53 lines
1.8 KiB
Markdown
53 lines
1.8 KiB
Markdown
# tor-bytes
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Utilities to decode/encode things into bytes.
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## Overview
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The `tor-bytes` crate is part of
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[Arti](https://gitlab.torproject.org/tpo/core/arti/), a project to
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implement [Tor](https://www.torproject.org/) in Rust.
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Other crates in Arti use it to build and handle all the byte-encoded
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objects from the Tor protocol. For textual directory items, see
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the [`tor-netdoc`] crate.
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This crate is generally useful for encoding and decoding
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byte-oriented formats that are not regular enough to qualify for
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serde, and not complex enough to need a full meta-language. It is
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probably not suitable for handling anything bigger than a few
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kilobytes in size.
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### Alternatives
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The Reader/Writer traits in std::io are more appropriate for
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operations that can fail because of some IO problem. This crate
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can't handle that: it is for handling things that are already in
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memory.
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TODO: Look into using the "bytes" crate more here.
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TODO: The "untrusted" crate has similar goals to our [`Reader`],
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but takes more steps to make sure it can never panic. Perhaps we
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should see if we can learn any tricks from it.
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TODO: Do we really want to keep `Reader` as a struct and
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`Writer` as a trait?
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## Contents and concepts
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This crate is structured around four key types:
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* [`Reader`]: A view of a byte slice, from which data can be decoded.
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* [`Writer`]: Trait to represent a growable buffer of bytes.
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(`Vec<u8>` and [`bytes::BytesMut`] implement this.)
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* [`Writeable`]: Trait for an object that can be encoded onto a [`Writer`]
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* [`Readable`]: Trait for an object that can be decoded from a [`Reader`].
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Every object you want to encode or decode should implement
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[`Writeable`] or [`Readable`] respectively.
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Once you implement these traits, you can use Reader and Writer to
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handle your type, and other types that are built around it.
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License: MIT OR Apache-2.0
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