| <!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="Source of the Rust file `/root/.cargo/registry/src/github.com-1ecc6299db9ec823/crc32fast-1.3.2/src/baseline.rs`."><meta name="keywords" content="rust, rustlang, rust-lang"><title>baseline.rs - source</title><link rel="preload" as="font" type="font/woff2" crossorigin href="../../SourceSerif4-Regular.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../FiraSans-Regular.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../FiraSans-Medium.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../SourceCodePro-Regular.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../SourceSerif4-Bold.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../SourceCodePro-Semibold.ttf.woff2"><link rel="stylesheet" href="../../normalize.css"><link rel="stylesheet" href="../../rustdoc.css" id="mainThemeStyle"><link rel="stylesheet" href="../../ayu.css" disabled><link rel="stylesheet" href="../../dark.css" disabled><link rel="stylesheet" href="../../light.css" id="themeStyle"><script id="default-settings" ></script><script src="../../storage.js"></script><script defer src="../../source-script.js"></script><script defer src="../../source-files.js"></script><script defer src="../../main.js"></script><noscript><link rel="stylesheet" href="../../noscript.css"></noscript><link rel="alternate icon" type="image/png" href="../../favicon-16x16.png"><link rel="alternate icon" type="image/png" href="../../favicon-32x32.png"><link rel="icon" type="image/svg+xml" href="../../favicon.svg"></head><body class="rustdoc source"><!--[if lte IE 11]><div class="warning">This old browser is unsupported and will most likely display funky things.</div><![endif]--><nav class="sidebar"><a class="sidebar-logo" href="../../crc32fast/index.html"><div class="logo-container"><img class="rust-logo" src="../../rust-logo.svg" alt="logo"></div></a></nav><main><div class="width-limiter"><nav class="sub"><a class="sub-logo-container" href="../../crc32fast/index.html"><img class="rust-logo" src="../../rust-logo.svg" alt="logo"></a><form class="search-form"><div class="search-container"><span></span><input class="search-input" name="search" autocomplete="off" spellcheck="false" placeholder="Click or press ‘S’ to search, ‘?’ for more options…" type="search"><div id="help-button" title="help" tabindex="-1"><a href="../../help.html">?</a></div><div id="settings-menu" tabindex="-1"><a href="../../settings.html" title="settings"><img width="22" height="22" alt="Change settings" src="../../wheel.svg"></a></div></div></form></nav><section id="main-content" class="content"><div class="example-wrap"><pre class="src-line-numbers"><span id="1">1</span> |
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| </pre><pre class="rust"><code><span class="kw">use </span>table::CRC32_TABLE; |
| |
| <span class="attribute">#[derive(Clone)] |
| </span><span class="kw">pub struct </span>State { |
| state: u32, |
| } |
| |
| <span class="kw">impl </span>State { |
| <span class="kw">pub fn </span>new(state: u32) -> <span class="self">Self </span>{ |
| State { state } |
| } |
| |
| <span class="kw">pub fn </span>update(<span class="kw-2">&mut </span><span class="self">self</span>, buf: <span class="kw-2">&</span>[u8]) { |
| <span class="self">self</span>.state = update_fast_16(<span class="self">self</span>.state, buf); |
| } |
| |
| <span class="kw">pub fn </span>finalize(<span class="self">self</span>) -> u32 { |
| <span class="self">self</span>.state |
| } |
| |
| <span class="kw">pub fn </span>reset(<span class="kw-2">&mut </span><span class="self">self</span>) { |
| <span class="self">self</span>.state = <span class="number">0</span>; |
| } |
| |
| <span class="kw">pub fn </span>combine(<span class="kw-2">&mut </span><span class="self">self</span>, other: u32, amount: u64) { |
| <span class="self">self</span>.state = ::combine::combine(<span class="self">self</span>.state, other, amount); |
| } |
| } |
| |
| <span class="kw">pub</span>(<span class="kw">crate</span>) <span class="kw">fn </span>update_fast_16(prev: u32, <span class="kw-2">mut </span>buf: <span class="kw-2">&</span>[u8]) -> u32 { |
| <span class="kw">const </span>UNROLL: usize = <span class="number">4</span>; |
| <span class="kw">const </span>BYTES_AT_ONCE: usize = <span class="number">16 </span>* UNROLL; |
| |
| <span class="kw">let </span><span class="kw-2">mut </span>crc = !prev; |
| |
| <span class="kw">while </span>buf.len() >= BYTES_AT_ONCE { |
| <span class="kw">for _ in </span><span class="number">0</span>..UNROLL { |
| crc = CRC32_TABLE[<span class="number">0x0</span>][buf[<span class="number">0xf</span>] <span class="kw">as </span>usize] |
| ^ CRC32_TABLE[<span class="number">0x1</span>][buf[<span class="number">0xe</span>] <span class="kw">as </span>usize] |
| ^ CRC32_TABLE[<span class="number">0x2</span>][buf[<span class="number">0xd</span>] <span class="kw">as </span>usize] |
| ^ CRC32_TABLE[<span class="number">0x3</span>][buf[<span class="number">0xc</span>] <span class="kw">as </span>usize] |
| ^ CRC32_TABLE[<span class="number">0x4</span>][buf[<span class="number">0xb</span>] <span class="kw">as </span>usize] |
| ^ CRC32_TABLE[<span class="number">0x5</span>][buf[<span class="number">0xa</span>] <span class="kw">as </span>usize] |
| ^ CRC32_TABLE[<span class="number">0x6</span>][buf[<span class="number">0x9</span>] <span class="kw">as </span>usize] |
| ^ CRC32_TABLE[<span class="number">0x7</span>][buf[<span class="number">0x8</span>] <span class="kw">as </span>usize] |
| ^ CRC32_TABLE[<span class="number">0x8</span>][buf[<span class="number">0x7</span>] <span class="kw">as </span>usize] |
| ^ CRC32_TABLE[<span class="number">0x9</span>][buf[<span class="number">0x6</span>] <span class="kw">as </span>usize] |
| ^ CRC32_TABLE[<span class="number">0xa</span>][buf[<span class="number">0x5</span>] <span class="kw">as </span>usize] |
| ^ CRC32_TABLE[<span class="number">0xb</span>][buf[<span class="number">0x4</span>] <span class="kw">as </span>usize] |
| ^ CRC32_TABLE[<span class="number">0xc</span>][buf[<span class="number">0x3</span>] <span class="kw">as </span>usize ^ ((crc >> <span class="number">0x18</span>) & <span class="number">0xFF</span>) <span class="kw">as </span>usize] |
| ^ CRC32_TABLE[<span class="number">0xd</span>][buf[<span class="number">0x2</span>] <span class="kw">as </span>usize ^ ((crc >> <span class="number">0x10</span>) & <span class="number">0xFF</span>) <span class="kw">as </span>usize] |
| ^ CRC32_TABLE[<span class="number">0xe</span>][buf[<span class="number">0x1</span>] <span class="kw">as </span>usize ^ ((crc >> <span class="number">0x08</span>) & <span class="number">0xFF</span>) <span class="kw">as </span>usize] |
| ^ CRC32_TABLE[<span class="number">0xf</span>][buf[<span class="number">0x0</span>] <span class="kw">as </span>usize ^ ((crc >> <span class="number">0x00</span>) & <span class="number">0xFF</span>) <span class="kw">as </span>usize]; |
| buf = <span class="kw-2">&</span>buf[<span class="number">16</span>..]; |
| } |
| } |
| |
| update_slow(!crc, buf) |
| } |
| |
| <span class="kw">pub</span>(<span class="kw">crate</span>) <span class="kw">fn </span>update_slow(prev: u32, buf: <span class="kw-2">&</span>[u8]) -> u32 { |
| <span class="kw">let </span><span class="kw-2">mut </span>crc = !prev; |
| |
| <span class="kw">for </span><span class="kw-2">&</span>byte <span class="kw">in </span>buf.iter() { |
| crc = CRC32_TABLE[<span class="number">0</span>][((crc <span class="kw">as </span>u8) ^ byte) <span class="kw">as </span>usize] ^ (crc >> <span class="number">8</span>); |
| } |
| |
| !crc |
| } |
| |
| <span class="attribute">#[cfg(test)] |
| </span><span class="kw">mod </span>test { |
| <span class="attribute">#[test] |
| </span><span class="kw">fn </span>slow() { |
| <span class="macro">assert_eq!</span>(<span class="kw">super</span>::update_slow(<span class="number">0</span>, <span class="string">b""</span>), <span class="number">0</span>); |
| |
| <span class="comment">// test vectors from the iPXE project (input and output are bitwise negated) |
| </span><span class="macro">assert_eq!</span>(<span class="kw">super</span>::update_slow(!<span class="number">0x12345678</span>, <span class="string">b""</span>), !<span class="number">0x12345678</span>); |
| <span class="macro">assert_eq!</span>(<span class="kw">super</span>::update_slow(!<span class="number">0xffffffff</span>, <span class="string">b"hello world"</span>), !<span class="number">0xf2b5ee7a</span>); |
| <span class="macro">assert_eq!</span>(<span class="kw">super</span>::update_slow(!<span class="number">0xffffffff</span>, <span class="string">b"hello"</span>), !<span class="number">0xc9ef5979</span>); |
| <span class="macro">assert_eq!</span>(<span class="kw">super</span>::update_slow(!<span class="number">0xc9ef5979</span>, <span class="string">b" world"</span>), !<span class="number">0xf2b5ee7a</span>); |
| |
| <span class="comment">// Some vectors found on Rosetta code |
| </span><span class="macro">assert_eq!</span>(<span class="kw">super</span>::update_slow(<span class="number">0</span>, <span class="string">b"\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"</span>), <span class="number">0x190A55AD</span>); |
| <span class="macro">assert_eq!</span>(<span class="kw">super</span>::update_slow(<span class="number">0</span>, <span class="string">b"\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF"</span>), <span class="number">0xFF6CAB0B</span>); |
| <span class="macro">assert_eq!</span>(<span class="kw">super</span>::update_slow(<span class="number">0</span>, <span class="string">b"\x00\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0A\x0B\x0C\x0D\x0E\x0F\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1A\x1B\x1C\x1D\x1E\x1F"</span>), <span class="number">0x91267E8A</span>); |
| } |
| |
| <span class="macro">quickcheck! </span>{ |
| <span class="kw">fn </span>fast_16_is_the_same_as_slow(crc: u32, bytes: Vec<u8>) -> bool { |
| <span class="kw">super</span>::update_fast_16(crc, <span class="kw-2">&</span>bytes) == <span class="kw">super</span>::update_slow(crc, <span class="kw-2">&</span>bytes) |
| } |
| } |
| } |
| </code></pre></div> |
| </section></div></main><div id="rustdoc-vars" data-root-path="../../" data-current-crate="crc32fast" data-themes="ayu,dark,light" data-resource-suffix="" data-rustdoc-version="1.66.0-nightly (5c8bff74b 2022-10-21)" ></div></body></html> |