| <!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/hyper-0.14.26/src/common/io/rewind.rs`."><meta name="keywords" content="rust, rustlang, rust-lang"><title>rewind.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="../../../../hyper/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="../../../../hyper/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>std::marker::Unpin; |
| <span class="kw">use </span>std::{cmp, io}; |
| |
| <span class="kw">use </span>bytes::{Buf, Bytes}; |
| <span class="kw">use </span>tokio::io::{AsyncRead, AsyncWrite, ReadBuf}; |
| |
| <span class="kw">use </span><span class="kw">crate</span>::common::{task, Pin, Poll}; |
| |
| <span class="doccomment">/// Combine a buffer with an IO, rewinding reads to use the buffer. |
| </span><span class="attribute">#[derive(Debug)] |
| </span><span class="kw">pub</span>(<span class="kw">crate</span>) <span class="kw">struct </span>Rewind<T> { |
| pre: <span class="prelude-ty">Option</span><Bytes>, |
| inner: T, |
| } |
| |
| <span class="kw">impl</span><T> Rewind<T> { |
| <span class="attribute">#[cfg(any(all(feature = <span class="string">"http2"</span>, feature = <span class="string">"server"</span>), test))] |
| </span><span class="kw">pub</span>(<span class="kw">crate</span>) <span class="kw">fn </span>new(io: T) -> <span class="self">Self </span>{ |
| Rewind { |
| pre: <span class="prelude-val">None</span>, |
| inner: io, |
| } |
| } |
| |
| <span class="kw">pub</span>(<span class="kw">crate</span>) <span class="kw">fn </span>new_buffered(io: T, buf: Bytes) -> <span class="self">Self </span>{ |
| Rewind { |
| pre: <span class="prelude-val">Some</span>(buf), |
| inner: io, |
| } |
| } |
| |
| <span class="attribute">#[cfg(any(all(feature = <span class="string">"http1"</span>, feature = <span class="string">"http2"</span>, feature = <span class="string">"server"</span>), test))] |
| </span><span class="kw">pub</span>(<span class="kw">crate</span>) <span class="kw">fn </span>rewind(<span class="kw-2">&mut </span><span class="self">self</span>, bs: Bytes) { |
| <span class="macro">debug_assert!</span>(<span class="self">self</span>.pre.is_none()); |
| <span class="self">self</span>.pre = <span class="prelude-val">Some</span>(bs); |
| } |
| |
| <span class="kw">pub</span>(<span class="kw">crate</span>) <span class="kw">fn </span>into_inner(<span class="self">self</span>) -> (T, Bytes) { |
| (<span class="self">self</span>.inner, <span class="self">self</span>.pre.unwrap_or_else(Bytes::new)) |
| } |
| |
| <span class="comment">// pub(crate) fn get_mut(&mut self) -> &mut T { |
| // &mut self.inner |
| // } |
| </span>} |
| |
| <span class="kw">impl</span><T> AsyncRead <span class="kw">for </span>Rewind<T> |
| <span class="kw">where |
| </span>T: AsyncRead + Unpin, |
| { |
| <span class="kw">fn </span>poll_read( |
| <span class="kw-2">mut </span><span class="self">self</span>: Pin<<span class="kw-2">&mut </span><span class="self">Self</span>>, |
| cx: <span class="kw-2">&mut </span>task::Context<<span class="lifetime">'_</span>>, |
| buf: <span class="kw-2">&mut </span>ReadBuf<<span class="lifetime">'_</span>>, |
| ) -> Poll<io::Result<()>> { |
| <span class="kw">if let </span><span class="prelude-val">Some</span>(<span class="kw-2">mut </span>prefix) = <span class="self">self</span>.pre.take() { |
| <span class="comment">// If there are no remaining bytes, let the bytes get dropped. |
| </span><span class="kw">if </span>!prefix.is_empty() { |
| <span class="kw">let </span>copy_len = cmp::min(prefix.len(), buf.remaining()); |
| <span class="comment">// TODO: There should be a way to do following two lines cleaner... |
| </span>buf.put_slice(<span class="kw-2">&</span>prefix[..copy_len]); |
| prefix.advance(copy_len); |
| <span class="comment">// Put back what's left |
| </span><span class="kw">if </span>!prefix.is_empty() { |
| <span class="self">self</span>.pre = <span class="prelude-val">Some</span>(prefix); |
| } |
| |
| <span class="kw">return </span>Poll::Ready(<span class="prelude-val">Ok</span>(())); |
| } |
| } |
| Pin::new(<span class="kw-2">&mut </span><span class="self">self</span>.inner).poll_read(cx, buf) |
| } |
| } |
| |
| <span class="kw">impl</span><T> AsyncWrite <span class="kw">for </span>Rewind<T> |
| <span class="kw">where |
| </span>T: AsyncWrite + Unpin, |
| { |
| <span class="kw">fn </span>poll_write( |
| <span class="kw-2">mut </span><span class="self">self</span>: Pin<<span class="kw-2">&mut </span><span class="self">Self</span>>, |
| cx: <span class="kw-2">&mut </span>task::Context<<span class="lifetime">'_</span>>, |
| buf: <span class="kw-2">&</span>[u8], |
| ) -> Poll<io::Result<usize>> { |
| Pin::new(<span class="kw-2">&mut </span><span class="self">self</span>.inner).poll_write(cx, buf) |
| } |
| |
| <span class="kw">fn </span>poll_write_vectored( |
| <span class="kw-2">mut </span><span class="self">self</span>: Pin<<span class="kw-2">&mut </span><span class="self">Self</span>>, |
| cx: <span class="kw-2">&mut </span>task::Context<<span class="lifetime">'_</span>>, |
| bufs: <span class="kw-2">&</span>[io::IoSlice<<span class="lifetime">'_</span>>], |
| ) -> Poll<io::Result<usize>> { |
| Pin::new(<span class="kw-2">&mut </span><span class="self">self</span>.inner).poll_write_vectored(cx, bufs) |
| } |
| |
| <span class="kw">fn </span>poll_flush(<span class="kw-2">mut </span><span class="self">self</span>: Pin<<span class="kw-2">&mut </span><span class="self">Self</span>>, cx: <span class="kw-2">&mut </span>task::Context<<span class="lifetime">'_</span>>) -> Poll<io::Result<()>> { |
| Pin::new(<span class="kw-2">&mut </span><span class="self">self</span>.inner).poll_flush(cx) |
| } |
| |
| <span class="kw">fn </span>poll_shutdown(<span class="kw-2">mut </span><span class="self">self</span>: Pin<<span class="kw-2">&mut </span><span class="self">Self</span>>, cx: <span class="kw-2">&mut </span>task::Context<<span class="lifetime">'_</span>>) -> Poll<io::Result<()>> { |
| Pin::new(<span class="kw-2">&mut </span><span class="self">self</span>.inner).poll_shutdown(cx) |
| } |
| |
| <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="attribute">#[cfg(test)] |
| </span><span class="kw">mod </span>tests { |
| <span class="comment">// FIXME: re-implement tests with `async/await`, this import should |
| // trigger a warning to remind us |
| </span><span class="kw">use </span><span class="kw">super</span>::Rewind; |
| <span class="kw">use </span>bytes::Bytes; |
| <span class="kw">use </span>tokio::io::AsyncReadExt; |
| |
| <span class="attribute">#[tokio::test] |
| </span><span class="kw">async fn </span>partial_rewind() { |
| <span class="kw">let </span>underlying = [<span class="number">104</span>, <span class="number">101</span>, <span class="number">108</span>, <span class="number">108</span>, <span class="number">111</span>]; |
| |
| <span class="kw">let </span>mock = tokio_test::io::Builder::new().read(<span class="kw-2">&</span>underlying).build(); |
| |
| <span class="kw">let </span><span class="kw-2">mut </span>stream = Rewind::new(mock); |
| |
| <span class="comment">// Read off some bytes, ensure we filled o1 |
| </span><span class="kw">let </span><span class="kw-2">mut </span>buf = [<span class="number">0</span>; <span class="number">2</span>]; |
| stream.read_exact(<span class="kw-2">&mut </span>buf).<span class="kw">await</span>.expect(<span class="string">"read1"</span>); |
| |
| <span class="comment">// Rewind the stream so that it is as if we never read in the first place. |
| </span>stream.rewind(Bytes::copy_from_slice(<span class="kw-2">&</span>buf[..])); |
| |
| <span class="kw">let </span><span class="kw-2">mut </span>buf = [<span class="number">0</span>; <span class="number">5</span>]; |
| stream.read_exact(<span class="kw-2">&mut </span>buf).<span class="kw">await</span>.expect(<span class="string">"read1"</span>); |
| |
| <span class="comment">// At this point we should have read everything that was in the MockStream |
| </span><span class="macro">assert_eq!</span>(<span class="kw-2">&</span>buf, <span class="kw-2">&</span>underlying); |
| } |
| |
| <span class="attribute">#[tokio::test] |
| </span><span class="kw">async fn </span>full_rewind() { |
| <span class="kw">let </span>underlying = [<span class="number">104</span>, <span class="number">101</span>, <span class="number">108</span>, <span class="number">108</span>, <span class="number">111</span>]; |
| |
| <span class="kw">let </span>mock = tokio_test::io::Builder::new().read(<span class="kw-2">&</span>underlying).build(); |
| |
| <span class="kw">let </span><span class="kw-2">mut </span>stream = Rewind::new(mock); |
| |
| <span class="kw">let </span><span class="kw-2">mut </span>buf = [<span class="number">0</span>; <span class="number">5</span>]; |
| stream.read_exact(<span class="kw-2">&mut </span>buf).<span class="kw">await</span>.expect(<span class="string">"read1"</span>); |
| |
| <span class="comment">// Rewind the stream so that it is as if we never read in the first place. |
| </span>stream.rewind(Bytes::copy_from_slice(<span class="kw-2">&</span>buf[..])); |
| |
| <span class="kw">let </span><span class="kw-2">mut </span>buf = [<span class="number">0</span>; <span class="number">5</span>]; |
| stream.read_exact(<span class="kw-2">&mut </span>buf).<span class="kw">await</span>.expect(<span class="string">"read1"</span>); |
| } |
| } |
| </code></pre></div> |
| </section></div></main><div id="rustdoc-vars" data-root-path="../../../../" data-current-crate="hyper" data-themes="ayu,dark,light" data-resource-suffix="" data-rustdoc-version="1.66.0-nightly (5c8bff74b 2022-10-21)" ></div></body></html> |
