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<?php
namespace Sabre\Event\Promise;
use Sabre\Event\Promise;
/**
* This file contains a set of functions that are useful for dealing with the
* Promise object.
*
* @copyright Copyright (C) 2013-2015 fruux GmbH (https://fruux.com/).
* @author Evert Pot (http://evertpot.com/)
* @license http://sabre.io/license/ Modified BSD License
*/
/**
* This function takes an array of Promises, and returns a Promise that
* resolves when all of the given arguments have resolved.
*
* The returned Promise will resolve with a value that's an array of all the
* values the given promises have been resolved with.
*
* This array will be in the exact same order as the array of input promises.
*
* If any of the given Promises fails, the returned promise will immidiately
* fail with the first Promise that fails, and its reason.
*
* @param Promise[] $promises
* @return Promise
*/
function all(array $promises) {
return new Promise(function($success, $fail) use ($promises) {
$successCount = 0;
$completeResult = [];
foreach ($promises as $promiseIndex => $subPromise) {
$subPromise->then(
function($result) use ($promiseIndex, &$completeResult, &$successCount, $success, $promises) {
$completeResult[$promiseIndex] = $result;
$successCount++;
if ($successCount === count($promises)) {
$success($completeResult);
}
return $result;
}
)->error(
function($reason) use ($fail) {
$fail($reason);
}
);
}
});
}
/**
* The race function returns a promise that resolves or rejects as soon as
* one of the promises in the argument resolves or rejects.
*
* The returned promise will resolve or reject with the value or reason of
* that first promise.
*
* @param Promise[] $promises
* @return Promise
*/
function race(array $promises) {
return new Promise(function($success, $fail) use ($promises) {
$alreadyDone = false;
foreach ($promises as $promise) {
$promise->then(
function($result) use ($success, &$alreadyDone) {
if ($alreadyDone) {
return;
}
$alreadyDone = true;
$success($result);
},
function($reason) use ($fail, &$alreadyDone) {
if ($alreadyDone) {
return;
}
$alreadyDone = true;
$fail($reason);
}
);
}
});
}
/**
* Returns a Promise that resolves with the given value.
*
* If the value is a promise, the returned promise will attach itself to that
* promise and eventually get the same state as the followed promise.
*
* @param mixed $value
* @return Promise
*/
function resolve($value) {
if ($value instanceof Promise) {
return $value->then();
} else {
$promise = new Promise();
$promise->fulfill($value);
return $promise;
}
}
/**
* Returns a Promise that will reject with the given reason.
*
* @param mixed $reason
* @return Promise
*/
function reject($reason) {
$promise = new Promise();
$promise->reject($reason);
return $promise;
}
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