column.data_type() {
1567                ArrowDataType::Null => {
1568                    let array = Int32Array::new_null(column.len());
1569                    write_primitive(typed, array.values(), levels)
1570                }
1571                ArrowDataType::Int8 => {
1572                    let array: Int32Array = column.as_primitive::<Int8Type>().unary(|x| x as i32);
1573                    write_primitive(typed, array.values(), levels)
1574                }
1575                ArrowDataType::Int16 => {
1576                    let array: Int32Array = column.as_primitive::<Int16Type>().unary(|x| x as i32);
1577                    write_primitive(typed, array.values(), levels)
1578                }
1579                ArrowDataType::Int32 => {
1580                    write_primitive(typed, column.as_primitive::<Int32Type>().values(), levels)
1581                }
1582                ArrowDataType::UInt8 => {
1583                    let array: Int32Array = column.as_primitive::<UInt8Type>().unary(|x| x as i32);
1584                    write_primitive(typed, array.values(), levels)
1585                }
1586                ArrowDataType::UInt16 => {
1587                    let array: Int32Array = column.as_primitive::<UInt16Type>().unary(|x| x as i32);
1588                    write_primitive(typed, array.values(), levels)
1589                }
1590                ArrowDataType::UInt32 => {
1591                    // follow C++ implementation and use overflow/reinterpret cast from  u32 to i32 which will map
1592                    // `(i32::MAX as u32)..u32::MAX` to `i32::MIN..0`
1593                    let array = column.as_primitive::<UInt32Type>();
1594                    write_primitive(typed, array.values().inner().typed_data(), levels)
1595                }
1596                ArrowDataType::Date32 => {
1597                    let array = column.as_primitive::<Date32Type>();
1598                    write_primitive(typed, array.values(), levels)
1599                }
1600                ArrowDataType::Time32(TimeUnit::Second) => {
1601                    let array = column.as_primitive::<Time32SecondType>();
1602                    write_primitive(typed, array.values(), levels)
1603                }
1604                ArrowDataType::Time32(TimeUnit::Millisecond) => {
1605                    let array = column.as_primitive::<Time32MillisecondType>();
1606                    write_primitive(typed, array.values(), levels)
1607                }
1608                ArrowDataType::Date64 => {
1609                    // If the column is a Date64, we truncate it
1610                    let array: Int32Array = column
1611                        .as_primitive::<Date64Type>()
1612                        .unary(|x| (x / 86_400_000) as _);
1613
1614                    write_primitive(typed, array.values(), levels)
1615                }
1616                ArrowDataType::Decimal32(_, _) => {
1617                    let array = column
1618                        .as_primitive::<Decimal32Type>()
1619                        .unary::<_, Int32Type>(|v| v);
1620                    write_primitive(typed, array.values(), levels)
1621                }
1622                ArrowDataType::Decimal64(_, _) => {
1623                    // use the int32 to represent the decimal with low precision
1624                    let array = column
1625                        .as_primitive::<Decimal64Type>()
1626                        .unary::<_, Int32Type>(|v| v as i32);
1627                    write_primitive(typed, array.values(), levels)
1628                }
1629                ArrowDataType::Decimal128(_, _) => {
1630                    // use the int32 to represent the decimal with low precision
1631                    let array = column
1632                        .as_primitive::<Decimal128Type>()
1633                        .unary::<_, Int32Type>(|v| v as i32);
1634                    write_primitive(typed, array.values(), levels)
1635                }
1636                ArrowDataType::Decimal256(_, _) => {
1637                    // use the int32 to represent the decimal with low precision
1638                    let array = column
1639                        .as_primitive::<Decimal256Type>()
1640                        .unary::<_, Int32Type>(|v| v.as_i128() as i32);
1641                    write_primitive(typed, array.values(), levels)
1642                }
1643                d => Err(ParquetError::General(format!("Cannot coerce {d} to I32"))),
1644            }
1645        }
1646        ColumnWriter::BoolColumnWriter(typed) => {
1647            let array = column.as_boolean();
1648            let values = get_bool_array_slice(array, indices.iter().copied());
1649            typed.write_batch_internal(
1650                values.as_slice(),
1651                None,
1652                levels.def_level_data().as_ref(),
1653                levels.rep_level_data().as_ref(),
1654                None,
1655                None,
1656                None,
1657            )
1658        }
1659        ColumnWriter::Int64ColumnWriter(typed) => {
1660            match column.data_type() {
1661                ArrowDataType::Date64 => {
1662                    let array = column
1663                        .as_primitive::<Date64Type>()
1664                        .reinterpret_cast::<Int64Type>();
1665
1666                    write_primitive(typed, array.values(), levels)
1667                }
1668                ArrowDataType::Int64 => {
1669                    let array = column.as_primitive::<Int64Type>();
1670                    write_primitive(typed, array.values(), levels)
1671                }
1672                ArrowDataType::UInt64 => {
1673                    let values = column.as_primitive::<UInt64Type>().values();
1674                    // follow C++ implementation and use overflow/reinterpret cast from  u64 to i64 which will map
1675                    // `(i64::MAX as u64)..u64::MAX` to `i64::MIN..0`
1676                    let array = values.inner().typed_data::<i64>();
1677                    write_primitive(typed, array, levels)
1678                }
1679                ArrowDataType::Time64(TimeUnit::Microsecond) => {
1680                    let array = column.as_primitive::<Time64MicrosecondType>();
1681                    write_primitive(typed, array.values(), levels)
1682                }
1683                ArrowDataType::Time64(TimeUnit::Nanosecond) => {
1684                    let array = column.as_primitive::<Time64NanosecondType>();
1685                    write_primitive(typed, array.values(), levels)
1686                }
1687                ArrowDataType::Timestamp(unit, _) => match unit {
1688                    TimeUnit::Second => {
1689                        let array = column.as_primitive::<TimestampSecondType>();
1690                        write_primitive(typed, array.values(), levels)
1691                    }
1692                    TimeUnit::Millisecond => {
1693                        let array = column.as_primitive::<TimestampMillisecondType>();
1694                        write_primitive(typed, array.values(), levels)
1695                    }
1696                    TimeUnit::Microsecond => {
1697                        let array = column.as_primitive::<TimestampMicrosecondType>();
1698                        write_primitive(typed, array.values(), levels)
1699                    }
1700                    TimeUnit::Nanosecond => {
1701                        let array = column.as_primitive::<TimestampNanosecondType>();
1702                        write_primitive(typed, array.values(), levels)
1703                    }
1704                },
1705                ArrowDataType::Duration(unit) => match unit {
1706                    TimeUnit::Second => {
1707                        let array = column.as_primitive::<DurationSecondType>();
1708                        write_primitive(typed, array.values(), levels)
1709                    }
1710                    TimeUnit::Millisecond => {
1711                        let array = column.as_primitive::<DurationMillisecondType>();
1712                        write_primitive(typed, array.values(), levels)
1713                    }
1714                    TimeUnit::Microsecond => {
1715                        let array = column.as_primitive::<DurationMicrosecondType>();
1716                        write_primitive(typed, array.values(), levels)
1717                    }
1718                    TimeUnit::Nanosecond => {
1719                        let array = column.as_primitive::<DurationNanosecondType>();
1720                        write_primitive(typed, array.values(), levels)
1721                    }
1722                },
1723                ArrowDataType::Decimal64(_, _) => {
1724                    let array = column
1725                        .as_primitive::<Decimal64Type>()
1726                        .reinterpret_cast::<Int64Type>();
1727                    write_primitive(typed, array.values(), levels)
1728                }
1729                ArrowDataType::Decimal128(_, _) => {
1730                    // use the int64 to represent the decimal with low precision
1731                    let array = column
1732                        .as_primitive::<Decimal128Type>()
1733                        .unary::<_, Int64Type>(|v| v as i64);
1734                    write_primitive(typed, array.values(), levels)
1735                }
1736                ArrowDataType::Decimal256(_, _) => {
1737                    // use the int64 to represent the decimal with low precision
1738                    let array = column
1739                        .as_primitive::<Decimal256Type>()
1740                        .unary::<_, Int64Type>(|v| v.as_i128() as i64);
1741                    write_primitive(typed, array.values(), levels)
1742                }
1743                d => Err(ParquetError::General(format!("Cannot coerce {d} to I64"))),
1744            }
1745        }
1746        ColumnWriter::Int96ColumnWriter(_typed) => {
1747            unreachable!("Currently unreachable because data type not supported")
1748        }
1749        ColumnWriter::FloatColumnWriter(typed) => {
1750            let array = column.as_primitive::<Float32Type>();
1751            write_primitive(typed, array.values(), levels)
1752        }
1753        ColumnWriter::DoubleColumnWriter(typed) => {
1754            let array = column.as_primitive::<Float64Type>();
1755            write_primitive(typed, array.values(), levels)
1756        }
1757        ColumnWriter::ByteArrayColumnWriter(_) => {
1758            unreachable!("should use ByteArrayWriter")
1759        }
1760        ColumnWriter::FixedLenByteArrayColumnWriter(typed) => {
1761            let bytes = match column.data_type() {
1762                ArrowDataType::Interval(interval_unit) => match interval_unit {
1763                    IntervalUnit::YearMonth => {
1764                        let array = column.as_primitive::<IntervalYearMonthType>();
1765                        get_interval_ym_array_slice(array, indices.iter().copied())
1766                    }
1767                    IntervalUnit::DayTime => {
1768                        let array = column.as_primitive::<IntervalDayTimeType>();
1769                        get_interval_dt_array_slice(array, indices.iter().copied())
1770                    }
1771                    IntervalUnit::MonthDayNano => {
1772                        return Err(ParquetError::NYI(format!(
1773                            "Attempting to write an Arrow interval type {interval_unit:?} to parquet that is not yet implemented"
1774                        )));
1775                    }
1776                },
1777                ArrowDataType::FixedSizeBinary(_) => {
1778                    let array = column.as_fixed_size_binary();
1779                    get_fsb_array_slice(array, indices.iter().copied())
1780                }
1781                ArrowDataType::Decimal32(_, _) => {
1782                    let array = column.as_primitive::<Decimal32Type>();
1783                    get_decimal_array_slice(array, indices.iter().copied())
1784                }
1785                ArrowDataType::Decimal64(_, _) => {
1786                    let array = column.as_primitive::<Decimal64Type>();
1787                    get_decimal_array_slice(array, indices.iter().copied())
1788                }
1789                ArrowDataType::Decimal128(_, _) => {
1790                    let array = column.as_primitive::<Decimal128Type>();
1791                    get_decimal_array_slice(array, indices.iter().copied())
1792                }
1793                ArrowDataType::Decimal256(_, _) => {
1794                    let array = column.as_primitive::<Decimal256Type>();
1795                    get_decimal_array_slice(array, indices.iter().copied())
1796                }
1797                ArrowDataType::Float16 => {
1798                    let array = column.as_primitive::<Float16Type>();
1799                    get_float_16_array_slice(array, indices.iter().copied())
1800                }
1801                _ => {
1802                    return Err(ParquetError::NYI(
1803                        "Attempting to write an Arrow type that is not yet implemented".to_string(),
1804                    ));
1805                }
1806            };
1807            typed.write_batch_internal(
1808                bytes.as_slice(),
1809                None,
1810                levels.def_level_data().as_ref(),
1811                levels.rep_level_data().as_ref(),
1812                None,
1813                None,
1814                None,
1815            )
1816        }
1817    }
1818}
1819
1820fn write_primitive<E: ColumnValueEncoder>(
1821    writer: &mut GenericColumnWriter<E>,
1822    values: &E::Values,
1823    levels: &ArrayLevels,
1824) -> Result<usize> {
1825    writer.write_batch_internal(
1826        values,
1827        Some(levels.non_null_indices()),
1828        levels.def_level_data().as_ref(),
1829        levels.rep_level_data().as_ref(),
1830        None,
1831        None,
1832        None,
1833    )
1834}
1835
1836fn get_bool_array_slice(
1837    array: &arrow_array::BooleanArray,
1838    indices: impl ExactSizeIterator<Item = usize>,
1839) -> Vec<bool> {
1840    let mut values = Vec::with_capacity(indices.len());
1841    for i in indices {
1842        values.push(array.value(i))
1843    }
1844    values
1845}
1846
1847/// Returns 12-byte values representing 3 values of months, days and milliseconds (4-bytes each).
1848/// An Arrow YearMonth interval only stores months, thus only the first 4 bytes are populated.
1849fn get_interval_ym_array_slice(
1850    array: &arrow_array::IntervalYearMonthArray,
1851    indices: impl ExactSizeIterator<Item = usize>,
1852) -> Vec<FixedLenByteArray> {
1853    chunk_array_slice(12, indices, move |i, chunk| {
1854        let value = array.value(i);
1855        chunk[0..4].copy_from_slice(&value.to_le_bytes());
1856    })
1857}
1858
1859/// Returns 12-byte values representing 3 values of months, days and milliseconds (4-bytes each).
1860/// An Arrow DayTime interval only stores days and millis, thus the first 4 bytes are not populated.
1861fn get_interval_dt_array_slice(
1862    array: &arrow_array::IntervalDayTimeArray,
1863    indices: impl ExactSizeIterator<Item = usize>,
1864) -> Vec<FixedLenByteArray> {
1865    chunk_array_slice(12, indices, move |i, chunk| {
1866        let value = array.value(i);
1867        chunk[4..8].copy_from_slice(&value.days.to_le_bytes());
1868        chunk[8..12].copy_from_slice(&value.milliseconds.to_le_bytes());
1869    })
1870}
1871
1872trait NativeDecimalType: DecimalType {
1873    type NativeBytes: AsRef<[u8]>;
1874
1875    fn to_be_bytes(value: Self::Native) -> Self::NativeBytes;
1876}
1877impl NativeDecimalType for Decimal32Type {
1878    type NativeBytes = [u8; Self::BYTE_LENGTH];
1879
1880    fn to_be_bytes(value: Self::Native) -> Self::NativeBytes {
1881        value.to_be_bytes()
1882    }
1883}
1884impl NativeDecimalType for Decimal64Type {
1885    type NativeBytes = [u8; Self::BYTE_LENGTH];
1886
1887    fn to_be_bytes(value: Self::Native) -> Self::NativeBytes {
1888        value.to_be_bytes()
1889    }
1890}
1891impl NativeDecimalType for Decimal128Type {
1892    type NativeBytes = [u8; Self::BYTE_LENGTH];
1893
1894    fn to_be_bytes(value: Self::Native) -> Self::NativeBytes {
1895        value.to_be_bytes()
1896    }
1897}
1898impl NativeDecimalType for Decimal256Type {
1899    type NativeBytes = [u8; Self::BYTE_LENGTH];
1900
1901    fn to_be_bytes(value: Self::Native) -> Self::NativeBytes {
1902        value.to_be_bytes()
1903    }
1904}
1905
1906fn get_decimal_array_slice<T: NativeDecimalType>(
1907    array: &PrimitiveArray<T>,
1908    indices: impl ExactSizeIterator<Item = usize>,
1909) -> Vec<FixedLenByteArray> {
1910    let chunk_size = decimal_length_from_precision(array.precision());
1911    assert!(chunk_size <= T::BYTE_LENGTH);
1912
1913    if chunk_size == T::BYTE_LENGTH {
1914        // Special-case that allows inlining memcpy.
1915        chunk_array_slice(chunk_size, indices, move |i, chunk| {
1916            let as_be_bytes = T::to_be_bytes(array.value(i));
1917            chunk.copy_from_slice(as_be_bytes.as_ref());
1918        })
1919    } else {
1920        chunk_array_slice(chunk_size, indices, move |i, chunk| {
1921            let as_be_bytes = T::to_be_bytes(array.value(i));
1922            let resized_value = &as_be_bytes.as_ref()[(T::BYTE_LENGTH - chunk.len())..];
1923            chunk.copy_from_slice(resized_value);
1924        })
1925    }
1926}
1927
1928fn get_float_16_array_slice(
1929    array: &arrow_array::Float16Array,
1930    indices: impl ExactSizeIterator<Item = usize>,
1931) -> Vec<FixedLenByteArray> {
1932    chunk_array_slice(2, indices, move |i, chunk| {
1933        let value = array.value(i).to_le_bytes();
1934        chunk.copy_from_slice(&value);
1935    })
1936}
1937
1938fn get_fsb_array_slice(
1939    array: &arrow_array::FixedSizeBinaryArray,
1940    indices: impl ExactSizeIterator<Item = usize>,
1941) -> Vec<FixedLenByteArray> {
1942    chunk_array_slice(array.value_size(), indices, move |i, chunk| {
1943        let value = array.value(i);
1944        chunk.copy_from_slice(value);
1945    })
1946}
1947
1948#[inline]
1949fn chunk_array_slice(
1950    chunk_size: usize,
1951    indices: impl ExactSizeIterator<Item = usize>,
1952    writer: impl Fn(usize, &mut [u8]),
1953) -> Vec<FixedLenByteArray> {
1954    let capacity = indices.len() * chunk_size;
1955    // TODO: This could be done with Vec::spare_capacity_mut,
1956    //       but [MaybeUninit]::write_copy_of_slice is gated behind MSRV 1.93
1957    let mut arena = vec![0; capacity];
1958    for (i, chunk) in indices.zip(arena.chunks_exact_mut(chunk_size)) {
1959        writer(i, chunk);
1960    }
1961    chunk_contiguous_vec(arena, chunk_size)
1962}
1963
1964fn chunk_contiguous_vec(arena: Vec<u8>, chunk_size: usize) -> Vec<FixedLenByteArray> {
1965    let mut values = Vec::with_capacity(arena.len() / chunk_size);
1966    let mut arena = Bytes::from(arena);
1967    while arena.len() >= chunk_size {
1968        let slice = arena.split_to(chunk_size);
1969        values.push(FixedLenByteArray::from(ByteArray::from(slice)));
1970    }
1971    values
1972}
1973
1974/// Hash a byte slice to a u64 for NDV tracking.
1975#[inline]
1976fn hash_bytes(bytes: &[u8]) -> u64 {
1977    twox_hash::XxHash64::oneshot(0, bytes)
1978}
1979
1980/// Returns the fixed byte width for primitive Arrow types, or `None` for variable-length types.
1981fn fixed_byte_width(dt: &ArrowDataType) -> Option<usize> {
1982    use ArrowDataType::*;
1983    match dt {
1984        Int8 | UInt8 => Some(1),
1985        Int16 | UInt16 | Float16 => Some(2),
1986        Int32 | UInt32 | Float32 | Date32 | Time32(_) | Decimal32(_, _) => Some(4),
1987        Int64
1988        | UInt64
1989        | Float64
1990        | Date64
1991        | Time64(_)
1992        | Timestamp(_, _)
1993        | Duration(_)
1994        | Decimal64(_, _) => Some(8),
1995        Interval(IntervalUnit::YearMonth) => Some(4),
1996        Interval(IntervalUnit::DayTime) => Some(8),
1997        Interval(IntervalUnit::MonthDayNano) => Some(16),
1998        Decimal128(_, _) => Some(16),
1999        Decimal256(_, _) => Some(32),
2000        _ => None,
2001    }
2002}
2003
2004/// Hash the non-null values in `array` (at `non_null_indices`) into `seen`.
2005///
2006/// Handles primitive, boolean, fixed-size-binary, and variable-length (Utf8/Binary)
2007/// arrays. Unsupported types are silently skipped, leaving `seen` unchanged for
2008/// those values (NDV is best-effort).
2009fn update_distinct_values_seen(
2010    array: &dyn arrow_array::Array,
2011    non_null_indices: &[usize],
2012    seen: &mut DistinctValuesSet,
2013) {
2014    let data = array.to_data();
2015    let offset = data.offset();
2016
2017    match array.data_type() {
2018        ArrowDataType::Boolean => {
2019            let arr = array
2020                .as_any()
2021                .downcast_ref::<arrow_array::BooleanArray>()
2022                .unwrap();
2023            for &row in non_null_indices {
2024                seen.insert(arr.value(row) as u64);
2025            }
2026        }
2027        ArrowDataType::Utf8 | ArrowDataType::Binary => {
2028            let offsets = data.buffers()[0].typed_data::<i32>();
2029            let values = data.buffers()[1].as_slice();
2030            for &row in non_null_indices {
2031                let start = offsets[offset + row] as usize;
2032                let end = offsets[offset + row + 1] as usize;
2033                seen.insert(hash_bytes(&values[start..end]));
2034            }
2035        }
2036        ArrowDataType::LargeUtf8 | ArrowDataType::LargeBinary => {
2037            let offsets = data.buffers()[0].typed_data::<i64>();
2038            let values = data.buffers()[1].as_slice();
2039            for &row in non_null_indices {
2040                let start = offsets[offset + row] as usize;
2041                let end = offsets[offset + row + 1] as usize;
2042                seen.insert(hash_bytes(&values[start..end]));
2043            }
2044        }
2045        ArrowDataType::FixedSizeBinary(byte_width) => {
2046            let byte_width = *byte_width as usize;
2047            let buffer = data.buffers()[0].as_slice();
2048            for &row in non_null_indices {
2049                let start = (offset + row) * byte_width;
2050                seen.insert(hash_bytes(&buffer[start..start + byte_width]));
2051            }
2052        }
2053        ArrowDataType::Utf8View => {
2054            let string_view_array = array.as_string_view();
2055            for &row in non_null_indices {
2056                seen.insert(hash_bytes(string_view_array.value(row).as_bytes()));
2057            }
2058        }
2059        ArrowDataType::BinaryView => {
2060            let binary_view_array = array.as_binary_view();
2061            for &row in non_null_indices {
2062                seen.insert(hash_bytes(binary_view_array.value(row)));
2063            }
2064        }
2065        data_type => {
2066            if let Some(width) = fixed_byte_width(data_type) {
2067                let buffer = data.buffers()[0].as_slice();
2068                for &row in non_null_indices {
2069                    let pos = (offset + row) * width;
2070                    seen.insert(hash_bytes(&buffer[pos..pos + width]));
2071                }
2072            }
2073            // nested types (List, LargeList, etc.) are Parquet groups, not leaf columns: skip
2074        }
2075    }
2076}
2077
2078// Allow the helpers to use the same imports in unit and integration tests.
2079#[cfg(test)]
2080use crate as parquet_crate;
2081
2082#[cfg(test)]
2083#[path = "../../../tests/arrow_writer/roundtrip_helpers.rs"]
2084mod roundtrip_helpers;
2085
2086#[cfg(test)]
2087mod tests {
2088    use super::roundtrip_helpers::{
2089        RoundTripTest, SMALL_SIZE, required_and_optional, roundtrip, roundtrip_opts,
2090        roundtrip_opts_with_array_validation,
2091    };
2092    use super::*;
2093    use std::cmp::Ordering;
2094    use std::collections::HashMap;
2095
2096    use std::fs::File;
2097
2098    use crate::arrow::arrow_reader::{ParquetRecordBatchReader, ParquetRecordBatchReaderBuilder};
2099    use crate::arrow::{ARROW_SCHEMA_META_KEY, PARQUET_FIELD_ID_META_KEY};
2100    use crate::column::page::{Page, PageReader};
2101    use crate::file::metadata::thrift::PageHeader;
2102    use crate::file::page_index::column_index::ColumnIndexMetaData;
2103    use crate::file::reader::SerializedPageReader;
2104    use crate::parquet_thrift::{ReadThrift, ThriftSliceInputProtocol};
2105    use crate::schema::types::ColumnPath;
2106    use arrow::datatypes::{DataType, Schema};
2107    use arrow::error::Result as ArrowResult;
2108    use arrow::util::data_gen::create_random_array;
2109    use arrow::util::pretty::pretty_format_batches;
2110    use arrow::{array::*, buffer::Buffer};
2111    use arrow_buffer::{IntervalDayTime, IntervalMonthDayNano, NullBuffer, OffsetBuffer};
2112    use arrow_schema::Fields;
2113    use half::f16;
2114    use tempfile::tempfile;
2115
2116    use crate::basic::{Encoding, EncodingMask};
2117    use crate::data_type::AsBytes;
2118    use crate::file::metadata::{ColumnChunkMetaData, ParquetMetaData, ParquetMetaDataReader};
2119    use crate::file::properties::{
2120        BloomFilterPosition, EnabledStatistics, ReaderProperties, WriterVersion,
2121    };
2122    use crate::file::serialized_reader::ReadOptionsBuilder;
2123    use crate::file::{
2124        reader::{FileReader, SerializedFileReader},
2125        statistics::Statistics,
2126    };
2127
2128    /// A [`PageStore`] that allocates *sparse, non-contiguous* handles and keeps
2129    /// blobs in a `HashMap` — nothing like the default `Vec<Bytes>`. Used to
2130    /// prove the writer relies only on the opaque-handle contract and never on
2131    /// handles being dense `Vec` indices. Records how many blobs were stored.
2132    #[derive(Debug, Default)]
2133    struct RecordingPageStore {
2134        next: u64,
2135        blobs: HashMap<u64, Bytes>,
2136        puts: Arc<std::sync::atomic::AtomicUsize>,
2137    }
2138
2139    impl PageStore for RecordingPageStore {
2140        fn put(&mut self, value: Bytes) -> Result<PageKey> {
2141            // Deliberately non-sequential, never-zero handles.
2142            let id = 100 + self.next * 7;
2143            self.next += 1;
2144            self.puts.fetch_add(1, std::sync::atomic::Ordering::Relaxed);
2145            self.blobs.insert(id, value);
2146            Ok(PageKey::new(id))
2147        }
2148
2149        fn take(&mut self, key: PageKey) -> Result<Bytes> {
2150            self.blobs
2151                .remove(&key.get())
2152                .ok_or_else(|| ParquetError::General(format!("missing key {}", key.get())))
2153        }
2154    }
2155
2156    #[derive(Debug)]
2157    struct RecordingPageStoreFactory {
2158        puts: Arc<std::sync::atomic::AtomicUsize>,
2159    }
2160
2161    impl PageStoreFactory for RecordingPageStoreFactory {
2162        fn create(&self, _args: &PageStoreArgs<'_>) -> Result<Box<dyn PageStore>> {
2163            Ok(Box::new(RecordingPageStore {
2164                puts: self.puts.clone(),
2165                ..Default::default()
2166            }))
2167        }
2168    }
2169
2170    /// A custom [`PageStore`] must produce byte-identical files to the in-memory
2171    /// default, across dictionary and non-dictionary columns and multiple row
2172    /// groups (so multiple store instances are exercised).
2173    #[test]
2174    fn custom_page_store_is_byte_identical_to_default() {
2175        let schema = Arc::new(Schema::new(vec![
2176            Field::new("i", DataType::Int32, true),
2177            // A low-cardinality string column to exercise the dictionary path.
2178            Field::new("s", DataType::Utf8, true),
2179        ]));
2180        let i = Int32Array::from(vec![Some(1), None, Some(3), Some(4), Some(5), Some(6)]);
2181        let s = StringArray::from(vec![
2182            Some("a"),
2183            Some("bb"),
2184            Some("a"),
2185            None,
2186            Some("bb"),
2187            Some("ccc"),
2188        ]);
2189        let batch = RecordBatch::try_new(schema.clone(), vec![Arc::new(i), Arc::new(s)]).unwrap();
2190
2191        // Small row groups so multiple column chunks (hence multiple store
2192        // instances) are produced.
2193        let props = WriterProperties::builder()
2194            .set_max_row_group_row_count(Some(3))
2195            .build();
2196
2197        let write = |factory: Option<Arc<dyn PageStoreFactory>>| {
2198            let mut buffer = Vec::new();
2199            let mut opts = ArrowWriterOptions::new().with_properties(props.clone());
2200            if let Some(factory) = factory {
2201                opts = opts.with_page_store_factory(factory);
2202            }
2203            let mut writer =
2204                ArrowWriter::try_new_with_options(&mut buffer, schema.clone(), opts).unwrap();
2205            writer.write(&batch).unwrap();
2206            writer.close().unwrap();
2207            buffer
2208        };
2209
2210        let default_bytes = write(None);
2211
2212        let puts = Arc::new(std::sync::atomic::AtomicUsize::new(0));
2213        let custom_bytes = write(Some(Arc::new(RecordingPageStoreFactory {
2214            puts: puts.clone(),
2215        })));
2216
2217        assert!(
2218            puts.load(std::sync::atomic::Ordering::Relaxed) > 0,
2219            "custom PageStore was never written to"
2220        );
2221        assert_eq!(
2222            default_bytes, custom_bytes,
2223            "a custom PageStore must produce byte-identical output to the default"
2224        );
2225    }
2226
2227    /// A dictionary-encoded column written through the deferred-ordering Arrow
2228    /// path must round-trip correctly even with the offset index disabled, when
2229    /// only the chunk-level dictionary/data page offsets are rewritten (there is
2230    /// no offset index to rebuild). Spans multiple data pages so the
2231    /// dictionary-first reordering is exercised.
2232    #[test]
2233    #[cfg_attr(miri, ignore)] // Takes too long
2234    fn dictionary_column_round_trips_with_offset_index_disabled() {
2235        let schema = Arc::new(Schema::new(vec![Field::new("k", DataType::Int32, true)]));
2236
2237        // Low cardinality so the column stays dictionary-encoded; enough rows to
2238        // span several data pages within a single row group.
2239        let values: Vec<Option<i32>> = (0..50_000).map(|i| Some(i % 8)).collect();
2240        let array = Int32Array::from(values.clone());
2241        let batch = RecordBatch::try_new(schema.clone(), vec![Arc::new(array)]).unwrap();
2242
2243        let props = WriterProperties::builder()
2244            .set_offset_index_disabled(true)
2245            .set_data_page_row_count_limit(4096)
2246            .build();
2247        let opts = ArrowWriterOptions::new().with_properties(props);
2248
2249        let mut buffer = Vec::new();
2250        let mut writer =
2251            ArrowWriter::try_new_with_options(&mut buffer, schema.clone(), opts).unwrap();
2252        writer.write(&batch).unwrap();
2253        writer.close().unwrap();
2254
2255        let reader = ParquetRecordBatchReader::try_new(Bytes::from(buffer), values.len()).unwrap();
2256        let read: Vec<RecordBatch> = reader.collect::<ArrowResult<_>>().unwrap();
2257        let read_values: Vec<Option<i32>> = read
2258            .iter()
2259            .flat_map(|b| b.column(0).as_primitive::<Int32Type>().iter())
2260            .collect();
2261        assert_eq!(read_values, values);
2262    }
2263
2264    /// The dictionary page is routed through the [`PageStore`] like any other
2265    /// page rather than held resident in memory, so a dictionary column chunk's
2266    /// *entire* serialized size — dictionary page included — passes through the
2267    /// store.
2268    #[test]
2269    fn dictionary_page_is_routed_through_the_store() {
2270        /// A store that sums the bytes handed to `put`.
2271        #[derive(Debug, Default)]
2272        struct SizeRecordingPageStore {
2273            blobs: Vec<Bytes>,
2274            bytes_put: Arc<std::sync::atomic::AtomicUsize>,
2275        }
2276        impl PageStore for SizeRecordingPageStore {
2277            fn put(&mut self, value: Bytes) -> Result<PageKey> {
2278                self.bytes_put
2279                    .fetch_add(value.len(), std::sync::atomic::Ordering::Relaxed);
2280                let key = PageKey::new(self.blobs.len() as u64);
2281                self.blobs.push(value);
2282                Ok(key)
2283            }
2284            fn take(&mut self, key: PageKey) -> Result<Bytes> {
2285                Ok(std::mem::take(&mut self.blobs[key.get() as usize]))
2286            }
2287        }
2288        #[derive(Debug)]
2289        struct Factory {
2290            bytes_put: Arc<std::sync::atomic::AtomicUsize>,
2291        }
2292        impl PageStoreFactory for Factory {
2293            fn create(&self, _args: &PageStoreArgs<'_>) -> Result<Box<dyn PageStore>> {
2294                Ok(Box::new(SizeRecordingPageStore {
2295                    bytes_put: self.bytes_put.clone(),
2296                    ..Default::default()
2297                }))
2298            }
2299        }
2300
2301        let schema = Arc::new(Schema::new(vec![Field::new("s", DataType::Utf8, false)]));
2302        // Low cardinality keeps the column dictionary-encoded with a real,
2303        // non-empty dictionary page.
2304        let values: Vec<&str> = (0..2048)
2305            .map(|i| ["alpha", "beta", "gamma", "delta"][i % 4])
2306            .collect();
2307        let batch = RecordBatch::try_new(schema.clone(), vec![Arc::new(StringArray::from(values))])
2308            .unwrap();
2309
2310        let bytes_put = Arc::new(std::sync::atomic::AtomicUsize::new(0));
2311        let opts = ArrowWriterOptions::new().with_page_store_factory(Arc::new(Factory {
2312            bytes_put: bytes_put.clone(),
2313        }));
2314
2315        // A single batch / single column means exactly one row group and one
2316        // store instance, so the bytes it saw map to one column chunk.
2317        let mut buffer = Vec::new();
2318        let mut writer =
2319            ArrowWriter::try_new_with_options(&mut buffer, schema.clone(), opts).unwrap();
2320        writer.write(&batch).unwrap();
2321        writer.close().unwrap();
2322
2323        let reader = SerializedFileReader::new(Bytes::from(buffer)).unwrap();
2324        let column = reader.metadata().row_group(0).column(0);
2325        assert!(
2326            column.dictionary_page_offset().is_some(),
2327            "expected the column to be dictionary-encoded"
2328        );
2329
2330        // The bytes the store was handed must account for the whole chunk,
2331        // dictionary page included. Holding the dictionary page apart from the
2332        // store would make this fall short by the dictionary page's size.
2333        assert_eq!(
2334            bytes_put.load(std::sync::atomic::Ordering::Relaxed) as i64,
2335            column.compressed_size(),
2336            "the dictionary page must pass through the store like any other page"
2337        );
2338    }
2339
2340    #[test]
2341    fn arrow_writer() {
2342        // define schema
2343        let schema = 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 batch = RecordBatch::try_new(Arc::new(schema), vec![Arc::new(a), Arc::new(b)]).unwrap();
2354
2355        roundtrip(batch, Some(SMALL_SIZE / 2));
2356    }
2357
2358    fn get_bytes_after_close(schema: SchemaRef, expected_batch: &RecordBatch) -> Vec<u8> {
2359        let mut buffer = vec![];
2360
2361        let mut writer = ArrowWriter::try_new(&mut buffer, schema, None).unwrap();
2362        writer.write(expected_batch).unwrap();
2363        writer.close().unwrap();
2364
2365        buffer
2366    }
2367
2368    fn get_bytes_by_into_inner(schema: SchemaRef, expected_batch: &RecordBatch) -> Vec<u8> {
2369        let mut writer = ArrowWriter::try_new(Vec::new(), schema, None).unwrap();
2370        writer.write(expected_batch).unwrap();
2371        writer.into_inner().unwrap()
2372    }
2373
2374    #[test]
2375    fn roundtrip_bytes() {
2376        // define schema
2377        let schema = Arc::new(Schema::new(vec![
2378            Field::new("a", DataType::Int32, false),
2379            Field::new("b", DataType::Int32, true),
2380        ]));
2381
2382        // create some data
2383        let a = Int32Array::from(vec![1, 2, 3, 4, 5]);
2384        let b = Int32Array::from(vec![Some(1), None, None, Some(4), Some(5)]);
2385
2386        // build a record batch
2387        let expected_batch =
2388            RecordBatch::try_new(schema.clone(), vec![Arc::new(a), Arc::new(b)]).unwrap();
2389
2390        for buffer in [
2391            get_bytes_after_close(schema.clone(), &expected_batch),
2392            get_bytes_by_into_inner(schema, &expected_batch),
2393        ] {
2394            let cursor = Bytes::from(buffer);
2395            let mut record_batch_reader = ParquetRecordBatchReader::try_new(cursor, 1024).unwrap();
2396
2397            let actual_batch = record_batch_reader
2398                .next()
2399                .expect("No batch found")
2400                .expect("Unable to get batch");
2401
2402            assert_eq!(expected_batch.schema(), actual_batch.schema());
2403            assert_eq!(expected_batch.num_columns(), actual_batch.num_columns());
2404            assert_eq!(expected_batch.num_rows(), actual_batch.num_rows());
2405            for i in 0..expected_batch.num_columns() {
2406                let expected_data = expected_batch.column(i).to_data();
2407                let actual_data = actual_batch.column(i).to_data();
2408
2409                assert_eq!(expected_data, actual_data);
2410            }
2411        }
2412    }
2413
2414    #[test]
2415    #[cfg_attr(miri, ignore)] // Takes too long
2416    fn arrow_writer_non_null() {
2417        let schema = Schema::new(vec![Field::new("a", DataType::Int32, false)]);
2418        let a = Int32Array::from(vec![1, 2, 3, 4, 5]);
2419
2420        RoundTripTest::new(Arc::new(a))
2421            .with_schema(Arc::new(schema))
2422            .run();
2423    }
2424
2425    #[test]
2426    #[cfg_attr(miri, ignore)] // Takes too long
2427    fn arrow_writer_binary() {
2428        let raw_string_values = vec!["foo", "bar", "baz", "quux"];
2429        let raw_binary_values = [
2430            b"foo".to_vec(),
2431            b"bar".to_vec(),
2432            b"baz".to_vec(),
2433            b"quux".to_vec(),
2434        ];
2435        let raw_binary_value_refs = raw_binary_values
2436            .iter()
2437            .map(|x| x.as_slice())
2438            .collect::<Vec<_>>();
2439
2440        let string_values = StringArray::from(raw_string_values.clone());
2441        let binary_values = BinaryArray::from(raw_binary_value_refs);
2442        assert_eq!(string_values.null_count(), 0);
2443        assert_eq!(binary_values.null_count(), 0);
2444
2445        RoundTripTest::new(Arc::new(string_values)).run();
2446        RoundTripTest::new(Arc::new(binary_values)).run();
2447    }
2448
2449    #[test]
2450    #[cfg_attr(miri, ignore)] // Takes too long
2451    fn arrow_writer_binary_view() {
2452        let raw_string_values = vec!["foo", "bar", "large payload over 12 bytes", "lulu"];
2453        let raw_binary_values = vec![
2454            b"foo".to_vec(),
2455            b"bar".to_vec(),
2456            b"large payload over 12 bytes".to_vec(),
2457            b"lulu".to_vec(),
2458        ];
2459        let nullable_string_values =
2460            vec![Some("foo"), None, Some("large payload over 12 bytes"), None];
2461
2462        let string_view_values = StringViewArray::from(raw_string_values);
2463        let binary_view_values = BinaryViewArray::from_iter_values(raw_binary_values);
2464        let nullable_string_view_values = StringViewArray::from(nullable_string_values);
2465
2466        RoundTripTest::new(Arc::new(string_view_values)).run();
2467        RoundTripTest::new(Arc::new(binary_view_values)).run();
2468        RoundTripTest::new(Arc::new(nullable_string_view_values)).run();
2469    }
2470
2471    #[test]
2472    #[cfg_attr(miri, ignore)] // Takes too long
2473    fn arrow_writer_binary_view_long_value() {
2474        // There is special case validation for long values (greater than 128)
2475        // 128 encodes as 0x80 0x00 0x00 0x00 in little endian, which should
2476        // trigger the long-string UTF-8 validation branch in the plain decoder.
2477        let long = "a".repeat(128);
2478        let raw_string_values = vec!["foo", long.as_str(), "bar"];
2479        let raw_binary_values = vec![b"foo".to_vec(), long.as_bytes().to_vec(), b"bar".to_vec()];
2480
2481        let string_view_values: ArrayRef = Arc::new(StringViewArray::from(raw_string_values));
2482        let binary_view_values: ArrayRef =
2483            Arc::new(BinaryViewArray::from_iter_values(raw_binary_values));
2484
2485        RoundTripTest::new(Arc::clone(&string_view_values))
2486            .with_nullable(false)
2487            .run();
2488        RoundTripTest::new(Arc::clone(&binary_view_values))
2489            .with_nullable(false)
2490            .run();
2491    }
2492
2493    fn get_decimal_batch(precision: u8, scale: i8) -> RecordBatch {
2494        let decimal_field = Field::new("a", DataType::Decimal128(precision, scale), false);
2495        let schema = Schema::new(vec![decimal_field]);
2496
2497        let decimal_values = vec![10_000, 50_000, 0, -100]
2498            .into_iter()
2499            .map(Some)
2500            .collect::<Decimal128Array>()
2501            .with_precision_and_scale(precision, scale)
2502            .unwrap();
2503
2504        RecordBatch::try_new(Arc::new(schema), vec![Arc::new(decimal_values)]).unwrap()
2505    }
2506
2507    #[test]
2508    fn arrow_writer_decimal() {
2509        // int32 to store the decimal value
2510        let batch_int32_decimal = get_decimal_batch(5, 2);
2511        roundtrip(batch_int32_decimal, Some(SMALL_SIZE / 2));
2512        // int64 to store the decimal value
2513        let batch_int64_decimal = get_decimal_batch(12, 2);
2514        roundtrip(batch_int64_decimal, Some(SMALL_SIZE / 2));
2515        // fixed_length_byte_array to store the decimal value
2516        let batch_fixed_len_byte_array_decimal = get_decimal_batch(30, 2);
2517        roundtrip(batch_fixed_len_byte_array_decimal, Some(SMALL_SIZE / 2));
2518    }
2519
2520    #[test]
2521    fn arrow_writer_page_size() {
2522        let schema = Arc::new(Schema::new(vec![Field::new("col", DataType::Utf8, false)]));
2523
2524        let mut builder = StringBuilder::with_capacity(100, 329 * 10_000);
2525
2526        // Generate an array of 10 unique 10 character string
2527        for i in 0..10 {
2528            let value = i
2529                .to_string()
2530                .repeat(10)
2531                .chars()
2532                .take(10)
2533                .collect::<String>();
2534
2535            builder.append_value(value);
2536        }
2537
2538        let array = Arc::new(builder.finish());
2539
2540        let batch = RecordBatch::try_new(schema, vec![array]).unwrap();
2541
2542        let file = tempfile::tempfile().unwrap();
2543
2544        // Set everything very low so we fallback to PLAIN encoding after the first row
2545        let props = WriterProperties::builder()
2546            .set_data_page_size_limit(1)
2547            .set_dictionary_page_size_limit(1)
2548            .set_write_batch_size(1)
2549            .build();
2550
2551        let mut writer =
2552            ArrowWriter::try_new(file.try_clone().unwrap(), batch.schema(), Some(props))
2553                .expect("Unable to write file");
2554        writer.write(&batch).unwrap();
2555        writer.close().unwrap();
2556
2557        let options = ReadOptionsBuilder::new().with_page_index().build();
2558        let reader =
2559            SerializedFileReader::new_with_options(file.try_clone().unwrap(), options).unwrap();
2560
2561        let column = reader.metadata().row_group(0).columns();
2562
2563        assert_eq!(column.len(), 1);
2564
2565        // We should write one row before falling back to PLAIN encoding so there should still be a
2566        // dictionary page.
2567        assert!(
2568            column[0].dictionary_page_offset().is_some(),
2569            "Expected a dictionary page"
2570        );
2571
2572        let page_index = reader
2573            .metadata()
2574            .page_index()
2575            .expect("page index should be present");
2576        let page_locations = page_index
2577            .page_locations(0, 0)
2578            .expect("page locations should exist");
2579
2580        // We should fallback to PLAIN encoding after the first row and our max page size is 1 bytes
2581        // so we expect one dictionary encoded page and then a page per row thereafter.
2582        assert_eq!(
2583            page_locations.len(),
2584            10,
2585            "Expected 10 pages but got {page_locations:#?}"
2586        );
2587    }
2588
2589    #[test]
2590    #[cfg_attr(miri, ignore)] // inline assembly is not supported
2591    fn arrow_writer_float_nans() {
2592        let f16_field = Field::new("a", DataType::Float16, false);
2593        let f32_field = Field::new("b", DataType::Float32, false);
2594        let f64_field = Field::new("c", DataType::Float64, false);
2595        let schema = Schema::new(vec![f16_field, f32_field, f64_field]);
2596
2597        let f16_values = (0..MEDIUM_SIZE)
2598            .map(|i| {
2599                Some(if i % 2 == 0 {
2600                    f16::NAN
2601                } else {
2602                    f16::from_f32(i as f32)
2603                })
2604            })
2605            .collect::<Float16Array>();
2606
2607        let f32_values = (0..MEDIUM_SIZE)
2608            .map(|i| Some(if i % 2 == 0 { f32::NAN } else { i as f32 }))
2609            .collect::<Float32Array>();
2610
2611        let f64_values = (0..MEDIUM_SIZE)
2612            .map(|i| Some(if i % 2 == 0 { f64::NAN } else { i as f64 }))
2613            .collect::<Float64Array>();
2614
2615        let batch = RecordBatch::try_new(
2616            Arc::new(schema),
2617            vec![
2618                Arc::new(f16_values),
2619                Arc::new(f32_values),
2620                Arc::new(f64_values),
2621            ],
2622        )
2623        .unwrap();
2624
2625        roundtrip(batch, None);
2626    }
2627
2628    const MEDIUM_SIZE: usize = 63;
2629
2630    fn check_bloom_filter<T: AsBytes>(
2631        files: Vec<Bytes>,
2632        file_column: String,
2633        positive_values: Vec<T>,
2634        negative_values: Vec<T>,
2635    ) {
2636        files.into_iter().take(1).for_each(|file| {
2637            let file_reader = SerializedFileReader::new_with_options(
2638                file,
2639                ReadOptionsBuilder::new()
2640                    .with_reader_properties(
2641                        ReaderProperties::builder()
2642                            .set_read_bloom_filter(true)
2643                            .build(),
2644                    )
2645                    .build(),
2646            )
2647            .expect("Unable to open file as Parquet");
2648            let metadata = file_reader.metadata();
2649
2650            // Gets bloom filters from all row groups.
2651            let mut bloom_filters: Vec<_> = vec![];
2652            for (ri, row_group) in metadata.row_groups().iter().enumerate() {
2653                if let Some((column_index, _)) = row_group
2654                    .columns()
2655                    .iter()
2656                    .enumerate()
2657                    .find(|(_, column)| column.column_path().string() == file_column)
2658                {
2659                    let row_group_reader = file_reader
2660                        .get_row_group(ri)
2661                        .expect("Unable to read row group");
2662                    if let Some(sbbf) = row_group_reader.get_column_bloom_filter(column_index) {
2663                        bloom_filters.push(sbbf.clone());
2664                    } else {
2665                        panic!("No bloom filter for column named {file_column} found");
2666                    }
2667                } else {
2668                    panic!("No column named {file_column} found");
2669                }
2670            }
2671
2672            positive_values.iter().for_each(|value| {
2673                let found = bloom_filters.iter().find(|sbbf| sbbf.check(value));
2674                assert!(
2675                    found.is_some(),
2676                    "{}",
2677                    format!("Value {:?} should be in bloom filter", value.as_bytes())
2678                );
2679            });
2680
2681            negative_values.iter().for_each(|value| {
2682                let found = bloom_filters.iter().find(|sbbf| sbbf.check(value));
2683                assert!(
2684                    found.is_none(),
2685                    "{}",
2686                    format!("Value {:?} should not be in bloom filter", value.as_bytes())
2687                );
2688            });
2689        });
2690    }
2691
2692    #[test]
2693    #[cfg_attr(miri, ignore)] // Takes too long
2694    fn all_null_primitive_single_column() {
2695        let values = Arc::new(Int32Array::from(vec![None; SMALL_SIZE]));
2696        RoundTripTest::new(values).run();
2697    }
2698    #[test]
2699    #[cfg_attr(miri, ignore)] // Takes too long
2700    fn null_single_column() {
2701        let values = Arc::new(NullArray::new(SMALL_SIZE));
2702        RoundTripTest::new(values).run();
2703        // null arrays are always nullable, a test with non-nullable nulls fails
2704    }
2705
2706    #[test]
2707    #[cfg_attr(miri, ignore)] // Takes too long
2708    fn bool_single_column() {
2709        required_and_optional::<BooleanArray, _>(
2710            [true, false].iter().cycle().copied().take(SMALL_SIZE),
2711        );
2712    }
2713
2714    #[test]
2715    #[cfg_attr(miri, ignore)] // Takes too long
2716    fn bool_large_single_column() {
2717        let values = Arc::new(
2718            [None, Some(true), Some(false)]
2719                .iter()
2720                .cycle()
2721                .copied()
2722                .take(200_000)
2723                .collect::<BooleanArray>(),
2724        );
2725        let schema = Schema::new(vec![Field::new("col", values.data_type().clone(), true)]);
2726        let expected_batch = RecordBatch::try_new(Arc::new(schema), vec![values]).unwrap();
2727        let file = tempfile::tempfile().unwrap();
2728
2729        let mut writer =
2730            ArrowWriter::try_new(file.try_clone().unwrap(), expected_batch.schema(), None)
2731                .expect("Unable to write file");
2732        writer.write(&expected_batch).unwrap();
2733        writer.close().unwrap();
2734    }
2735
2736    #[test]
2737    fn check_page_offset_index_with_nan() {
2738        let values = Arc::new(Float64Array::from(vec![f64::NAN; 10]));
2739        let schema = Schema::new(vec![Field::new("col", DataType::Float64, true)]);
2740        let batch = RecordBatch::try_new(Arc::new(schema), vec![values]).unwrap();
2741
2742        let mut out = Vec::with_capacity(1024);
2743        let mut writer =
2744            ArrowWriter::try_new(&mut out, batch.schema(), None).expect("Unable to write file");
2745        writer.write(&batch).unwrap();
2746        let file_meta_data = writer.close().unwrap();
2747        for row_group in file_meta_data.row_groups() {
2748            for column in row_group.columns() {
2749                assert!(column.offset_index_offset().is_some());
2750                assert!(column.offset_index_length().is_some());
2751                assert!(column.column_index_offset().is_some());
2752                assert!(column.column_index_length().is_some());
2753            }
2754        }
2755        if let Some(page_index) = file_meta_data.page_index() {
2756            for rg in 0..file_meta_data.num_row_groups() {
2757                for col in 0..file_meta_data.row_group(rg).num_columns() {
2758                    let idx = page_index
2759                        .column_index(rg, col)
2760                        .expect("column index should exist");
2761                    assert!(idx.nan_counts().is_some());
2762                    let ColumnIndexMetaData::DOUBLE(float_idx) = idx else {
2763                        panic!("expected double statistics")
2764                    };
2765                    for i in 0..idx.num_pages() as usize {
2766                        assert_eq!(float_idx.nan_count(i), Some(10));
2767                        assert_eq!(
2768                            f64::NAN.total_cmp(float_idx.min_value(i).unwrap()),
2769                            Ordering::Equal
2770                        );
2771                        assert_eq!(
2772                            f64::NAN.total_cmp(float_idx.max_value(i).unwrap()),
2773                            Ordering::Equal
2774                        );
2775                    }
2776                }
2777            }
2778        } else {
2779            panic!("page index should be present");
2780        }
2781    }
2782
2783    #[test]
2784    fn check_page_offset_index_with_mixed_nan() {
2785        let schema = Arc::new(Schema::new(vec![Field::new(
2786            "col",
2787            DataType::Float64,
2788            true,
2789        )]));
2790
2791        let mut out = Vec::with_capacity(1024);
2792        let props = WriterProperties::builder()
2793            .set_data_page_row_count_limit(10)
2794            .build();
2795        let mut writer = ArrowWriter::try_new(&mut out, schema.clone(), Some(props))
2796            .expect("Unable to write file");
2797
2798        // write a page of all NaN (since batch min and max are NaN, global min/max are NaN)
2799        let values = Arc::new(Float64Array::from(vec![f64::NAN; 10]));
2800        let batch = RecordBatch::try_new(schema.clone(), vec![values]).unwrap();
2801        writer.write(&batch).unwrap();
2802
2803        // write a page of all -NaN (batch min/max is -NaN, should update global min to -NaN)
2804        let values = Arc::new(Float64Array::from(vec![-f64::NAN; 10]));
2805        let batch = RecordBatch::try_new(schema.clone(), vec![values]).unwrap();
2806        writer.write(&batch).unwrap();
2807
2808        // write a page of all 0 (non-NaN should override global min/max, now 0/0)
2809        let values = Arc::new(Float64Array::from(vec![0_f64; 10]));
2810        let batch = RecordBatch::try_new(schema.clone(), vec![values]).unwrap();
2811        writer.write(&batch).unwrap();
2812
2813        // write a mixed page (should now have min -1, max 1)
2814        let values = Arc::new(Float64Array::from(vec![
2815            -1.0,
2816            0.0,
2817            f64::NAN,
2818            -f64::NAN,
2819            1.0,
2820        ]));
2821        let batch = RecordBatch::try_new(schema.clone(), vec![values]).unwrap();
2822        writer.write(&batch).unwrap();
2823
2824        let file_meta_data = writer.close().unwrap();
2825
2826        // check the column chunk stats are correct
2827        let col_stats = file_meta_data
2828            .row_group(0)
2829            .column(0)
2830            .statistics()
2831            .expect("missing column chunk statistics");
2832
2833        assert_eq!(col_stats.nan_count_opt(), Some(22));
2834        assert_eq!(col_stats.min_bytes_opt(), Some((-1.0f64).as_bytes()));
2835        assert_eq!(col_stats.max_bytes_opt(), Some(1.0f64.as_bytes()));
2836
2837        assert!(file_meta_data.page_index().is_some());
2838        let col_idx = &file_meta_data.page_index().unwrap().column_index(0, 0);
2839        assert_eq!(col_idx.as_ref().unwrap().num_pages(), 4);
2840
2841        // test each page
2842        let Some(ColumnIndexMetaData::DOUBLE(float_idx)) = col_idx else {
2843            panic!("expected double statistics")
2844        };
2845
2846        assert_eq!(float_idx.nan_counts, Some(vec![10, 10, 0, 2]));
2847        assert_eq!(
2848            f64::NAN.total_cmp(float_idx.min_value(0).unwrap()),
2849            Ordering::Equal
2850        );
2851        assert_eq!(
2852            f64::NAN.total_cmp(float_idx.max_value(0).unwrap()),
2853            Ordering::Equal
2854        );
2855        assert_eq!(
2856            (-f64::NAN).total_cmp(float_idx.min_value(1).unwrap()),
2857            Ordering::Equal
2858        );
2859        assert_eq!(
2860            (-f64::NAN).total_cmp(float_idx.max_value(1).unwrap()),
2861            Ordering::Equal
2862        );
2863        assert_eq!(float_idx.min_value(2), Some(&0.0));
2864        assert_eq!(float_idx.max_value(2), Some(&0.0));
2865        assert_eq!(float_idx.min_value(3), Some(&-1.0));
2866        assert_eq!(float_idx.max_value(3), Some(&1.0));
2867    }
2868
2869    #[test]
2870    #[cfg_attr(miri, ignore)] // Takes too long
2871    fn interval_year_month_single_column() {
2872        required_and_optional::<IntervalYearMonthArray, _>(0..SMALL_SIZE as i32);
2873    }
2874
2875    #[test]
2876    #[cfg_attr(miri, ignore)] // Takes too long
2877    fn interval_day_time_single_column() {
2878        required_and_optional::<IntervalDayTimeArray, _>(vec![
2879            IntervalDayTime::new(0, 1),
2880            IntervalDayTime::new(0, 3),
2881            IntervalDayTime::new(3, -2),
2882            IntervalDayTime::new(-200, 4),
2883        ]);
2884    }
2885
2886    #[test]
2887    #[should_panic(
2888        expected = "Attempting to write an Arrow interval type MonthDayNano to parquet that is not yet implemented"
2889    )]
2890    fn interval_month_day_nano_single_column() {
2891        required_and_optional::<IntervalMonthDayNanoArray, _>(vec![
2892            IntervalMonthDayNano::new(0, 1, 5),
2893            IntervalMonthDayNano::new(0, 3, 2),
2894            IntervalMonthDayNano::new(3, -2, -5),
2895            IntervalMonthDayNano::new(-200, 4, -1),
2896        ]);
2897    }
2898
2899    #[test]
2900    #[cfg_attr(miri, ignore)] // Takes too long
2901    fn i32_column_bloom_filter_at_end() {
2902        let array = Arc::new(Int32Array::from_iter(0..SMALL_SIZE as i32));
2903        let files = RoundTripTest::new(array)
2904            .with_nullable(false)
2905            .with_bloom_filter(true)
2906            .with_bloom_filter_position(BloomFilterPosition::End)
2907            .run();
2908
2909        check_bloom_filter(
2910            files,
2911            "col".to_string(),
2912            (0..SMALL_SIZE as i32).collect(),
2913            (SMALL_SIZE as i32 + 1..SMALL_SIZE as i32 + 10).collect(),
2914        );
2915    }
2916
2917    #[test]
2918    #[cfg_attr(miri, ignore)] // Takes too long
2919    fn i32_column_bloom_filter() {
2920        let array = Arc::new(Int32Array::from_iter(0..SMALL_SIZE as i32));
2921        let files = RoundTripTest::new(array)
2922            .with_nullable(false)
2923            .with_bloom_filter(true)
2924            .run();
2925
2926        check_bloom_filter(
2927            files,
2928            "col".to_string(),
2929            (0..SMALL_SIZE as i32).collect(),
2930            (SMALL_SIZE as i32 + 1..SMALL_SIZE as i32 + 10).collect(),
2931        );
2932    }
2933
2934    fn write_with_bloom_filter(array: ArrayRef, dictionary_page_size_limit: usize) -> Bytes {
2935        let schema = Arc::new(Schema::new(vec![Field::new(
2936            "col",
2937            array.data_type().clone(),
2938            false,
2939        )]));
2940        let batch = RecordBatch::try_new(schema.clone(), vec![array]).unwrap();
2941        let props = WriterProperties::builder()
2942            .set_dictionary_enabled(true)
2943            .set_dictionary_page_size_limit(dictionary_page_size_limit)
2944            .set_write_batch_size(256)
2945            .set_bloom_filter_enabled(true)
2946            .build();
2947        let mut buf = Vec::new();
2948        let mut writer = ArrowWriter::try_new(&mut buf, schema, Some(props)).unwrap();
2949        writer.write(&batch).unwrap();
2950        writer.close().unwrap();
2951        Bytes::from(buf)
2952    }
2953
2954    fn data_page_encoding_mask(file: &Bytes) -> EncodingMask {
2955        let metadata = ParquetMetaDataReader::new().parse_and_finish(file).unwrap();
2956        *metadata
2957            .row_group(0)
2958            .column(0)
2959            .page_encoding_stats_mask()
2960            .unwrap()
2961    }
2962
2963    /// While a column is dictionary encoded the bloom filter is populated from the dictionary
2964    /// when it is flushed, so a chunk that stays dictionary encoded must still contain every value.
2965    #[test]
2966    fn string_column_bloom_filter_populated_from_dictionary() {
2967        let values: Vec<String> = (0..2000).map(|i| format!("value-{}", i % 10)).collect();
2968        let array = Arc::new(StringArray::from_iter_values(&values));
2969        let file = write_with_bloom_filter(array, 1024 * 1024);
2970        assert!(data_page_encoding_mask(&file).is_only(Encoding::RLE_DICTIONARY));
2971
2972        check_bloom_filter(
2973            vec![file],
2974            "col".to_string(),
2975            (0..10).map(|i| format!("value-{i}").into_bytes()).collect(),
2976            (10..20)
2977                .map(|i| format!("value-{i}").into_bytes())
2978                .collect(),
2979        );
2980    }
2981
2982    /// After falling back from dictionary encoding the filter holds the dictionary's values
2983    /// and every value written plain afterwards.
2984    #[test]
2985    fn string_column_bloom_filter_across_dictionary_fallback() {
2986        let values: Vec<String> = (0..2000).map(|i| format!("value-{i}")).collect();
2987        let array = Arc::new(StringArray::from_iter_values(&values));
2988        let file = write_with_bloom_filter(array, 1024);
2989        let encodings = data_page_encoding_mask(&file);
2990        assert!(
2991            encodings.is_set(Encoding::RLE_DICTIONARY) && encodings.is_set(Encoding::PLAIN),
2992            "expected dictionary and plain data pages, got {encodings:?}"
2993        );
2994
2995        check_bloom_filter(
2996            vec![file],
2997            "col".to_string(),
2998            values.into_iter().map(String::into_bytes).collect(),
2999            (2000..2010)
3000                .map(|i| format!("value-{i}").into_bytes())
3001                .collect(),
3002        );
3003    }
3004
3005    #[test]
3006    fn i64_column_bloom_filter_populated_from_dictionary() {
3007        let array = Arc::new(Int64Array::from_iter_values((0..2000).map(|i| i % 10)));
3008        let file = write_with_bloom_filter(array, 1024 * 1024);
3009        assert!(data_page_encoding_mask(&file).is_only(Encoding::RLE_DICTIONARY));
3010
3011        check_bloom_filter(
3012            vec![file],
3013            "col".to_string(),
3014            (0..10i64).collect(),
3015            (10..20i64).collect(),
3016        );
3017    }
3018
3019    #[test]
3020    fn i64_column_bloom_filter_across_dictionary_fallback() {
3021        let array = Arc::new(Int64Array::from_iter_values(0..2000i64));
3022        let file = write_with_bloom_filter(array, 1024);
3023        let encodings = data_page_encoding_mask(&file);
3024        assert!(
3025            encodings.is_set(Encoding::RLE_DICTIONARY) && encodings.is_set(Encoding::PLAIN),
3026            "expected dictionary and plain data pages, got {encodings:?}"
3027        );
3028
3029        check_bloom_filter(
3030            vec![file],
3031            "col".to_string(),
3032            (0..2000i64).collect(),
3033            (2000..2010i64).collect(),
3034        );
3035    }
3036
3037    /// Test that bloom filter folding produces correct results even when
3038    /// the configured NDV differs significantly from actual NDV.
3039    /// A large NDV means a larger initial filter that gets folded down;
3040    /// a small NDV means a smaller initial filter.
3041    #[test]
3042    #[cfg_attr(miri, ignore)] // Takes too long
3043    fn i32_column_bloom_filter_fixed_ndv() {
3044        let array = Arc::new(Int32Array::from_iter(0..SMALL_SIZE as i32));
3045
3046        // NDV much larger than actual distinct values — tests folding a large filter down
3047        let files = RoundTripTest::new(array.clone())
3048            .with_nullable(false)
3049            .with_bloom_filter(true)
3050            .with_bloom_filter_ndv(1_000_000)
3051            .run();
3052
3053        check_bloom_filter(
3054            files,
3055            "col".to_string(),
3056            (0..SMALL_SIZE as i32).collect(),
3057            (SMALL_SIZE as i32 + 1..SMALL_SIZE as i32 + 10).collect(),
3058        );
3059
3060        // NDV smaller than actual distinct values — tests the underestimate path
3061        let files = RoundTripTest::new(array)
3062            .with_nullable(false)
3063            .with_bloom_filter(true)
3064            .with_bloom_filter_ndv(3)
3065            .run();
3066
3067        check_bloom_filter(
3068            files,
3069            "col".to_string(),
3070            (0..SMALL_SIZE as i32).collect(),
3071            (SMALL_SIZE as i32 + 1..SMALL_SIZE as i32 + 10).collect(),
3072        );
3073    }
3074
3075    #[test]
3076    #[cfg_attr(miri, ignore)] // Takes too long
3077    fn binary_column_bloom_filter() {
3078        let one_vec: Vec<u8> = (0..SMALL_SIZE as u8).collect();
3079        let many_vecs: Vec<_> = std::iter::repeat_n(one_vec, SMALL_SIZE).collect();
3080        let many_vecs_iter = many_vecs.iter().map(|v| v.as_slice());
3081
3082        let array = Arc::new(BinaryArray::from_iter_values(many_vecs_iter));
3083        let files = RoundTripTest::new(array)
3084            .with_nullable(false)
3085            .with_bloom_filter(true)
3086            .run();
3087
3088        check_bloom_filter(
3089            files,
3090            "col".to_string(),
3091            many_vecs,
3092            vec![vec![(SMALL_SIZE + 1) as u8]],
3093        );
3094    }
3095
3096    #[test]
3097    #[cfg_attr(miri, ignore)] // Takes too long
3098    fn empty_string_null_column_bloom_filter() {
3099        let raw_values: Vec<_> = (0..SMALL_SIZE).map(|i| i.to_string()).collect();
3100        let raw_strs = raw_values.iter().map(|s| s.as_str());
3101
3102        let array = Arc::new(StringArray::from_iter_values(raw_strs));
3103        let files = RoundTripTest::new(array)
3104            .with_nullable(false)
3105            .with_bloom_filter(true)
3106            .run();
3107
3108        let optional_raw_values: Vec<_> = raw_values
3109            .iter()
3110            .enumerate()
3111            .filter_map(|(i, v)| if i % 2 == 0 { None } else { Some(v.as_str()) })
3112            .collect();
3113        // For null slots, empty string should not be in bloom filter.
3114        check_bloom_filter(files, "col".to_string(), optional_raw_values, vec![""]);
3115    }
3116
3117    #[test]
3118    fn list_and_map_coerced_names() {
3119        // Create map and list with non-Parquet naming
3120        let list_field =
3121            Field::new_list("my_list", Field::new("item", DataType::Int32, false), false);
3122        let map_field = Field::new_map(
3123            "my_map",
3124            "my_entries",
3125            Field::new("my_keys", DataType::Int32, false),
3126            Field::new("my_values", DataType::Int32, true),
3127            false,
3128            true,
3129        );
3130
3131        let list_array = create_random_array(&list_field, 100, 0.0, 0.0).unwrap();
3132        let map_array = create_random_array(&map_field, 100, 0.0, 0.0).unwrap();
3133
3134        let arrow_schema = Arc::new(Schema::new(vec![list_field, map_field]));
3135
3136        // Write data to Parquet but coerce names to match spec
3137        let props = Some(WriterProperties::builder().set_coerce_types(true).build());
3138        let file = tempfile::tempfile().unwrap();
3139        let mut writer =
3140            ArrowWriter::try_new(file.try_clone().unwrap(), arrow_schema.clone(), props).unwrap();
3141
3142        let batch = RecordBatch::try_new(arrow_schema, vec![list_array, map_array]).unwrap();
3143        writer.write(&batch).unwrap();
3144        let file_metadata = writer.close().unwrap();
3145
3146        let schema = file_metadata.file_metadata().schema();
3147        // Coerced name of "item" should be "element"
3148        let list_field = &schema.get_fields()[0].get_fields()[0];
3149        assert_eq!(list_field.get_fields()[0].name(), "element");
3150
3151        let map_field = &schema.get_fields()[1].get_fields()[0];
3152        // Coerced name of "entries" should be "key_value"
3153        assert_eq!(map_field.name(), "key_value");
3154        // Coerced name of "my_keys" should be "key"
3155        assert_eq!(map_field.get_fields()[0].name(), "key");
3156        // Coerced name of "my_values" should be "value"
3157        assert_eq!(map_field.get_fields()[1].name(), "value");
3158
3159        // Double check schema after reading from the file
3160        let reader = SerializedFileReader::new(file).unwrap();
3161        let file_schema = reader.metadata().file_metadata().schema();
3162        let fields = file_schema.get_fields();
3163        let list_field = &fields[0].get_fields()[0];
3164        assert_eq!(list_field.get_fields()[0].name(), "element");
3165        let map_field = &fields[1].get_fields()[0];
3166        assert_eq!(map_field.name(), "key_value");
3167        assert_eq!(map_field.get_fields()[0].name(), "key");
3168        assert_eq!(map_field.get_fields()[1].name(), "value");
3169    }
3170
3171    #[test]
3172    #[cfg_attr(miri, ignore)] // Takes too long
3173    fn fallback_flush_data_page() {
3174        //tests if the Fallback::flush_data_page clears all buffers correctly
3175        let raw_values: Vec<_> = (0..MEDIUM_SIZE).map(|i| i.to_string()).collect();
3176        let values = Arc::new(StringArray::from(raw_values));
3177        let encodings = vec![
3178            Encoding::DELTA_BYTE_ARRAY,
3179            Encoding::DELTA_LENGTH_BYTE_ARRAY,
3180        ];
3181        let data_type = values.data_type().clone();
3182        let schema = Arc::new(Schema::new(vec![Field::new("col", data_type, false)]));
3183        let expected_batch = RecordBatch::try_new(schema, vec![values]).unwrap();
3184
3185        let row_group_sizes = [1024, SMALL_SIZE, SMALL_SIZE / 2, SMALL_SIZE / 2 + 1, 10];
3186        let data_page_size_limit: usize = 32;
3187        let write_batch_size: usize = 16;
3188
3189        for encoding in &encodings {
3190            for row_group_size in row_group_sizes {
3191                let props = WriterProperties::builder()
3192                    .set_writer_version(WriterVersion::PARQUET_2_0)
3193                    .set_max_row_group_row_count(Some(row_group_size))
3194                    .set_dictionary_enabled(false)
3195                    .set_encoding(*encoding)
3196                    .set_data_page_size_limit(data_page_size_limit)
3197                    .set_write_batch_size(write_batch_size)
3198                    .build();
3199
3200                roundtrip_opts_with_array_validation(&expected_batch, props, |a, b| {
3201                    let string_array_a = StringArray::from(a.clone());
3202                    let string_array_b = StringArray::from(b.clone());
3203                    let vec_a: Vec<&str> = string_array_a.iter().map(|v| v.unwrap()).collect();
3204                    let vec_b: Vec<&str> = string_array_b.iter().map(|v| v.unwrap()).collect();
3205                    assert_eq!(
3206                        vec_a, vec_b,
3207                        "failed for encoder: {encoding:?} and row_group_size: {row_group_size:?}"
3208                    );
3209                });
3210            }
3211        }
3212    }
3213
3214    #[test]
3215    fn arrow_writer_test_type_compatibility() {
3216        fn ensure_compatible_write<T1, T2>(array1: T1, array2: T2, expected_result: T1)
3217        where
3218            T1: Array + 'static,
3219            T2: Array + 'static,
3220        {
3221            let schema1 = Arc::new(Schema::new(vec![Field::new(
3222                "a",
3223                array1.data_type().clone(),
3224                false,
3225            )]));
3226
3227            let file = tempfile().unwrap();
3228            let mut writer =
3229                ArrowWriter::try_new(file.try_clone().unwrap(), schema1.clone(), None).unwrap();
3230
3231            let rb1 = RecordBatch::try_new(schema1.clone(), vec![Arc::new(array1)]).unwrap();
3232            writer.write(&rb1).unwrap();
3233
3234            let schema2 = Arc::new(Schema::new(vec![Field::new(
3235                "a",
3236                array2.data_type().clone(),
3237                false,
3238            )]));
3239            let rb2 = RecordBatch::try_new(schema2, vec![Arc::new(array2)]).unwrap();
3240            writer.write(&rb2).unwrap();
3241
3242            writer.close().unwrap();
3243
3244            let mut record_batch_reader =
3245                ParquetRecordBatchReader::try_new(file.try_clone().unwrap(), 1024).unwrap();
3246            let actual_batch = record_batch_reader.next().unwrap().unwrap();
3247
3248            let expected_batch =
3249                RecordBatch::try_new(schema1, vec![Arc::new(expected_result)]).unwrap();
3250            assert_eq!(actual_batch, expected_batch);
3251        }
3252
3253        // check compatibility between native and dictionaries
3254
3255        ensure_compatible_write(
3256            DictionaryArray::new(
3257                UInt8Array::from_iter_values(vec![0]),
3258                Arc::new(StringArray::from_iter_values(vec!["parquet"])),
3259            ),
3260            StringArray::from_iter_values(vec!["barquet"]),
3261            DictionaryArray::new(
3262                UInt8Array::from_iter_values(vec![0, 1]),
3263                Arc::new(StringArray::from_iter_values(vec!["parquet", "barquet"])),
3264            ),
3265        );
3266
3267        ensure_compatible_write(
3268            StringArray::from_iter_values(vec!["parquet"]),
3269            DictionaryArray::new(
3270                UInt8Array::from_iter_values(vec![0]),
3271                Arc::new(StringArray::from_iter_values(vec!["barquet"])),
3272            ),
3273            StringArray::from_iter_values(vec!["parquet", "barquet"]),
3274        );
3275
3276        // check compatibility between dictionaries with different key types
3277
3278        ensure_compatible_write(
3279            DictionaryArray::new(
3280                UInt8Array::from_iter_values(vec![0]),
3281                Arc::new(StringArray::from_iter_values(vec!["parquet"])),
3282            ),
3283            DictionaryArray::new(
3284                UInt16Array::from_iter_values(vec![0]),
3285                Arc::new(StringArray::from_iter_values(vec!["barquet"])),
3286            ),
3287            DictionaryArray::new(
3288                UInt8Array::from_iter_values(vec![0, 1]),
3289                Arc::new(StringArray::from_iter_values(vec!["parquet", "barquet"])),
3290            ),
3291        );
3292
3293        // check compatibility between dictionaries with different value types
3294        ensure_compatible_write(
3295            DictionaryArray::new(
3296                UInt8Array::from_iter_values(vec![0]),
3297                Arc::new(StringArray::from_iter_values(vec!["parquet"])),
3298            ),
3299            DictionaryArray::new(
3300                UInt8Array::from_iter_values(vec![0]),
3301                Arc::new(LargeStringArray::from_iter_values(vec!["barquet"])),
3302            ),
3303            DictionaryArray::new(
3304                UInt8Array::from_iter_values(vec![0, 1]),
3305                Arc::new(StringArray::from_iter_values(vec!["parquet", "barquet"])),
3306            ),
3307        );
3308
3309        // check compatibility between a dictionary and a native array with a different type
3310        ensure_compatible_write(
3311            DictionaryArray::new(
3312                UInt8Array::from_iter_values(vec![0]),
3313                Arc::new(StringArray::from_iter_values(vec!["parquet"])),
3314            ),
3315            LargeStringArray::from_iter_values(vec!["barquet"]),
3316            DictionaryArray::new(
3317                UInt8Array::from_iter_values(vec![0, 1]),
3318                Arc::new(StringArray::from_iter_values(vec!["parquet", "barquet"])),
3319            ),
3320        );
3321
3322        // check compatibility for string types
3323
3324        ensure_compatible_write(
3325            StringArray::from_iter_values(vec!["parquet"]),
3326            LargeStringArray::from_iter_values(vec!["barquet"]),
3327            StringArray::from_iter_values(vec!["parquet", "barquet"]),
3328        );
3329
3330        ensure_compatible_write(
3331            LargeStringArray::from_iter_values(vec!["parquet"]),
3332            StringArray::from_iter_values(vec!["barquet"]),
3333            LargeStringArray::from_iter_values(vec!["parquet", "barquet"]),
3334        );
3335
3336        ensure_compatible_write(
3337            StringArray::from_iter_values(vec!["parquet"]),
3338            StringViewArray::from_iter_values(vec!["barquet"]),
3339            StringArray::from_iter_values(vec!["parquet", "barquet"]),
3340        );
3341
3342        ensure_compatible_write(
3343            StringViewArray::from_iter_values(vec!["parquet"]),
3344            StringArray::from_iter_values(vec!["barquet"]),
3345            StringViewArray::from_iter_values(vec!["parquet", "barquet"]),
3346        );
3347
3348        ensure_compatible_write(
3349            LargeStringArray::from_iter_values(vec!["parquet"]),
3350            StringViewArray::from_iter_values(vec!["barquet"]),
3351            LargeStringArray::from_iter_values(vec!["parquet", "barquet"]),
3352        );
3353
3354        ensure_compatible_write(
3355            StringViewArray::from_iter_values(vec!["parquet"]),
3356            LargeStringArray::from_iter_values(vec!["barquet"]),
3357            StringViewArray::from_iter_values(vec!["parquet", "barquet"]),
3358        );
3359
3360        // check compatibility for binary types
3361
3362        ensure_compatible_write(
3363            BinaryArray::from_iter_values(vec![b"parquet"]),
3364            LargeBinaryArray::from_iter_values(vec![b"barquet"]),
3365            BinaryArray::from_iter_values(vec![b"parquet", b"barquet"]),
3366        );
3367
3368        ensure_compatible_write(
3369            LargeBinaryArray::from_iter_values(vec![b"parquet"]),
3370            BinaryArray::from_iter_values(vec![b"barquet"]),
3371            LargeBinaryArray::from_iter_values(vec![b"parquet", b"barquet"]),
3372        );
3373
3374        ensure_compatible_write(
3375            BinaryArray::from_iter_values(vec![b"parquet"]),
3376            BinaryViewArray::from_iter_values(vec![b"barquet"]),
3377            BinaryArray::from_iter_values(vec![b"parquet", b"barquet"]),
3378        );
3379
3380        ensure_compatible_write(
3381            BinaryViewArray::from_iter_values(vec![b"parquet"]),
3382            BinaryArray::from_iter_values(vec![b"barquet"]),
3383            BinaryViewArray::from_iter_values(vec![b"parquet", b"barquet"]),
3384        );
3385
3386        ensure_compatible_write(
3387            BinaryViewArray::from_iter_values(vec![b"parquet"]),
3388            LargeBinaryArray::from_iter_values(vec![b"barquet"]),
3389            BinaryViewArray::from_iter_values(vec![b"parquet", b"barquet"]),
3390        );
3391
3392        ensure_compatible_write(
3393            LargeBinaryArray::from_iter_values(vec![b"parquet"]),
3394            BinaryViewArray::from_iter_values(vec![b"barquet"]),
3395            LargeBinaryArray::from_iter_values(vec![b"parquet", b"barquet"]),
3396        );
3397
3398        // check compatibility for list types
3399
3400        let list_field_metadata = HashMap::from_iter(vec![(
3401            PARQUET_FIELD_ID_META_KEY.to_string(),
3402            "1".to_string(),
3403        )]);
3404        let list_field = Field::new_list_field(DataType::Int32, false);
3405
3406        let values1 = Arc::new(Int32Array::from(vec![0, 1, 2, 3, 4]));
3407        let offsets1 = OffsetBuffer::new(vec![0, 2, 5].into());
3408
3409        let values2 = Arc::new(Int32Array::from(vec![5, 6, 7, 8, 9]));
3410        let offsets2 = OffsetBuffer::new(vec![0, 3, 5].into());
3411
3412        let values_expected = Arc::new(Int32Array::from(vec![0, 1, 2, 3, 4, 5, 6, 7, 8, 9]));
3413        let offsets_expected = OffsetBuffer::new(vec![0, 2, 5, 8, 10].into());
3414
3415        ensure_compatible_write(
3416            // when the initial schema has the metadata ...
3417            ListArray::try_new(
3418                Arc::new(
3419                    list_field
3420                        .clone()
3421                        .with_metadata(list_field_metadata.clone()),
3422                ),
3423                offsets1,
3424                values1,
3425                None,
3426            )
3427            .unwrap(),
3428            // ... and some intermediate schema doesn't have the metadata
3429            ListArray::try_new(Arc::new(list_field.clone()), offsets2, values2, None).unwrap(),
3430            // ... the write will still go through, and the resulting schema will inherit the initial metadata
3431            ListArray::try_new(
3432                Arc::new(
3433                    list_field
3434                        .clone()
3435                        .with_metadata(list_field_metadata.clone()),
3436                ),
3437                offsets_expected,
3438                values_expected,
3439                None,
3440            )
3441            .unwrap(),
3442        );
3443    }
3444
3445    #[test]
3446    #[cfg_attr(miri, ignore)] // Takes too long
3447    fn u32_min_max() {
3448        // check values roundtrip through parquet
3449        let src = [
3450            u32::MIN,
3451            1,
3452            (i32::MAX as u32) - 1,
3453            i32::MAX as u32,
3454            (i32::MAX as u32) + 1,
3455            u32::MAX - 1,
3456            u32::MAX,
3457        ];
3458        let values = Arc::new(UInt32Array::from_iter_values(src.iter().copied()));
3459        let files = RoundTripTest::new(values).with_nullable(false).run();
3460
3461        for file in files {
3462            // check statistics are valid
3463            let reader = SerializedFileReader::new(file).unwrap();
3464            let metadata = reader.metadata();
3465
3466            let mut row_offset = 0;
3467            for row_group in metadata.row_groups() {
3468                assert_eq!(row_group.num_columns(), 1);
3469                let column = row_group.column(0);
3470
3471                let num_values = column.num_values() as usize;
3472                let src_slice = &src[row_offset..row_offset + num_values];
3473                row_offset += column.num_values() as usize;
3474
3475                let stats = column.statistics().unwrap();
3476                if let Statistics::Int32(stats) = stats {
3477                    assert_eq!(
3478                        *stats.min_opt().unwrap() as u32,
3479                        *src_slice.iter().min().unwrap()
3480                    );
3481                    assert_eq!(
3482                        *stats.max_opt().unwrap() as u32,
3483                        *src_slice.iter().max().unwrap()
3484                    );
3485                } else {
3486                    panic!("Statistics::Int32 missing")
3487                }
3488            }
3489        }
3490    }
3491
3492    #[test]
3493    #[cfg_attr(miri, ignore)] // Takes too long
3494    fn u64_min_max() {
3495        // check values roundtrip through parquet
3496        let src = [
3497            u64::MIN,
3498            1,
3499            (i64::MAX as u64) - 1,
3500            i64::MAX as u64,
3501            (i64::MAX as u64) + 1,
3502            u64::MAX - 1,
3503            u64::MAX,
3504        ];
3505        let values = Arc::new(UInt64Array::from_iter_values(src.iter().copied()));
3506        let files = RoundTripTest::new(values).with_nullable(false).run();
3507
3508        for file in files {
3509            // check statistics are valid
3510            let reader = SerializedFileReader::new(file).unwrap();
3511            let metadata = reader.metadata();
3512
3513            let mut row_offset = 0;
3514            for row_group in metadata.row_groups() {
3515                assert_eq!(row_group.num_columns(), 1);
3516                let column = row_group.column(0);
3517
3518                let num_values = column.num_values() as usize;
3519                let src_slice = &src[row_offset..row_offset + num_values];
3520                row_offset += column.num_values() as usize;
3521
3522                let stats = column.statistics().unwrap();
3523                if let Statistics::Int64(stats) = stats {
3524                    assert_eq!(
3525                        *stats.min_opt().unwrap() as u64,
3526                        *src_slice.iter().min().unwrap()
3527                    );
3528                    assert_eq!(
3529                        *stats.max_opt().unwrap() as u64,
3530                        *src_slice.iter().max().unwrap()
3531                    );
3532                } else {
3533                    panic!("Statistics::Int64 missing")
3534                }
3535            }
3536        }
3537    }
3538
3539    #[test]
3540    #[cfg_attr(miri, ignore)] // Takes too long
3541    fn statistics_null_counts_only_nulls() {
3542        // check that null-count statistics for "only NULL"-columns are correct
3543        let values = Arc::new(UInt64Array::from(vec![None, None]));
3544        let files = RoundTripTest::new(values).run();
3545
3546        for file in files {
3547            // check statistics are valid
3548            let reader = SerializedFileReader::new(file).unwrap();
3549            let metadata = reader.metadata();
3550            assert_eq!(metadata.num_row_groups(), 1);
3551            let row_group = metadata.row_group(0);
3552            assert_eq!(row_group.num_columns(), 1);
3553            let column = row_group.column(0);
3554            let stats = column.statistics().unwrap();
3555            assert_eq!(stats.null_count_opt(), Some(2));
3556        }
3557    }
3558
3559    #[test]
3560    #[cfg_attr(miri, ignore)] // Takes too long
3561    fn test_list_of_struct_roundtrip() {
3562        // define schema
3563        let int_field = Field::new("a", DataType::Int32, true);
3564        let int_field2 = Field::new("b", DataType::Int32, true);
3565
3566        let int_builder = Int32Builder::with_capacity(10);
3567        let int_builder2 = Int32Builder::with_capacity(10);
3568
3569        let struct_builder = StructBuilder::new(
3570            vec![int_field, int_field2],
3571            vec![Box::new(int_builder), Box::new(int_builder2)],
3572        );
3573        let mut list_builder = ListBuilder::new(struct_builder);
3574
3575        // Construct the following array
3576        // [{a: 1, b: 2}], [], null, [null, null], [{a: null, b: 3}], [{a: 2, b: null}]
3577
3578        // [{a: 1, b: 2}]
3579        let values = list_builder.values();
3580        values
3581            .field_builder::<Int32Builder>(0)
3582            .unwrap()
3583            .append_value(1);
3584        values
3585            .field_builder::<Int32Builder>(1)
3586            .unwrap()
3587            .append_value(2);
3588        values.append(true);
3589        list_builder.append(true);
3590
3591        // []
3592        list_builder.append(true);
3593
3594        // null
3595        list_builder.append(false);
3596
3597        // [null, null]
3598        let values = list_builder.values();
3599        values
3600            .field_builder::<Int32Builder>(0)
3601            .unwrap()
3602            .append_null();
3603        values
3604            .field_builder::<Int32Builder>(1)
3605            .unwrap()
3606            .append_null();
3607        values.append(false);
3608        values
3609            .field_builder::<Int32Builder>(0)
3610            .unwrap()
3611            .append_null();
3612        values
3613            .field_builder::<Int32Builder>(1)
3614            .unwrap()
3615            .append_null();
3616        values.append(false);
3617        list_builder.append(true);
3618
3619        // [{a: null, b: 3}]
3620        let values = list_builder.values();
3621        values
3622            .field_builder::<Int32Builder>(0)
3623            .unwrap()
3624            .append_null();
3625        values
3626            .field_builder::<Int32Builder>(1)
3627            .unwrap()
3628            .append_value(3);
3629        values.append(true);
3630        list_builder.append(true);
3631
3632        // [{a: 2, b: null}]
3633        let values = list_builder.values();
3634        values
3635            .field_builder::<Int32Builder>(0)
3636            .unwrap()
3637            .append_value(2);
3638        values
3639            .field_builder::<Int32Builder>(1)
3640            .unwrap()
3641            .append_null();
3642        values.append(true);
3643        list_builder.append(true);
3644
3645        let array = Arc::new(list_builder.finish());
3646
3647        RoundTripTest::new(array).run();
3648    }
3649
3650    fn row_group_sizes(metadata: &ParquetMetaData) -> Vec<i64> {
3651        metadata.row_groups().iter().map(|x| x.num_rows()).collect()
3652    }
3653
3654    #[test]
3655    fn test_aggregates_records() {
3656        let arrays = [
3657            Int32Array::from((0..100).collect::<Vec<_>>()),
3658            Int32Array::from((0..50).collect::<Vec<_>>()),
3659            Int32Array::from((200..500).collect::<Vec<_>>()),
3660        ];
3661
3662        let schema = Arc::new(Schema::new(vec![Field::new(
3663            "int",
3664            ArrowDataType::Int32,
3665            false,
3666        )]));
3667
3668        let file = tempfile::tempfile().unwrap();
3669
3670        let props = WriterProperties::builder()
3671            .set_max_row_group_row_count(Some(200))
3672            .build();
3673
3674        let mut writer =
3675            ArrowWriter::try_new(file.try_clone().unwrap(), schema.clone(), Some(props)).unwrap();
3676
3677        for array in arrays {
3678            let batch = RecordBatch::try_new(schema.clone(), vec![Arc::new(array)]).unwrap();
3679            writer.write(&batch).unwrap();
3680        }
3681
3682        writer.close().unwrap();
3683
3684        let builder = ParquetRecordBatchReaderBuilder::try_new(file).unwrap();
3685        assert_eq!(&row_group_sizes(builder.metadata()), &[200, 200, 50]);
3686
3687        let batches = builder
3688            .with_batch_size(100)
3689            .build()
3690            .unwrap()
3691            .collect::<ArrowResult<Vec<_>>>()
3692            .unwrap();
3693
3694        assert_eq!(batches.len(), 5);
3695        assert!(batches.iter().all(|x| x.num_columns() == 1));
3696
3697        let batch_sizes: Vec<_> = batches.iter().map(|x| x.num_rows()).collect();
3698
3699        assert_eq!(&batch_sizes, &[100, 100, 100, 100, 50]);
3700
3701        let values: Vec<_> = batches
3702            .iter()
3703            .flat_map(|x| {
3704                x.column(0)
3705                    .as_any()
3706                    .downcast_ref::<Int32Array>()
3707                    .unwrap()
3708                    .values()
3709                    .iter()
3710                    .copied()
3711            })
3712            .collect();
3713
3714        let expected_values: Vec<_> = [0..100, 0..50, 200..500].into_iter().flatten().collect();
3715        assert_eq!(&values, &expected_values)
3716    }
3717
3718    #[test]
3719    fn complex_aggregate() {
3720        // Tests aggregating nested data
3721        let field_a = Arc::new(Field::new("leaf_a", DataType::Int32, false));
3722        let field_b = Arc::new(Field::new("leaf_b", DataType::Int32, true));
3723        let struct_a = Arc::new(Field::new(
3724            "struct_a",
3725            DataType::Struct(vec![field_a.clone(), field_b.clone()].into()),
3726            true,
3727        ));
3728
3729        let list_a = Arc::new(Field::new("list", DataType::List(struct_a), true));
3730        let struct_b = Arc::new(Field::new(
3731            "struct_b",
3732            DataType::Struct(vec![list_a.clone()].into()),
3733            false,
3734        ));
3735
3736        let schema = Arc::new(Schema::new(vec![struct_b]));
3737
3738        // create nested data
3739        let field_a_array = Int32Array::from(vec![1, 2, 3, 4, 5, 6]);
3740        let field_b_array =
3741            Int32Array::from_iter(vec![Some(1), None, Some(2), None, None, Some(6)]);
3742
3743        let struct_a_array = StructArray::from(vec![
3744            (field_a.clone(), Arc::new(field_a_array) as ArrayRef),
3745            (field_b.clone(), Arc::new(field_b_array) as ArrayRef),
3746        ]);
3747
3748        let list_data = ArrayDataBuilder::new(list_a.data_type().clone())
3749            .len(5)
3750            .add_buffer(Buffer::from_iter(vec![
3751                0_i32, 1_i32, 1_i32, 3_i32, 3_i32, 5_i32,
3752            ]))
3753            .null_bit_buffer(Some(Buffer::from_iter(vec![
3754                true, false, true, false, true,
3755            ])))
3756            .child_data(vec![struct_a_array.into_data()])
3757            .build()
3758            .unwrap();
3759
3760        let list_a_array = Arc::new(ListArray::from(list_data)) as ArrayRef;
3761        let struct_b_array = StructArray::from(vec![(list_a.clone(), list_a_array)]);
3762
3763        let batch1 =
3764            RecordBatch::try_from_iter(vec![("struct_b", Arc::new(struct_b_array) as ArrayRef)])
3765                .unwrap();
3766
3767        let field_a_array = Int32Array::from(vec![6, 7, 8, 9, 10]);
3768        let field_b_array = Int32Array::from_iter(vec![None, None, None, Some(1), None]);
3769
3770        let struct_a_array = StructArray::from(vec![
3771            (field_a, Arc::new(field_a_array) as ArrayRef),
3772            (field_b, Arc::new(field_b_array) as ArrayRef),
3773        ]);
3774
3775        let list_data = ArrayDataBuilder::new(list_a.data_type().clone())
3776            .len(2)
3777            .add_buffer(Buffer::from_iter(vec![0_i32, 4_i32, 5_i32]))
3778            .child_data(vec![struct_a_array.into_data()])
3779            .build()
3780            .unwrap();
3781
3782        let list_a_array = Arc::new(ListArray::from(list_data)) as ArrayRef;
3783        let struct_b_array = StructArray::from(vec![(list_a, list_a_array)]);
3784
3785        let batch2 =
3786            RecordBatch::try_from_iter(vec![("struct_b", Arc::new(struct_b_array) as ArrayRef)])
3787                .unwrap();
3788
3789        let batches = &[batch1, batch2];
3790
3791        // Verify data is as expected
3792
3793        let expected = r"
3794            +-------------------------------------------------------------------------------------------------------+
3795            | struct_b                                                                                              |
3796            +-------------------------------------------------------------------------------------------------------+
3797            | {list: [{leaf_a: 1, leaf_b: 1}]}                                                                      |
3798            | {list: }                                                                                              |
3799            | {list: [{leaf_a: 2, leaf_b: }, {leaf_a: 3, leaf_b: 2}]}                                               |
3800            | {list: }                                                                                              |
3801            | {list: [{leaf_a: 4, leaf_b: }, {leaf_a: 5, leaf_b: }]}                                                |
3802            | {list: [{leaf_a: 6, leaf_b: }, {leaf_a: 7, leaf_b: }, {leaf_a: 8, leaf_b: }, {leaf_a: 9, leaf_b: 1}]} |
3803            | {list: [{leaf_a: 10, leaf_b: }]}                                                                      |
3804            +-------------------------------------------------------------------------------------------------------+
3805        ".trim().split('\n').map(|x| x.trim()).collect::<Vec<_>>().join("\n");
3806
3807        let actual = pretty_format_batches(batches).unwrap().to_string();
3808        assert_eq!(actual, expected);
3809
3810        // Write data
3811        let file = tempfile::tempfile().unwrap();
3812        let props = WriterProperties::builder()
3813            .set_max_row_group_row_count(Some(6))
3814            .build();
3815
3816        let mut writer =
3817            ArrowWriter::try_new(file.try_clone().unwrap(), schema, Some(props)).unwrap();
3818
3819        for batch in batches {
3820            writer.write(batch).unwrap();
3821        }
3822        writer.close().unwrap();
3823
3824        // Read Data
3825        // Should have written entire first batch and first row of second to the first row group
3826        // leaving a single row in the second row group
3827
3828        let builder = ParquetRecordBatchReaderBuilder::try_new(file).unwrap();
3829        assert_eq!(&row_group_sizes(builder.metadata()), &[6, 1]);
3830
3831        let batches = builder
3832            .with_batch_size(2)
3833            .build()
3834            .unwrap()
3835            .collect::<ArrowResult<Vec<_>>>()
3836            .unwrap();
3837
3838        assert_eq!(batches.len(), 4);
3839        let batch_counts: Vec<_> = batches.iter().map(|x| x.num_rows()).collect();
3840        assert_eq!(&batch_counts, &[2, 2, 2, 1]);
3841
3842        let actual = pretty_format_batches(&batches).unwrap().to_string();
3843        assert_eq!(actual, expected);
3844    }
3845
3846    #[test]
3847    fn test_arrow_writer_metadata() {
3848        let batch_schema = Schema::new(vec![Field::new("int32", DataType::Int32, false)]);
3849        let file_schema = batch_schema.clone().with_metadata([("foo", "bar")]);
3850
3851        let batch = RecordBatch::try_new(
3852            Arc::new(batch_schema),
3853            vec![Arc::new(Int32Array::from(vec![1, 2, 3, 4])) as _],
3854        )
3855        .unwrap();
3856
3857        let mut buf = Vec::with_capacity(1024);
3858        let mut writer = ArrowWriter::try_new(&mut buf, Arc::new(file_schema), None).unwrap();
3859        writer.write(&batch).unwrap();
3860        writer.close().unwrap();
3861    }
3862
3863    #[test]
3864    fn test_arrow_writer_nullable() {
3865        let batch_schema = Schema::new(vec![Field::new("int32", DataType::Int32, false)]);
3866        let file_schema = Schema::new(vec![Field::new("int32", DataType::Int32, true)]);
3867        let file_schema = Arc::new(file_schema);
3868
3869        let batch = RecordBatch::try_new(
3870            Arc::new(batch_schema),
3871            vec![Arc::new(Int32Array::from(vec![1, 2, 3, 4])) as _],
3872        )
3873        .unwrap();
3874
3875        let mut buf = Vec::with_capacity(1024);
3876        let mut writer = ArrowWriter::try_new(&mut buf, file_schema.clone(), None).unwrap();
3877        writer.write(&batch).unwrap();
3878        writer.close().unwrap();
3879
3880        let mut read = ParquetRecordBatchReader::try_new(Bytes::from(buf), 1024).unwrap();
3881        let back = read.next().unwrap().unwrap();
3882        assert_eq!(back.schema(), file_schema);
3883        assert_ne!(back.schema(), batch.schema());
3884        assert_eq!(back.column(0).as_ref(), batch.column(0).as_ref());
3885    }
3886
3887    #[test]
3888    fn in_progress_accounting() {
3889        // define schema
3890        let schema = Schema::new(vec![Field::new("a", DataType::Int32, false)]);
3891
3892        // create some data
3893        let a = Int32Array::from(vec![1, 2, 3, 4, 5]);
3894
3895        // build a record batch
3896        let batch = RecordBatch::try_new(Arc::new(schema), vec![Arc::new(a)]).unwrap();
3897
3898        let mut writer = ArrowWriter::try_new(vec![], batch.schema(), None).unwrap();
3899
3900        // starts empty
3901        assert_eq!(writer.in_progress_size(), 0);
3902        assert_eq!(writer.in_progress_rows(), 0);
3903        assert_eq!(writer.memory_size(), 0);
3904        assert_eq!(writer.bytes_written(), 4); // Initial header
3905        writer.write(&batch).unwrap();
3906
3907        // updated on write
3908        let initial_size = writer.in_progress_size();
3909        assert!(initial_size > 0);
3910        assert_eq!(writer.in_progress_rows(), 5);
3911        let initial_memory = writer.memory_size();
3912        assert!(initial_memory > 0);
3913        // memory estimate is larger than estimated encoded size
3914        assert!(
3915            initial_size <= initial_memory,
3916            "{initial_size} <= {initial_memory}"
3917        );
3918
3919        // updated on second write
3920        writer.write(&batch).unwrap();
3921        assert!(writer.in_progress_size() > initial_size);
3922        assert_eq!(writer.in_progress_rows(), 10);
3923        assert!(writer.memory_size() > initial_memory);
3924        assert!(
3925            writer.in_progress_size() <= writer.memory_size(),
3926            "in_progress_size {} <= memory_size {}",
3927            writer.in_progress_size(),
3928            writer.memory_size()
3929        );
3930
3931        // in progress tracking is cleared, but the overall data written is updated
3932        let pre_flush_bytes_written = writer.bytes_written();
3933        writer.flush().unwrap();
3934        assert_eq!(writer.in_progress_size(), 0);
3935        assert_eq!(writer.memory_size(), 0);
3936        assert!(writer.bytes_written() > pre_flush_bytes_written);
3937
3938        writer.close().unwrap();
3939    }
3940
3941    #[test]
3942    fn test_writer_all_null() {
3943        let a = Int32Array::from(vec![1, 2, 3, 4, 5]);
3944        let b = Int32Array::new(vec![0; 5].into(), Some(NullBuffer::new_null(5)));
3945        let batch = RecordBatch::try_from_iter(vec![
3946            ("a", Arc::new(a) as ArrayRef),
3947            ("b", Arc::new(b) as ArrayRef),
3948        ])
3949        .unwrap();
3950
3951        let mut buf = Vec::with_capacity(1024);
3952        let mut writer = ArrowWriter::try_new(&mut buf, batch.schema(), None).unwrap();
3953        writer.write(&batch).unwrap();
3954        writer.close().unwrap();
3955
3956        let bytes = Bytes::from(buf);
3957        let options = ReadOptionsBuilder::new().with_page_index().build();
3958        let reader = SerializedFileReader::new_with_options(bytes, options).unwrap();
3959        let index = reader.metadata().page_index().unwrap();
3960
3961        assert_eq!(index.num_data_pages(0, 0), Some(1)); // 1 page
3962        assert_eq!(index.num_data_pages(0, 1), Some(1)); // 1 page
3963    }
3964
3965    #[test]
3966    fn test_disabled_statistics_with_page() {
3967        let file_schema = Schema::new(vec![
3968            Field::new("a", DataType::Utf8, true),
3969            Field::new("b", DataType::Utf8, true),
3970        ]);
3971        let file_schema = Arc::new(file_schema);
3972
3973        let batch = RecordBatch::try_new(
3974            file_schema.clone(),
3975            vec![
3976                Arc::new(StringArray::from(vec!["a", "b", "c", "d"])) as _,
3977                Arc::new(StringArray::from(vec!["w", "x", "y", "z"])) as _,
3978            ],
3979        )
3980        .unwrap();
3981
3982        let props = WriterProperties::builder()
3983            .set_statistics_enabled(EnabledStatistics::None)
3984            .set_column_statistics_enabled("a".into(), EnabledStatistics::Page)
3985            .build();
3986
3987        let mut buf = Vec::with_capacity(1024);
3988        let mut writer = ArrowWriter::try_new(&mut buf, file_schema.clone(), Some(props)).unwrap();
3989        writer.write(&batch).unwrap();
3990
3991        let metadata = writer.close().unwrap();
3992        assert_eq!(metadata.num_row_groups(), 1);
3993        let row_group = metadata.row_group(0);
3994        assert_eq!(row_group.num_columns(), 2);
3995        // Column "a" has both offset and column index, as requested
3996        assert!(row_group.column(0).offset_index_offset().is_some());
3997        assert!(row_group.column(0).column_index_offset().is_some());
3998        // Column "b" should only have offset index
3999        assert!(row_group.column(1).offset_index_offset().is_some());
4000        assert!(row_group.column(1).column_index_offset().is_none());
4001
4002        let options = ReadOptionsBuilder::new().with_page_index().build();
4003        let reader = SerializedFileReader::new_with_options(Bytes::from(buf), options).unwrap();
4004
4005        let row_group = reader.get_row_group(0).unwrap();
4006        let a_col = row_group.metadata().column(0);
4007        let b_col = row_group.metadata().column(1);
4008
4009        // Column chunk of column "a" should have chunk level statistics
4010        if let Statistics::ByteArray(byte_array_stats) = a_col.statistics().unwrap() {
4011            let min = byte_array_stats.min_opt().unwrap();
4012            let max = byte_array_stats.max_opt().unwrap();
4013
4014            assert_eq!(min.as_bytes(), b"a");
4015            assert_eq!(max.as_bytes(), b"d");
4016        } else {
4017            panic!("expecting Statistics::ByteArray");
4018        }
4019
4020        // The column chunk for column "b" shouldn't have statistics
4021        assert!(b_col.statistics().is_none());
4022
4023        let page_index = reader.metadata().page_index().unwrap();
4024
4025        let a_idx = page_index.column_index(0, 0);
4026        assert!(
4027            matches!(a_idx, Some(ColumnIndexMetaData::BYTE_ARRAY(_))),
4028            "{a_idx:?}"
4029        );
4030        let b_idx = page_index.column_index(0, 1);
4031        assert!(b_idx.is_none(), "{b_idx:?}");
4032    }
4033
4034    #[test]
4035    fn test_disabled_statistics_with_chunk() {
4036        let file_schema = Schema::new(vec![
4037            Field::new("a", DataType::Utf8, true),
4038            Field::new("b", DataType::Utf8, true),
4039        ]);
4040        let file_schema = Arc::new(file_schema);
4041
4042        let batch = RecordBatch::try_new(
4043            file_schema.clone(),
4044            vec![
4045                Arc::new(StringArray::from(vec!["a", "b", "c", "d"])) as _,
4046                Arc::new(StringArray::from(vec!["w", "x", "y", "z"])) as _,
4047            ],
4048        )
4049        .unwrap();
4050
4051        let props = WriterProperties::builder()
4052            .set_statistics_enabled(EnabledStatistics::None)
4053            .set_column_statistics_enabled("a".into(), EnabledStatistics::Chunk)
4054            .build();
4055
4056        let mut buf = Vec::with_capacity(1024);
4057        let mut writer = ArrowWriter::try_new(&mut buf, file_schema.clone(), Some(props)).unwrap();
4058        writer.write(&batch).unwrap();
4059
4060        let metadata = writer.close().unwrap();
4061        assert_eq!(metadata.num_row_groups(), 1);
4062        let row_group = metadata.row_group(0);
4063        assert_eq!(row_group.num_columns(), 2);
4064        // Column "a" should only have offset index
4065        assert!(row_group.column(0).offset_index_offset().is_some());
4066        assert!(row_group.column(0).column_index_offset().is_none());
4067        // Column "b" should only have offset index
4068        assert!(row_group.column(1).offset_index_offset().is_some());
4069        assert!(row_group.column(1).column_index_offset().is_none());
4070
4071        let options = ReadOptionsBuilder::new().with_page_index().build();
4072        let reader = SerializedFileReader::new_with_options(Bytes::from(buf), options).unwrap();
4073
4074        let row_group = reader.get_row_group(0).unwrap();
4075        let a_col = row_group.metadata().column(0);
4076        let b_col = row_group.metadata().column(1);
4077
4078        // Column chunk of column "a" should have chunk level statistics
4079        if let Statistics::ByteArray(byte_array_stats) = a_col.statistics().unwrap() {
4080            let min = byte_array_stats.min_opt().unwrap();
4081            let max = byte_array_stats.max_opt().unwrap();
4082
4083            assert_eq!(min.as_bytes(), b"a");
4084            assert_eq!(max.as_bytes(), b"d");
4085        } else {
4086            panic!("expecting Statistics::ByteArray");
4087        }
4088
4089        // The column chunk for column "b"  shouldn't have statistics
4090        assert!(b_col.statistics().is_none());
4091
4092        let page_index = reader.metadata().page_index().unwrap();
4093
4094        let a_idx = page_index.column_index(0, 0);
4095        assert!(a_idx.is_none(), "{a_idx:?}");
4096        let b_idx = page_index.column_index(0, 1);
4097        assert!(b_idx.is_none(), "{b_idx:?}");
4098    }
4099
4100    #[test]
4101    fn test_arrow_writer_skip_metadata() {
4102        let batch_schema = Schema::new(vec![Field::new("int32", DataType::Int32, false)]);
4103        let file_schema = Arc::new(batch_schema.clone());
4104
4105        let batch = RecordBatch::try_new(
4106            Arc::new(batch_schema),
4107            vec![Arc::new(Int32Array::from(vec![1, 2, 3, 4])) as _],
4108        )
4109        .unwrap();
4110        let skip_options = ArrowWriterOptions::new().with_skip_arrow_metadata(true);
4111
4112        let mut buf = Vec::with_capacity(1024);
4113        let mut writer =
4114            ArrowWriter::try_new_with_options(&mut buf, file_schema.clone(), skip_options).unwrap();
4115        writer.write(&batch).unwrap();
4116        writer.close().unwrap();
4117
4118        let bytes = Bytes::from(buf);
4119        let reader_builder = ParquetRecordBatchReaderBuilder::try_new(bytes).unwrap();
4120        assert_eq!(file_schema, *reader_builder.schema());
4121        if let Some(key_value_metadata) = reader_builder
4122            .metadata()
4123            .file_metadata()
4124            .key_value_metadata()
4125        {
4126            assert!(
4127                !key_value_metadata
4128                    .iter()
4129                    .any(|kv| kv.key.as_str() == ARROW_SCHEMA_META_KEY)
4130            );
4131        }
4132    }
4133
4134    #[test]
4135    fn test_arrow_writer_skip_path_in_schema() {
4136        let batch_schema = Schema::new(vec![Field::new("int32", DataType::Int32, false)]);
4137        let file_schema = Arc::new(batch_schema.clone());
4138
4139        let batch = RecordBatch::try_new(
4140            Arc::new(batch_schema),
4141            vec![Arc::new(Int32Array::from(vec![1, 2, 3, 4])) as _],
4142        )
4143        .unwrap();
4144
4145        // default options should still write path_in_schema
4146        let skip_options = ArrowWriterOptions::new();
4147
4148        let mut buf = Vec::with_capacity(1024);
4149        let mut writer =
4150            ArrowWriter::try_new_with_options(&mut buf, file_schema.clone(), skip_options).unwrap();
4151        writer.write(&batch).unwrap();
4152        writer.close().unwrap();
4153
4154        // override to not write path_in_schema
4155        let skip_options = ArrowWriterOptions::new().with_properties(
4156            WriterProperties::builder()
4157                .set_write_path_in_schema(false)
4158                .build(),
4159        );
4160
4161        let mut buf2 = Vec::with_capacity(1024);
4162        let mut writer =
4163            ArrowWriter::try_new_with_options(&mut buf2, file_schema.clone(), skip_options)
4164                .unwrap();
4165        writer.write(&batch).unwrap();
4166        writer.close().unwrap();
4167
4168        // buf2 should be a bit smaller due to lack of path_in_schema
4169        assert!(buf.len() > buf2.len());
4170    }
4171
4172    #[test]
4173    fn mismatched_schemas() {
4174        let batch_schema = Schema::new(vec![Field::new("count", DataType::Int32, false)]);
4175        let file_schema = Arc::new(Schema::new(vec![Field::new(
4176            "temperature",
4177            DataType::Float64,
4178            false,
4179        )]));
4180
4181        let batch = RecordBatch::try_new(
4182            Arc::new(batch_schema),
4183            vec![Arc::new(Int32Array::from(vec![1, 2, 3, 4])) as _],
4184        )
4185        .unwrap();
4186
4187        let mut buf = Vec::with_capacity(1024);
4188        let mut writer = ArrowWriter::try_new(&mut buf, file_schema.clone(), None).unwrap();
4189
4190        let err = writer.write(&batch).unwrap_err().to_string();
4191        assert_eq!(
4192            err,
4193            "Arrow: Incompatible type. Field 'temperature' has type Float64, array has type Int32"
4194        );
4195    }
4196
4197    #[test]
4198    // https://github.com/apache/arrow-rs/issues/6988
4199    fn test_roundtrip_empty_schema() {
4200        // create empty record batch with empty schema
4201        let empty_batch = RecordBatch::try_new_with_options(
4202            Arc::new(Schema::empty()),
4203            vec![],
4204            &RecordBatchOptions::default().with_row_count(Some(0)),
4205        )
4206        .unwrap();
4207
4208        // write to parquet
4209        let mut parquet_bytes: Vec<u8> = Vec::new();
4210        let mut writer =
4211            ArrowWriter::try_new(&mut parquet_bytes, empty_batch.schema(), None).unwrap();
4212        writer.write(&empty_batch).unwrap();
4213        writer.close().unwrap();
4214
4215        // read from parquet
4216        let bytes = Bytes::from(parquet_bytes);
4217        let reader = ParquetRecordBatchReaderBuilder::try_new(bytes).unwrap();
4218        assert_eq!(reader.schema(), &empty_batch.schema());
4219        let batches: Vec<_> = reader
4220            .build()
4221            .unwrap()
4222            .collect::<ArrowResult<Vec<_>>>()
4223            .unwrap();
4224        assert_eq!(batches.len(), 0);
4225    }
4226
4227    #[test]
4228    fn test_page_stats_not_written_by_default() {
4229        let string_field = Field::new("a", DataType::Utf8, false);
4230        let schema = Schema::new(vec![string_field]);
4231        let raw_string_values = vec!["Blart Versenwald III"];
4232        let string_values = StringArray::from(raw_string_values.clone());
4233        let batch = RecordBatch::try_new(Arc::new(schema), vec![Arc::new(string_values)]).unwrap();
4234
4235        let props = WriterProperties::builder()
4236            .set_statistics_enabled(EnabledStatistics::Page)
4237            .set_dictionary_enabled(false)
4238            .set_encoding(Encoding::PLAIN)
4239            .set_compression(crate::basic::Compression::UNCOMPRESSED)
4240            .build();
4241
4242        let file = roundtrip_opts(&batch, props);
4243
4244        // read file and decode page headers
4245        // Note: use the thrift API as there is no Rust API to access the statistics in the page headers
4246
4247        // decode first page header
4248        let first_page = &file[4..];
4249        let mut prot = ThriftSliceInputProtocol::new(first_page);
4250        let hdr = PageHeader::read_thrift(&mut prot).unwrap();
4251        let stats = hdr.data_page_header.unwrap().statistics;
4252
4253        assert!(stats.is_none());
4254    }
4255
4256    #[test]
4257    fn test_page_stats_when_enabled() {
4258        let string_field = Field::new("a", DataType::Utf8, false);
4259        let schema = Schema::new(vec![string_field]);
4260        let raw_string_values = vec!["Blart Versenwald III", "Andrew Lamb"];
4261        let string_values = StringArray::from(raw_string_values.clone());
4262        let batch = RecordBatch::try_new(Arc::new(schema), vec![Arc::new(string_values)]).unwrap();
4263
4264        let props = WriterProperties::builder()
4265            .set_statistics_enabled(EnabledStatistics::Page)
4266            .set_dictionary_enabled(false)
4267            .set_encoding(Encoding::PLAIN)
4268            .set_write_page_header_statistics(true)
4269            .set_compression(crate::basic::Compression::UNCOMPRESSED)
4270            .build();
4271
4272        let file = roundtrip_opts(&batch, props);
4273
4274        // read file and decode page headers
4275        // Note: use the thrift API as there is no Rust API to access the statistics in the page headers
4276
4277        // decode first page header
4278        let first_page = &file[4..];
4279        let mut prot = ThriftSliceInputProtocol::new(first_page);
4280        let hdr = PageHeader::read_thrift(&mut prot).unwrap();
4281        let stats = hdr.data_page_header.unwrap().statistics;
4282
4283        let stats = stats.unwrap();
4284        // check that min/max were actually written to the page
4285        assert!(stats.is_max_value_exact.unwrap());
4286        assert!(stats.is_min_value_exact.unwrap());
4287        assert_eq!(stats.max_value.unwrap(), b"Blart Versenwald III");
4288        assert_eq!(stats.min_value.unwrap(), b"Andrew Lamb");
4289    }
4290
4291    #[test]
4292    fn test_page_stats_truncation() {
4293        let string_field = Field::new("a", DataType::Utf8, false);
4294        let binary_field = Field::new("b", DataType::Binary, false);
4295        let schema = Schema::new(vec![string_field, binary_field]);
4296
4297        let raw_string_values = vec!["Blart Versenwald III"];
4298        let raw_binary_values = [b"Blart Versenwald III".to_vec()];
4299        let raw_binary_value_refs = raw_binary_values
4300            .iter()
4301            .map(|x| x.as_slice())
4302            .collect::<Vec<_>>();
4303
4304        let string_values = StringArray::from(raw_string_values.clone());
4305        let binary_values = BinaryArray::from(raw_binary_value_refs);
4306        let batch = RecordBatch::try_new(
4307            Arc::new(schema),
4308            vec![Arc::new(string_values), Arc::new(binary_values)],
4309        )
4310        .unwrap();
4311
4312        let props = WriterProperties::builder()
4313            .set_statistics_truncate_length(Some(2))
4314            .set_dictionary_enabled(false)
4315            .set_encoding(Encoding::PLAIN)
4316            .set_write_page_header_statistics(true)
4317            .set_compression(crate::basic::Compression::UNCOMPRESSED)
4318            .build();
4319
4320        let file = roundtrip_opts(&batch, props);
4321
4322        // read file and decode page headers
4323        // Note: use the thrift API as there is no Rust API to access the statistics in the page headers
4324
4325        // decode first page header
4326        let first_page = &file[4..];
4327        let mut prot = ThriftSliceInputProtocol::new(first_page);
4328        let hdr = PageHeader::read_thrift(&mut prot).unwrap();
4329        let stats = hdr.data_page_header.unwrap().statistics;
4330        assert!(stats.is_some());
4331        let stats = stats.unwrap();
4332        // check that min/max were properly truncated
4333        assert!(!stats.is_max_value_exact.unwrap());
4334        assert!(!stats.is_min_value_exact.unwrap());
4335        assert_eq!(stats.max_value.unwrap(), b"Bm");
4336        assert_eq!(stats.min_value.unwrap(), b"Bl");
4337
4338        // check second page now
4339        let second_page = &prot.as_slice()[hdr.compressed_page_size as usize..];
4340        let mut prot = ThriftSliceInputProtocol::new(second_page);
4341        let hdr = PageHeader::read_thrift(&mut prot).unwrap();
4342        let stats = hdr.data_page_header.unwrap().statistics;
4343        assert!(stats.is_some());
4344        let stats = stats.unwrap();
4345        // check that min/max were properly truncated
4346        assert!(!stats.is_max_value_exact.unwrap());
4347        assert!(!stats.is_min_value_exact.unwrap());
4348        assert_eq!(stats.max_value.unwrap(), b"Bm");
4349        assert_eq!(stats.min_value.unwrap(), b"Bl");
4350    }
4351
4352    #[test]
4353    fn test_page_encoding_statistics_roundtrip() {
4354        let batch_schema = Schema::new(vec![Field::new(
4355            "int32",
4356            arrow_schema::DataType::Int32,
4357            false,
4358        )]);
4359
4360        let batch = RecordBatch::try_new(
4361            Arc::new(batch_schema.clone()),
4362            vec![Arc::new(Int32Array::from(vec![1, 2, 3, 4])) as _],
4363        )
4364        .unwrap();
4365
4366        let mut file: File = tempfile::tempfile().unwrap();
4367        let mut writer = ArrowWriter::try_new(&mut file, Arc::new(batch_schema), None).unwrap();
4368        writer.write(&batch).unwrap();
4369        let file_metadata = writer.close().unwrap();
4370
4371        assert_eq!(file_metadata.num_row_groups(), 1);
4372        assert_eq!(file_metadata.row_group(0).num_columns(), 1);
4373        assert!(
4374            file_metadata
4375                .row_group(0)
4376                .column(0)
4377                .page_encoding_stats()
4378                .is_some()
4379        );
4380        let chunk_page_stats = file_metadata
4381            .row_group(0)
4382            .column(0)
4383            .page_encoding_stats()
4384            .unwrap();
4385
4386        // check that the read metadata is also correct
4387        let options = ReadOptionsBuilder::new()
4388            .with_page_index()
4389            .with_encoding_stats_as_mask(false)
4390            .build();
4391        let reader = SerializedFileReader::new_with_options(file, options).unwrap();
4392
4393        let rowgroup = reader.get_row_group(0).expect("row group missing");
4394        assert_eq!(rowgroup.num_columns(), 1);
4395        let column = rowgroup.metadata().column(0);
4396        assert!(column.page_encoding_stats().is_some());
4397        let file_page_stats = column.page_encoding_stats().unwrap();
4398        assert_eq!(chunk_page_stats, file_page_stats);
4399    }
4400
4401    #[test]
4402    #[cfg_attr(miri, ignore)] // Takes too long
4403    fn test_different_dict_page_size_limit() {
4404        let array = Arc::new(Int64Array::from_iter(0..1024 * 1024));
4405        let schema = Arc::new(Schema::new(vec![
4406            Field::new("col0", arrow_schema::DataType::Int64, false),
4407            Field::new("col1", arrow_schema::DataType::Int64, false),
4408        ]));
4409        let batch =
4410            arrow_array::RecordBatch::try_new(schema.clone(), vec![array.clone(), array]).unwrap();
4411
4412        let props = WriterProperties::builder()
4413            .set_dictionary_page_size_limit(1024 * 1024)
4414            .set_column_dictionary_page_size_limit(ColumnPath::from("col1"), 1024 * 1024 * 4)
4415            .build();
4416        let mut writer = ArrowWriter::try_new(Vec::new(), schema, Some(props)).unwrap();
4417        writer.write(&batch).unwrap();
4418        let data = Bytes::from(writer.into_inner().unwrap());
4419
4420        let mut metadata = ParquetMetaDataReader::new();
4421        metadata.try_parse(&data).unwrap();
4422        let metadata = metadata.finish().unwrap();
4423        let col0_meta = metadata.row_group(0).column(0);
4424        let col1_meta = metadata.row_group(0).column(1);
4425
4426        let get_dict_page_size = move |meta: &ColumnChunkMetaData| {
4427            let mut reader =
4428                SerializedPageReader::new(Arc::new(data.clone()), meta, 0, None).unwrap();
4429            let page = reader.get_next_page().unwrap().unwrap();
4430            match page {
4431                Page::DictionaryPage { buf, .. } => buf.len(),
4432                _ => panic!("expected DictionaryPage"),
4433            }
4434        };
4435
4436        assert_eq!(get_dict_page_size(col0_meta), 1024 * 1024);
4437        assert_eq!(get_dict_page_size(col1_meta), 1024 * 1024 * 4);
4438    }
4439
4440    #[test]
4441    #[cfg_attr(miri, ignore)] // Takes too long
4442    fn test_arrow_writer_granular_mode_roundtrip() {
4443        // Granular mode subdivides chunks and writes more pages than the
4444        // default batched path. Make sure the data we write back is
4445        // bit-identical to what went in — page-count assertions elsewhere
4446        // only prove pages were cut, not that the encoded data is correct.
4447        //
4448        // Mix value sizes so that the cumulative-byte-budget cutoff
4449        // lands mid-chunk, exercising both batched and granular paths
4450        // within the same `write_batch_internal` call.
4451        let small = "tiny".to_string();
4452        let big = "x".repeat(64 * 1024);
4453        let strings: Vec<String> = (0..256)
4454            .map(|i| {
4455                if i % 16 == 0 {
4456                    big.clone()
4457                } else {
4458                    small.clone()
4459                }
4460            })
4461            .collect();
4462
4463        let schema = Arc::new(Schema::new(vec![Field::new(
4464            "col",
4465            ArrowDataType::Utf8,
4466            false,
4467        )]));
4468        let batch = RecordBatch::try_new(
4469            schema.clone(),
4470            vec![Arc::new(StringArray::from(strings.clone())) as _],
4471        )
4472        .unwrap();
4473
4474        let props = WriterProperties::builder()
4475            .set_dictionary_enabled(false)
4476            .set_data_page_size_limit(16 * 1024)
4477            .build();
4478        let mut writer = ArrowWriter::try_new(Vec::new(), schema, Some(props)).unwrap();
4479        writer.write(&batch).unwrap();
4480        let data = Bytes::from(writer.into_inner().unwrap());
4481
4482        let mut reader = ParquetRecordBatchReader::try_new(data, 1024).unwrap();
4483        let read = reader.next().unwrap().unwrap();
4484        assert!(reader.next().is_none(), "expected one batch");
4485        let col = read
4486            .column(0)
4487            .as_any()
4488            .downcast_ref::<StringArray>()
4489            .unwrap();
4490        assert_eq!(col.len(), strings.len());
4491        for (i, expected) in strings.iter().enumerate() {
4492            assert_eq!(
4493                col.value(i),
4494                expected.as_str(),
4495                "value mismatch at index {i}"
4496            );
4497        }
4498    }
4499
4500    #[test]
4501    fn test_arrow_writer_all_null_string_column() {
4502        // The `LevelDataRef::value_count` Uniform branch with
4503        // `value != max_def` (entirely-null chunk) must return 0 so the
4504        // sub-batch sizer short-circuits to batch mode without trying
4505        // to estimate byte budgets for non-existent values.
4506        let num_rows = 1024;
4507        let schema = Arc::new(Schema::new(vec![Field::new(
4508            "col",
4509            ArrowDataType::Utf8,
4510            true,
4511        )]));
4512        let nulls: Vec<Option<&str>> = vec![None; num_rows];
4513        let batch = RecordBatch::try_new(
4514            schema.clone(),
4515            vec![Arc::new(StringArray::from(nulls)) as _],
4516        )
4517        .unwrap();
4518
4519        let props = WriterProperties::builder()
4520            .set_dictionary_enabled(false)
4521            .set_data_page_size_limit(16 * 1024)
4522            .build();
4523        let mut writer = ArrowWriter::try_new(Vec::new(), schema, Some(props)).unwrap();
4524        writer.write(&batch).unwrap();
4525        let data = Bytes::from(writer.into_inner().unwrap());
4526
4527        // Re-parse the file: row group has one column, every row is
4528        // null, all data pages report `num_rows / page_count` rows.
4529        let mut metadata = ParquetMetaDataReader::new();
4530        metadata.try_parse(&data).unwrap();
4531        let metadata = metadata.finish().unwrap();
4532        let row_group = metadata.row_group(0);
4533        let col_meta = row_group.column(0);
4534        assert_eq!(row_group.num_rows() as usize, num_rows);
4535        // Statistics record `null_count = num_rows` — proves every value
4536        // was written as null.
4537        if let Some(stats) = col_meta.statistics() {
4538            assert_eq!(
4539                stats.null_count_opt().unwrap_or(0) as usize,
4540                num_rows,
4541                "expected all-null column to report null_count = num_rows"
4542            );
4543        }
4544
4545        let mut reader =
4546            SerializedPageReader::new(Arc::new(data.clone()), col_meta, num_rows, None).unwrap();
4547        let mut total_values = 0u32;
4548        while let Some(page) = reader.get_next_page().unwrap() {
4549            if matches!(page, Page::DataPage { .. } | Page::DataPageV2 { .. }) {
4550                total_values += page.num_values();
4551            }
4552        }
4553        assert_eq!(
4554            total_values as usize, num_rows,
4555            "expected every level position to be represented in some page"
4556        );
4557    }
4558
4559    struct WriteBatchesShape {
4560        num_batches: usize,
4561        rows_per_batch: usize,
4562        row_size: usize,
4563    }
4564
4565    /// Helper function to write batches with the provided `WriteBatchesShape` into an `ArrowWriter`
4566    fn write_batches(
4567        WriteBatchesShape {
4568            num_batches,
4569            rows_per_batch,
4570            row_size,
4571        }: WriteBatchesShape,
4572        props: WriterProperties,
4573    ) -> ParquetRecordBatchReaderBuilder<File> {
4574        let schema = Arc::new(Schema::new(vec![Field::new(
4575            "str",
4576            ArrowDataType::Utf8,
4577            false,
4578        )]));
4579        let file = tempfile::tempfile().unwrap();
4580        let mut writer =
4581            ArrowWriter::try_new(file.try_clone().unwrap(), schema.clone(), Some(props)).unwrap();
4582
4583        for batch_idx in 0..num_batches {
4584            let strings: Vec<String> = (0..rows_per_batch)
4585                .map(|i| format!("{:0>width$}", batch_idx * 10 + i, width = row_size))
4586                .collect();
4587            let array = StringArray::from(strings);
4588            let batch = RecordBatch::try_new(schema.clone(), vec![Arc::new(array)]).unwrap();
4589            writer.write(&batch).unwrap();
4590        }
4591        writer.close().unwrap();
4592        ParquetRecordBatchReaderBuilder::try_new(file).unwrap()
4593    }
4594
4595    #[test]
4596    // When both limits are None, all data should go into a single row group
4597    fn test_row_group_limit_none_writes_single_row_group() {
4598        let props = WriterProperties::builder()
4599            .set_max_row_group_row_count(None)
4600            .set_max_row_group_bytes(None)
4601            .build();
4602
4603        let builder = write_batches(
4604            WriteBatchesShape {
4605                num_batches: 1,
4606                rows_per_batch: 1000,
4607                row_size: 4,
4608            },
4609            props,
4610        );
4611
4612        assert_eq!(
4613            &row_group_sizes(builder.metadata()),
4614            &[1000],
4615            "With no limits, all rows should be in a single row group"
4616        );
4617    }
4618
4619    #[test]
4620    // When only max_row_group_size is set, respect the row limit
4621    fn test_row_group_limit_rows_only() {
4622        let props = WriterProperties::builder()
4623            .set_max_row_group_row_count(Some(300))
4624            .set_max_row_group_bytes(None)
4625            .build();
4626
4627        let builder = write_batches(
4628            WriteBatchesShape {
4629                num_batches: 1,
4630                rows_per_batch: 1000,
4631                row_size: 4,
4632            },
4633            props,
4634        );
4635
4636        assert_eq!(
4637            &row_group_sizes(builder.metadata()),
4638            &[300, 300, 300, 100],
4639            "Row groups should be split by row count"
4640        );
4641    }
4642
4643    #[test]
4644    #[cfg_attr(miri, ignore)] // Takes too long
4645    // A row limit far smaller than the batch splits it many times over; the split must not
4646    // consume stack proportional to the number of row groups.
4647    fn test_row_group_limit_rows_only_many_splits() {
4648        let props = WriterProperties::builder()
4649            .set_max_row_group_row_count(Some(1))
4650            .set_max_row_group_bytes(None)
4651            .build();
4652
4653        let rows = 50_000;
4654        let builder = write_batches(
4655            WriteBatchesShape {
4656                num_batches: 1,
4657                rows_per_batch: rows,
4658                row_size: 4,
4659            },
4660            props,
4661        );
4662
4663        let sizes = row_group_sizes(builder.metadata());
4664        assert_eq!(sizes.len(), rows, "Every row should get its own row group");
4665        assert_eq!(
4666            sizes.iter().sum::<i64>(),
4667            rows as i64,
4668            "Total rows should be preserved"
4669        );
4670    }
4671
4672    #[test]
4673    // When only max_row_group_bytes is set, respect the byte limit
4674    fn test_row_group_limit_bytes_only() {
4675        let props = WriterProperties::builder()
4676            .set_max_row_group_row_count(None)
4677            // Set byte limit to approximately fit ~30 rows worth of data (~100 bytes each)
4678            .set_max_row_group_bytes(Some(3500))
4679            .build();
4680
4681        let builder = write_batches(
4682            WriteBatchesShape {
4683                num_batches: 10,
4684                rows_per_batch: 10,
4685                row_size: 100,
4686            },
4687            props,
4688        );
4689
4690        let sizes = row_group_sizes(builder.metadata());
4691
4692        assert!(
4693            sizes.len() > 1,
4694            "Should have multiple row groups due to byte limit, got {sizes:?}",
4695        );
4696
4697        let total_rows: i64 = sizes.iter().sum();
4698        assert_eq!(total_rows, 100, "Total rows should be preserved");
4699    }
4700
4701    #[test]
4702    // If an in-progress row group is already oversized, it should be flushed before writing more.
4703    fn test_row_group_limit_bytes_flushes_when_current_group_already_too_large() {
4704        let schema = Arc::new(Schema::new(vec![Field::new(
4705            "str",
4706            ArrowDataType::Utf8,
4707            false,
4708        )]));
4709        let file = tempfile::tempfile().unwrap();
4710
4711        // Start with no byte limit so we can intentionally build an oversized in-progress row group.
4712        let props = WriterProperties::builder()
4713            .set_max_row_group_row_count(None)
4714            .set_max_row_group_bytes(None)
4715            .build();
4716        let mut writer =
4717            ArrowWriter::try_new(file.try_clone().unwrap(), schema.clone(), Some(props)).unwrap();
4718
4719        let first_array = StringArray::from(
4720            (0..10)
4721                .map(|i| format!("{i:0>100}"))
4722                .collect::<Vec<String>>(),
4723        );
4724        let first_batch =
4725            RecordBatch::try_new(schema.clone(), vec![Arc::new(first_array)]).unwrap();
4726        writer.write(&first_batch).unwrap();
4727        assert_eq!(writer.in_progress_rows(), 10);
4728
4729        // Tighten the limit below the current in-progress bytes to exercise:
4730        // `if current_bytes >= max_bytes { self.flush()?; ... }`
4731        writer.max_row_group_bytes = Some(1);
4732
4733        let second_array = StringArray::from(vec!["x".to_string()]);
4734        let second_batch =
4735            RecordBatch::try_new(schema.clone(), vec![Arc::new(second_array)]).unwrap();
4736        writer.write(&second_batch).unwrap();
4737        writer.close().unwrap();
4738        let builder = ParquetRecordBatchReaderBuilder::try_new(file).unwrap();
4739
4740        assert_eq!(
4741            &row_group_sizes(builder.metadata()),
4742            &[10, 1],
4743            "The second write should flush an oversized in-progress row group first",
4744        );
4745    }
4746
4747    #[test]
4748    // When both limits are set, the row limit triggers first
4749    fn test_row_group_limit_both_row_wins_single_batch() {
4750        let props = WriterProperties::builder()
4751            .set_max_row_group_row_count(Some(200)) // Will trigger at 200 rows
4752            .set_max_row_group_bytes(Some(1024 * 1024)) // 1MB - won't trigger for small int data
4753            .build();
4754
4755        let builder = write_batches(
4756            WriteBatchesShape {
4757                num_batches: 1,
4758                row_size: 4,
4759                rows_per_batch: 1000,
4760            },
4761            props,
4762        );
4763
4764        assert_eq!(
4765            &row_group_sizes(builder.metadata()),
4766            &[200, 200, 200, 200, 200],
4767            "Row limit should trigger before byte limit"
4768        );
4769    }
4770
4771    #[test]
4772    // When both limits are set, the row limit triggers first
4773    fn test_row_group_limit_both_row_wins_multiple_batches() {
4774        let props = WriterProperties::builder()
4775            .set_max_row_group_row_count(Some(5)) // Will trigger every 5 rows
4776            .set_max_row_group_bytes(Some(9999)) // Won't trigger
4777            .build();
4778
4779        let builder = write_batches(
4780            WriteBatchesShape {
4781                num_batches: 10,
4782                rows_per_batch: 10,
4783                row_size: 100,
4784            },
4785            props,
4786        );
4787
4788        assert_eq!(
4789            &row_group_sizes(builder.metadata()),
4790            &[5; 20],
4791            "Row limit should trigger before byte limit"
4792        );
4793    }
4794
4795    #[test]
4796    // When both limits are set, the byte limit triggers first
4797    fn test_row_group_limit_both_bytes_wins() {
4798        let props = WriterProperties::builder()
4799            .set_max_row_group_row_count(Some(1000)) // Won't trigger for 100 rows
4800            .set_max_row_group_bytes(Some(3500)) // Will trigger at ~30-35 rows
4801            .build();
4802
4803        let builder = write_batches(
4804            WriteBatchesShape {
4805                num_batches: 10,
4806                rows_per_batch: 10,
4807                row_size: 100,
4808            },
4809            props,
4810        );
4811
4812        let sizes = row_group_sizes(builder.metadata());
4813
4814        assert!(
4815            sizes.len() > 1,
4816            "Byte limit should trigger before row limit, got {sizes:?}",
4817        );
4818
4819        assert!(
4820            sizes.iter().all(|&s| s < 1000),
4821            "No row group should hit the row limit"
4822        );
4823
4824        let total_rows: i64 = sizes.iter().sum();
4825        assert_eq!(total_rows, 100, "Total rows should be preserved");
4826    }
4827
4828    #[test]
4829    // Both limits can apply to the same batch: the row limit trims it to 5 rows, and the
4830    // byte limit then trims those 5 down to 4.
4831    fn test_row_group_limit_both_apply_to_same_batch() {
4832        let props = WriterProperties::builder()
4833            .set_max_row_group_row_count(Some(15))
4834            .set_max_row_group_bytes(Some(1500))
4835            .build();
4836
4837        let builder = write_batches(
4838            WriteBatchesShape {
4839                num_batches: 2,
4840                rows_per_batch: 10,
4841                row_size: 100,
4842            },
4843            props,
4844        );
4845
4846        assert_eq!(
4847            &row_group_sizes(builder.metadata()),
4848            &[14, 6],
4849            "Byte limit should still apply to a batch the row limit already split"
4850        );
4851    }
4852
4853    #[test]
4854    fn arrow_column_chunk_close_mut_drops_column_index() {
4855        use crate::arrow::ArrowSchemaConverter;
4856        use crate::file::writer::SerializedFileWriter;
4857
4858        let schema = Arc::new(Schema::new(vec![Field::new("i", DataType::Int32, false)]));
4859        let props = Arc::new(
4860            WriterProperties::builder()
4861                .set_statistics_enabled(EnabledStatistics::Page)
4862                .build(),
4863        );
4864        let parquet_schema = ArrowSchemaConverter::new()
4865            .with_coerce_types(props.coerce_types())
4866            .convert(&schema)
4867            .unwrap();
4868
4869        let mut buf = Vec::with_capacity(1024);
4870        let mut writer =
4871            SerializedFileWriter::new(&mut buf, parquet_schema.root_schema_ptr(), props.clone())
4872                .unwrap();
4873
4874        let factory = ArrowRowGroupWriterFactory::new(&writer, Arc::clone(&schema));
4875        let mut col_writers = factory.create_column_writers(0).unwrap();
4876        let arr: ArrayRef = Arc::new(Int32Array::from_iter_values(0..64));
4877        for leaves in compute_leaves(schema.field(0), &arr).unwrap() {
4878            col_writers[0].write(&leaves).unwrap();
4879        }
4880        let mut chunk = col_writers.pop().unwrap().close().unwrap();
4881
4882        // Immutable accessor exposes the close result produced at close time.
4883        assert!(
4884            chunk.close().column_index.is_some(),
4885            "EnabledStatistics::Page should produce a column_index"
4886        );
4887
4888        // Mutable accessor lets callers drop the page-level index before append.
4889        chunk.close_mut().column_index = None;
4890        assert!(chunk.close().column_index.is_none());
4891
4892        let mut rg = writer.next_row_group().unwrap();
4893        chunk.append_to_row_group(&mut rg).unwrap();
4894        rg.close().unwrap();
4895        let file_meta = writer.close().unwrap();
4896
4897        // After dropping column_index, the resulting file records no column
4898        // index offset/length for this chunk.
4899        let cc = file_meta.row_group(0).column(0);
4900        assert!(cc.column_index_range().is_none());
4901    }
4902
4903    /// Writes a single-column RecordBatch to an in-memory Parquet buffer.
4904    fn write_column_to_bytes(array: ArrayRef) -> Bytes {
4905        let schema = Arc::new(Schema::new(vec![Field::new(
4906            "col",
4907            array.data_type().clone(),
4908            true,
4909        )]));
4910        let buf = get_bytes_after_close(
4911            schema.clone(),
4912            &RecordBatch::try_new(schema, vec![array]).unwrap(),
4913        );
4914        Bytes::from(buf)
4915    }
4916
4917    /// Reads column 0 from a single-row-group Parquet buffer, projecting it with the given schema.
4918    /// Passing a flat schema when the buffer was written from a REE array lets callers decode
4919    /// the physical values without the run-end encoding wrapper.
4920    fn read_column_with_schema(bytes: Bytes, schema: SchemaRef) -> ArrayRef {
4921        let opts = crate::arrow::arrow_reader::ArrowReaderOptions::new().with_schema(schema);
4922        ParquetRecordBatchReaderBuilder::try_new_with_options(bytes, opts)
4923            .unwrap()
4924            .build()
4925            .unwrap()
4926            .next()
4927            .unwrap()
4928            .unwrap()
4929            .column(0)
4930            .clone()
4931    }
4932
4933    fn ree_write_read_roundtrip(ree: ArrayRef, flat: ArrayRef) {
4934        let flat_schema = Arc::new(Schema::new(vec![Field::new(
4935            "col",
4936            flat.data_type().clone(),
4937            true,
4938        )]));
4939        let ree_bytes = write_column_to_bytes(ree);
4940        let flat_bytes = write_column_to_bytes(flat.clone());
4941        assert_eq!(
4942            ree_bytes, flat_bytes,
4943            "REE and flat bytes should be identical"
4944        );
4945
4946        let decoded_ree = read_column_with_schema(ree_bytes, flat_schema.clone());
4947        let decoded_flat = read_column_with_schema(flat_bytes, flat_schema);
4948
4949        assert_eq!(decoded_ree.as_ref(), flat.as_ref());
4950        assert_eq!(decoded_ree.as_ref(), decoded_flat.as_ref());
4951    }
4952
4953    #[test]
4954    fn ree_string() {
4955        let ree: ArrayRef = Arc::new(
4956            [Some("a"), Some("a"), None, Some("b"), Some("b")]
4957                .into_iter()
4958                .collect::<Int32RunArray>(),
4959        );
4960        let flat: ArrayRef = Arc::new(StringArray::from(vec![
4961            Some("a"),
4962            Some("a"),
4963            None,
4964            Some("b"),
4965            Some("b"),
4966        ]));
4967        ree_write_read_roundtrip(ree, flat);
4968    }
4969
4970    #[test]
4971    fn ree_int32() {
4972        let mut b = PrimitiveRunBuilder::<Int32Type, Int32Type>::new();
4973        for v in [Some(1), Some(1), None, Some(2), Some(2)] {
4974            b.append_option(v);
4975        }
4976        let ree: ArrayRef = Arc::new(b.finish());
4977        let flat: ArrayRef = Arc::new(Int32Array::from(vec![
4978            Some(1),
4979            Some(1),
4980            None,
4981            Some(2),
4982            Some(2),
4983        ]));
4984        ree_write_read_roundtrip(ree, flat);
4985    }
4986
4987    #[test]
4988    fn ree_bool() {
4989        // run_ends [3, 5, 7] → [T,T,T, null,null, F,F]
4990        let ree: ArrayRef = Arc::new(
4991            RunArray::try_new(
4992                &Int32Array::from(vec![3, 5, 7]),
4993                &BooleanArray::from(vec![Some(true), None, Some(false)]),
4994            )
4995            .unwrap(),
4996        );
4997        let flat: ArrayRef = Arc::new(BooleanArray::from(vec![
4998            Some(true),
4999            Some(true),
5000            Some(true),
5001            None,
5002            None,
5003            Some(false),
5004            Some(false),
5005        ]));
5006        ree_write_read_roundtrip(ree, flat);
5007    }
5008
5009    #[test]
5010    fn ree_fixed_size_binary() {
5011        let mk = |vals: &[Option<&[u8]>]| -> FixedSizeBinaryArray {
5012            let mut b = FixedSizeBinaryBuilder::new(2);
5013            for v in vals {
5014                match v {
5015                    Some(x) => b.append_value(x).unwrap(),
5016                    None => b.append_null(),
5017                }
5018            }
5019            b.finish()
5020        };
5021        // run_ends [2, 4, 6] → [aa,aa, null,null, bb,bb]
5022        let ree: ArrayRef = Arc::new(
5023            RunArray::try_new(
5024                &Int32Array::from(vec![2, 4, 6]),
5025                &mk(&[Some(b"aa"), None, Some(b"bb")]),
5026            )
5027            .unwrap(),
5028        );
5029        let flat: ArrayRef = Arc::new(mk(&[
5030            Some(b"aa"),
5031            Some(b"aa"),
5032            None,
5033            None,
5034            Some(b"bb"),
5035            Some(b"bb"),
5036        ]));
5037        ree_write_read_roundtrip(ree, flat);
5038    }
5039
5040    #[test]
5041    fn ree_single_run() {
5042        let ree: ArrayRef = Arc::new(["x", "x", "x"].into_iter().collect::<Int32RunArray>());
5043        let flat: ArrayRef = Arc::new(StringArray::from(vec!["x", "x", "x"]));
5044        ree_write_read_roundtrip(ree, flat);
5045    }
5046
5047    #[test]
5048    fn ree_float32() {
5049        // run_ends [2, 4, 5] → [1.0, 1.0, null, null, 2.5]
5050        let ree: ArrayRef = Arc::new(
5051            RunArray::try_new(
5052                &Int32Array::from(vec![2, 4, 5]),
5053                &Float32Array::from(vec![Some(1.0_f32), None, Some(2.5_f32)]),
5054            )
5055            .unwrap(),
5056        );
5057        let flat: ArrayRef = Arc::new(Float32Array::from(vec![
5058            Some(1.0_f32),
5059            Some(1.0_f32),
5060            None,
5061            None,
5062            Some(2.5_f32),
5063        ]));
5064        ree_write_read_roundtrip(ree, flat);
5065    }
5066
5067    #[test]
5068    fn ree_sliced() {
5069        // A sliced (non-zero offset) REE array: verify that get_physical_index
5070        // correctly accounts for the logical offset when expanding.
5071        // Full array: run_ends [3, 5, 7] → [a,a,a, b,b, c,c]
5072        // After slice(2, 5) the logical view is [a, b, b, c, c].
5073        let full: ArrayRef = Arc::new(
5074            RunArray::try_new(
5075                &Int32Array::from(vec![3, 5, 7]),
5076                &StringArray::from(vec!["a", "b", "c"]),
5077            )
5078            .unwrap(),
5079        );
5080        let sliced = full.slice(2, 5);
5081        let flat: ArrayRef = Arc::new(StringArray::from(vec!["a", "b", "b", "c", "c"]));
5082        ree_write_read_roundtrip(sliced, flat);
5083    }
5084
5085    #[test]
5086    #[cfg_attr(miri, ignore)] // Takes too long
5087    fn test_number_distinct_values_exact_count() {
5088        // 50 distinct Int32 values repeated across 100k rows, with every 7th row null.
5089        // Nulls must not be counted as a distinct value.
5090        let cardinality = 50u32;
5091        let array: ArrayRef = Arc::new(Int32Array::from_iter((0..100_000u32).map(|i| {
5092            if i % 7 == 0 {
5093                None
5094            } else {
5095                Some((i % cardinality) as i32)
5096            }
5097        })));
5098        let schema = Arc::new(Schema::new(vec![Field::new("x", DataType::Int32, true)]));
5099        let batch = RecordBatch::try_new(schema, vec![array]).unwrap();
5100
5101        let props = WriterProperties::builder()
5102            .set_write_row_group_number_distinct_values(true)
5103            .build();
5104        let mut buf = Vec::new();
5105        let mut writer = ArrowWriter::try_new(&mut buf, batch.schema(), Some(props)).unwrap();
5106        writer.write(&batch).unwrap();
5107        let metadata = writer.close().unwrap();
5108
5109        let count = metadata
5110            .row_group(0)
5111            .column(0)
5112            .statistics()
5113            .and_then(|s| s.distinct_count_opt())
5114            .expect("distinct_count should be set");
5115        // Must equal cardinality exactly; nulls must not inflate the count.
5116        assert_eq!(count, cardinality as u64);
5117    }
5118
5119    #[test]
5120    fn test_number_distinct_values_view_types() {
5121        // 5 distinct values repeated across 30 rows, with every 4th row null.
5122        // Verifies Utf8View is counted correctly (BinaryView shares the same code path).
5123        let cardinality = 5u32;
5124        let distinct_strings = ["alpha", "beta", "gamma", "delta", "epsilon"];
5125
5126        let string_view_col: ArrayRef = Arc::new(StringViewArray::from_iter((0..30u32).map(|i| {
5127            if i % 4 == 0 {
5128                None
5129            } else {
5130                Some(distinct_strings[(i % cardinality) as usize])
5131            }
5132        })));
5133
5134        let schema = Arc::new(Schema::new(vec![Field::new(
5135            "string_view_col",
5136            DataType::Utf8View,
5137            true,
5138        )]));
5139        let batch = RecordBatch::try_new(schema, vec![string_view_col]).unwrap();
5140
5141        let props = WriterProperties::builder()
5142            .set_write_row_group_number_distinct_values(true)
5143            .build();
5144        let mut parquet_bytes = Vec::new();
5145        let mut writer =
5146            ArrowWriter::try_new(&mut parquet_bytes, batch.schema(), Some(props)).unwrap();
5147        writer.write(&batch).unwrap();
5148        let metadata = writer.close().unwrap();
5149
5150        let distinct_count = metadata
5151            .row_group(0)
5152            .column(0)
5153            .statistics()
5154            .and_then(|s| s.distinct_count_opt())
5155            .expect("distinct_count should be set for Utf8View column");
5156        assert_eq!(distinct_count, cardinality as u64);
5157    }
5158
5159    #[test]
5160    fn test_number_distinct_values_not_written_by_default() {
5161        let array: ArrayRef = Arc::new(Int32Array::from_iter_values(0..100));
5162        let schema = Arc::new(Schema::new(vec![Field::new("x", DataType::Int32, false)]));
5163        let batch = RecordBatch::try_new(schema, vec![array]).unwrap();
5164
5165        let mut buf = Vec::new();
5166        let mut writer = ArrowWriter::try_new(&mut buf, batch.schema(), None).unwrap();
5167        writer.write(&batch).unwrap();
5168        let metadata = writer.close().unwrap();
5169
5170        let count = metadata
5171            .row_group(0)
5172            .column(0)
5173            .statistics()
5174            .and_then(|s| s.distinct_count_opt());
5175        assert!(count.is_none());
5176    }
5177
5178    #[test]
5179    fn test_dictionary_ndv_single_batch() {
5180        // Dictionary array with 3 distinct string values repeated many times.
5181        // NDV must equal the number of distinct values in the dictionary (3),
5182        // not the number of rows.
5183        let keys = Int32Array::from(vec![0, 1, 2, 0, 1, 2, 0, 1, 2]);
5184        let values: ArrayRef = Arc::new(StringArray::from(vec!["cat", "dog", "bird"]));
5185        let dict: ArrayRef = Arc::new(DictionaryArray::<Int32Type>::try_new(keys, values).unwrap());
5186
5187        let schema = Arc::new(Schema::new(vec![Field::new(
5188            "x",
5189            DataType::Dictionary(Box::new(DataType::Int32), Box::new(DataType::Utf8)),
5190            false,
5191        )]));
5192        let batch = RecordBatch::try_new(schema, vec![dict]).unwrap();
5193
5194        let props = WriterProperties::builder()
5195            .set_write_row_group_number_distinct_values(true)
5196            .build();
5197        let mut buf = Vec::new();
5198        let mut writer = ArrowWriter::try_new(&mut buf, batch.schema(), Some(props)).unwrap();
5199        writer.write(&batch).unwrap();
5200        let metadata = writer.close().unwrap();
5201
5202        let count = metadata
5203            .row_group(0)
5204            .column(0)
5205            .statistics()
5206            .and_then(|s| s.distinct_count_opt())
5207            .expect("distinct_count should be set");
5208        assert_eq!(count, 3);
5209    }
5210
5211    #[test]
5212    fn test_dictionary_ndv_excludes_unreferenced_values() {
5213        // Keys only reference indices 0 and 1; value at index 2 ("unreferenced") should not
5214        // count toward NDV even though it appears in the dictionary's values array.
5215        let keys = Int32Array::from(vec![0, 1, 0, 1]);
5216        let values: ArrayRef = Arc::new(StringArray::from(vec!["cat", "dog", "unreferenced"]));
5217        let dict: ArrayRef = Arc::new(DictionaryArray::<Int32Type>::try_new(keys, values).unwrap());
5218
5219        let schema = Arc::new(Schema::new(vec![Field::new(
5220            "x",
5221            DataType::Dictionary(Box::new(DataType::Int32), Box::new(DataType::Utf8)),
5222            false,
5223        )]));
5224        let batch = RecordBatch::try_new(schema, vec![dict]).unwrap();
5225
5226        let props = WriterProperties::builder()
5227            .set_write_row_group_number_distinct_values(true)
5228            .build();
5229        let mut buf = Vec::new();
5230        let mut writer = ArrowWriter::try_new(&mut buf, batch.schema(), Some(props)).unwrap();
5231        writer.write(&batch).unwrap();
5232        let metadata = writer.close().unwrap();
5233
5234        let count = metadata
5235            .row_group(0)
5236            .column(0)
5237            .statistics()
5238            .and_then(|s| s.distinct_count_opt())
5239            .expect("distinct_count should be set");
5240        assert_eq!(
5241            count, 2,
5242            "unreferenced dictionary values must not count toward NDV"
5243        );
5244    }
5245
5246    #[test]
5247    fn test_dictionary_ndv_across_batches_regression() {
5248        // Regression test for https://github.com/apache/arrow-rs/issues/11172.
5249        let make_dict_batch = |a: &str, b: &str| -> RecordBatch {
5250            let keys = Int32Array::from(vec![0, 1, 0, 1]);
5251            let values: ArrayRef = Arc::new(StringArray::from(vec![a, b]));
5252            let dict: ArrayRef =
5253                Arc::new(DictionaryArray::<Int32Type>::try_new(keys, values).unwrap());
5254            let schema = Arc::new(Schema::new(vec![Field::new(
5255                "x",
5256                DataType::Dictionary(Box::new(DataType::Int32), Box::new(DataType::Utf8)),
5257                false,
5258            )]));
5259            RecordBatch::try_new(schema, vec![dict]).unwrap()
5260        };
5261
5262        // batch1: dict = ["cat", "dog"], batch2: dict = ["fish", "cat"]
5263        // Distinct values across both batches: "cat", "dog", "fish" NDV = 3
5264        let batch1 = make_dict_batch("cat", "dog");
5265        let batch2 = make_dict_batch("fish", "cat");
5266
5267        let props = WriterProperties::builder()
5268            .set_write_row_group_number_distinct_values(true)
5269            .build();
5270        let mut buf = Vec::new();
5271        let mut writer = ArrowWriter::try_new(&mut buf, batch1.schema(), Some(props)).unwrap();
5272        writer.write(&batch1).unwrap();
5273        writer.write(&batch2).unwrap();
5274        let metadata = writer.close().unwrap();
5275
5276        let count = metadata
5277            .row_group(0)
5278            .column(0)
5279            .statistics()
5280            .and_then(|s| s.distinct_count_opt())
5281            .expect("distinct_count should be set");
5282        assert_eq!(
5283            count, 3,
5284            "NDV should count distinct values, not distinct key indices"
5285        );
5286    }
5287
5288    #[test]
5289    fn ree_struct_with_ree_child() {
5290        // Struct with a REE string field and a REE int field — confirms
5291        // recursion visits every child and each collapses to the right leaf type.
5292        let run_ends = Int32Array::from(vec![2i32, 3, 5]);
5293
5294        let col_a: ArrayRef = Arc::new(
5295            RunArray::try_new(
5296                &run_ends,
5297                &StringArray::from(vec![Some("foo"), None, Some("bar")]),
5298            )
5299            .unwrap(),
5300        );
5301        let col_b: ArrayRef = Arc::new(
5302            RunArray::try_new(&run_ends, &Int32Array::from(vec![Some(1), None, Some(2)])).unwrap(),
5303        );
5304
5305        let struct_array: ArrayRef = Arc::new(StructArray::new(
5306            Fields::from(vec![
5307                Field::new("a", col_a.data_type().clone(), true),
5308                Field::new("b", col_b.data_type().clone(), true),
5309            ]),
5310            vec![col_a, col_b],
5311            None,
5312        ));
5313
5314        let schema = Arc::new(Schema::new(vec![Field::new(
5315            "row",
5316            struct_array.data_type().clone(),
5317            true,
5318        )]));
5319        let batch = RecordBatch::try_new(schema.clone(), vec![struct_array]).unwrap();
5320
5321        let mut buf = Vec::new();
5322        let mut writer = ArrowWriter::try_new(&mut buf, schema, None).unwrap();
5323        writer.write(&batch).unwrap();
5324        let metadata = writer.close().unwrap();
5325
5326        let parquet_schema = metadata.file_metadata().schema_descr();
5327        assert_eq!(parquet_schema.num_columns(), 2);
5328        assert_eq!(
5329            parquet_schema.column(0).physical_type(),
5330            crate::basic::Type::BYTE_ARRAY
5331        );
5332        assert_eq!(parquet_schema.column(0).path().string(), "row.a");
5333        assert_eq!(
5334            parquet_schema.column(1).physical_type(),
5335            crate::basic::Type::INT32
5336        );
5337        assert_eq!(parquet_schema.column(1).path().string(), "row.b");
5338    }
5339}