| <!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/miniz_oxide-0.7.1/src/deflate/mod.rs`."><meta name="keywords" content="rust, rustlang, rust-lang"><title>mod.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="../../../miniz_oxide/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="../../../miniz_oxide/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="doccomment">//! This module contains functionality for compression. |
| |
| </span><span class="kw">use </span><span class="kw">crate</span>::alloc::vec; |
| <span class="kw">use </span><span class="kw">crate</span>::alloc::vec::Vec; |
| |
| <span class="kw">mod </span>buffer; |
| <span class="kw">pub mod </span>core; |
| <span class="kw">pub mod </span>stream; |
| <span class="kw">use </span><span class="self">self</span>::core::<span class="kw-2">*</span>; |
| |
| <span class="doccomment">/// How much processing the compressor should do to compress the data. |
| /// `NoCompression` and `Bestspeed` have special meanings, the other levels determine the number |
| /// of checks for matches in the hash chains and whether to use lazy or greedy parsing. |
| </span><span class="attribute">#[repr(i32)] |
| #[derive(Debug, Copy, Clone, PartialEq, Eq, Hash)] |
| </span><span class="kw">pub enum </span>CompressionLevel { |
| <span class="doccomment">/// Don't do any compression, only output uncompressed blocks. |
| </span>NoCompression = <span class="number">0</span>, |
| <span class="doccomment">/// Fast compression. Uses a special compression routine that is optimized for speed. |
| </span>BestSpeed = <span class="number">1</span>, |
| <span class="doccomment">/// Slow/high compression. Do a lot of checks to try to find good matches. |
| </span>BestCompression = <span class="number">9</span>, |
| <span class="doccomment">/// Even more checks, can be very slow. |
| </span>UberCompression = <span class="number">10</span>, |
| <span class="doccomment">/// Default compromise between speed and compression. |
| </span>DefaultLevel = <span class="number">6</span>, |
| <span class="doccomment">/// Use the default compression level. |
| </span>DefaultCompression = -<span class="number">1</span>, |
| } |
| |
| <span class="comment">// Missing safe rust analogue (this and mem-to-mem are quite similar) |
| /* |
| fn tdefl_compress( |
| d: Option<&mut CompressorOxide>, |
| in_buf: *const c_void, |
| in_size: Option<&mut usize>, |
| out_buf: *mut c_void, |
| out_size: Option<&mut usize>, |
| flush: TDEFLFlush, |
| ) -> TDEFLStatus { |
| let res = match d { |
| None => { |
| in_size.map(|size| *size = 0); |
| out_size.map(|size| *size = 0); |
| (TDEFLStatus::BadParam, 0, 0) |
| }, |
| Some(compressor) => { |
| let callback_res = CallbackOxide::new( |
| compressor.callback_func.clone(), |
| in_buf, |
| in_size, |
| out_buf, |
| out_size, |
| ); |
| |
| if let Ok(mut callback) = callback_res { |
| let res = compress(compressor, &mut callback, flush); |
| callback.update_size(Some(res.1), Some(res.2)); |
| res |
| } else { |
| (TDEFLStatus::BadParam, 0, 0) |
| } |
| } |
| }; |
| res.0 |
| }*/ |
| |
| // Missing safe rust analogue |
| /* |
| fn tdefl_init( |
| d: Option<&mut CompressorOxide>, |
| put_buf_func: PutBufFuncPtr, |
| put_buf_user: *mut c_void, |
| flags: c_int, |
| ) -> TDEFLStatus { |
| if let Some(d) = d { |
| *d = CompressorOxide::new( |
| put_buf_func.map(|func| |
| CallbackFunc { put_buf_func: func, put_buf_user: put_buf_user } |
| ), |
| flags as u32, |
| ); |
| TDEFLStatus::Okay |
| } else { |
| TDEFLStatus::BadParam |
| } |
| }*/ |
| |
| // Missing safe rust analogue (though maybe best served by flate2 front-end instead) |
| /* |
| fn tdefl_compress_mem_to_output( |
| buf: *const c_void, |
| buf_len: usize, |
| put_buf_func: PutBufFuncPtr, |
| put_buf_user: *mut c_void, |
| flags: c_int, |
| ) -> bool*/ |
| |
| // Missing safe Rust analogue |
| /* |
| fn tdefl_compress_mem_to_mem( |
| out_buf: *mut c_void, |
| out_buf_len: usize, |
| src_buf: *const c_void, |
| src_buf_len: usize, |
| flags: c_int, |
| ) -> usize*/ |
| |
| </span><span class="doccomment">/// Compress the input data to a vector, using the specified compression level (0-10). |
| </span><span class="kw">pub fn </span>compress_to_vec(input: <span class="kw-2">&</span>[u8], level: u8) -> Vec<u8> { |
| compress_to_vec_inner(input, level, <span class="number">0</span>, <span class="number">0</span>) |
| } |
| |
| <span class="doccomment">/// Compress the input data to a vector, using the specified compression level (0-10), and with a |
| /// zlib wrapper. |
| </span><span class="kw">pub fn </span>compress_to_vec_zlib(input: <span class="kw-2">&</span>[u8], level: u8) -> Vec<u8> { |
| compress_to_vec_inner(input, level, <span class="number">1</span>, <span class="number">0</span>) |
| } |
| |
| <span class="doccomment">/// Simple function to compress data to a vec. |
| </span><span class="kw">fn </span>compress_to_vec_inner(input: <span class="kw-2">&</span>[u8], level: u8, window_bits: i32, strategy: i32) -> Vec<u8> { |
| <span class="comment">// The comp flags function sets the zlib flag if the window_bits parameter is > 0. |
| </span><span class="kw">let </span>flags = create_comp_flags_from_zip_params(level.into(), window_bits, strategy); |
| <span class="kw">let </span><span class="kw-2">mut </span>compressor = CompressorOxide::new(flags); |
| <span class="kw">let </span><span class="kw-2">mut </span>output = <span class="macro">vec!</span>[<span class="number">0</span>; ::core::cmp::max(input.len() / <span class="number">2</span>, <span class="number">2</span>)]; |
| |
| <span class="kw">let </span><span class="kw-2">mut </span>in_pos = <span class="number">0</span>; |
| <span class="kw">let </span><span class="kw-2">mut </span>out_pos = <span class="number">0</span>; |
| <span class="kw">loop </span>{ |
| <span class="kw">let </span>(status, bytes_in, bytes_out) = compress( |
| <span class="kw-2">&mut </span>compressor, |
| <span class="kw-2">&</span>input[in_pos..], |
| <span class="kw-2">&mut </span>output[out_pos..], |
| TDEFLFlush::Finish, |
| ); |
| |
| out_pos += bytes_out; |
| in_pos += bytes_in; |
| |
| <span class="kw">match </span>status { |
| TDEFLStatus::Done => { |
| output.truncate(out_pos); |
| <span class="kw">break</span>; |
| } |
| TDEFLStatus::Okay => { |
| <span class="comment">// We need more space, so resize the vector. |
| </span><span class="kw">if </span>output.len().saturating_sub(out_pos) < <span class="number">30 </span>{ |
| output.resize(output.len() * <span class="number">2</span>, <span class="number">0</span>) |
| } |
| } |
| <span class="comment">// Not supposed to happen unless there is a bug. |
| </span><span class="kw">_ </span>=> <span class="macro">panic!</span>(<span class="string">"Bug! Unexpectedly failed to compress!"</span>), |
| } |
| } |
| |
| output |
| } |
| |
| <span class="attribute">#[cfg(test)] |
| </span><span class="kw">mod </span>test { |
| <span class="kw">use super</span>::{compress_to_vec, compress_to_vec_inner, CompressionStrategy}; |
| <span class="kw">use </span><span class="kw">crate</span>::inflate::decompress_to_vec; |
| <span class="kw">use </span>alloc::vec; |
| |
| <span class="doccomment">/// Test deflate example. |
| /// |
| /// Check if the encoder produces the same code as the example given by Mark Adler here: |
| /// https://stackoverflow.com/questions/17398931/deflate-encoding-with-static-huffman-codes/17415203 |
| </span><span class="attribute">#[test] |
| </span><span class="kw">fn </span>compress_small() { |
| <span class="kw">let </span>test_data = <span class="string">b"Deflate late"</span>; |
| <span class="kw">let </span>check = [ |
| <span class="number">0x73</span>, <span class="number">0x49</span>, <span class="number">0x4d</span>, <span class="number">0xcb</span>, <span class="number">0x49</span>, <span class="number">0x2c</span>, <span class="number">0x49</span>, <span class="number">0x55</span>, <span class="number">0x00</span>, <span class="number">0x11</span>, <span class="number">0x00</span>, |
| ]; |
| |
| <span class="kw">let </span>res = compress_to_vec(test_data, <span class="number">1</span>); |
| <span class="macro">assert_eq!</span>(<span class="kw-2">&</span>check[..], res.as_slice()); |
| |
| <span class="kw">let </span>res = compress_to_vec(test_data, <span class="number">9</span>); |
| <span class="macro">assert_eq!</span>(<span class="kw-2">&</span>check[..], res.as_slice()); |
| } |
| |
| <span class="attribute">#[test] |
| </span><span class="kw">fn </span>compress_huff_only() { |
| <span class="kw">let </span>test_data = <span class="string">b"Deflate late"</span>; |
| |
| <span class="kw">let </span>res = compress_to_vec_inner(test_data, <span class="number">1</span>, <span class="number">0</span>, CompressionStrategy::HuffmanOnly <span class="kw">as </span>i32); |
| <span class="kw">let </span>d = decompress_to_vec(res.as_slice()).expect(<span class="string">"Failed to decompress!"</span>); |
| <span class="macro">assert_eq!</span>(test_data, d.as_slice()); |
| } |
| |
| <span class="doccomment">/// Test that a raw block compresses fine. |
| </span><span class="attribute">#[test] |
| </span><span class="kw">fn </span>compress_raw() { |
| <span class="kw">let </span>text = <span class="string">b"Hello, zlib!"</span>; |
| <span class="kw">let </span>encoded = { |
| <span class="kw">let </span>len = text.len(); |
| <span class="kw">let </span>notlen = !len; |
| <span class="kw">let </span><span class="kw-2">mut </span>encoded = <span class="macro">vec!</span>[ |
| <span class="number">1</span>, |
| len <span class="kw">as </span>u8, |
| (len >> <span class="number">8</span>) <span class="kw">as </span>u8, |
| notlen <span class="kw">as </span>u8, |
| (notlen >> <span class="number">8</span>) <span class="kw">as </span>u8, |
| ]; |
| encoded.extend_from_slice(<span class="kw-2">&</span>text[..]); |
| encoded |
| }; |
| |
| <span class="kw">let </span>res = compress_to_vec(text, <span class="number">0</span>); |
| <span class="macro">assert_eq!</span>(encoded, res.as_slice()); |
| } |
| |
| <span class="attribute">#[test] |
| </span><span class="kw">fn </span>short() { |
| <span class="kw">let </span>test_data = [<span class="number">10</span>, <span class="number">10</span>, <span class="number">10</span>, <span class="number">10</span>, <span class="number">10</span>, <span class="number">55</span>]; |
| <span class="kw">let </span>c = compress_to_vec(<span class="kw-2">&</span>test_data, <span class="number">9</span>); |
| |
| <span class="kw">let </span>d = decompress_to_vec(c.as_slice()).expect(<span class="string">"Failed to decompress!"</span>); |
| <span class="macro">assert_eq!</span>(<span class="kw-2">&</span>test_data, d.as_slice()); |
| <span class="comment">// Check that a static block is used here, rather than a raw block |
| // , so the data is actually compressed. |
| // (The optimal compressed length would be 5, but neither miniz nor zlib manages that either |
| // as neither checks matches against the byte at index 0.) |
| </span><span class="macro">assert!</span>(c.len() <= <span class="number">6</span>); |
| } |
| } |
| </code></pre></div> |
| </section></div></main><div id="rustdoc-vars" data-root-path="../../../" data-current-crate="miniz_oxide" data-themes="ayu,dark,light" data-resource-suffix="" data-rustdoc-version="1.66.0-nightly (5c8bff74b 2022-10-21)" ></div></body></html> |
