parallel-functions/docs/index.md

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Introduction	/

amphp/parallel-functions is a simplifying layer on top of amphp/parallel.

{:.warning}

This library uses jeremeamia/SuperClosure to serialize closures, so its restrictions apply if you use closures. If serialization of a particular closure doesn't work, you can always write an autoloadable function and call that by name instead.

Installation

This package can be installed as a Composer dependency.

composer require amphp/parallel-functions

Usage

Like all other amphp libraries, this library works in a fully asynchronous world. It returns promises as placeholders for future results of operations.

You don't need to know any details to use this library in traditional, fully synchronous applications. All you need is wrapping every function returning an Amp\Promise with Amp\Promise\wait().

<?php

use Amp\Promise;
use function Amp\ParallelFunctions\map;

$values = Promise\wait(map([1, 2, 3], function ($time) {
    \sleep($time); // a blocking function call, might also do blocking I/O here

    return $time * $time;
}));

parallel()

Amp\ParallelFunctions\parallel(callable): callable wraps a callable, so it's executed in another thread / process on invocation. All arguments have to be serializable.

Currently this function only supports a direct string as function name or instances of \Closure. Support for other callable types might be added in the future.

map()

Amp\ParallelFunctions\map(array, callable): Promise works similar to array_map(), but has a different signature. It accepts only one array instead of being variadic. It's thereby consistent with Amp\ParallelFunctions\filter().

Restrictions of Amp\ParallelFunctions\parallel() apply.

filter()

Amp\ParallelFunctions\filter(array, callable, int): Promise works like array_filter(), but returns a promise and executes in parallel.

Restrictions of Amp\ParallelFunctions\parallel() apply.