| <!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/tokio-stream-0.1.14/src/stream_ext/collect.rs`."><meta name="keywords" content="rust, rustlang, rust-lang"><title>collect.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_stream/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_stream/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><span class="kw">crate</span>::Stream; |
| |
| <span class="kw">use </span>core::future::Future; |
| <span class="kw">use </span>core::marker::PhantomPinned; |
| <span class="kw">use </span>core::mem; |
| <span class="kw">use </span>core::pin::Pin; |
| <span class="kw">use </span>core::task::{Context, Poll}; |
| <span class="kw">use </span>pin_project_lite::pin_project; |
| |
| <span class="comment">// Do not export this struct until `FromStream` can be unsealed. |
| </span><span class="macro">pin_project! </span>{ |
| <span class="doccomment">/// Future returned by the [`collect`](super::StreamExt::collect) method. |
| </span><span class="attribute">#[must_use = <span class="string">"futures do nothing unless you `.await` or poll them"</span>] |
| #[derive(Debug)] |
| </span><span class="kw">pub struct </span>Collect<T, U> |
| <span class="kw">where |
| </span>T: Stream, |
| U: FromStream<T::Item>, |
| { |
| <span class="attribute">#[pin] |
| </span>stream: T, |
| collection: U::InternalCollection, |
| <span class="comment">// Make this future `!Unpin` for compatibility with async trait methods. |
| </span><span class="attribute">#[pin] |
| </span>_pin: PhantomPinned, |
| } |
| } |
| |
| <span class="doccomment">/// Convert from a [`Stream`](crate::Stream). |
| /// |
| /// This trait is not intended to be used directly. Instead, call |
| /// [`StreamExt::collect()`](super::StreamExt::collect). |
| /// |
| /// # Implementing |
| /// |
| /// Currently, this trait may not be implemented by third parties. The trait is |
| /// sealed in order to make changes in the future. Stabilization is pending |
| /// enhancements to the Rust language. |
| </span><span class="kw">pub trait </span>FromStream<T>: sealed::FromStreamPriv<T> {} |
| |
| <span class="kw">impl</span><T, U> Collect<T, U> |
| <span class="kw">where |
| </span>T: Stream, |
| U: FromStream<T::Item>, |
| { |
| <span class="kw">pub</span>(<span class="kw">super</span>) <span class="kw">fn </span>new(stream: T) -> Collect<T, U> { |
| <span class="kw">let </span>(lower, upper) = stream.size_hint(); |
| <span class="kw">let </span>collection = U::initialize(sealed::Internal, lower, upper); |
| |
| Collect { |
| stream, |
| collection, |
| _pin: PhantomPinned, |
| } |
| } |
| } |
| |
| <span class="kw">impl</span><T, U> Future <span class="kw">for </span>Collect<T, U> |
| <span class="kw">where |
| </span>T: Stream, |
| U: FromStream<T::Item>, |
| { |
| <span class="kw">type </span>Output = U; |
| |
| <span class="kw">fn </span>poll(<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>Context<<span class="lifetime">'_</span>>) -> Poll<U> { |
| <span class="kw">use </span>Poll::Ready; |
| |
| <span class="kw">loop </span>{ |
| <span class="kw">let </span>me = <span class="self">self</span>.as_mut().project(); |
| |
| <span class="kw">let </span>item = <span class="kw">match </span><span class="macro">ready!</span>(me.stream.poll_next(cx)) { |
| <span class="prelude-val">Some</span>(item) => item, |
| <span class="prelude-val">None </span>=> { |
| <span class="kw">return </span>Ready(U::finalize(sealed::Internal, me.collection)); |
| } |
| }; |
| |
| <span class="kw">if </span>!U::extend(sealed::Internal, me.collection, item) { |
| <span class="kw">return </span>Ready(U::finalize(sealed::Internal, me.collection)); |
| } |
| } |
| } |
| } |
| |
| <span class="comment">// ===== FromStream implementations |
| |
| </span><span class="kw">impl </span>FromStream<()> <span class="kw">for </span>() {} |
| |
| <span class="kw">impl </span>sealed::FromStreamPriv<()> <span class="kw">for </span>() { |
| <span class="kw">type </span>InternalCollection = (); |
| |
| <span class="kw">fn </span>initialize(<span class="kw">_</span>: sealed::Internal, _lower: usize, _upper: <span class="prelude-ty">Option</span><usize>) {} |
| |
| <span class="kw">fn </span>extend(<span class="kw">_</span>: sealed::Internal, _collection: <span class="kw-2">&mut </span>(), _item: ()) -> bool { |
| <span class="bool-val">true |
| </span>} |
| |
| <span class="kw">fn </span>finalize(<span class="kw">_</span>: sealed::Internal, _collection: <span class="kw-2">&mut </span>()) {} |
| } |
| |
| <span class="kw">impl</span><T: AsRef<str>> FromStream<T> <span class="kw">for </span>String {} |
| |
| <span class="kw">impl</span><T: AsRef<str>> sealed::FromStreamPriv<T> <span class="kw">for </span>String { |
| <span class="kw">type </span>InternalCollection = String; |
| |
| <span class="kw">fn </span>initialize(<span class="kw">_</span>: sealed::Internal, _lower: usize, _upper: <span class="prelude-ty">Option</span><usize>) -> String { |
| String::new() |
| } |
| |
| <span class="kw">fn </span>extend(<span class="kw">_</span>: sealed::Internal, collection: <span class="kw-2">&mut </span>String, item: T) -> bool { |
| collection.push_str(item.as_ref()); |
| <span class="bool-val">true |
| </span>} |
| |
| <span class="kw">fn </span>finalize(<span class="kw">_</span>: sealed::Internal, collection: <span class="kw-2">&mut </span>String) -> String { |
| mem::take(collection) |
| } |
| } |
| |
| <span class="kw">impl</span><T> FromStream<T> <span class="kw">for </span>Vec<T> {} |
| |
| <span class="kw">impl</span><T> sealed::FromStreamPriv<T> <span class="kw">for </span>Vec<T> { |
| <span class="kw">type </span>InternalCollection = Vec<T>; |
| |
| <span class="kw">fn </span>initialize(<span class="kw">_</span>: sealed::Internal, lower: usize, _upper: <span class="prelude-ty">Option</span><usize>) -> Vec<T> { |
| Vec::with_capacity(lower) |
| } |
| |
| <span class="kw">fn </span>extend(<span class="kw">_</span>: sealed::Internal, collection: <span class="kw-2">&mut </span>Vec<T>, item: T) -> bool { |
| collection.push(item); |
| <span class="bool-val">true |
| </span>} |
| |
| <span class="kw">fn </span>finalize(<span class="kw">_</span>: sealed::Internal, collection: <span class="kw-2">&mut </span>Vec<T>) -> Vec<T> { |
| mem::take(collection) |
| } |
| } |
| |
| <span class="kw">impl</span><T> FromStream<T> <span class="kw">for </span>Box<[T]> {} |
| |
| <span class="kw">impl</span><T> sealed::FromStreamPriv<T> <span class="kw">for </span>Box<[T]> { |
| <span class="kw">type </span>InternalCollection = Vec<T>; |
| |
| <span class="kw">fn </span>initialize(<span class="kw">_</span>: sealed::Internal, lower: usize, upper: <span class="prelude-ty">Option</span><usize>) -> Vec<T> { |
| <Vec<T> <span class="kw">as </span>sealed::FromStreamPriv<T>>::initialize(sealed::Internal, lower, upper) |
| } |
| |
| <span class="kw">fn </span>extend(<span class="kw">_</span>: sealed::Internal, collection: <span class="kw-2">&mut </span>Vec<T>, item: T) -> bool { |
| <Vec<T> <span class="kw">as </span>sealed::FromStreamPriv<T>>::extend(sealed::Internal, collection, item) |
| } |
| |
| <span class="kw">fn </span>finalize(<span class="kw">_</span>: sealed::Internal, collection: <span class="kw-2">&mut </span>Vec<T>) -> Box<[T]> { |
| <Vec<T> <span class="kw">as </span>sealed::FromStreamPriv<T>>::finalize(sealed::Internal, collection) |
| .into_boxed_slice() |
| } |
| } |
| |
| <span class="kw">impl</span><T, U, E> FromStream<<span class="prelude-ty">Result</span><T, E>> <span class="kw">for </span><span class="prelude-ty">Result</span><U, E> <span class="kw">where </span>U: FromStream<T> {} |
| |
| <span class="kw">impl</span><T, U, E> sealed::FromStreamPriv<<span class="prelude-ty">Result</span><T, E>> <span class="kw">for </span><span class="prelude-ty">Result</span><U, E> |
| <span class="kw">where |
| </span>U: FromStream<T>, |
| { |
| <span class="kw">type </span>InternalCollection = <span class="prelude-ty">Result</span><U::InternalCollection, E>; |
| |
| <span class="kw">fn </span>initialize( |
| <span class="kw">_</span>: sealed::Internal, |
| lower: usize, |
| upper: <span class="prelude-ty">Option</span><usize>, |
| ) -> <span class="prelude-ty">Result</span><U::InternalCollection, E> { |
| <span class="prelude-val">Ok</span>(U::initialize(sealed::Internal, lower, upper)) |
| } |
| |
| <span class="kw">fn </span>extend( |
| <span class="kw">_</span>: sealed::Internal, |
| collection: <span class="kw-2">&mut </span><span class="self">Self</span>::InternalCollection, |
| item: <span class="prelude-ty">Result</span><T, E>, |
| ) -> bool { |
| <span class="macro">assert!</span>(collection.is_ok()); |
| <span class="kw">match </span>item { |
| <span class="prelude-val">Ok</span>(item) => { |
| <span class="kw">let </span>collection = collection.as_mut().ok().expect(<span class="string">"invalid state"</span>); |
| U::extend(sealed::Internal, collection, item) |
| } |
| <span class="prelude-val">Err</span>(err) => { |
| <span class="kw-2">*</span>collection = <span class="prelude-val">Err</span>(err); |
| <span class="bool-val">false |
| </span>} |
| } |
| } |
| |
| <span class="kw">fn </span>finalize(<span class="kw">_</span>: sealed::Internal, collection: <span class="kw-2">&mut </span><span class="self">Self</span>::InternalCollection) -> <span class="prelude-ty">Result</span><U, E> { |
| <span class="kw">if let </span><span class="prelude-val">Ok</span>(collection) = collection.as_mut() { |
| <span class="prelude-val">Ok</span>(U::finalize(sealed::Internal, collection)) |
| } <span class="kw">else </span>{ |
| <span class="kw">let </span>res = mem::replace(collection, <span class="prelude-val">Ok</span>(U::initialize(sealed::Internal, <span class="number">0</span>, <span class="prelude-val">Some</span>(<span class="number">0</span>)))); |
| |
| <span class="prelude-val">Err</span>(res.map(drop).unwrap_err()) |
| } |
| } |
| } |
| |
| <span class="kw">pub</span>(<span class="kw">crate</span>) <span class="kw">mod </span>sealed { |
| <span class="attribute">#[doc(hidden)] |
| </span><span class="kw">pub trait </span>FromStreamPriv<T> { |
| <span class="doccomment">/// Intermediate type used during collection process |
| /// |
| /// The name of this type is internal and cannot be relied upon. |
| </span><span class="kw">type </span>InternalCollection; |
| |
| <span class="doccomment">/// Initialize the collection |
| </span><span class="kw">fn </span>initialize( |
| internal: Internal, |
| lower: usize, |
| upper: <span class="prelude-ty">Option</span><usize>, |
| ) -> <span class="self">Self</span>::InternalCollection; |
| |
| <span class="doccomment">/// Extend the collection with the received item |
| /// |
| /// Return `true` to continue streaming, `false` complete collection. |
| </span><span class="kw">fn </span>extend(internal: Internal, collection: <span class="kw-2">&mut </span><span class="self">Self</span>::InternalCollection, item: T) -> bool; |
| |
| <span class="doccomment">/// Finalize collection into target type. |
| </span><span class="kw">fn </span>finalize(internal: Internal, collection: <span class="kw-2">&mut </span><span class="self">Self</span>::InternalCollection) -> <span class="self">Self</span>; |
| } |
| |
| <span class="attribute">#[allow(missing_debug_implementations)] |
| </span><span class="kw">pub struct </span>Internal; |
| } |
| </code></pre></div> |
| </section></div></main><div id="rustdoc-vars" data-root-path="../../../" data-current-crate="tokio_stream" data-themes="ayu,dark,light" data-resource-suffix="" data-rustdoc-version="1.66.0-nightly (5c8bff74b 2022-10-21)" ></div></body></html> |
