parquet/file/metadata/
writer.rs

1// Licensed to the Apache Software Foundation (ASF) under one
2// or more contributor license agreements.  See the NOTICE file
3// distributed with this work for additional information
4// regarding copyright ownership.  The ASF licenses this file
5// to you under the Apache License, Version 2.0 (the
6// "License"); you may not use this file except in compliance
7// with the License.  You may obtain a copy of the License at
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
13// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
14// KIND, either express or implied.  See the License for the
15// specific language governing permissions and limitations
16// under the License.
17
18use crate::file::metadata::thrift::FileMeta;
19use crate::file::metadata::{ColumnChunkMetaData, PageIndex, RowGroupMetaData};
20use crate::schema::types::{SchemaDescPtr, SchemaDescriptor};
21use crate::{
22    basic::ColumnOrder,
23    file::metadata::{FileMetaData, ParquetMetaDataBuilder},
24};
25#[cfg(feature = "encryption")]
26use crate::{
27    encryption::{
28        encrypt::{FileEncryptor, encrypt_thrift_object, write_signed_plaintext_thrift_object},
29        modules::{ModuleType, create_footer_aad, create_module_aad},
30    },
31    file::column_crypto_metadata::ColumnCryptoMetaData,
32    file::metadata::thrift::encryption::{AesGcmV1, EncryptionAlgorithm, FileCryptoMetaData},
33};
34use crate::{errors::Result, file::page_index::column_index::ColumnIndexMetaData};
35
36use crate::{
37    file::writer::{TrackedWrite, get_file_magic},
38    parquet_thrift::WriteThrift,
39};
40use crate::{
41    file::{
42        metadata::{KeyValue, ParquetMetaData},
43        page_index::offset_index::OffsetIndexMetaData,
44    },
45    parquet_thrift::ThriftCompactOutputProtocol,
46};
47use std::io::Write;
48use std::sync::Arc;
49
50/// Writes `crate::file::metadata` structures to a thrift encoded byte stream
51///
52/// See [`ParquetMetaDataWriter`] for background and example.
53pub(crate) struct ThriftMetadataWriter<'a, W: Write> {
54    buf: &'a mut TrackedWrite<W>,
55    schema_descr: &'a SchemaDescPtr,
56    row_groups: Vec<RowGroupMetaData>,
57    column_indexes: Option<Vec<Vec<Option<ColumnIndexMetaData>>>>,
58    offset_indexes: Option<Vec<Vec<Option<OffsetIndexMetaData>>>>,
59    key_value_metadata: Option<Vec<KeyValue>>,
60    created_by: Option<String>,
61    object_writer: MetadataObjectWriter,
62    writer_version: i32,
63    write_path_in_schema: bool,
64}
65
66impl<'a, W: Write> ThriftMetadataWriter<'a, W> {
67    /// Serialize all the offset indexes to `self.buf`,
68    ///
69    /// Note: also updates the `ColumnChunk::offset_index_offset` and
70    /// `ColumnChunk::offset_index_length` to reflect the position and length
71    /// of the serialized offset indexes.
72    fn write_offset_indexes(
73        &mut self,
74        offset_indexes: &[Vec<Option<OffsetIndexMetaData>>],
75    ) -> Result<()> {
76        // iter row group
77        // iter each column
78        // write offset index to the file
79        for (row_group_idx, row_group) in self.row_groups.iter_mut().enumerate() {
80            for (column_idx, column_metadata) in row_group.columns.iter_mut().enumerate() {
81                if let Some(offset_index) = &offset_indexes[row_group_idx][column_idx] {
82                    let start_offset = self.buf.bytes_written();
83                    self.object_writer.write_offset_index(
84                        offset_index,
85                        column_metadata,
86                        row_group_idx,
87                        column_idx,
88                        &mut self.buf,
89                    )?;
90                    let end_offset = self.buf.bytes_written();
91                    // set offset and index for offset index
92                    column_metadata.offset_index_offset = Some(start_offset as i64);
93                    column_metadata.offset_index_length = Some((end_offset - start_offset) as i32);
94                }
95            }
96        }
97        Ok(())
98    }
99
100    /// Serialize all the column indexes to the `self.buf`
101    ///
102    /// Note: also updates the `ColumnChunk::column_index_offset` and
103    /// `ColumnChunk::column_index_length` to reflect the position and length
104    /// of the serialized column indexes.
105    fn write_column_indexes(
106        &mut self,
107        column_indexes: &[Vec<Option<ColumnIndexMetaData>>],
108    ) -> Result<()> {
109        // iter row group
110        // iter each column
111        // write column index to the file
112        for (row_group_idx, row_group) in self.row_groups.iter_mut().enumerate() {
113            for (column_idx, column_metadata) in row_group.columns.iter_mut().enumerate() {
114                if let Some(column_index) = &column_indexes[row_group_idx][column_idx] {
115                    let start_offset = self.buf.bytes_written();
116                    // only update column_metadata if the write succeeds
117                    if self.object_writer.write_column_index(
118                        column_index,
119                        column_metadata,
120                        row_group_idx,
121                        column_idx,
122                        &mut self.buf,
123                    )? {
124                        let end_offset = self.buf.bytes_written();
125                        // set offset and index for offset index
126                        column_metadata.column_index_offset = Some(start_offset as i64);
127                        column_metadata.column_index_length =
128                            Some((end_offset - start_offset) as i32);
129                    }
130                }
131            }
132        }
133        Ok(())
134    }
135
136    /// Serialize the column indexes and transform to `Option<ParquetColumnIndex>`
137    fn finalize_column_indexes(&mut self) -> Result<Option<Vec<Vec<Option<ColumnIndexMetaData>>>>> {
138        let column_indexes = std::mem::take(&mut self.column_indexes);
139
140        // Write column indexes to file
141        if let Some(column_indexes) = column_indexes.as_ref() {
142            self.write_column_indexes(column_indexes)?;
143        }
144
145        // check to see if the index is `None` for every row group and column chunk
146        let all_none = column_indexes
147            .as_ref()
148            .is_some_and(|ci| ci.iter().all(|cii| cii.iter().all(|idx| idx.is_none())));
149
150        if all_none {
151            Ok(None)
152        } else {
153            Ok(column_indexes)
154        }
155    }
156
157    /// Serialize the offset indexes and transform to `Option<ParquetOffsetIndex>`
158    fn finalize_offset_indexes(&mut self) -> Result<Option<Vec<Vec<Option<OffsetIndexMetaData>>>>> {
159        let offset_indexes = std::mem::take(&mut self.offset_indexes);
160
161        // Write offset indexes to file
162        if let Some(offset_indexes) = offset_indexes.as_ref() {
163            self.write_offset_indexes(offset_indexes)?;
164        }
165
166        // check to see if the index is `None` for every row group and column chunk
167        let all_none = offset_indexes
168            .as_ref()
169            .is_some_and(|oi| oi.iter().all(|oii| oii.iter().all(|idx| idx.is_none())));
170
171        if all_none {
172            Ok(None)
173        } else {
174            Ok(offset_indexes)
175        }
176    }
177
178    /// Assembles and writes the final metadata to self.buf
179    pub fn finish(mut self) -> Result<ParquetMetaData> {
180        let num_rows = self.row_groups.iter().map(|x| x.num_rows).sum();
181
182        // serialize page indexes and transform to the proper form for use in ParquetMetaData
183        let column_indexes = self.finalize_column_indexes()?;
184        let offset_indexes = self.finalize_offset_indexes()?;
185
186        // We only include ColumnOrder for leaf nodes.
187        let column_orders = self
188            .schema_descr
189            .columns()
190            .iter()
191            .map(|col| {
192                ColumnOrder::column_order_for_type(
193                    col.logical_type_ref(),
194                    col.converted_type(),
195                    col.physical_type(),
196                )
197            })
198            .collect();
199
200        // This field is optional, perhaps in cases where no min/max fields are set
201        // in any Statistics or ColumnIndex object in the whole file.
202        // But for simplicity we always set this field.
203        let column_orders = Some(column_orders);
204
205        let (row_groups, unencrypted_row_groups) = self
206            .object_writer
207            .apply_row_group_encryption(self.row_groups)?;
208
209        #[cfg(feature = "encryption")]
210        let (encryption_algorithm, footer_signing_key_metadata) =
211            self.object_writer.get_plaintext_footer_crypto_metadata();
212        #[cfg(feature = "encryption")]
213        let file_metadata = FileMetaData::new(
214            self.writer_version,
215            num_rows,
216            self.created_by,
217            self.key_value_metadata,
218            self.schema_descr.clone(),
219            column_orders,
220        )
221        .with_encryption_algorithm(encryption_algorithm)
222        .with_footer_signing_key_metadata(footer_signing_key_metadata);
223
224        #[cfg(not(feature = "encryption"))]
225        let file_metadata = FileMetaData::new(
226            self.writer_version,
227            num_rows,
228            self.created_by,
229            self.key_value_metadata,
230            self.schema_descr.clone(),
231            column_orders,
232        );
233
234        let file_meta = FileMeta {
235            file_metadata: &file_metadata,
236            row_groups: &row_groups,
237            write_path_in_schema: self.write_path_in_schema,
238        };
239
240        // Write file metadata
241        let start_pos = self.buf.bytes_written();
242        self.object_writer
243            .write_file_metadata(&file_meta, &mut self.buf)?;
244        let end_pos = self.buf.bytes_written();
245
246        // Write footer
247        let metadata_len = (end_pos - start_pos) as u32;
248
249        self.buf.write_all(&metadata_len.to_le_bytes())?;
250        self.buf.write_all(self.object_writer.get_file_magic())?;
251
252        // If row group metadata was encrypted, we replace the encrypted row groups with
253        // unencrypted metadata before it is returned to users. This allows the metadata
254        // to be usable for retrieving the row group statistics for example, without users
255        // needing to decrypt the metadata.
256        let builder = ParquetMetaDataBuilder::new(file_metadata)
257            .set_page_index(Some(PageIndex::new(column_indexes, offset_indexes)));
258
259        Ok(match unencrypted_row_groups {
260            Some(rg) => builder.set_row_groups(rg).build(),
261            None => builder.set_row_groups(row_groups).build(),
262        })
263    }
264
265    pub fn new(
266        buf: &'a mut TrackedWrite<W>,
267        schema_descr: &'a SchemaDescPtr,
268        row_groups: Vec<RowGroupMetaData>,
269        created_by: Option<String>,
270        writer_version: i32,
271        write_path_in_schema: bool,
272    ) -> Self {
273        Self {
274            buf,
275            schema_descr,
276            row_groups,
277            column_indexes: None,
278            offset_indexes: None,
279            key_value_metadata: None,
280            created_by,
281            object_writer: Default::default(),
282            writer_version,
283            write_path_in_schema,
284        }
285    }
286
287    pub fn with_column_indexes(
288        mut self,
289        column_indexes: Vec<Vec<Option<ColumnIndexMetaData>>>,
290    ) -> Self {
291        self.column_indexes = Some(column_indexes);
292        self
293    }
294
295    pub fn with_offset_indexes(
296        mut self,
297        offset_indexes: Vec<Vec<Option<OffsetIndexMetaData>>>,
298    ) -> Self {
299        self.offset_indexes = Some(offset_indexes);
300        self
301    }
302
303    pub fn with_key_value_metadata(mut self, key_value_metadata: Vec<KeyValue>) -> Self {
304        self.key_value_metadata = Some(key_value_metadata);
305        self
306    }
307
308    #[cfg(feature = "encryption")]
309    pub fn with_file_encryptor(mut self, file_encryptor: Option<Arc<FileEncryptor>>) -> Self {
310        self.object_writer = self.object_writer.with_file_encryptor(file_encryptor);
311        self
312    }
313}
314
315/// Writes [`ParquetMetaData`] to a byte stream
316///
317/// This structure handles the details of writing the various parts of Parquet
318/// metadata into a byte stream. It is used to write the metadata into a parquet
319/// file and can also write metadata into other locations (such as a store of
320/// bytes).
321///
322/// # Discussion
323///
324/// The process of writing Parquet metadata is tricky because the
325/// metadata is not stored as a single inline thrift structure. It can have
326/// several "out of band" structures such as the [`OffsetIndex`] and
327/// BloomFilters stored in separate structures whose locations are stored as
328/// offsets from the beginning of the file.
329///
330/// Note: this writer does not directly write BloomFilters. In order to write
331/// BloomFilters, write the bloom filters into the buffer before creating the
332/// metadata writer. Then set the corresponding `bloom_filter_offset` and
333/// `bloom_filter_length` on [`ColumnChunkMetaData`] passed to this writer.
334///
335/// # Output Format
336///
337/// The format of the metadata is as follows:
338///
339/// 1. Optional [`ColumnIndex`] (thrift encoded)
340/// 2. Optional [`OffsetIndex`] (thrift encoded)
341/// 3. [`FileMetaData`] (thrift encoded)
342/// 4. Length of encoded `FileMetaData` (4 bytes, little endian)
343/// 5. Parquet Magic Bytes (4 bytes)
344///
345/// [`FileMetaData`]: https://github.com/apache/parquet-format/tree/master?tab=readme-ov-file#metadata
346/// [`ColumnChunkMetaData`]: crate::file::metadata::ColumnChunkMetaData
347/// [`ColumnIndex`]: https://github.com/apache/parquet-format/blob/master/PageIndex.md
348/// [`OffsetIndex`]: https://github.com/apache/parquet-format/blob/master/PageIndex.md
349///
350/// ```text
351/// ┌──────────────────────┐
352/// │                      │
353/// │         ...          │
354/// │                      │
355/// │┌ ─ ─ ─ ─ ─ ─ ─ ─ ─ ┐ │
356/// │     ColumnIndex     ◀│─ ─ ─
357/// ││    (Optional)     │ │     │
358/// │ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─  │
359/// │┌ ─ ─ ─ ─ ─ ─ ─ ─ ─ ┐ │     │ FileMetadata
360/// │     OffsetIndex      │       contains embedded
361/// ││    (Optional)     │◀┼ ─   │ offsets to
362/// │ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─  │  │    ColumnIndex and
363/// │╔═══════════════════╗ │     │ OffsetIndex
364/// │║                   ║ │  │
365/// │║                   ║ ┼ ─   │
366/// │║   FileMetadata    ║ │
367/// │║                   ║ ┼ ─ ─ ┘
368/// │║                   ║ │
369/// │╚═══════════════════╝ │
370/// │┌───────────────────┐ │
371/// ││  metadata length  │ │ length of FileMetadata  (only)
372/// │└───────────────────┘ │
373/// │┌───────────────────┐ │
374/// ││      'PAR1'       │ │ Parquet Magic Bytes
375/// │└───────────────────┘ │
376/// └──────────────────────┘
377///      Output Buffer
378/// ```
379///
380/// # Example
381/// ```no_run
382/// # use parquet::file::metadata::{ParquetMetaData, ParquetMetaDataWriter};
383/// # fn get_metadata() -> ParquetMetaData { unimplemented!(); }
384/// // write parquet metadata to an in-memory buffer
385/// let mut buffer = vec![];
386/// let metadata: ParquetMetaData = get_metadata();
387/// let writer = ParquetMetaDataWriter::new(&mut buffer, &metadata);
388/// // write the metadata to the buffer
389/// writer.finish().unwrap();
390/// assert!(!buffer.is_empty());
391/// ```
392pub struct ParquetMetaDataWriter<'a, W: Write> {
393    buf: TrackedWrite<W>,
394    metadata: &'a ParquetMetaData,
395    write_path_in_schema: bool,
396}
397
398impl<'a, W: Write> ParquetMetaDataWriter<'a, W> {
399    /// Create a new `ParquetMetaDataWriter` to write to `buf`
400    ///
401    /// Note any embedded offsets in the metadata will be written assuming the
402    /// metadata is at the start of the buffer. If the metadata is being written
403    /// to a location other than the start of the buffer, see [`Self::new_with_tracked`]
404    ///
405    /// See example on the struct level documentation
406    pub fn new(buf: W, metadata: &'a ParquetMetaData) -> Self {
407        Self::new_with_tracked(TrackedWrite::new(buf), metadata)
408    }
409
410    /// Create a new ParquetMetaDataWriter to write to `buf`
411    ///
412    /// This method is used when the metadata is being written to a location other
413    /// than the start of the buffer.
414    ///
415    /// See example on the struct level documentation
416    pub fn new_with_tracked(buf: TrackedWrite<W>, metadata: &'a ParquetMetaData) -> Self {
417        Self {
418            buf,
419            metadata,
420            write_path_in_schema: true,
421        }
422    }
423
424    /// Set whether or not to write the `path_in_schema` field in the Thrift `ColumnMetaData`
425    /// struct.
426    pub fn with_write_path_in_schema(self, val: bool) -> Self {
427        Self {
428            write_path_in_schema: val,
429            ..self
430        }
431    }
432
433    /// Write the metadata to the buffer
434    pub fn finish(mut self) -> Result<()> {
435        let file_metadata = self.metadata.file_metadata();
436
437        let schema = Arc::new(file_metadata.schema().clone());
438        let schema_descr = Arc::new(SchemaDescriptor::new(schema.clone()));
439        let created_by = file_metadata.created_by().map(str::to_string);
440
441        let row_groups = self.metadata.row_groups.clone();
442
443        let key_value_metadata = file_metadata.key_value_metadata().cloned();
444
445        let page_index = self.metadata.page_index().cloned();
446
447        let mut encoder = ThriftMetadataWriter::new(
448            &mut self.buf,
449            &schema_descr,
450            row_groups,
451            created_by,
452            file_metadata.version(),
453            self.write_path_in_schema,
454        );
455
456        if let Some(PageIndex {
457            column_indexes,
458            offset_indexes,
459        }) = page_index
460        {
461            if let Some(column_indexes) = column_indexes {
462                encoder = encoder.with_column_indexes(column_indexes);
463            }
464
465            if let Some(offset_indexes) = offset_indexes {
466                encoder = encoder.with_offset_indexes(offset_indexes);
467            }
468        }
469
470        if let Some(key_value_metadata) = key_value_metadata {
471            encoder = encoder.with_key_value_metadata(key_value_metadata);
472        }
473        encoder.finish()?;
474
475        Ok(())
476    }
477}
478
479#[derive(Debug, Default)]
480struct MetadataObjectWriter {
481    #[cfg(feature = "encryption")]
482    file_encryptor: Option<Arc<FileEncryptor>>,
483}
484
485impl MetadataObjectWriter {
486    #[inline]
487    fn write_thrift_object(object: &impl WriteThrift, sink: impl Write) -> Result<()> {
488        let mut protocol = ThriftCompactOutputProtocol::new(sink);
489        object.write_thrift(&mut protocol)?;
490        Ok(())
491    }
492}
493
494/// Implementations of [`MetadataObjectWriter`] methods for when encryption is disabled
495#[cfg(not(feature = "encryption"))]
496impl MetadataObjectWriter {
497    /// Write [`FileMetaData`] in Thrift format
498    ///
499    /// [`FileMetaData`]: https://github.com/apache/parquet-format/tree/master?tab=readme-ov-file#metadata
500    fn write_file_metadata(&self, file_metadata: &FileMeta, sink: impl Write) -> Result<()> {
501        Self::write_thrift_object(file_metadata, sink)
502    }
503
504    /// Write a column [`OffsetIndex`] in Thrift format
505    ///
506    /// [`OffsetIndex`]: https://github.com/apache/parquet-format/blob/master/PageIndex.md
507    fn write_offset_index(
508        &self,
509        offset_index: &OffsetIndexMetaData,
510        _column_chunk: &ColumnChunkMetaData,
511        _row_group_idx: usize,
512        _column_idx: usize,
513        sink: impl Write,
514    ) -> Result<()> {
515        Self::write_thrift_object(offset_index, sink)
516    }
517
518    /// Write a column [`ColumnIndex`] in Thrift format
519    ///
520    /// Returns `true` unless there is an error.
521    ///
522    /// [`ColumnIndex`]: https://github.com/apache/parquet-format/blob/master/PageIndex.md
523    fn write_column_index(
524        &self,
525        column_index: &ColumnIndexMetaData,
526        _column_chunk: &ColumnChunkMetaData,
527        _row_group_idx: usize,
528        _column_idx: usize,
529        sink: impl Write,
530    ) -> Result<bool> {
531        Self::write_thrift_object(column_index, sink)?;
532        Ok(true)
533    }
534
535    /// No-op implementation of row-group metadata encryption
536    fn apply_row_group_encryption(
537        &self,
538        row_groups: Vec<RowGroupMetaData>,
539    ) -> Result<(Vec<RowGroupMetaData>, Option<Vec<RowGroupMetaData>>)> {
540        Ok((row_groups, None))
541    }
542
543    /// Get the "magic" bytes identifying the file type
544    pub fn get_file_magic(&self) -> &[u8; 4] {
545        get_file_magic()
546    }
547}
548
549/// Implementations of [`MetadataObjectWriter`] methods that rely on encryption being enabled
550#[cfg(feature = "encryption")]
551impl MetadataObjectWriter {
552    /// Set the file encryptor to use
553    fn with_file_encryptor(mut self, encryptor: Option<Arc<FileEncryptor>>) -> Self {
554        self.file_encryptor = encryptor;
555        self
556    }
557
558    /// Write [`FileMetaData`] in Thrift format, possibly encrypting it if required
559    ///
560    /// [`FileMetaData`]: https://github.com/apache/parquet-format/tree/master?tab=readme-ov-file#metadata
561    fn write_file_metadata(&self, file_metadata: &FileMeta, mut sink: impl Write) -> Result<()> {
562        match self.file_encryptor.as_ref() {
563            Some(file_encryptor) if file_encryptor.properties().encrypt_footer() => {
564                // First write FileCryptoMetadata
565                let crypto_metadata = Self::file_crypto_metadata(file_encryptor)?;
566                let mut protocol = ThriftCompactOutputProtocol::new(&mut sink);
567                crypto_metadata.write_thrift(&mut protocol)?;
568
569                // Then write encrypted footer
570                let aad = create_footer_aad(file_encryptor.file_aad())?;
571                let mut encryptor = file_encryptor.get_footer_encryptor()?;
572                encrypt_thrift_object(file_metadata, &mut encryptor, &mut sink, &aad)
573            }
574            Some(file_encryptor) if file_metadata.file_metadata.encryption_algorithm.is_some() => {
575                let aad = create_footer_aad(file_encryptor.file_aad())?;
576                let mut encryptor = file_encryptor.get_footer_encryptor()?;
577                write_signed_plaintext_thrift_object(file_metadata, &mut encryptor, &mut sink, &aad)
578            }
579            _ => Self::write_thrift_object(file_metadata, &mut sink),
580        }
581    }
582
583    /// Write a column [`OffsetIndex`] in Thrift format, possibly encrypting it if required
584    ///
585    /// [`OffsetIndex`]: https://github.com/apache/parquet-format/blob/master/PageIndex.md
586    fn write_offset_index(
587        &self,
588        offset_index: &OffsetIndexMetaData,
589        column_chunk: &ColumnChunkMetaData,
590        row_group_idx: usize,
591        column_idx: usize,
592        sink: impl Write,
593    ) -> Result<()> {
594        match &self.file_encryptor {
595            Some(file_encryptor) => Self::write_thrift_object_with_encryption(
596                offset_index,
597                sink,
598                file_encryptor,
599                column_chunk,
600                ModuleType::OffsetIndex,
601                row_group_idx,
602                column_idx,
603            ),
604            None => Self::write_thrift_object(offset_index, sink),
605        }
606    }
607
608    /// Write a column [`ColumnIndex`] in Thrift format, possibly encrypting it if required
609    ///
610    /// Returns `true` unless there is an error.
611    ///
612    /// [`ColumnIndex`]: https://github.com/apache/parquet-format/blob/master/PageIndex.md
613    fn write_column_index(
614        &self,
615        column_index: &ColumnIndexMetaData,
616        column_chunk: &ColumnChunkMetaData,
617        row_group_idx: usize,
618        column_idx: usize,
619        sink: impl Write,
620    ) -> Result<bool> {
621        match &self.file_encryptor {
622            Some(file_encryptor) => Self::write_thrift_object_with_encryption(
623                column_index,
624                sink,
625                file_encryptor,
626                column_chunk,
627                ModuleType::ColumnIndex,
628                row_group_idx,
629                column_idx,
630            )?,
631            None => Self::write_thrift_object(column_index, sink)?,
632        }
633        Ok(true)
634    }
635
636    /// If encryption is enabled and configured, encrypt row group metadata.
637    /// Returns a tuple of the row group metadata to write,
638    /// and possibly unencrypted metadata to be returned to clients if data was encrypted.
639    fn apply_row_group_encryption(
640        &self,
641        row_groups: Vec<RowGroupMetaData>,
642    ) -> Result<(Vec<RowGroupMetaData>, Option<Vec<RowGroupMetaData>>)> {
643        match &self.file_encryptor {
644            Some(file_encryptor) => {
645                let unencrypted_row_groups = row_groups.clone();
646                let encrypted_row_groups = Self::encrypt_row_groups(row_groups, file_encryptor)?;
647                Ok((encrypted_row_groups, Some(unencrypted_row_groups)))
648            }
649            None => Ok((row_groups, None)),
650        }
651    }
652
653    /// Get the "magic" bytes identifying the file type
654    fn get_file_magic(&self) -> &[u8; 4] {
655        get_file_magic(
656            self.file_encryptor
657                .as_ref()
658                .map(|encryptor| encryptor.properties()),
659        )
660    }
661
662    fn write_thrift_object_with_encryption(
663        object: &impl WriteThrift,
664        mut sink: impl Write,
665        file_encryptor: &FileEncryptor,
666        column_metadata: &ColumnChunkMetaData,
667        module_type: ModuleType,
668        row_group_index: usize,
669        column_index: usize,
670    ) -> Result<()> {
671        let column_path_vec = column_metadata.column_path().as_ref();
672
673        let joined_column_path;
674        let column_path = if column_path_vec.len() == 1 {
675            &column_path_vec[0]
676        } else {
677            joined_column_path = column_path_vec.join(".");
678            &joined_column_path
679        };
680
681        if file_encryptor.is_column_encrypted(column_path) {
682            use crate::encryption::encrypt::encrypt_thrift_object;
683
684            let aad = create_module_aad(
685                file_encryptor.file_aad(),
686                module_type,
687                row_group_index,
688                column_index,
689                None,
690            )?;
691            let mut encryptor = file_encryptor.get_column_encryptor(column_path)?;
692            encrypt_thrift_object(object, &mut encryptor, &mut sink, &aad)
693        } else {
694            Self::write_thrift_object(object, sink)
695        }
696    }
697
698    fn get_plaintext_footer_crypto_metadata(
699        &self,
700    ) -> (Option<EncryptionAlgorithm>, Option<Vec<u8>>) {
701        // Only plaintext footers may contain encryption algorithm and footer key metadata.
702        if let Some(file_encryptor) = self.file_encryptor.as_ref() {
703            let encryption_properties = file_encryptor.properties();
704            if !encryption_properties.encrypt_footer() {
705                return (
706                    Some(Self::encryption_algorithm_from_encryptor(file_encryptor)),
707                    encryption_properties.footer_key_metadata().cloned(),
708                );
709            }
710        }
711        (None, None)
712    }
713
714    fn encryption_algorithm_from_encryptor(file_encryptor: &FileEncryptor) -> EncryptionAlgorithm {
715        let supply_aad_prefix = file_encryptor
716            .properties()
717            .aad_prefix()
718            .map(|_| !file_encryptor.properties().store_aad_prefix());
719        let aad_prefix = if file_encryptor.properties().store_aad_prefix() {
720            file_encryptor.properties().aad_prefix()
721        } else {
722            None
723        };
724        EncryptionAlgorithm::AES_GCM_V1(AesGcmV1 {
725            aad_prefix: aad_prefix.cloned(),
726            aad_file_unique: Some(file_encryptor.aad_file_unique().clone()),
727            supply_aad_prefix,
728        })
729    }
730
731    fn file_crypto_metadata(file_encryptor: &'_ FileEncryptor) -> Result<FileCryptoMetaData<'_>> {
732        let properties = file_encryptor.properties();
733        Ok(FileCryptoMetaData {
734            encryption_algorithm: Self::encryption_algorithm_from_encryptor(file_encryptor),
735            key_metadata: properties.footer_key_metadata().map(|v| v.as_slice()),
736        })
737    }
738
739    fn encrypt_row_groups(
740        row_groups: Vec<RowGroupMetaData>,
741        file_encryptor: &Arc<FileEncryptor>,
742    ) -> Result<Vec<RowGroupMetaData>> {
743        row_groups
744            .into_iter()
745            .enumerate()
746            .map(|(rg_idx, mut rg)| {
747                let cols: Result<Vec<ColumnChunkMetaData>> = rg
748                    .columns
749                    .into_iter()
750                    .enumerate()
751                    .map(|(col_idx, c)| {
752                        Self::encrypt_column_chunk(c, file_encryptor, rg_idx, col_idx)
753                    })
754                    .collect();
755                rg.columns = cols?;
756                Ok(rg)
757            })
758            .collect()
759    }
760
761    /// Apply column encryption to column chunk metadata
762    fn encrypt_column_chunk(
763        mut column_chunk: ColumnChunkMetaData,
764        file_encryptor: &Arc<FileEncryptor>,
765        row_group_index: usize,
766        column_index: usize,
767    ) -> Result<ColumnChunkMetaData> {
768        // Column crypto metadata should have already been set when the column was created.
769        // Here we apply the encryption by encrypting the column metadata if required.
770        let encryptor = match column_chunk.column_crypto_metadata.as_deref() {
771            None => None,
772            Some(ColumnCryptoMetaData::ENCRYPTION_WITH_FOOTER_KEY) => {
773                let is_footer_encrypted = file_encryptor.properties().encrypt_footer();
774
775                // When uniform encryption is used the footer is already encrypted,
776                // so the column chunk does not need additional encryption.
777                // Except if we're in plaintext footer mode, then we need to encrypt
778                // the column metadata here.
779                if !is_footer_encrypted {
780                    Some(file_encryptor.get_footer_encryptor()?)
781                } else {
782                    None
783                }
784            }
785            Some(ColumnCryptoMetaData::ENCRYPTION_WITH_COLUMN_KEY(col_key)) => {
786                let column_path = col_key.path_in_schema.join(".");
787                Some(file_encryptor.get_column_encryptor(&column_path)?)
788            }
789        };
790
791        if let Some(mut encryptor) = encryptor {
792            use crate::file::metadata::thrift::serialize_column_meta_data;
793
794            let aad = create_module_aad(
795                file_encryptor.file_aad(),
796                ModuleType::ColumnMetaData,
797                row_group_index,
798                column_index,
799                None,
800            )?;
801            // create temp ColumnMetaData that we can encrypt
802            let mut buffer: Vec<u8> = vec![];
803            {
804                let mut prot = ThriftCompactOutputProtocol::new(&mut buffer);
805                serialize_column_meta_data(&column_chunk, &mut prot)?;
806            }
807            let ciphertext = encryptor.encrypt(&buffer, &aad)?;
808            column_chunk.encrypted_column_metadata = Some(ciphertext);
809            // Track whether the footer is plaintext, which affects how we serialize
810            // the column metadata (we need to write stripped metadata for backward compatibility)
811            column_chunk.plaintext_footer_mode = !file_encryptor.properties().encrypt_footer();
812        }
813
814        Ok(column_chunk)
815    }
816}
parquet/file/metadata/writer.rs

parquet/file/metadata/
writer.rs
