Edit file File name : Promise.php Content :<?php declare (strict_types=1); namespace YoastSEO_Vendor\GuzzleHttp\Promise; /** * Promises/A+ implementation that avoids recursion when possible. * * @see https://promisesaplus.com/ * * @final */ class Promise implements \YoastSEO_Vendor\GuzzleHttp\Promise\PromiseInterface { private $state = self::PENDING; private $result; private $cancelFn; private $waitFn; private $waitList; private $handlers = []; /** * @param callable $waitFn Fn that when invoked resolves the promise. * @param callable $cancelFn Fn that when invoked cancels the promise. */ public function __construct(callable $waitFn = null, callable $cancelFn = null) { $this->waitFn = $waitFn; $this->cancelFn = $cancelFn; } public function then(callable $onFulfilled = null, callable $onRejected = null) : \YoastSEO_Vendor\GuzzleHttp\Promise\PromiseInterface { if ($this->state === self::PENDING) { $p = new \YoastSEO_Vendor\GuzzleHttp\Promise\Promise(null, [$this, 'cancel']); $this->handlers[] = [$p, $onFulfilled, $onRejected]; $p->waitList = $this->waitList; $p->waitList[] = $this; return $p; } // Return a fulfilled promise and immediately invoke any callbacks. if ($this->state === self::FULFILLED) { $promise = \YoastSEO_Vendor\GuzzleHttp\Promise\Create::promiseFor($this->result); return $onFulfilled ? $promise->then($onFulfilled) : $promise; } // It's either cancelled or rejected, so return a rejected promise // and immediately invoke any callbacks. $rejection = \YoastSEO_Vendor\GuzzleHttp\Promise\Create::rejectionFor($this->result); return $onRejected ? $rejection->then(null, $onRejected) : $rejection; } public function otherwise(callable $onRejected) : \YoastSEO_Vendor\GuzzleHttp\Promise\PromiseInterface { return $this->then(null, $onRejected); } public function wait(bool $unwrap = \true) { $this->waitIfPending(); if ($this->result instanceof \YoastSEO_Vendor\GuzzleHttp\Promise\PromiseInterface) { return $this->result->wait($unwrap); } if ($unwrap) { if ($this->state === self::FULFILLED) { return $this->result; } // It's rejected so "unwrap" and throw an exception. throw \YoastSEO_Vendor\GuzzleHttp\Promise\Create::exceptionFor($this->result); } } public function getState() : string { return $this->state; } public function cancel() : void { if ($this->state !== self::PENDING) { return; } $this->waitFn = $this->waitList = null; if ($this->cancelFn) { $fn = $this->cancelFn; $this->cancelFn = null; try { $fn(); } catch (\Throwable $e) { $this->reject($e); } } // Reject the promise only if it wasn't rejected in a then callback. /** @psalm-suppress RedundantCondition */ if ($this->state === self::PENDING) { $this->reject(new \YoastSEO_Vendor\GuzzleHttp\Promise\CancellationException('Promise has been cancelled')); } } public function resolve($value) : void { $this->settle(self::FULFILLED, $value); } public function reject($reason) : void { $this->settle(self::REJECTED, $reason); } private function settle(string $state, $value) : void { if ($this->state !== self::PENDING) { // Ignore calls with the same resolution. if ($state === $this->state && $value === $this->result) { return; } throw $this->state === $state ? new \LogicException("The promise is already {$state}.") : new \LogicException("Cannot change a {$this->state} promise to {$state}"); } if ($value === $this) { throw new \LogicException('Cannot fulfill or reject a promise with itself'); } // Clear out the state of the promise but stash the handlers. $this->state = $state; $this->result = $value; $handlers = $this->handlers; $this->handlers = null; $this->waitList = $this->waitFn = null; $this->cancelFn = null; if (!$handlers) { return; } // If the value was not a settled promise or a thenable, then resolve // it in the task queue using the correct ID. if (!\is_object($value) || !\method_exists($value, 'then')) { $id = $state === self::FULFILLED ? 1 : 2; // It's a success, so resolve the handlers in the queue. \YoastSEO_Vendor\GuzzleHttp\Promise\Utils::queue()->add(static function () use($id, $value, $handlers) : void { foreach ($handlers as $handler) { self::callHandler($id, $value, $handler); } }); } elseif ($value instanceof \YoastSEO_Vendor\GuzzleHttp\Promise\Promise && \YoastSEO_Vendor\GuzzleHttp\Promise\Is::pending($value)) { // We can just merge our handlers onto the next promise. $value->handlers = \array_merge($value->handlers, $handlers); } else { // Resolve the handlers when the forwarded promise is resolved. $value->then(static function ($value) use($handlers) : void { foreach ($handlers as $handler) { self::callHandler(1, $value, $handler); } }, static function ($reason) use($handlers) : void { foreach ($handlers as $handler) { self::callHandler(2, $reason, $handler); } }); } } /** * Call a stack of handlers using a specific callback index and value. * * @param int $index 1 (resolve) or 2 (reject). * @param mixed $value Value to pass to the callback. * @param array $handler Array of handler data (promise and callbacks). */ private static function callHandler(int $index, $value, array $handler) : void { /** @var PromiseInterface $promise */ $promise = $handler[0]; // The promise may have been cancelled or resolved before placing // this thunk in the queue. if (\YoastSEO_Vendor\GuzzleHttp\Promise\Is::settled($promise)) { return; } try { if (isset($handler[$index])) { /* * If $f throws an exception, then $handler will be in the exception * stack trace. Since $handler contains a reference to the callable * itself we get a circular reference. We clear the $handler * here to avoid that memory leak. */ $f = $handler[$index]; unset($handler); $promise->resolve($f($value)); } elseif ($index === 1) { // Forward resolution values as-is. $promise->resolve($value); } else { // Forward rejections down the chain. $promise->reject($value); } } catch (\Throwable $reason) { $promise->reject($reason); } } private function waitIfPending() : void { if ($this->state !== self::PENDING) { return; } elseif ($this->waitFn) { $this->invokeWaitFn(); } elseif ($this->waitList) { $this->invokeWaitList(); } else { // If there's no wait function, then reject the promise. $this->reject('Cannot wait on a promise that has ' . 'no internal wait function. You must provide a wait ' . 'function when constructing the promise to be able to ' . 'wait on a promise.'); } \YoastSEO_Vendor\GuzzleHttp\Promise\Utils::queue()->run(); /** @psalm-suppress RedundantCondition */ if ($this->state === self::PENDING) { $this->reject('Invoking the wait callback did not resolve the promise'); } } private function invokeWaitFn() : void { try { $wfn = $this->waitFn; $this->waitFn = null; $wfn(\true); } catch (\Throwable $reason) { if ($this->state === self::PENDING) { // The promise has not been resolved yet, so reject the promise // with the exception. $this->reject($reason); } else { // The promise was already resolved, so there's a problem in // the application. throw $reason; } } } private function invokeWaitList() : void { $waitList = $this->waitList; $this->waitList = null; foreach ($waitList as $result) { do { $result->waitIfPending(); $result = $result->result; } while ($result instanceof \YoastSEO_Vendor\GuzzleHttp\Promise\Promise); if ($result instanceof \YoastSEO_Vendor\GuzzleHttp\Promise\PromiseInterface) { $result->wait(\false); } } } } Save