v3.4.1

What's Changed

This is a focused decode-side optimization. The numbers below come from pytest-benchmark on Apple M1 / CPython 3.14 (PGO-built wheels), comparing v3.4.0 → v3.4.1 head-to-head.

⚡ Decode (DAG-CBOR)

Fixture	v3.4.0	v3.4.1	Speedup
canada	4.75 ms	4.43 ms	1.07x (+7%)
github	69 µs	66 µs	1.05x (+5%)
twitter	790 µs	766 µs	1.03x (+3%)
citm_catalog	1.79 ms	1.77 ms	1.01x (+1%)

The decoder used to fetch the Python recursion limit on every recursive step. We now read it once per top-level decode call and pass it through, closing the last decode gap with cbrrr (we're within 0.7% of it on canada and 30–40% ahead on the others).

🔧 Optimizations

• Optimize DAG-CBOR decode by reading Py_GetRecursionLimit once per call by @MarshalX in #NNN

Deserialization v3.4.0 → v3.4.1

Serialization v3.4.0 → v3.4.1

Full Changelog: v3.4.0...v3.4.1

v3.4.0

What's Changed

❗ Up to ~2x faster DAG-CBOR encode and decode!

This release is all about throughput. The numbers below come from pytest-benchmark on an Apple M1 / CPython 3.14, comparing v3.3.2 → v3.4.0 head-to-head.

⚡ Decode (DAG-CBOR)

Fixture	v3.3.2	v3.4.0	Speedup
github	138 µs	70 µs	1.96x (+96%)
twitter	1.44 ms	0.80 ms	1.81x (+81%)
citm_catalog	2.87 ms	1.81 ms	1.59x (+59%)
canada	5.49 ms	4.77 ms	1.15x (+15%)

⚡ Encode (DAG-CBOR)

Fixture	v3.3.2	v3.4.0	Speedup
canada	2.31 ms	1.17 ms	1.98x (+98%)
citm_catalog	2.25 ms	1.26 ms	1.79x (+79%)
twitter	902 µs	635 µs	1.42x (+42%)
github	75.4 µs	69.7 µs	1.08x (+8%)

🔧 Optimizations

• Optimize DAG-CBOR encode/decode and CAR block parsing by @MarshalX in #104
• Optimize DAG-CBOR string decode with an ASCII fast path by @MarshalX in #105
• Optimize DAG-CBOR map decode with a key-intern cache and KnownHash insert by @MarshalX in #106
• Optimize int encode with a direct PyLong digit read by @MarshalX in #107

🧰 Toolchain & Build

• Bump to Rust 1.95 and PyO3 0.28 by @MarshalX in #102
• Drop the macos-13 PGO runner; cross-compile x86_64 macOS wheels from arm64 by @MarshalX in #108
• Bump CI actions (Node 24) and pytest-codspeed v5 by @MarshalX in #103

📊 Benchmarks & Docs

• Add a head-to-head benchmark against other Python DAG-CBOR libs by @MarshalX in #109
• Update README and copyright years by @MarshalX in #110

Deserialization v3.3.2 → v3.4.0

Serialization v3.3.2 → v3.4.0

🏎️ Old-style performance comparison. Before (v3.3.2) VS After (v3.4.0):

Full Changelog: v3.3.2...v3.4.0

v3.3.2

What's Changed

• Fix DASL testing CI by @MarshalX in #99
• Fix leading zero handling of CIDs in DAG-CBOR by @MarshalX in #98

Full Changelog: v3.3.1...v3.3.2

v3.3.1

What's Changed

• Add DASL testing harnesses to CI workflow by @MarshalX in #97
• Fix error handling in array and map length checks by @MarshalX in #95
• Fix error handling in CID and ULEB128 processing functions by @MarshalX in #96

Full Changelog: v3.3.0...v3.3.1

v3.3.0

What's Changed

❗ Almost x2 speed for CAR decoding (Bluesky firehose), ~25-35% faster DAG-CBOR decoding, and ~17% faster CID decoding!

I do have more ideas on what to try to speed it up even further! For example, applying BOLT on top of the existing PGO.

⚡ Optimizations

• Huge performance gain for DAG-CBOR decoding and CID by replacing deprecated Rust crate libipld with cbor4ii by @vmx in #80 and even contributed upstream!
• Optimize DAG-CBOR encoding for arrays and maps by @MarshalX in #88
• Optimize CAR decoding by reducing allocations by @MarshalX in #90
• Optimize executable size (panic = "abort") by @MarshalX in #86

Other

• Add pytest-benchmark GitHub Actions workflow by @MarshalX in #82
• Add lint and format check GHA workflow by @MarshalX in #83
• Add CONTRIBUTING.md by @MarshalX in #85
• Update CodSpeed by @MarshalX in #81
• Fix formatting in profiling by @MarshalX in #84

🏎️ Performance comparison. Before (v3.2.0) VS After (v3.3.0):

You can find more benchmark results here: #92

New Contributors

• @vmx made their first contribution in #80

Full Changelog: v3.2.0...v3.3.0

v3.2.0

What's Changed

❗ Possible breaking change for you: dropped support for PyPy 3.9 and PyPy 3.10 (both no longer supported upstream) in #77. CPython is still supported from 3.8 to 3.14.

• Add Python 3.14 support by @moreati in #74
• Update Rust to 1.90 by @MarshalX in #75
• Update PyO3 to 0.27.1 by @MarshalX in #75
• Fix repository URL specification in pyproject.toml file by @moreati in #73
• Fix clippy warnings by @MarshalX in #76
• Fix CodSpeed by @MarshalX in #78

New Contributors

• @moreati made their first contribution in #73

Full Changelog: v3.1.1...v3.2.0

v3.1.1

What's Changed

• Bump rust to 1.87.0 by @MarshalX in #67
• Specify Rust version using env variable in workflows by @MarshalX in #67
• Fix bignum encoding by @MarshalX in #66

Full Changelog: v3.1.0...v3.1.1

v3.1.0

What's Changed

• Add type stubs by @zzstoatzz in #56
• Add PyPy 3.11 support by @MarshalX in #63
• Update PyO3 to 0.25.1 with performance optimizations by @MarshalX in #63
• Update README by @MarshalX in #64
• Fix panic on encoding map with integer keys by @MarshalX in #60
• Fix panic on non UTF-8 string by @MarshalX in #59
• Fix smallest and largest CBOR integer roundtrip by @MarshalX in #58
• Fix decoding of infinities and NaNs according to specs by @MarshalX in #62
• Fix handling of concatenated objects / CBOR sequence by @MarshalX in #65

New Contributors

• @zzstoatzz made their first contribution in #56
• @makew0rld reported a lot of bugs in #57 during the work on test suite for DASL

Full Changelog: v3.0.1...v3.1.0

v3.0.1

What's Changed

• Update PyO3 to 0.23.4 by @MarshalX in #54
• Specify the dynamic version in pyproject.toml by @fxcoudert in #53
• Fix stack overflow when decoding deeply nested structures like arrays and maps by @MarshalX in #51

Possible breaking change for you: dropped support for PyPy 3.8

New Contributors

• @fxcoudert made their first contribution in #53

Full Changelog: v3.0.0...v3.0.1

v3.0.0

What's Changed

❗ Breaking changes

• Drop Python 3.7 support by @MarshalX in #50

🆕 Features

• Add Python 3.13 support by @MarshalX in #50

Other

• Update PyO3 to 0.22.5 by @MarshalX in #50
• Update decode_car signature, bytes CIDs instead of str in README by @snarfed in #49

New Contributors

• @snarfed made their first contribution in #49

Full Changelog: v2.0.0...v3.0.0