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Diffstat (limited to 'vendor/guzzlehttp/promises/src/Coroutine.php')
-rw-r--r-- | vendor/guzzlehttp/promises/src/Coroutine.php | 169 |
1 files changed, 169 insertions, 0 deletions
diff --git a/vendor/guzzlehttp/promises/src/Coroutine.php b/vendor/guzzlehttp/promises/src/Coroutine.php new file mode 100644 index 0000000..670da47 --- /dev/null +++ b/vendor/guzzlehttp/promises/src/Coroutine.php @@ -0,0 +1,169 @@ +<?php + +namespace GuzzleHttp\Promise; + +use Exception; +use Generator; +use Throwable; + +/** + * Creates a promise that is resolved using a generator that yields values or + * promises (somewhat similar to C#'s async keyword). + * + * When called, the Coroutine::of method will start an instance of the generator + * and returns a promise that is fulfilled with its final yielded value. + * + * Control is returned back to the generator when the yielded promise settles. + * This can lead to less verbose code when doing lots of sequential async calls + * with minimal processing in between. + * + * use GuzzleHttp\Promise; + * + * function createPromise($value) { + * return new Promise\FulfilledPromise($value); + * } + * + * $promise = Promise\Coroutine::of(function () { + * $value = (yield createPromise('a')); + * try { + * $value = (yield createPromise($value . 'b')); + * } catch (\Exception $e) { + * // The promise was rejected. + * } + * yield $value . 'c'; + * }); + * + * // Outputs "abc" + * $promise->then(function ($v) { echo $v; }); + * + * @param callable $generatorFn Generator function to wrap into a promise. + * + * @return Promise + * + * @link https://github.com/petkaantonov/bluebird/blob/master/API.md#generators inspiration + */ +final class Coroutine implements PromiseInterface +{ + /** + * @var PromiseInterface|null + */ + private $currentPromise; + + /** + * @var Generator + */ + private $generator; + + /** + * @var Promise + */ + private $result; + + public function __construct(callable $generatorFn) + { + $this->generator = $generatorFn(); + $this->result = new Promise(function () { + while (isset($this->currentPromise)) { + $this->currentPromise->wait(); + } + }); + try { + $this->nextCoroutine($this->generator->current()); + } catch (\Exception $exception) { + $this->result->reject($exception); + } catch (Throwable $throwable) { + $this->result->reject($throwable); + } + } + + /** + * Create a new coroutine. + * + * @return self + */ + public static function of(callable $generatorFn) + { + return new self($generatorFn); + } + + public function then( + callable $onFulfilled = null, + callable $onRejected = null + ) { + return $this->result->then($onFulfilled, $onRejected); + } + + public function otherwise(callable $onRejected) + { + return $this->result->otherwise($onRejected); + } + + public function wait($unwrap = true) + { + return $this->result->wait($unwrap); + } + + public function getState() + { + return $this->result->getState(); + } + + public function resolve($value) + { + $this->result->resolve($value); + } + + public function reject($reason) + { + $this->result->reject($reason); + } + + public function cancel() + { + $this->currentPromise->cancel(); + $this->result->cancel(); + } + + private function nextCoroutine($yielded) + { + $this->currentPromise = Create::promiseFor($yielded) + ->then([$this, '_handleSuccess'], [$this, '_handleFailure']); + } + + /** + * @internal + */ + public function _handleSuccess($value) + { + unset($this->currentPromise); + try { + $next = $this->generator->send($value); + if ($this->generator->valid()) { + $this->nextCoroutine($next); + } else { + $this->result->resolve($value); + } + } catch (Exception $exception) { + $this->result->reject($exception); + } catch (Throwable $throwable) { + $this->result->reject($throwable); + } + } + + /** + * @internal + */ + public function _handleFailure($reason) + { + unset($this->currentPromise); + try { + $nextYield = $this->generator->throw(Create::exceptionFor($reason)); + // The throw was caught, so keep iterating on the coroutine + $this->nextCoroutine($nextYield); + } catch (Exception $exception) { + $this->result->reject($exception); + } catch (Throwable $throwable) { + $this->result->reject($throwable); + } + } +} |