rtic/1/api/hash32/index.html
2024-12-06 13:35:18 +00:00

46 lines
No EOL
8.6 KiB
HTML
Raw Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

<!DOCTYPE html><html lang="en"><head><meta charset="utf-8"><meta name="viewport" content="width=device-width, initial-scale=1.0"><meta name="generator" content="rustdoc"><meta name="description" content="32-bit hashing machinery"><title>hash32 - Rust</title><script>if(window.location.protocol!=="file:")document.head.insertAdjacentHTML("beforeend","SourceSerif4-Regular-46f98efaafac5295.ttf.woff2,FiraSans-Regular-018c141bf0843ffd.woff2,FiraSans-Medium-8f9a781e4970d388.woff2,SourceCodePro-Regular-562dcc5011b6de7d.ttf.woff2,SourceCodePro-Semibold-d899c5a5c4aeb14a.ttf.woff2".split(",").map(f=>`<link rel="preload" as="font" type="font/woff2" crossorigin href="../static.files/${f}">`).join(""))</script><link rel="stylesheet" href="../static.files/normalize-76eba96aa4d2e634.css"><link rel="stylesheet" href="../static.files/rustdoc-b0742ba02757f159.css"><meta name="rustdoc-vars" data-root-path="../" data-static-root-path="../static.files/" data-current-crate="hash32" data-themes="" data-resource-suffix="" data-rustdoc-version="1.83.0 (90b35a623 2024-11-26)" data-channel="1.83.0" data-search-js="search-f0d225181b97f9a4.js" data-settings-js="settings-805db61a62df4bd2.js" ><script src="../static.files/storage-1d39b6787ed640ff.js"></script><script defer src="../crates.js"></script><script defer src="../static.files/main-f070b9041d14864c.js"></script><noscript><link rel="stylesheet" href="../static.files/noscript-0111fcff984fae8f.css"></noscript><link rel="alternate icon" type="image/png" href="../static.files/favicon-32x32-422f7d1d52889060.png"><link rel="icon" type="image/svg+xml" href="../static.files/favicon-2c020d218678b618.svg"></head><body class="rustdoc mod crate"><!--[if lte IE 11]><div class="warning">This old browser is unsupported and will most likely display funky things.</div><![endif]--><nav class="mobile-topbar"><button class="sidebar-menu-toggle" title="show sidebar"></button></nav><nav class="sidebar"><div class="sidebar-crate"><h2><a href="../hash32/index.html">hash32</a><span class="version">0.2.1</span></h2></div><div class="sidebar-elems"><ul class="block"><li><a id="all-types" href="all.html">All Items</a></li></ul><section id="rustdoc-toc"><h3><a href="#">Sections</a></h3><ul class="block top-toc"><li><a href="#why" title="Why?">Why?</a></li><li><a href="#relationship-to-corehash" title="Relationship to `core::hash`">Relationship to <code>core::hash</code></a></li><li><a href="#derivehash32" title="`#[derive(Hash32)]`"><code>#[derive(Hash32)]</code></a></li><li><a href="#hashers" title="Hashers">Hashers</a></li><li><a href="#msrv" title="MSRV">MSRV</a></li><li><a href="#future" title="Future">Future</a></li></ul><h3><a href="#structs">Crate Items</a></h3><ul class="block"><li><a href="#structs" title="Structs">Structs</a></li><li><a href="#traits" title="Traits">Traits</a></li></ul></section><div id="rustdoc-modnav"></div></div></nav><div class="sidebar-resizer"></div><main><div class="width-limiter"><rustdoc-search></rustdoc-search><section id="main-content" class="content"><div class="main-heading"><h1>Crate <span>hash32</span><button id="copy-path" title="Copy item path to clipboard">Copy item path</button></h1><rustdoc-toolbar></rustdoc-toolbar><span class="sub-heading"><a class="src" href="../src/hash32/lib.rs.html#1-363">source</a> </span></div><details class="toggle top-doc" open><summary class="hideme"><span>Expand description</span></summary><div class="docblock"><p>32-bit hashing machinery</p>
<h2 id="why"><a class="doc-anchor" href="#why">§</a>Why?</h2>
<p>Because 32-bit architectures are a thing (e.g. ARM Cortex-M) and you dont want your hashing
function to pull in a bunch of slow 64-bit compiler intrinsics (software implementations of
64-bit operations).</p>
<h2 id="relationship-to-corehash"><a class="doc-anchor" href="#relationship-to-corehash">§</a>Relationship to <code>core::hash</code></h2>
<p>This crate exposes the same interfaces youll find in <a href="https://doc.rust-lang.org/std/hash/index.html"><code>core::hash</code></a>: <code>Hash</code>, <code>Hasher</code>,
<code>BuildHasher</code> and <code>BuildHasherDefault</code>. The main difference is that <code>hash32::Hasher::finish</code>
returns a <code>u32</code> instead of <code>u64</code>, and the contract of <code>hash32::Hasher</code> forbids the implementer
from performing 64-bit (or 128-bit) operations while computing the hash.</p>
<h2 id="derivehash32"><a class="doc-anchor" href="#derivehash32">§</a><code>#[derive(Hash32)]</code></h2>
<p>The easiest way to implement <code>hash32::Hash</code> for a <code>struct</code> is to use the <code>#[derive(Hash32)]</code>.</p>
<p>Note that you need to <em>explicitly</em> depend on both <code>hash32</code> <em>and</em> <code>hash32_derive</code>; both crates
must appear in your <code>Cargo.toml</code>.</p>
<div class="example-wrap ignore"><a href="#" class="tooltip" title="This example is not tested"></a><pre class="rust rust-example-rendered"><code><span class="kw">use </span>hash32_derive::Hash32;
<span class="attr">#[derive(Hash32)]
</span><span class="kw">struct </span>Ipv4Addr([u8; <span class="number">4</span>]);
</code></pre></div>
<h2 id="hashers"><a class="doc-anchor" href="#hashers">§</a>Hashers</h2>
<p>This crate provides implementations of the following 32-bit hashing algorithms:</p>
<ul>
<li><a href="struct.FnvHasher.html">Fowler-Noll-Vo</a></li>
<li><a href="struct.Murmur3Hasher.html">MurmurHash3</a></li>
</ul>
<h2 id="msrv"><a class="doc-anchor" href="#msrv">§</a>MSRV</h2>
<p>This crate is guaranteed to compile on latest stable Rust. It <em>might</em> compile on older
versions but that may change in any new patch release.</p>
<h2 id="future"><a class="doc-anchor" href="#future">§</a>Future</h2>
<p>In the future wed like to deprecate this crate in favor of making <code>core::hash::Hasher</code> generic
over the size of the computed hash. Below is shown the planned change (but it doesnt work due
to limitations in the <code>associated_type_defaults</code> feature):</p>
<div class="example-wrap ignore"><a href="#" class="tooltip" title="This example is not tested"></a><pre class="rust rust-example-rendered"><code><span class="attr">#![feature(associated_type_defaults)]
</span><span class="kw">trait </span>Hasher {
<span class="kw">type </span>Hash = u64; <span class="comment">// default type for backwards compatibility
</span><span class="kw">fn </span>finish(<span class="kw-2">&amp;</span><span class="self">self</span>) -&gt; <span class="self">Self</span>::Hash; <span class="comment">// changed
</span><span class="kw">fn </span>write(<span class="kw-2">&amp;mut </span><span class="self">self</span>, bytes: <span class="kw-2">&amp;</span>[u8]);
}</code></pre></div>
<p>With this change a single <code>#[derive(Hash)]</code> would enough to make a type hashable with 32-bit and
64-bit hashers.</p>
</div></details><h2 id="structs" class="section-header">Structs<a href="#structs" class="anchor">§</a></h2><ul class="item-table"><li><div class="item-name"><a class="struct" href="struct.BuildHasherDefault.html" title="struct hash32::BuildHasherDefault">Build<wbr>Hasher<wbr>Default</a></div><div class="desc docblock-short">See <a href="https://doc.rust-lang.org/core/hash/struct.BuildHasherDefault.html"><code>core::hash::BuildHasherDefault</code></a> for details</div></li><li><div class="item-name"><a class="struct" href="struct.FnvHasher.html" title="struct hash32::FnvHasher">FnvHasher</a></div><div class="desc docblock-short">32-bit Fowler-Noll-Vo hasher</div></li><li><div class="item-name"><a class="struct" href="struct.Murmur3Hasher.html" title="struct hash32::Murmur3Hasher">Murmur3<wbr>Hasher</a></div><div class="desc docblock-short">32-bit MurmurHash3 hasher</div></li></ul><h2 id="traits" class="section-header">Traits<a href="#traits" class="anchor">§</a></h2><ul class="item-table"><li><div class="item-name"><a class="trait" href="trait.BuildHasher.html" title="trait hash32::BuildHasher">Build<wbr>Hasher</a></div><div class="desc docblock-short">See <a href="https://doc.rust-lang.org/core/hash/trait.BuildHasher.html"><code>core::hash::BuildHasher</code></a> for details</div></li><li><div class="item-name"><a class="trait" href="trait.Hash.html" title="trait hash32::Hash">Hash</a></div><div class="desc docblock-short">See <a href="https://doc.rust-lang.org/core/hash/trait.Hash.html"><code>core::hash::Hash</code></a> for details</div></li><li><div class="item-name"><a class="trait" href="trait.Hasher.html" title="trait hash32::Hasher">Hasher</a></div><div class="desc docblock-short">See <a href="https://doc.rust-lang.org/core/hash/trait.Hasher.html"><code>core::hash::Hasher</code></a> for details</div></li></ul></section></div></main></body></html>