Crate fashex 

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.

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

^{Licensed under either of Apache License, Version 2.0 or MIT license at your option.}
_{Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in these crates by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.}

Modules

bufferdocsrs

Traits and implementations for buffers used by this crate.

Macros

decode

Helper macro for decoding hexadecimal strings to byte arrays in const contexts.

encode

Helper macro for encoding byte arrays as hexadecimal strings in const contexts.

Structs

Displayalloc

A wrapper for displaying a byte slice as a hexadecimal string.

InvalidInput

A generic error type indicating invalid input.

Constants

HEX_CHARS_LOWER

The lowercase hexadecimal chars: "0123456789abcdef".

HEX_CHARS_UPPER

The uppercase hexadecimal chars: "0123456789ABCDEF".

Traits

Hex

A trait for encoding / decoding a hexadecimal string from / into the raw bytes.

Functions

decode

Decodes src (a hexadecimal string, case insensitive) into raw bytes, writes them into dst, and returns a reference to the written bytes.

decode_generic

decode(), but const-evaluable at the cost of performance.

encode

Encodes src as a hexadecimal string into dst and returns a reference to the written string.

encode_generic

encode(), but const-evaluable at the cost of performance.