AlexLike/ParquetKit

Elegant, fast, and feature-rich reading and writing of Apache Parquet files in Swift.

Installation

Add ParquetKit to your Package.swift:

dependencies: [
  .package(url: "https://github.com/alexlike/ParquetKit", from: "1.0.0"),
],
targets: [
  .target(name: "MyTarget", dependencies: ["ParquetKit"]),
]

Xcode users may encounter an error when compiling for the first time. To use any macros, including @Parquet, click the Error message and confirm the pop-up dialog.

Note ParquetKit uses the official Rust parquet crate as a backend but ships a pre-built XCFramework, so no Rust toolchain is required when consuming the package.

Documentation

Comprehensive API documentation and examples are available at SwiftPackageIndex/ParquetKit.

Supported types

| Swift type | Parquet type | Notes | | -------------------------------------------------- | ------------------------------------ | -------------------------------------- | | Bool | BOOLEAN | | | Int8 | INT8 | | | Int16 | INT16 | | | Int32 | INT32 | | | Int64 | INT64 | | | UInt8 | UINT8 | | | UInt16 | UINT16 | | | UInt32 | UINT32 | | | UInt64 | UINT64 | | | Float | FLOAT | | | Double | DOUBLE | | | Float16 | FLOAT16 | macOS 11+, iOS 14+ | | String | STRING (UTF-8) | | | Data | BYTE_ARRAY | | | UUID | FIXED_LEN_BYTE_ARRAY(16) or UUID | | | Optional<T> | nullable column | any supported type | | [T] | LIST | any supported element type | | nested @Parquet struct | STRUCT | | | ParquetDate | DATE | days since Unix epoch | | ParquetTimestamp + @ParquetTimestamp(unit:) | TIMESTAMP | millis/micros/nanos, UTC or wall-clock | | ParquetTime + @ParquetTime(unit:) | TIME | defaults to microseconds | | Decimal128 + @ParquetDecimal(precision:scale:) | DECIMAL | | | ParquetInterval | INTERVAL | months, days, milliseconds | | Duration | DURATION (nanoseconds) | Swift Concurrency Duration |

Encodings

| Encoding | Best for | | ----------------------- | ---------------------------------------------------------------- | | .plain | Default | | .deltaBinaryPacked | Sorted or slowly-changing integers and timestamps | | .deltaLengthByteArray | Variable-length strings with similar lengths | | .deltaByteArray | Strings with shared prefixes (URLs, paths) | | .rleDictionary | Low-cardinality string or integer columns | | .byteStreamSplit | Floating-point and fixed-width columns; improves codec ratio |

Compression

| Codec | Notes | | ----------------- | -------------------------------------------- | | .none | No compression | | .snappy | Fast | | .lz4 | Lower ratio than Snappy; very fast | | .gzip(level:) | Levels 1–9 | | .zstd(level:) | Default (level 3); levels 1–22; high ratio | | .brotli(level:) | Levels 0–11 |

Contributing

Pull requests are welcome, including small improvements or first-time contributions. :)

Prerequisites: Swift (and optionally Xcode 16+), Rust (toolchain is auto-installed from Driver/rust-toolchain.toml)

Available Scripts:

# General Tools

# 1 Auto-format Swift and Rust sources
./scripts/auto-format

# 2 Run Swift and Rust tests
./scripts/run-tests

# 3 Build and preview DocC documentation in your browser
./scripts/preview-docs

# When modifying the Rust Driver

# 4 Build the Rust driver and generate the xcframework + Swift bindings
./scripts/build-xcframework

# 5 Tell Swift to use the fresh local xcframework instead of the old and prebuilt one
./scripts/use-local-binary

# 6 Check whether the Swift bindings are up-to-date
./scripts/check-bindings-sync

To catch formatting or binary recompilation issues before they reach CI, install the pre-commit hook once via

ln -sf ../../scripts/pre-commit .git/hooks/pre-commit

This will block commiting malformated source code or source code that references an old build of the Rust driver.

Use Conventional Commits (feat:, fix:, etc.). Commit messages drive the changelog and version bumps.

License

Licensed under the Apache License, Version 2.0. See LICENSE for details and NOTICE for attributions.

Alternatives

ParquetKit may be just perfect for your use case. However, these alternatives might too:

parquet-swift, a pure Swift implementation of the Parquet file format still under development. At the time of writing this, many encodings and compression algos are still missing.
SwiftArrowParquet, a basic wrapper around the Apache Arrow GLibC library.

Package Metadata

Repository: AlexLike/ParquetKit

Stars: 3

Forks: 0

Open issues: 0

Default branch: main

Primary language: swift

License: Apache-2.0

README: README.md