fashex - fast hexadecimal encoding and decoding

Hexadecimal string encoding and decoding with best-effort SIMD acceleration.

Highlights

• Best-effort SIMD acceleration.
• Small, focused public APIs.
• APIs that work in const contexts.
• Unlike crates const-hex, faster-hex, etc., this crate accepts uninitialized output buffers (MaybeUninit<u8>).

Performance

This crate offers performance comparable to const-hex or hex-simd on x86 / x86_64 architectures.

For benchmark results, please refer to BENCHMARK.md.

Disclaimer

Although all tests are passing and hours of fuzzing show no failures, latent bugs may still exist in the code.

1. The SIMD-accelerated code paths for x86 / x86_64 architecture are well tested and fuzzed.
2. The SIMD-accelerated code paths for aarch64 architecture are tested and fuzzed.
3. The SIMD-accelerated code paths for loongarch64 architecture have not been tested or fuzzed on real hardware.

If you find any bugs, please report them.

Acknowledgements

This crate is inspired by the following repositories:

• const-hex, SPDX-License-Identifier: MIT OR Apache-2.0
• hex-simd, SPDX-License-Identifier: MIT
• faster-hex, SPDX-License-Identifier: MIT OR Apache-2.0

License