comparison vendor/guzzlehttp/promises/src/functions.php @ 0:4c8ae668cc8c

Initial import (non-working)
author Chris Cannam
date Wed, 29 Nov 2017 16:09:58 +0000
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1 <?php
2 namespace GuzzleHttp\Promise;
3
4 /**
5 * Get the global task queue used for promise resolution.
6 *
7 * This task queue MUST be run in an event loop in order for promises to be
8 * settled asynchronously. It will be automatically run when synchronously
9 * waiting on a promise.
10 *
11 * <code>
12 * while ($eventLoop->isRunning()) {
13 * GuzzleHttp\Promise\queue()->run();
14 * }
15 * </code>
16 *
17 * @param TaskQueueInterface $assign Optionally specify a new queue instance.
18 *
19 * @return TaskQueueInterface
20 */
21 function queue(TaskQueueInterface $assign = null)
22 {
23 static $queue;
24
25 if ($assign) {
26 $queue = $assign;
27 } elseif (!$queue) {
28 $queue = new TaskQueue();
29 }
30
31 return $queue;
32 }
33
34 /**
35 * Adds a function to run in the task queue when it is next `run()` and returns
36 * a promise that is fulfilled or rejected with the result.
37 *
38 * @param callable $task Task function to run.
39 *
40 * @return PromiseInterface
41 */
42 function task(callable $task)
43 {
44 $queue = queue();
45 $promise = new Promise([$queue, 'run']);
46 $queue->add(function () use ($task, $promise) {
47 try {
48 $promise->resolve($task());
49 } catch (\Throwable $e) {
50 $promise->reject($e);
51 } catch (\Exception $e) {
52 $promise->reject($e);
53 }
54 });
55
56 return $promise;
57 }
58
59 /**
60 * Creates a promise for a value if the value is not a promise.
61 *
62 * @param mixed $value Promise or value.
63 *
64 * @return PromiseInterface
65 */
66 function promise_for($value)
67 {
68 if ($value instanceof PromiseInterface) {
69 return $value;
70 }
71
72 // Return a Guzzle promise that shadows the given promise.
73 if (method_exists($value, 'then')) {
74 $wfn = method_exists($value, 'wait') ? [$value, 'wait'] : null;
75 $cfn = method_exists($value, 'cancel') ? [$value, 'cancel'] : null;
76 $promise = new Promise($wfn, $cfn);
77 $value->then([$promise, 'resolve'], [$promise, 'reject']);
78 return $promise;
79 }
80
81 return new FulfilledPromise($value);
82 }
83
84 /**
85 * Creates a rejected promise for a reason if the reason is not a promise. If
86 * the provided reason is a promise, then it is returned as-is.
87 *
88 * @param mixed $reason Promise or reason.
89 *
90 * @return PromiseInterface
91 */
92 function rejection_for($reason)
93 {
94 if ($reason instanceof PromiseInterface) {
95 return $reason;
96 }
97
98 return new RejectedPromise($reason);
99 }
100
101 /**
102 * Create an exception for a rejected promise value.
103 *
104 * @param mixed $reason
105 *
106 * @return \Exception|\Throwable
107 */
108 function exception_for($reason)
109 {
110 return $reason instanceof \Exception || $reason instanceof \Throwable
111 ? $reason
112 : new RejectionException($reason);
113 }
114
115 /**
116 * Returns an iterator for the given value.
117 *
118 * @param mixed $value
119 *
120 * @return \Iterator
121 */
122 function iter_for($value)
123 {
124 if ($value instanceof \Iterator) {
125 return $value;
126 } elseif (is_array($value)) {
127 return new \ArrayIterator($value);
128 } else {
129 return new \ArrayIterator([$value]);
130 }
131 }
132
133 /**
134 * Synchronously waits on a promise to resolve and returns an inspection state
135 * array.
136 *
137 * Returns a state associative array containing a "state" key mapping to a
138 * valid promise state. If the state of the promise is "fulfilled", the array
139 * will contain a "value" key mapping to the fulfilled value of the promise. If
140 * the promise is rejected, the array will contain a "reason" key mapping to
141 * the rejection reason of the promise.
142 *
143 * @param PromiseInterface $promise Promise or value.
144 *
145 * @return array
146 */
147 function inspect(PromiseInterface $promise)
148 {
149 try {
150 return [
151 'state' => PromiseInterface::FULFILLED,
152 'value' => $promise->wait()
153 ];
154 } catch (RejectionException $e) {
155 return ['state' => PromiseInterface::REJECTED, 'reason' => $e->getReason()];
156 } catch (\Throwable $e) {
157 return ['state' => PromiseInterface::REJECTED, 'reason' => $e];
158 } catch (\Exception $e) {
159 return ['state' => PromiseInterface::REJECTED, 'reason' => $e];
160 }
161 }
162
163 /**
164 * Waits on all of the provided promises, but does not unwrap rejected promises
165 * as thrown exception.
166 *
167 * Returns an array of inspection state arrays.
168 *
169 * @param PromiseInterface[] $promises Traversable of promises to wait upon.
170 *
171 * @return array
172 * @see GuzzleHttp\Promise\inspect for the inspection state array format.
173 */
174 function inspect_all($promises)
175 {
176 $results = [];
177 foreach ($promises as $key => $promise) {
178 $results[$key] = inspect($promise);
179 }
180
181 return $results;
182 }
183
184 /**
185 * Waits on all of the provided promises and returns the fulfilled values.
186 *
187 * Returns an array that contains the value of each promise (in the same order
188 * the promises were provided). An exception is thrown if any of the promises
189 * are rejected.
190 *
191 * @param mixed $promises Iterable of PromiseInterface objects to wait on.
192 *
193 * @return array
194 * @throws \Exception on error
195 * @throws \Throwable on error in PHP >=7
196 */
197 function unwrap($promises)
198 {
199 $results = [];
200 foreach ($promises as $key => $promise) {
201 $results[$key] = $promise->wait();
202 }
203
204 return $results;
205 }
206
207 /**
208 * Given an array of promises, return a promise that is fulfilled when all the
209 * items in the array are fulfilled.
210 *
211 * The promise's fulfillment value is an array with fulfillment values at
212 * respective positions to the original array. If any promise in the array
213 * rejects, the returned promise is rejected with the rejection reason.
214 *
215 * @param mixed $promises Promises or values.
216 *
217 * @return PromiseInterface
218 */
219 function all($promises)
220 {
221 $results = [];
222 return each(
223 $promises,
224 function ($value, $idx) use (&$results) {
225 $results[$idx] = $value;
226 },
227 function ($reason, $idx, Promise $aggregate) {
228 $aggregate->reject($reason);
229 }
230 )->then(function () use (&$results) {
231 ksort($results);
232 return $results;
233 });
234 }
235
236 /**
237 * Initiate a competitive race between multiple promises or values (values will
238 * become immediately fulfilled promises).
239 *
240 * When count amount of promises have been fulfilled, the returned promise is
241 * fulfilled with an array that contains the fulfillment values of the winners
242 * in order of resolution.
243 *
244 * This prommise is rejected with a {@see GuzzleHttp\Promise\AggregateException}
245 * if the number of fulfilled promises is less than the desired $count.
246 *
247 * @param int $count Total number of promises.
248 * @param mixed $promises Promises or values.
249 *
250 * @return PromiseInterface
251 */
252 function some($count, $promises)
253 {
254 $results = [];
255 $rejections = [];
256
257 return each(
258 $promises,
259 function ($value, $idx, PromiseInterface $p) use (&$results, $count) {
260 if ($p->getState() !== PromiseInterface::PENDING) {
261 return;
262 }
263 $results[$idx] = $value;
264 if (count($results) >= $count) {
265 $p->resolve(null);
266 }
267 },
268 function ($reason) use (&$rejections) {
269 $rejections[] = $reason;
270 }
271 )->then(
272 function () use (&$results, &$rejections, $count) {
273 if (count($results) !== $count) {
274 throw new AggregateException(
275 'Not enough promises to fulfill count',
276 $rejections
277 );
278 }
279 ksort($results);
280 return array_values($results);
281 }
282 );
283 }
284
285 /**
286 * Like some(), with 1 as count. However, if the promise fulfills, the
287 * fulfillment value is not an array of 1 but the value directly.
288 *
289 * @param mixed $promises Promises or values.
290 *
291 * @return PromiseInterface
292 */
293 function any($promises)
294 {
295 return some(1, $promises)->then(function ($values) { return $values[0]; });
296 }
297
298 /**
299 * Returns a promise that is fulfilled when all of the provided promises have
300 * been fulfilled or rejected.
301 *
302 * The returned promise is fulfilled with an array of inspection state arrays.
303 *
304 * @param mixed $promises Promises or values.
305 *
306 * @return PromiseInterface
307 * @see GuzzleHttp\Promise\inspect for the inspection state array format.
308 */
309 function settle($promises)
310 {
311 $results = [];
312
313 return each(
314 $promises,
315 function ($value, $idx) use (&$results) {
316 $results[$idx] = ['state' => PromiseInterface::FULFILLED, 'value' => $value];
317 },
318 function ($reason, $idx) use (&$results) {
319 $results[$idx] = ['state' => PromiseInterface::REJECTED, 'reason' => $reason];
320 }
321 )->then(function () use (&$results) {
322 ksort($results);
323 return $results;
324 });
325 }
326
327 /**
328 * Given an iterator that yields promises or values, returns a promise that is
329 * fulfilled with a null value when the iterator has been consumed or the
330 * aggregate promise has been fulfilled or rejected.
331 *
332 * $onFulfilled is a function that accepts the fulfilled value, iterator
333 * index, and the aggregate promise. The callback can invoke any necessary side
334 * effects and choose to resolve or reject the aggregate promise if needed.
335 *
336 * $onRejected is a function that accepts the rejection reason, iterator
337 * index, and the aggregate promise. The callback can invoke any necessary side
338 * effects and choose to resolve or reject the aggregate promise if needed.
339 *
340 * @param mixed $iterable Iterator or array to iterate over.
341 * @param callable $onFulfilled
342 * @param callable $onRejected
343 *
344 * @return PromiseInterface
345 */
346 function each(
347 $iterable,
348 callable $onFulfilled = null,
349 callable $onRejected = null
350 ) {
351 return (new EachPromise($iterable, [
352 'fulfilled' => $onFulfilled,
353 'rejected' => $onRejected
354 ]))->promise();
355 }
356
357 /**
358 * Like each, but only allows a certain number of outstanding promises at any
359 * given time.
360 *
361 * $concurrency may be an integer or a function that accepts the number of
362 * pending promises and returns a numeric concurrency limit value to allow for
363 * dynamic a concurrency size.
364 *
365 * @param mixed $iterable
366 * @param int|callable $concurrency
367 * @param callable $onFulfilled
368 * @param callable $onRejected
369 *
370 * @return PromiseInterface
371 */
372 function each_limit(
373 $iterable,
374 $concurrency,
375 callable $onFulfilled = null,
376 callable $onRejected = null
377 ) {
378 return (new EachPromise($iterable, [
379 'fulfilled' => $onFulfilled,
380 'rejected' => $onRejected,
381 'concurrency' => $concurrency
382 ]))->promise();
383 }
384
385 /**
386 * Like each_limit, but ensures that no promise in the given $iterable argument
387 * is rejected. If any promise is rejected, then the aggregate promise is
388 * rejected with the encountered rejection.
389 *
390 * @param mixed $iterable
391 * @param int|callable $concurrency
392 * @param callable $onFulfilled
393 *
394 * @return PromiseInterface
395 */
396 function each_limit_all(
397 $iterable,
398 $concurrency,
399 callable $onFulfilled = null
400 ) {
401 return each_limit(
402 $iterable,
403 $concurrency,
404 $onFulfilled,
405 function ($reason, $idx, PromiseInterface $aggregate) {
406 $aggregate->reject($reason);
407 }
408 );
409 }
410
411 /**
412 * Returns true if a promise is fulfilled.
413 *
414 * @param PromiseInterface $promise
415 *
416 * @return bool
417 */
418 function is_fulfilled(PromiseInterface $promise)
419 {
420 return $promise->getState() === PromiseInterface::FULFILLED;
421 }
422
423 /**
424 * Returns true if a promise is rejected.
425 *
426 * @param PromiseInterface $promise
427 *
428 * @return bool
429 */
430 function is_rejected(PromiseInterface $promise)
431 {
432 return $promise->getState() === PromiseInterface::REJECTED;
433 }
434
435 /**
436 * Returns true if a promise is fulfilled or rejected.
437 *
438 * @param PromiseInterface $promise
439 *
440 * @return bool
441 */
442 function is_settled(PromiseInterface $promise)
443 {
444 return $promise->getState() !== PromiseInterface::PENDING;
445 }
446
447 /**
448 * @see Coroutine
449 *
450 * @param callable $generatorFn
451 *
452 * @return PromiseInterface
453 */
454 function coroutine(callable $generatorFn)
455 {
456 return new Coroutine($generatorFn);
457 }