feat(puffin): add puffin file reader and writer#624
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zhaoxuan1994 wants to merge 1 commit intoapache:mainfrom
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feat(puffin): add puffin file reader and writer#624zhaoxuan1994 wants to merge 1 commit intoapache:mainfrom
zhaoxuan1994 wants to merge 1 commit intoapache:mainfrom
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zhaoxuan1994
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Apr 23, 2026
zhaoxuan1994
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- PuffinWriter: in-memory writer that builds complete Puffin files
- Add() writes blobs with optional compression
- Finish() serializes footer with JSON metadata
- Tracks BlobMetadata for all written blobs
- PuffinReader: in-memory reader that parses Puffin files
- ReadFileMetadata() parses footer and validates magic bytes
- ReadBlob() reads and decompresses individual blobs
- ReadAll() reads all blobs from metadata
- Expose Compress/Decompress as public API in puffin_format.h
- Register new sources in CMake and Meson build systems
- Add comprehensive tests
- PuffinWriter: in-memory writer that builds complete Puffin files - Add() writes blobs with optional compression - Finish() serializes footer with JSON metadata - Tracks BlobMetadata for all written blobs - PuffinReader: in-memory reader that parses Puffin files - ReadFileMetadata() parses footer and validates magic bytes - ReadBlob() reads and decompresses individual blobs - ReadAll() reads all blobs from metadata - Expose Compress/Decompress as public API in puffin_format.h - Register new sources in CMake and Meson build systems - Add comprehensive tests including Java binary compatibility
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Pull request overview
Adds an in-memory Puffin file writer/reader to the Iceberg C++ Puffin module, exposes compression helpers as public API, wires new sources into the build, and introduces round-trip + Java-compatibility tests.
Changes:
- Introduce
PuffinWriterfor building Puffin files in-memory (blob writing + footer serialization). - Introduce
PuffinReaderfor parsing Puffin files in-memory (footer parsing + blob reading). - Export
Compress/DecompressAPIs and register new sources/tests in CMake + Meson.
Reviewed changes
Copilot reviewed 12 out of 12 changed files in this pull request and generated 3 comments.
Show a summary per file
| File | Description |
|---|---|
| src/iceberg/puffin/puffin_writer.h | Declares the in-memory Puffin writer API. |
| src/iceberg/puffin/puffin_writer.cc | Implements Puffin file serialization (header, blobs, footer). |
| src/iceberg/puffin/puffin_reader.h | Declares the in-memory Puffin reader API. |
| src/iceberg/puffin/puffin_reader.cc | Implements footer parsing, magic validation, and blob reads. |
| src/iceberg/puffin/puffin_format.h | Exposes Compress/Decompress as public APIs. |
| src/iceberg/puffin/puffin_format.cc | Moves flag helpers and keeps compression stubs in the public namespace. |
| src/iceberg/puffin/meson.build | Installs new public headers for Meson builds. |
| src/iceberg/meson.build | Adds new Puffin reader/writer sources to the core library build. |
| src/iceberg/CMakeLists.txt | Adds new Puffin reader/writer sources to the CMake build. |
| src/iceberg/test/puffin_reader_writer_test.cc | Adds comprehensive writer/reader round-trip and Java-compat tests. |
| src/iceberg/test/meson.build | Adds the new Puffin reader/writer test to Meson test target. |
| src/iceberg/test/CMakeLists.txt | Adds the new Puffin reader/writer test to CMake test target. |
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| /// Parses a Puffin file from an in-memory buffer. Usage: | ||
| /// PuffinReader reader(file_data); | ||
| /// auto metadata = reader.ReadFileMetadata(); | ||
| /// auto blob = reader.ReadBlob(metadata->blobs[0]); |
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| auto payload_size = ReadLittleEndian<int32_t>( | ||
| data_.data() + footer_struct_offset + PuffinFormat::kFooterStructPayloadSizeOffset); | ||
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| // Calculate total footer size and validate | ||
| int64_t footer_size = PuffinFormat::kFooterStartMagicLength + | ||
| static_cast<int64_t>(payload_size) + | ||
| PuffinFormat::kFooterStructLength; | ||
| auto footer_offset = file_size - footer_size; | ||
| if (footer_offset < 0) { | ||
| return Invalid("Invalid file: footer size {} exceeds file size {}", footer_size, | ||
| file_size); | ||
| } | ||
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| // Validate footer start magic | ||
| ICEBERG_RETURN_UNEXPECTED(CheckMagic(data_, footer_offset)); | ||
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| // Check flags for footer compression | ||
| std::array<uint8_t, 4> flags{}; | ||
| std::memcpy( | ||
| flags.data(), | ||
| data_.data() + footer_struct_offset + PuffinFormat::kFooterStructFlagsOffset, 4); | ||
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| PuffinCompressionCodec footer_compression = PuffinCompressionCodec::kNone; | ||
| if (IsFlagSet(flags, PuffinFlag::kFooterPayloadCompressed)) { | ||
| footer_compression = PuffinFormat::kDefaultFooterCompressionCodec; | ||
| } | ||
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| // Extract footer payload | ||
| auto payload_offset = footer_offset + PuffinFormat::kFooterStartMagicLength; | ||
| std::span<const std::byte> payload_span(data_.data() + payload_offset, payload_size); | ||
| ICEBERG_ASSIGN_OR_RAISE(auto payload_bytes, | ||
| Decompress(footer_compression, payload_span)); |
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| if (blob_metadata.offset < 0 || | ||
| blob_metadata.offset + blob_metadata.length > file_size) { | ||
| return Invalid("Invalid blob: offset {} + length {} exceeds file size {}", | ||
| blob_metadata.offset, blob_metadata.length, file_size); | ||
| } | ||
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| std::span<const std::byte> raw_data(data_.data() + blob_metadata.offset, | ||
| blob_metadata.length); |
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