| <!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/git/checkouts/tokio-377c595163f99a10/dfe252d/tokio/src/io/util/buf_stream.rs`."><meta name="keywords" content="rust, rustlang, rust-lang"><title>buf_stream.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="../../../../tokio/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="../../../../tokio/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> |
| <span id="2">2</span> |
| <span id="3">3</span> |
| <span id="4">4</span> |
| <span id="5">5</span> |
| <span id="6">6</span> |
| <span id="7">7</span> |
| <span id="8">8</span> |
| <span id="9">9</span> |
| <span id="10">10</span> |
| <span id="11">11</span> |
| <span id="12">12</span> |
| <span id="13">13</span> |
| <span id="14">14</span> |
| <span id="15">15</span> |
| <span id="16">16</span> |
| <span id="17">17</span> |
| <span id="18">18</span> |
| <span id="19">19</span> |
| <span id="20">20</span> |
| <span id="21">21</span> |
| <span id="22">22</span> |
| <span id="23">23</span> |
| <span id="24">24</span> |
| <span id="25">25</span> |
| <span id="26">26</span> |
| <span id="27">27</span> |
| <span id="28">28</span> |
| <span id="29">29</span> |
| <span id="30">30</span> |
| <span id="31">31</span> |
| <span id="32">32</span> |
| <span id="33">33</span> |
| <span id="34">34</span> |
| <span id="35">35</span> |
| <span id="36">36</span> |
| <span id="37">37</span> |
| <span id="38">38</span> |
| <span id="39">39</span> |
| <span id="40">40</span> |
| <span id="41">41</span> |
| <span id="42">42</span> |
| <span id="43">43</span> |
| <span id="44">44</span> |
| <span id="45">45</span> |
| <span id="46">46</span> |
| <span id="47">47</span> |
| <span id="48">48</span> |
| <span id="49">49</span> |
| <span id="50">50</span> |
| <span id="51">51</span> |
| <span id="52">52</span> |
| <span id="53">53</span> |
| <span id="54">54</span> |
| <span id="55">55</span> |
| <span id="56">56</span> |
| <span id="57">57</span> |
| <span id="58">58</span> |
| <span id="59">59</span> |
| <span id="60">60</span> |
| <span id="61">61</span> |
| <span id="62">62</span> |
| <span id="63">63</span> |
| <span id="64">64</span> |
| <span id="65">65</span> |
| <span id="66">66</span> |
| <span id="67">67</span> |
| <span id="68">68</span> |
| <span id="69">69</span> |
| <span id="70">70</span> |
| <span id="71">71</span> |
| <span id="72">72</span> |
| <span id="73">73</span> |
| <span id="74">74</span> |
| <span id="75">75</span> |
| <span id="76">76</span> |
| <span id="77">77</span> |
| <span id="78">78</span> |
| <span id="79">79</span> |
| <span id="80">80</span> |
| <span id="81">81</span> |
| <span id="82">82</span> |
| <span id="83">83</span> |
| <span id="84">84</span> |
| <span id="85">85</span> |
| <span id="86">86</span> |
| <span id="87">87</span> |
| <span id="88">88</span> |
| <span id="89">89</span> |
| <span id="90">90</span> |
| <span id="91">91</span> |
| <span id="92">92</span> |
| <span id="93">93</span> |
| <span id="94">94</span> |
| <span id="95">95</span> |
| <span id="96">96</span> |
| <span id="97">97</span> |
| <span id="98">98</span> |
| <span id="99">99</span> |
| <span id="100">100</span> |
| <span id="101">101</span> |
| <span id="102">102</span> |
| <span id="103">103</span> |
| <span id="104">104</span> |
| <span id="105">105</span> |
| <span id="106">106</span> |
| <span id="107">107</span> |
| <span id="108">108</span> |
| <span id="109">109</span> |
| <span id="110">110</span> |
| <span id="111">111</span> |
| <span id="112">112</span> |
| <span id="113">113</span> |
| <span id="114">114</span> |
| <span id="115">115</span> |
| <span id="116">116</span> |
| <span id="117">117</span> |
| <span id="118">118</span> |
| <span id="119">119</span> |
| <span id="120">120</span> |
| <span id="121">121</span> |
| <span id="122">122</span> |
| <span id="123">123</span> |
| <span id="124">124</span> |
| <span id="125">125</span> |
| <span id="126">126</span> |
| <span id="127">127</span> |
| <span id="128">128</span> |
| <span id="129">129</span> |
| <span id="130">130</span> |
| <span id="131">131</span> |
| <span id="132">132</span> |
| <span id="133">133</span> |
| <span id="134">134</span> |
| <span id="135">135</span> |
| <span id="136">136</span> |
| <span id="137">137</span> |
| <span id="138">138</span> |
| <span id="139">139</span> |
| <span id="140">140</span> |
| <span id="141">141</span> |
| <span id="142">142</span> |
| <span id="143">143</span> |
| <span id="144">144</span> |
| <span id="145">145</span> |
| <span id="146">146</span> |
| <span id="147">147</span> |
| <span id="148">148</span> |
| <span id="149">149</span> |
| <span id="150">150</span> |
| <span id="151">151</span> |
| <span id="152">152</span> |
| <span id="153">153</span> |
| <span id="154">154</span> |
| <span id="155">155</span> |
| <span id="156">156</span> |
| <span id="157">157</span> |
| <span id="158">158</span> |
| <span id="159">159</span> |
| <span id="160">160</span> |
| <span id="161">161</span> |
| <span id="162">162</span> |
| <span id="163">163</span> |
| <span id="164">164</span> |
| <span id="165">165</span> |
| <span id="166">166</span> |
| <span id="167">167</span> |
| <span id="168">168</span> |
| <span id="169">169</span> |
| <span id="170">170</span> |
| <span id="171">171</span> |
| <span id="172">172</span> |
| <span id="173">173</span> |
| <span id="174">174</span> |
| <span id="175">175</span> |
| <span id="176">176</span> |
| <span id="177">177</span> |
| <span id="178">178</span> |
| <span id="179">179</span> |
| <span id="180">180</span> |
| <span id="181">181</span> |
| <span id="182">182</span> |
| <span id="183">183</span> |
| <span id="184">184</span> |
| <span id="185">185</span> |
| <span id="186">186</span> |
| <span id="187">187</span> |
| <span id="188">188</span> |
| <span id="189">189</span> |
| <span id="190">190</span> |
| <span id="191">191</span> |
| <span id="192">192</span> |
| <span id="193">193</span> |
| <span id="194">194</span> |
| <span id="195">195</span> |
| <span id="196">196</span> |
| <span id="197">197</span> |
| <span id="198">198</span> |
| <span id="199">199</span> |
| <span id="200">200</span> |
| <span id="201">201</span> |
| <span id="202">202</span> |
| <span id="203">203</span> |
| <span id="204">204</span> |
| <span id="205">205</span> |
| <span id="206">206</span> |
| <span id="207">207</span> |
| </pre><pre class="rust"><code><span class="kw">use </span><span class="kw">crate</span>::io::util::{BufReader, BufWriter}; |
| <span class="kw">use </span><span class="kw">crate</span>::io::{AsyncBufRead, AsyncRead, AsyncSeek, AsyncWrite, ReadBuf}; |
| |
| <span class="kw">use </span>pin_project_lite::pin_project; |
| <span class="kw">use </span>std::io::{<span class="self">self</span>, IoSlice, SeekFrom}; |
| <span class="kw">use </span>std::pin::Pin; |
| <span class="kw">use </span>std::task::{Context, Poll}; |
| |
| <span class="macro">pin_project! </span>{ |
| <span class="doccomment">/// Wraps a type that is [`AsyncWrite`] and [`AsyncRead`], and buffers its input and output. |
| /// |
| /// It can be excessively inefficient to work directly with something that implements [`AsyncWrite`] |
| /// and [`AsyncRead`]. For example, every `write`, however small, has to traverse the syscall |
| /// interface, and similarly, every read has to do the same. The [`BufWriter`] and [`BufReader`] |
| /// types aid with these problems respectively, but do so in only one direction. `BufStream` wraps |
| /// one in the other so that both directions are buffered. See their documentation for details. |
| </span><span class="attribute">#[derive(Debug)] |
| #[cfg_attr(docsrs, doc(cfg(feature = <span class="string">"io-util"</span>)))] |
| </span><span class="kw">pub struct </span>BufStream<RW> { |
| <span class="attribute">#[pin] |
| </span>inner: BufReader<BufWriter<RW>>, |
| } |
| } |
| |
| <span class="kw">impl</span><RW: AsyncRead + AsyncWrite> BufStream<RW> { |
| <span class="doccomment">/// Wraps a type in both [`BufWriter`] and [`BufReader`]. |
| /// |
| /// See the documentation for those types and [`BufStream`] for details. |
| </span><span class="kw">pub fn </span>new(stream: RW) -> BufStream<RW> { |
| BufStream { |
| inner: BufReader::new(BufWriter::new(stream)), |
| } |
| } |
| |
| <span class="doccomment">/// Creates a `BufStream` with the specified [`BufReader`] capacity and [`BufWriter`] |
| /// capacity. |
| /// |
| /// See the documentation for those types and [`BufStream`] for details. |
| </span><span class="kw">pub fn </span>with_capacity( |
| reader_capacity: usize, |
| writer_capacity: usize, |
| stream: RW, |
| ) -> BufStream<RW> { |
| BufStream { |
| inner: BufReader::with_capacity( |
| reader_capacity, |
| BufWriter::with_capacity(writer_capacity, stream), |
| ), |
| } |
| } |
| |
| <span class="doccomment">/// Gets a reference to the underlying I/O object. |
| /// |
| /// It is inadvisable to directly read from the underlying I/O object. |
| </span><span class="kw">pub fn </span>get_ref(<span class="kw-2">&</span><span class="self">self</span>) -> <span class="kw-2">&</span>RW { |
| <span class="self">self</span>.inner.get_ref().get_ref() |
| } |
| |
| <span class="doccomment">/// Gets a mutable reference to the underlying I/O object. |
| /// |
| /// It is inadvisable to directly read from the underlying I/O object. |
| </span><span class="kw">pub fn </span>get_mut(<span class="kw-2">&mut </span><span class="self">self</span>) -> <span class="kw-2">&mut </span>RW { |
| <span class="self">self</span>.inner.get_mut().get_mut() |
| } |
| |
| <span class="doccomment">/// Gets a pinned mutable reference to the underlying I/O object. |
| /// |
| /// It is inadvisable to directly read from the underlying I/O object. |
| </span><span class="kw">pub fn </span>get_pin_mut(<span class="self">self</span>: Pin<<span class="kw-2">&mut </span><span class="self">Self</span>>) -> Pin<<span class="kw-2">&mut </span>RW> { |
| <span class="self">self</span>.project().inner.get_pin_mut().get_pin_mut() |
| } |
| |
| <span class="doccomment">/// Consumes this `BufStream`, returning the underlying I/O object. |
| /// |
| /// Note that any leftover data in the internal buffer is lost. |
| </span><span class="kw">pub fn </span>into_inner(<span class="self">self</span>) -> RW { |
| <span class="self">self</span>.inner.into_inner().into_inner() |
| } |
| } |
| |
| <span class="kw">impl</span><RW> From<BufReader<BufWriter<RW>>> <span class="kw">for </span>BufStream<RW> { |
| <span class="kw">fn </span>from(b: BufReader<BufWriter<RW>>) -> <span class="self">Self </span>{ |
| BufStream { inner: b } |
| } |
| } |
| |
| <span class="kw">impl</span><RW> From<BufWriter<BufReader<RW>>> <span class="kw">for </span>BufStream<RW> { |
| <span class="kw">fn </span>from(b: BufWriter<BufReader<RW>>) -> <span class="self">Self </span>{ |
| <span class="comment">// we need to "invert" the reader and writer |
| </span><span class="kw">let </span>BufWriter { |
| inner: |
| BufReader { |
| inner, |
| buf: rbuf, |
| pos, |
| cap, |
| seek_state: rseek_state, |
| }, |
| buf: wbuf, |
| written, |
| seek_state: wseek_state, |
| } = b; |
| |
| BufStream { |
| inner: BufReader { |
| inner: BufWriter { |
| inner, |
| buf: wbuf, |
| written, |
| seek_state: wseek_state, |
| }, |
| buf: rbuf, |
| pos, |
| cap, |
| seek_state: rseek_state, |
| }, |
| } |
| } |
| } |
| |
| <span class="kw">impl</span><RW: AsyncRead + AsyncWrite> AsyncWrite <span class="kw">for </span>BufStream<RW> { |
| <span class="kw">fn </span>poll_write( |
| <span class="self">self</span>: Pin<<span class="kw-2">&mut </span><span class="self">Self</span>>, |
| cx: <span class="kw-2">&mut </span>Context<<span class="lifetime">'_</span>>, |
| buf: <span class="kw-2">&</span>[u8], |
| ) -> Poll<io::Result<usize>> { |
| <span class="self">self</span>.project().inner.poll_write(cx, buf) |
| } |
| |
| <span class="kw">fn </span>poll_write_vectored( |
| <span class="self">self</span>: Pin<<span class="kw-2">&mut </span><span class="self">Self</span>>, |
| cx: <span class="kw-2">&mut </span>Context<<span class="lifetime">'_</span>>, |
| bufs: <span class="kw-2">&</span>[IoSlice<<span class="lifetime">'_</span>>], |
| ) -> Poll<io::Result<usize>> { |
| <span class="self">self</span>.project().inner.poll_write_vectored(cx, bufs) |
| } |
| |
| <span class="kw">fn </span>is_write_vectored(<span class="kw-2">&</span><span class="self">self</span>) -> bool { |
| <span class="self">self</span>.inner.is_write_vectored() |
| } |
| |
| <span class="kw">fn </span>poll_flush(<span class="self">self</span>: Pin<<span class="kw-2">&mut </span><span class="self">Self</span>>, cx: <span class="kw-2">&mut </span>Context<<span class="lifetime">'_</span>>) -> Poll<io::Result<()>> { |
| <span class="self">self</span>.project().inner.poll_flush(cx) |
| } |
| |
| <span class="kw">fn </span>poll_shutdown(<span class="self">self</span>: Pin<<span class="kw-2">&mut </span><span class="self">Self</span>>, cx: <span class="kw-2">&mut </span>Context<<span class="lifetime">'_</span>>) -> Poll<io::Result<()>> { |
| <span class="self">self</span>.project().inner.poll_shutdown(cx) |
| } |
| } |
| |
| <span class="kw">impl</span><RW: AsyncRead + AsyncWrite> AsyncRead <span class="kw">for </span>BufStream<RW> { |
| <span class="kw">fn </span>poll_read( |
| <span class="self">self</span>: Pin<<span class="kw-2">&mut </span><span class="self">Self</span>>, |
| cx: <span class="kw-2">&mut </span>Context<<span class="lifetime">'_</span>>, |
| buf: <span class="kw-2">&mut </span>ReadBuf<<span class="lifetime">'_</span>>, |
| ) -> Poll<io::Result<()>> { |
| <span class="self">self</span>.project().inner.poll_read(cx, buf) |
| } |
| } |
| |
| <span class="doccomment">/// Seek to an offset, in bytes, in the underlying stream. |
| /// |
| /// The position used for seeking with `SeekFrom::Current(_)` is the |
| /// position the underlying stream would be at if the `BufStream` had no |
| /// internal buffer. |
| /// |
| /// Seeking always discards the internal buffer, even if the seek position |
| /// would otherwise fall within it. This guarantees that calling |
| /// `.into_inner()` immediately after a seek yields the underlying reader |
| /// at the same position. |
| /// |
| /// See [`AsyncSeek`] for more details. |
| /// |
| /// Note: In the edge case where you're seeking with `SeekFrom::Current(n)` |
| /// where `n` minus the internal buffer length overflows an `i64`, two |
| /// seeks will be performed instead of one. If the second seek returns |
| /// `Err`, the underlying reader will be left at the same position it would |
| /// have if you called `seek` with `SeekFrom::Current(0)`. |
| </span><span class="kw">impl</span><RW: AsyncRead + AsyncWrite + AsyncSeek> AsyncSeek <span class="kw">for </span>BufStream<RW> { |
| <span class="kw">fn </span>start_seek(<span class="self">self</span>: Pin<<span class="kw-2">&mut </span><span class="self">Self</span>>, position: SeekFrom) -> io::Result<()> { |
| <span class="self">self</span>.project().inner.start_seek(position) |
| } |
| |
| <span class="kw">fn </span>poll_complete(<span class="self">self</span>: Pin<<span class="kw-2">&mut </span><span class="self">Self</span>>, cx: <span class="kw-2">&mut </span>Context<<span class="lifetime">'_</span>>) -> Poll<io::Result<u64>> { |
| <span class="self">self</span>.project().inner.poll_complete(cx) |
| } |
| } |
| |
| <span class="kw">impl</span><RW: AsyncRead + AsyncWrite> AsyncBufRead <span class="kw">for </span>BufStream<RW> { |
| <span class="kw">fn </span>poll_fill_buf(<span class="self">self</span>: Pin<<span class="kw-2">&mut </span><span class="self">Self</span>>, cx: <span class="kw-2">&mut </span>Context<<span class="lifetime">'_</span>>) -> Poll<io::Result<<span class="kw-2">&</span>[u8]>> { |
| <span class="self">self</span>.project().inner.poll_fill_buf(cx) |
| } |
| |
| <span class="kw">fn </span>consume(<span class="self">self</span>: Pin<<span class="kw-2">&mut </span><span class="self">Self</span>>, amt: usize) { |
| <span class="self">self</span>.project().inner.consume(amt) |
| } |
| } |
| |
| <span class="attribute">#[cfg(test)] |
| </span><span class="kw">mod </span>tests { |
| <span class="kw">use super</span>::<span class="kw-2">*</span>; |
| |
| <span class="attribute">#[test] |
| </span><span class="kw">fn </span>assert_unpin() { |
| <span class="kw">crate</span>::is_unpin::<BufStream<()>>(); |
| } |
| } |
| </code></pre></div> |
| </section></div></main><div id="rustdoc-vars" data-root-path="../../../../" data-current-crate="tokio" data-themes="ayu,dark,light" data-resource-suffix="" data-rustdoc-version="1.66.0-nightly (5c8bff74b 2022-10-21)" ></div></body></html> |
