arti/crates/tor-bytes
Nick Mathewson 0f88c5131f tor-bytes: impl Readable and Writeable for CtByteArray. 2023-02-28 11:23:44 -05:00
..
fuzz Do not .gitignore crates/*/fuzz/corpus 2023-01-20 17:29:00 +00:00
src tor-bytes: impl Readable and Writeable for CtByteArray. 2023-02-28 11:23:44 -05:00
Cargo.toml Patchlevel bumps for remaining changed crates. 2023-02-28 07:13:27 -05:00
README.md doc: consistent summary line for the READMEs 2022-12-20 14:31:47 +01:00
semver.md tor-bytes: impl Readable and Writeable for CtByteArray. 2023-02-28 11:23:44 -05:00

README.md

tor-bytes

Utilities to decode/encode things into bytes.

Overview

The tor-bytes crate is part of Arti, a project to implement Tor in Rust. Other crates in Arti use it to build and handle all the byte-encoded objects from the Tor protocol. For textual directory items, see the [tor-netdoc] crate.

This crate is generally useful for encoding and decoding byte-oriented formats that are not regular enough to qualify for serde, and not complex enough to need a full meta-language. It is probably not suitable for handling anything bigger than a few kilobytes in size.

Alternatives

The Reader/Writer traits in std::io are more appropriate for operations that can fail because of some IO problem. This crate can't handle that: it is for handling things that are already in memory.

TODO: Look into using the "bytes" crate more here.

TODO: The "untrusted" crate has similar goals to our [Reader], but takes more steps to make sure it can never panic. Perhaps we should see if we can learn any tricks from it.

TODO: Do we really want to keep Reader as a struct and Writer as a trait?

Contents and concepts

This crate is structured around four key types:

  • [Reader]: A view of a byte slice, from which data can be decoded.
  • [Writer]: Trait to represent a growable buffer of bytes. (Vec<u8> and [bytes::BytesMut] implement this.)
  • [Writeable]: Trait for an object that can be encoded onto a [Writer]
  • [Readable]: Trait for an object that can be decoded from a [Reader].

Every object you want to encode or decode should implement [Writeable] or [Readable] respectively.

Once you implement these traits, you can use Reader and Writer to handle your type, and other types that are built around it.

License: MIT OR Apache-2.0