| <!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/rayon-3b3b152053499ede/a07ce2e/src/iter/plumbing/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="../../../../rayon/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="../../../../rayon/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">//! Traits and functions used to implement parallel iteration. These are |
| //! low-level details -- users of parallel iterators should not need to |
| //! interact with them directly. See [the `plumbing` README][r] for a general overview. |
| //! |
| //! [r]: https://github.com/rayon-rs/rayon/blob/master/src/iter/plumbing/README.md |
| |
| </span><span class="kw">use </span><span class="kw">crate</span>::join_context; |
| |
| <span class="kw">use </span><span class="kw">super</span>::IndexedParallelIterator; |
| |
| <span class="kw">use </span>std::cmp; |
| <span class="kw">use </span>std::usize; |
| |
| <span class="doccomment">/// The `ProducerCallback` trait is a kind of generic closure, |
| /// [analogous to `FnOnce`][FnOnce]. See [the corresponding section in |
| /// the plumbing README][r] for more details. |
| /// |
| /// [r]: https://github.com/rayon-rs/rayon/blob/master/src/iter/plumbing/README.md#producer-callback |
| /// [FnOnce]: https://doc.rust-lang.org/std/ops/trait.FnOnce.html |
| </span><span class="kw">pub trait </span>ProducerCallback<T> { |
| <span class="doccomment">/// The type of value returned by this callback. Analogous to |
| /// [`Output` from the `FnOnce` trait][Output]. |
| /// |
| /// [Output]: https://doc.rust-lang.org/std/ops/trait.FnOnce.html#associatedtype.Output |
| </span><span class="kw">type </span>Output; |
| |
| <span class="doccomment">/// Invokes the callback with the given producer as argument. The |
| /// key point of this trait is that this method is generic over |
| /// `P`, and hence implementors must be defined for any producer. |
| </span><span class="kw">fn </span>callback<P>(<span class="self">self</span>, producer: P) -> <span class="self">Self</span>::Output |
| <span class="kw">where |
| </span>P: Producer<Item = T>; |
| } |
| |
| <span class="doccomment">/// A `Producer` is effectively a "splittable `IntoIterator`". That |
| /// is, a producer is a value which can be converted into an iterator |
| /// at any time: at that point, it simply produces items on demand, |
| /// like any iterator. But what makes a `Producer` special is that, |
| /// *before* we convert to an iterator, we can also **split** it at a |
| /// particular point using the `split_at` method. This will yield up |
| /// two producers, one producing the items before that point, and one |
| /// producing the items after that point (these two producers can then |
| /// independently be split further, or be converted into iterators). |
| /// In Rayon, this splitting is used to divide between threads. |
| /// See [the `plumbing` README][r] for further details. |
| /// |
| /// Note that each producer will always produce a fixed number of |
| /// items N. However, this number N is not queryable through the API; |
| /// the consumer is expected to track it. |
| /// |
| /// NB. You might expect `Producer` to extend the `IntoIterator` |
| /// trait. However, [rust-lang/rust#20671][20671] prevents us from |
| /// declaring the DoubleEndedIterator and ExactSizeIterator |
| /// constraints on a required IntoIterator trait, so we inline |
| /// IntoIterator here until that issue is fixed. |
| /// |
| /// [r]: https://github.com/rayon-rs/rayon/blob/master/src/iter/plumbing/README.md |
| /// [20671]: https://github.com/rust-lang/rust/issues/20671 |
| </span><span class="kw">pub trait </span>Producer: Send + Sized { |
| <span class="doccomment">/// The type of item that will be produced by this producer once |
| /// it is converted into an iterator. |
| </span><span class="kw">type </span>Item; |
| |
| <span class="doccomment">/// The type of iterator we will become. |
| </span><span class="kw">type </span>IntoIter: Iterator<Item = <span class="self">Self</span>::Item> + DoubleEndedIterator + ExactSizeIterator; |
| |
| <span class="doccomment">/// Convert `self` into an iterator; at this point, no more parallel splits |
| /// are possible. |
| </span><span class="kw">fn </span>into_iter(<span class="self">self</span>) -> <span class="self">Self</span>::IntoIter; |
| |
| <span class="doccomment">/// The minimum number of items that we will process |
| /// sequentially. Defaults to 1, which means that we will split |
| /// all the way down to a single item. This can be raised higher |
| /// using the [`with_min_len`] method, which will force us to |
| /// create sequential tasks at a larger granularity. Note that |
| /// Rayon automatically normally attempts to adjust the size of |
| /// parallel splits to reduce overhead, so this should not be |
| /// needed. |
| /// |
| /// [`with_min_len`]: ../trait.IndexedParallelIterator.html#method.with_min_len |
| </span><span class="kw">fn </span>min_len(<span class="kw-2">&</span><span class="self">self</span>) -> usize { |
| <span class="number">1 |
| </span>} |
| |
| <span class="doccomment">/// The maximum number of items that we will process |
| /// sequentially. Defaults to MAX, which means that we can choose |
| /// not to split at all. This can be lowered using the |
| /// [`with_max_len`] method, which will force us to create more |
| /// parallel tasks. Note that Rayon automatically normally |
| /// attempts to adjust the size of parallel splits to reduce |
| /// overhead, so this should not be needed. |
| /// |
| /// [`with_max_len`]: ../trait.IndexedParallelIterator.html#method.with_max_len |
| </span><span class="kw">fn </span>max_len(<span class="kw-2">&</span><span class="self">self</span>) -> usize { |
| usize::MAX |
| } |
| |
| <span class="doccomment">/// Split into two producers; one produces items `0..index`, the |
| /// other `index..N`. Index must be less than or equal to `N`. |
| </span><span class="kw">fn </span>split_at(<span class="self">self</span>, index: usize) -> (<span class="self">Self</span>, <span class="self">Self</span>); |
| |
| <span class="doccomment">/// Iterate the producer, feeding each element to `folder`, and |
| /// stop when the folder is full (or all elements have been consumed). |
| /// |
| /// The provided implementation is sufficient for most iterables. |
| </span><span class="kw">fn </span>fold_with<F>(<span class="self">self</span>, folder: F) -> F |
| <span class="kw">where |
| </span>F: Folder<<span class="self">Self</span>::Item>, |
| { |
| folder.consume_iter(<span class="self">self</span>.into_iter()) |
| } |
| } |
| |
| <span class="doccomment">/// A consumer is effectively a [generalized "fold" operation][fold], |
| /// and in fact each consumer will eventually be converted into a |
| /// [`Folder`]. What makes a consumer special is that, like a |
| /// [`Producer`], it can be **split** into multiple consumers using |
| /// the `split_at` method. When a consumer is split, it produces two |
| /// consumers, as well as a **reducer**. The two consumers can be fed |
| /// items independently, and when they are done the reducer is used to |
| /// combine their two results into one. See [the `plumbing` |
| /// README][r] for further details. |
| /// |
| /// [r]: https://github.com/rayon-rs/rayon/blob/master/src/iter/plumbing/README.md |
| /// [fold]: https://doc.rust-lang.org/std/iter/trait.Iterator.html#method.fold |
| /// [`Folder`]: trait.Folder.html |
| /// [`Producer`]: trait.Producer.html |
| </span><span class="kw">pub trait </span>Consumer<Item>: Send + Sized { |
| <span class="doccomment">/// The type of folder that this consumer can be converted into. |
| </span><span class="kw">type </span>Folder: Folder<Item, <span class="prelude-ty">Result </span>= <span class="self">Self</span>::Result>; |
| |
| <span class="doccomment">/// The type of reducer that is produced if this consumer is split. |
| </span><span class="kw">type </span>Reducer: Reducer<<span class="self">Self</span>::Result>; |
| |
| <span class="doccomment">/// The type of result that this consumer will ultimately produce. |
| </span><span class="kw">type </span><span class="prelude-ty">Result</span>: Send; |
| |
| <span class="doccomment">/// Divide the consumer into two consumers, one processing items |
| /// `0..index` and one processing items from `index..`. Also |
| /// produces a reducer that can be used to reduce the results at |
| /// the end. |
| </span><span class="kw">fn </span>split_at(<span class="self">self</span>, index: usize) -> (<span class="self">Self</span>, <span class="self">Self</span>, <span class="self">Self</span>::Reducer); |
| |
| <span class="doccomment">/// Convert the consumer into a folder that can consume items |
| /// sequentially, eventually producing a final result. |
| </span><span class="kw">fn </span>into_folder(<span class="self">self</span>) -> <span class="self">Self</span>::Folder; |
| |
| <span class="doccomment">/// Hint whether this `Consumer` would like to stop processing |
| /// further items, e.g. if a search has been completed. |
| </span><span class="kw">fn </span>full(<span class="kw-2">&</span><span class="self">self</span>) -> bool; |
| } |
| |
| <span class="doccomment">/// The `Folder` trait encapsulates [the standard fold |
| /// operation][fold]. It can be fed many items using the `consume` |
| /// method. At the end, once all items have been consumed, it can then |
| /// be converted (using `complete`) into a final value. |
| /// |
| /// [fold]: https://doc.rust-lang.org/std/iter/trait.Iterator.html#method.fold |
| </span><span class="kw">pub trait </span>Folder<Item>: Sized { |
| <span class="doccomment">/// The type of result that will ultimately be produced by the folder. |
| </span><span class="kw">type </span><span class="prelude-ty">Result</span>; |
| |
| <span class="doccomment">/// Consume next item and return new sequential state. |
| </span><span class="kw">fn </span>consume(<span class="self">self</span>, item: Item) -> <span class="self">Self</span>; |
| |
| <span class="doccomment">/// Consume items from the iterator until full, and return new sequential state. |
| /// |
| /// This method is **optional**. The default simply iterates over |
| /// `iter`, invoking `consume` and checking after each iteration |
| /// whether `full` returns false. |
| /// |
| /// The main reason to override it is if you can provide a more |
| /// specialized, efficient implementation. |
| </span><span class="kw">fn </span>consume_iter<I>(<span class="kw-2">mut </span><span class="self">self</span>, iter: I) -> <span class="self">Self |
| </span><span class="kw">where |
| </span>I: IntoIterator<Item = Item>, |
| { |
| <span class="kw">for </span>item <span class="kw">in </span>iter { |
| <span class="self">self </span>= <span class="self">self</span>.consume(item); |
| <span class="kw">if </span><span class="self">self</span>.full() { |
| <span class="kw">break</span>; |
| } |
| } |
| <span class="self">self |
| </span>} |
| |
| <span class="doccomment">/// Finish consuming items, produce final result. |
| </span><span class="kw">fn </span>complete(<span class="self">self</span>) -> <span class="self">Self</span>::Result; |
| |
| <span class="doccomment">/// Hint whether this `Folder` would like to stop processing |
| /// further items, e.g. if a search has been completed. |
| </span><span class="kw">fn </span>full(<span class="kw-2">&</span><span class="self">self</span>) -> bool; |
| } |
| |
| <span class="doccomment">/// The reducer is the final step of a `Consumer` -- after a consumer |
| /// has been split into two parts, and each of those parts has been |
| /// fully processed, we are left with two results. The reducer is then |
| /// used to combine those two results into one. See [the `plumbing` |
| /// README][r] for further details. |
| /// |
| /// [r]: https://github.com/rayon-rs/rayon/blob/master/src/iter/plumbing/README.md |
| </span><span class="kw">pub trait </span>Reducer<<span class="prelude-ty">Result</span>> { |
| <span class="doccomment">/// Reduce two final results into one; this is executed after a |
| /// split. |
| </span><span class="kw">fn </span>reduce(<span class="self">self</span>, left: <span class="prelude-ty">Result</span>, right: <span class="prelude-ty">Result</span>) -> <span class="prelude-ty">Result</span>; |
| } |
| |
| <span class="doccomment">/// A stateless consumer can be freely copied. These consumers can be |
| /// used like regular consumers, but they also support a |
| /// `split_off_left` method that does not take an index to split, but |
| /// simply splits at some arbitrary point (`for_each`, for example, |
| /// produces an unindexed consumer). |
| </span><span class="kw">pub trait </span>UnindexedConsumer<I>: Consumer<I> { |
| <span class="doccomment">/// Splits off a "left" consumer and returns it. The `self` |
| /// consumer should then be used to consume the "right" portion of |
| /// the data. (The ordering matters for methods like find_first -- |
| /// values produced by the returned value are given precedence |
| /// over values produced by `self`.) Once the left and right |
| /// halves have been fully consumed, you should reduce the results |
| /// with the result of `to_reducer`. |
| </span><span class="kw">fn </span>split_off_left(<span class="kw-2">&</span><span class="self">self</span>) -> <span class="self">Self</span>; |
| |
| <span class="doccomment">/// Creates a reducer that can be used to combine the results from |
| /// a split consumer. |
| </span><span class="kw">fn </span>to_reducer(<span class="kw-2">&</span><span class="self">self</span>) -> <span class="self">Self</span>::Reducer; |
| } |
| |
| <span class="doccomment">/// A variant on `Producer` which does not know its exact length or |
| /// cannot represent it in a `usize`. These producers act like |
| /// ordinary producers except that they cannot be told to split at a |
| /// particular point. Instead, you just ask them to split 'somewhere'. |
| /// |
| /// (In principle, `Producer` could extend this trait; however, it |
| /// does not because to do so would require producers to carry their |
| /// own length with them.) |
| </span><span class="kw">pub trait </span>UnindexedProducer: Send + Sized { |
| <span class="doccomment">/// The type of item returned by this producer. |
| </span><span class="kw">type </span>Item; |
| |
| <span class="doccomment">/// Split midway into a new producer if possible, otherwise return `None`. |
| </span><span class="kw">fn </span>split(<span class="self">self</span>) -> (<span class="self">Self</span>, <span class="prelude-ty">Option</span><<span class="self">Self</span>>); |
| |
| <span class="doccomment">/// Iterate the producer, feeding each element to `folder`, and |
| /// stop when the folder is full (or all elements have been consumed). |
| </span><span class="kw">fn </span>fold_with<F>(<span class="self">self</span>, folder: F) -> F |
| <span class="kw">where |
| </span>F: Folder<<span class="self">Self</span>::Item>; |
| } |
| |
| <span class="doccomment">/// A splitter controls the policy for splitting into smaller work items. |
| /// |
| /// Thief-splitting is an adaptive policy that starts by splitting into |
| /// enough jobs for every worker thread, and then resets itself whenever a |
| /// job is actually stolen into a different thread. |
| </span><span class="attribute">#[derive(Clone, Copy)] |
| </span><span class="kw">struct </span>Splitter { |
| <span class="doccomment">/// The `splits` tell us approximately how many remaining times we'd |
| /// like to split this job. We always just divide it by two though, so |
| /// the effective number of pieces will be `next_power_of_two()`. |
| </span>splits: usize, |
| } |
| |
| <span class="kw">impl </span>Splitter { |
| <span class="attribute">#[inline] |
| </span><span class="kw">fn </span>new() -> Splitter { |
| Splitter { |
| splits: <span class="kw">crate</span>::current_num_threads(), |
| } |
| } |
| |
| <span class="attribute">#[inline] |
| </span><span class="kw">fn </span>try_split(<span class="kw-2">&mut </span><span class="self">self</span>, stolen: bool) -> bool { |
| <span class="kw">let </span>Splitter { splits } = <span class="kw-2">*</span><span class="self">self</span>; |
| |
| <span class="kw">if </span>stolen { |
| <span class="comment">// This job was stolen! Reset the number of desired splits to the |
| // thread count, if that's more than we had remaining anyway. |
| </span><span class="self">self</span>.splits = cmp::max(<span class="kw">crate</span>::current_num_threads(), <span class="self">self</span>.splits / <span class="number">2</span>); |
| <span class="bool-val">true |
| </span>} <span class="kw">else if </span>splits > <span class="number">0 </span>{ |
| <span class="comment">// We have splits remaining, make it so. |
| </span><span class="self">self</span>.splits /= <span class="number">2</span>; |
| <span class="bool-val">true |
| </span>} <span class="kw">else </span>{ |
| <span class="comment">// Not stolen, and no more splits -- we're done! |
| </span><span class="bool-val">false |
| </span>} |
| } |
| } |
| |
| <span class="doccomment">/// The length splitter is built on thief-splitting, but additionally takes |
| /// into account the remaining length of the iterator. |
| </span><span class="attribute">#[derive(Clone, Copy)] |
| </span><span class="kw">struct </span>LengthSplitter { |
| inner: Splitter, |
| |
| <span class="doccomment">/// The smallest we're willing to divide into. Usually this is just 1, |
| /// but you can choose a larger working size with `with_min_len()`. |
| </span>min: usize, |
| } |
| |
| <span class="kw">impl </span>LengthSplitter { |
| <span class="doccomment">/// Creates a new splitter based on lengths. |
| /// |
| /// The `min` is a hard lower bound. We'll never split below that, but |
| /// of course an iterator might start out smaller already. |
| /// |
| /// The `max` is an upper bound on the working size, used to determine |
| /// the minimum number of times we need to split to get under that limit. |
| /// The adaptive algorithm may very well split even further, but never |
| /// smaller than the `min`. |
| </span><span class="attribute">#[inline] |
| </span><span class="kw">fn </span>new(min: usize, max: usize, len: usize) -> LengthSplitter { |
| <span class="kw">let </span><span class="kw-2">mut </span>splitter = LengthSplitter { |
| inner: Splitter::new(), |
| min: cmp::max(min, <span class="number">1</span>), |
| }; |
| |
| <span class="comment">// Divide the given length by the max working length to get the minimum |
| // number of splits we need to get under that max. This rounds down, |
| // but the splitter actually gives `next_power_of_two()` pieces anyway. |
| // e.g. len 12345 / max 100 = 123 min_splits -> 128 pieces. |
| </span><span class="kw">let </span>min_splits = len / cmp::max(max, <span class="number">1</span>); |
| |
| <span class="comment">// Only update the value if it's not splitting enough already. |
| </span><span class="kw">if </span>min_splits > splitter.inner.splits { |
| splitter.inner.splits = min_splits; |
| } |
| |
| splitter |
| } |
| |
| <span class="attribute">#[inline] |
| </span><span class="kw">fn </span>try_split(<span class="kw-2">&mut </span><span class="self">self</span>, len: usize, stolen: bool) -> bool { |
| <span class="comment">// If splitting wouldn't make us too small, try the inner splitter. |
| </span>len / <span class="number">2 </span>>= <span class="self">self</span>.min && <span class="self">self</span>.inner.try_split(stolen) |
| } |
| } |
| |
| <span class="doccomment">/// This helper function is used to "connect" a parallel iterator to a |
| /// consumer. It will convert the `par_iter` into a producer P and |
| /// then pull items from P and feed them to `consumer`, splitting and |
| /// creating parallel threads as needed. |
| /// |
| /// This is useful when you are implementing your own parallel |
| /// iterators: it is often used as the definition of the |
| /// [`drive_unindexed`] or [`drive`] methods. |
| /// |
| /// [`drive_unindexed`]: ../trait.ParallelIterator.html#tymethod.drive_unindexed |
| /// [`drive`]: ../trait.IndexedParallelIterator.html#tymethod.drive |
| </span><span class="kw">pub fn </span>bridge<I, C>(par_iter: I, consumer: C) -> C::Result |
| <span class="kw">where |
| </span>I: IndexedParallelIterator, |
| C: Consumer<I::Item>, |
| { |
| <span class="kw">let </span>len = par_iter.len(); |
| <span class="kw">return </span>par_iter.with_producer(Callback { len, consumer }); |
| |
| <span class="kw">struct </span>Callback<C> { |
| len: usize, |
| consumer: C, |
| } |
| |
| <span class="kw">impl</span><C, I> ProducerCallback<I> <span class="kw">for </span>Callback<C> |
| <span class="kw">where |
| </span>C: Consumer<I>, |
| { |
| <span class="kw">type </span>Output = C::Result; |
| <span class="kw">fn </span>callback<P>(<span class="self">self</span>, producer: P) -> C::Result |
| <span class="kw">where |
| </span>P: Producer<Item = I>, |
| { |
| bridge_producer_consumer(<span class="self">self</span>.len, producer, <span class="self">self</span>.consumer) |
| } |
| } |
| } |
| |
| <span class="doccomment">/// This helper function is used to "connect" a producer and a |
| /// consumer. You may prefer to call [`bridge`], which wraps this |
| /// function. This function will draw items from `producer` and feed |
| /// them to `consumer`, splitting and creating parallel tasks when |
| /// needed. |
| /// |
| /// This is useful when you are implementing your own parallel |
| /// iterators: it is often used as the definition of the |
| /// [`drive_unindexed`] or [`drive`] methods. |
| /// |
| /// [`bridge`]: fn.bridge.html |
| /// [`drive_unindexed`]: ../trait.ParallelIterator.html#tymethod.drive_unindexed |
| /// [`drive`]: ../trait.IndexedParallelIterator.html#tymethod.drive |
| </span><span class="kw">pub fn </span>bridge_producer_consumer<P, C>(len: usize, producer: P, consumer: C) -> C::Result |
| <span class="kw">where |
| </span>P: Producer, |
| C: Consumer<P::Item>, |
| { |
| <span class="kw">let </span>splitter = LengthSplitter::new(producer.min_len(), producer.max_len(), len); |
| <span class="kw">return </span>helper(len, <span class="bool-val">false</span>, splitter, producer, consumer); |
| |
| <span class="kw">fn </span>helper<P, C>( |
| len: usize, |
| migrated: bool, |
| <span class="kw-2">mut </span>splitter: LengthSplitter, |
| producer: P, |
| consumer: C, |
| ) -> C::Result |
| <span class="kw">where |
| </span>P: Producer, |
| C: Consumer<P::Item>, |
| { |
| <span class="kw">if </span>consumer.full() { |
| consumer.into_folder().complete() |
| } <span class="kw">else if </span>splitter.try_split(len, migrated) { |
| <span class="kw">let </span>mid = len / <span class="number">2</span>; |
| <span class="kw">let </span>(left_producer, right_producer) = producer.split_at(mid); |
| <span class="kw">let </span>(left_consumer, right_consumer, reducer) = consumer.split_at(mid); |
| <span class="kw">let </span>(left_result, right_result) = join_context( |
| |context| { |
| helper( |
| mid, |
| context.migrated(), |
| splitter, |
| left_producer, |
| left_consumer, |
| ) |
| }, |
| |context| { |
| helper( |
| len - mid, |
| context.migrated(), |
| splitter, |
| right_producer, |
| right_consumer, |
| ) |
| }, |
| ); |
| reducer.reduce(left_result, right_result) |
| } <span class="kw">else </span>{ |
| producer.fold_with(consumer.into_folder()).complete() |
| } |
| } |
| } |
| |
| <span class="doccomment">/// A variant of [`bridge_producer_consumer`] where the producer is an unindexed producer. |
| /// |
| /// [`bridge_producer_consumer`]: fn.bridge_producer_consumer.html |
| </span><span class="kw">pub fn </span>bridge_unindexed<P, C>(producer: P, consumer: C) -> C::Result |
| <span class="kw">where |
| </span>P: UnindexedProducer, |
| C: UnindexedConsumer<P::Item>, |
| { |
| <span class="kw">let </span>splitter = Splitter::new(); |
| bridge_unindexed_producer_consumer(<span class="bool-val">false</span>, splitter, producer, consumer) |
| } |
| |
| <span class="kw">fn </span>bridge_unindexed_producer_consumer<P, C>( |
| migrated: bool, |
| <span class="kw-2">mut </span>splitter: Splitter, |
| producer: P, |
| consumer: C, |
| ) -> C::Result |
| <span class="kw">where |
| </span>P: UnindexedProducer, |
| C: UnindexedConsumer<P::Item>, |
| { |
| <span class="kw">if </span>consumer.full() { |
| consumer.into_folder().complete() |
| } <span class="kw">else if </span>splitter.try_split(migrated) { |
| <span class="kw">match </span>producer.split() { |
| (left_producer, <span class="prelude-val">Some</span>(right_producer)) => { |
| <span class="kw">let </span>(reducer, left_consumer, right_consumer) = |
| (consumer.to_reducer(), consumer.split_off_left(), consumer); |
| <span class="kw">let </span>bridge = bridge_unindexed_producer_consumer; |
| <span class="kw">let </span>(left_result, right_result) = join_context( |
| |context| bridge(context.migrated(), splitter, left_producer, left_consumer), |
| |context| bridge(context.migrated(), splitter, right_producer, right_consumer), |
| ); |
| reducer.reduce(left_result, right_result) |
| } |
| (producer, <span class="prelude-val">None</span>) => producer.fold_with(consumer.into_folder()).complete(), |
| } |
| } <span class="kw">else </span>{ |
| producer.fold_with(consumer.into_folder()).complete() |
| } |
| } |
| </code></pre></div> |
| </section></div></main><div id="rustdoc-vars" data-root-path="../../../../" data-current-crate="rayon" data-themes="ayu,dark,light" data-resource-suffix="" data-rustdoc-version="1.66.0-nightly (5c8bff74b 2022-10-21)" ></div></body></html> |
