<?php namespace GuzzleHttp\Promise; final class Utils { /** * Get the global task queue used for promise resolution. * * This task queue MUST be run in an event loop in order for promises to be * settled asynchronously. It will be automatically run when synchronously * waiting on a promise. * * <code> * while ($eventLoop->isRunning()) { * GuzzleHttp\Promise\Utils::queue()->run(); * } * </code> * * @param TaskQueueInterface $assign Optionally specify a new queue instance. * * @return TaskQueueInterface */ public static function queue(TaskQueueInterface $assign = null) { static $queue; if ($assign) { $queue = $assign; } elseif (!$queue) { $queue = new TaskQueue(); } return $queue; } /** * Adds a function to run in the task queue when it is next `run()` and * returns a promise that is fulfilled or rejected with the result. * * @param callable $task Task function to run. * * @return PromiseInterface */ public static function task(callable $task) { $queue = self::queue(); $promise = new Promise([$queue, 'run']); $queue->add(function () use ($task, $promise) { try { $promise->resolve($task()); } catch (\Throwable $e) { $promise->reject($e); } catch (\Exception $e) { $promise->reject($e); } }); return $promise; } /** * Synchronously waits on a promise to resolve and returns an inspection * state array. * * Returns a state associative array containing a "state" key mapping to a * valid promise state. If the state of the promise is "fulfilled", the * array will contain a "value" key mapping to the fulfilled value of the * promise. If the promise is rejected, the array will contain a "reason" * key mapping to the rejection reason of the promise. * * @param PromiseInterface $promise Promise or value. * * @return array */ public static function inspect(PromiseInterface $promise) { try { return [ 'state' => PromiseInterface::FULFILLED, 'value' => $promise->wait() ]; } catch (RejectionException $e) { return ['state' => PromiseInterface::REJECTED, 'reason' => $e->getReason()]; } catch (\Throwable $e) { return ['state' => PromiseInterface::REJECTED, 'reason' => $e]; } catch (\Exception $e) { return ['state' => PromiseInterface::REJECTED, 'reason' => $e]; } } /** * Waits on all of the provided promises, but does not unwrap rejected * promises as thrown exception. * * Returns an array of inspection state arrays. * * @see inspect for the inspection state array format. * * @param PromiseInterface[] $promises Traversable of promises to wait upon. * * @return array */ public static function inspectAll($promises) { $results = []; foreach ($promises as $key => $promise) { $results[$key] = inspect($promise); } return $results; } /** * Waits on all of the provided promises and returns the fulfilled values. * * Returns an array that contains the value of each promise (in the same * order the promises were provided). An exception is thrown if any of the * promises are rejected. * * @param iterable<PromiseInterface> $promises Iterable of PromiseInterface objects to wait on. * * @return array * * @throws \Exception on error * @throws \Throwable on error in PHP >=7 */ public static function unwrap($promises) { $results = []; foreach ($promises as $key => $promise) { $results[$key] = $promise->wait(); } return $results; } /** * Given an array of promises, return a promise that is fulfilled when all * the items in the array are fulfilled. * * The promise's fulfillment value is an array with fulfillment values at * respective positions to the original array. If any promise in the array * rejects, the returned promise is rejected with the rejection reason. * * @param mixed $promises Promises or values. * @param bool $recursive If true, resolves new promises that might have been added to the stack during its own resolution. * * @return PromiseInterface */ public static function all($promises, $recursive = false) { $results = []; $promise = Each::of( $promises, function ($value, $idx) use (&$results) { $results[$idx] = $value; }, function ($reason, $idx, Promise $aggregate) { $aggregate->reject($reason); } )->then(function () use (&$results) { ksort($results); return $results; }); if (true === $recursive) { $promise = $promise->then(function ($results) use ($recursive, &$promises) { foreach ($promises as $promise) { if (Is::pending($promise)) { return self::all($promises, $recursive); } } return $results; }); } return $promise; } /** * Initiate a competitive race between multiple promises or values (values * will become immediately fulfilled promises). * * When count amount of promises have been fulfilled, the returned promise * is fulfilled with an array that contains the fulfillment values of the * winners in order of resolution. * * This promise is rejected with a {@see AggregateException} if the number * of fulfilled promises is less than the desired $count. * * @param int $count Total number of promises. * @param mixed $promises Promises or values. * * @return PromiseInterface */ public static function some($count, $promises) { $results = []; $rejections = []; return Each::of( $promises, function ($value, $idx, PromiseInterface $p) use (&$results, $count) { if (Is::settled($p)) { return; } $results[$idx] = $value; if (count($results) >= $count) { $p->resolve(null); } }, function ($reason) use (&$rejections) { $rejections[] = $reason; } )->then( function () use (&$results, &$rejections, $count) { if (count($results) !== $count) { throw new AggregateException( 'Not enough promises to fulfill count', $rejections ); } ksort($results); return array_values($results); } ); } /** * Like some(), with 1 as count. However, if the promise fulfills, the * fulfillment value is not an array of 1 but the value directly. * * @param mixed $promises Promises or values. * * @return PromiseInterface */ public static function any($promises) { return self::some(1, $promises)->then(function ($values) { return $values[0]; }); } /** * Returns a promise that is fulfilled when all of the provided promises have * been fulfilled or rejected. * * The returned promise is fulfilled with an array of inspection state arrays. * * @see inspect for the inspection state array format. * * @param mixed $promises Promises or values. * * @return PromiseInterface */ public static function settle($promises) { $results = []; return Each::of( $promises, function ($value, $idx) use (&$results) { $results[$idx] = ['state' => PromiseInterface::FULFILLED, 'value' => $value]; }, function ($reason, $idx) use (&$results) { $results[$idx] = ['state' => PromiseInterface::REJECTED, 'reason' => $reason]; } )->then(function () use (&$results) { ksort($results); return $results; }); } }