mirror of
https://github.com/danog/amp.git
synced 2024-11-27 04:24:42 +01:00
734 lines
21 KiB
PHP
734 lines
21 KiB
PHP
<?php
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namespace Amp;
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use Interop\Async\Awaitable;
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use Interop\Async\Loop;
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/**
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* Returns a new function that when invoked runs the Generator returned by $worker as a coroutine.
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*
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* @param callable(mixed ...$args): \Generator $worker
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*
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* @return callable(mixed ...$args): \Amp\Coroutine
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*/
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function coroutine(callable $worker) {
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return function (/* ...$args */) use ($worker) {
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$generator = \call_user_func_array($worker, \func_get_args());
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if (!$generator instanceof \Generator) {
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throw new \LogicException("The callable did not return a Generator");
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}
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return new Coroutine($generator);
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};
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}
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/**
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* Registers a callback that will forward the failure reason to the Loop error handler if the awaitable fails.
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*
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* @param \Interop\Async\Awaitable $awaitable
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*/
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function rethrow(Awaitable $awaitable) {
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$awaitable->when(function ($exception) {
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if ($exception) {
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throw $exception;
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}
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});
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}
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/**
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* Runs the event loop until the awaitable is resolved. Should not be called within a running event loop.
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*
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* @param \Interop\Async\Awaitable $awaitable
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*
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* @return mixed Awaitable success value.
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*
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* @throws \Throwable|\Exception Awaitable failure reason.
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*/
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function wait(Awaitable $awaitable) {
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$resolved = false;
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Loop::execute(function () use (&$resolved, &$value, &$exception, $awaitable) {
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$awaitable->when(function ($e, $v) use (&$resolved, &$value, &$exception) {
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Loop::stop();
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$resolved = true;
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$exception = $e;
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$value = $v;
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});
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}, Loop::get());
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if (!$resolved) {
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throw new \LogicException("Loop emptied without resolving awaitable");
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}
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if ($exception) {
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throw $exception;
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}
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return $value;
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}
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/**
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* Pipe the promised value through the specified functor once it resolves.
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*
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* @param \Interop\Async\Awaitable $awaitable
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* @param callable(mixed $value): mixed $functor
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*
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* @return \Interop\Async\Awaitable
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*/
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function pipe(Awaitable $awaitable, callable $functor) {
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$deferred = new Deferred;
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$awaitable->when(function ($exception, $value) use ($deferred, $functor) {
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if ($exception) {
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$deferred->fail($exception);
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return;
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}
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try {
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$deferred->resolve($functor($value));
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} catch (\Throwable $exception) {
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$deferred->fail($exception);
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} catch (\Exception $exception) {
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$deferred->fail($exception);
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}
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});
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return $deferred->getAwaitable();
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}
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/**
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* @param \Interop\Async\Awaitable $awaitable
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* @param string $className Exception class name to capture. Given callback will only be invoked if the failure reason
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* is an instance of the given exception class name.
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* @param callable(\Throwable|\Exception $exception): mixed $functor
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*
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* @return \Interop\Async\Awaitable
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*/
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function capture(Awaitable $awaitable, $className, callable $functor) {
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$deferred = new Deferred;
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$awaitable->when(function ($exception, $value) use ($deferred, $className, $functor) {
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if (!$exception) {
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$deferred->resolve($value);
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return;
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}
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if (!$exception instanceof $className) {
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$deferred->fail($exception);
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return;
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}
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try {
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$deferred->resolve($functor($exception));
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} catch (\Throwable $exception) {
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$deferred->fail($exception);
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} catch (\Exception $exception) {
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$deferred->fail($exception);
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}
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});
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return $deferred->getAwaitable();
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}
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/**
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* Create an artificial timeout for any Awaitable.
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*
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* If the timeout expires before the awaitable is resolved, the returned awaitable fails with an instance of
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* \Amp\Exception\TimeoutException.
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*
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* @param \Interop\Async\Awaitable $awaitable
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* @param int $timeout Timeout in milliseconds.
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*
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* @return \Interop\Async\Awaitable
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*/
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function timeout(Awaitable $awaitable, $timeout) {
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$deferred = new Deferred;
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$resolved = false;
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$watcher = Loop::delay($timeout, function () use (&$resolved, $deferred) {
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if (!$resolved) {
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$resolved = true;
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$deferred->fail(new TimeoutException);
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}
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});
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$awaitable->when(function () use (&$resolved, $awaitable, $deferred, $watcher) {
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Loop::cancel($watcher);
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if ($resolved) {
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return;
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}
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$resolved = true;
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$deferred->resolve($awaitable);
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});
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return $deferred->getAwaitable();
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}
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/**
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* Returns a awaitable that calls $promisor only when the result of the awaitable is requested (e.g., then() or
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* done() is called on the returned awaitable). $promisor can return a awaitable or any value. If $promisor throws
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* an exception, the returned awaitable is rejected with that exception.
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*
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* @param callable $promisor
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* @param mixed ...$args
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*
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* @return \Interop\Async\Awaitable
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*/
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function lazy(callable $promisor /* ...$args */) {
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$args = \array_slice(\func_get_args(), 1);
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if (empty($args)) {
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return new Internal\LazyAwaitable($promisor);
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}
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return new Internal\LazyAwaitable(function () use ($promisor, $args) {
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return \call_user_func_array($promisor, $args);
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});
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}
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/**
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* Adapts any object with a then(callable $onFulfilled, callable $onRejected) method to a awaitable usable by
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* components depending on placeholders implementing Awaitable.
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*
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* @param object $thenable Object with a then() method.
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*
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* @return \Interop\Async\Awaitable Awaitable resolved by the $thenable object.
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*
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* @throws \InvalidArgumentException If the provided object does not have a then() method.
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*/
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function adapt($thenable) {
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if (!\is_object($thenable) || !\method_exists($thenable, "then")) {
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throw new \InvalidArgumentException("Must provide an object with a then() method");
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}
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$deferred = new Deferred;
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$thenable->then([$deferred, 'resolve'], [$deferred, 'fail']);
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return $deferred->getAwaitable();
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}
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/**
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* Wraps the given callable $worker in a awaitable aware function that has the same number of arguments as $worker,
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* but those arguments may be awaitables for the future argument value or just values. The returned function will
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* return a awaitable for the return value of $worker and will never throw. The $worker function will not be called
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* until each awaitable given as an argument is fulfilled. If any awaitable provided as an argument fails, the
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* awaitable returned by the returned function will be failed for the same reason. The awaitable succeeds with
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* the return value of $worker or failed if $worker throws.
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*
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* @param callable $worker
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*
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* @return callable
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*/
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function lift(callable $worker) {
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/**
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* @param mixed ...$args Awaitables or values.
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*
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* @return \Interop\Async\Awaitable
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*/
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return function (/* ...$args */) use ($worker) {
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$args = \func_get_args();
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foreach ($args as $key => $arg) {
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if (!$arg instanceof Awaitable) {
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$args[$key] = new Success($arg);
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}
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}
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if (1 === \count($args)) {
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return pipe($args[0], $worker);
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}
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return pipe(all($args), function (array $args) use ($worker) {
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return \call_user_func_array($worker, $args);
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});
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};
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}
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/**
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* Returns a awaitable that is resolved when all awaitables are resolved. The returned awaitable will not fail.
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* Returned awaitable succeeds with a two-item array delineating successful and failed awaitable results,
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* with keys identical and corresponding to the original given array.
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*
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* This function is the same as some() with the notable exception that it will never fail even
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* if all awaitables in the array resolve unsuccessfully.
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*
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* @param Awaitable[] $awaitables
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*
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* @return \Interop\Async\Awaitable
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*
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* @throws \InvalidArgumentException If a non-Awaitable is in the array.
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*/
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function any(array $awaitables) {
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if (empty($awaitables)) {
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return new Success([[], []]);
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}
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$deferred = new Deferred;
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$pending = \count($awaitables);
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$errors = [];
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$values = [];
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foreach ($awaitables as $key => $awaitable) {
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if (!$awaitable instanceof Awaitable) {
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throw new \InvalidArgumentException("Non-awaitable provided");
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}
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$awaitable->when(function ($error, $value) use (&$pending, &$errors, &$values, $key, $deferred) {
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if ($error) {
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$errors[$key] = $error;
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} else {
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$values[$key] = $value;
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}
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if (--$pending === 0) {
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$deferred->resolve([$errors, $values]);
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}
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});
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}
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return $deferred->getAwaitable();
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}
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/**
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* Returns a awaitable that succeeds when all awaitables succeed, and fails if any awaitable fails. Returned
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* awaitable succeeds with an array of values used to succeed each contained awaitable, with keys corresponding to
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* the array of awaitables.
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*
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* @param Awaitable[] $awaitables
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*
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* @return \Interop\Async\Awaitable
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*
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* @throws \InvalidArgumentException If a non-Awaitable is in the array.
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*/
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function all(array $awaitables) {
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if (empty($awaitables)) {
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return new Success([]);
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}
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$deferred = new Deferred;
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$pending = \count($awaitables);
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$resolved = false;
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$values = [];
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foreach ($awaitables as $key => $awaitable) {
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if (!$awaitable instanceof Awaitable) {
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throw new \InvalidArgumentException("Non-awaitable provided");
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}
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$awaitable->when(function ($exception, $value) use (&$values, &$pending, &$resolved, $key, $deferred) {
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if ($resolved) {
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return;
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}
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if ($exception) {
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$resolved = true;
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$deferred->fail($exception);
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return;
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}
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$values[$key] = $value;
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if (0 === --$pending) {
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$deferred->resolve($values);
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}
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});
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}
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return $deferred->getAwaitable();
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}
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/**
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* Returns a awaitable that succeeds when the first awaitable succeeds, and fails only if all awaitables fail.
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*
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* @param Awaitable[] $awaitables
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*
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* @return \Interop\Async\Awaitable
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*
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* @throws \InvalidArgumentException If the array is empty or a non-Awaitable is in the array.
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*/
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function first(array $awaitables) {
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if (empty($awaitables)) {
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throw new \InvalidArgumentException("No awaitables provided");
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}
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$deferred = new Deferred;
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$pending = \count($awaitables);
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$resolved = false;
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$exceptions = [];
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foreach ($awaitables as $key => $awaitable) {
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if (!$awaitable instanceof Awaitable) {
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throw new \InvalidArgumentException("Non-awaitable provided");
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}
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$awaitable->when(function ($exception, $value) use (&$exceptions, &$pending, &$resolved, $key, $deferred) {
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if ($resolved) {
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return;
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}
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if (!$exception) {
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$resolved = true;
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$deferred->resolve($value);
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return;
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}
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$exceptions[$key] = $exception;
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if (0 === --$pending) {
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$deferred->fail(new MultiReasonException($exceptions));
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}
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});
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}
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return $deferred->getAwaitable();
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}
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/**
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* Resolves with a two-item array delineating successful and failed Awaitable results.
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*
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* The returned awaitable will only fail if ALL of the awaitables fail.
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* @param Awaitable[] $awaitables
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*
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* @return \Interop\Async\Awaitable
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*/
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function some(array $awaitables) {
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if (empty($awaitables)) {
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throw new \InvalidArgumentException("No awaitables provided");
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}
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$pending = \count($awaitables);
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$deferred = new Deferred;
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$values = [];
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$exceptions = [];
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foreach ($awaitables as $key => $awaitable) {
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if (!$awaitable instanceof Awaitable) {
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throw new \InvalidArgumentException("Non-awaitable provided");
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}
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$awaitable->when(function ($exception, $value) use (&$values, &$exceptions, &$pending, $key, $deferred) {
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if ($exception) {
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$exceptions[$key] = $exception;
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} else {
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$values[$key] = $value;
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}
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if (0 === --$pending) {
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if (empty($values)) {
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$deferred->fail(new MultiReasonException($exceptions));
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return;
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}
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$deferred->resolve([$exceptions, $values]);
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}
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});
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}
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return $deferred->getAwaitable();
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}
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/**
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* Returns a awaitable that succeeds or fails when the first awaitable succeeds or fails.
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*
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* @param Awaitable[] $awaitables
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*
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* @return \Interop\Async\Awaitable
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*
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* @throws \InvalidArgumentException If the array is empty or a non-Awaitable is in the array.
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*/
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function choose(array $awaitables) {
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if (empty($awaitables)) {
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throw new \InvalidArgumentException("No awaitables provided");
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}
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$deferred = new Deferred;
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$resolved = false;
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foreach ($awaitables as $awaitable) {
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if (!$awaitable instanceof Awaitable) {
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throw new \InvalidArgumentException("Non-awaitable provided");
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}
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$awaitable->when(function ($exception, $value) use (&$resolved, $deferred) {
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if ($resolved) {
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return;
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}
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$resolved = true;
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if ($exception) {
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$deferred->fail($exception);
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return;
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}
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$deferred->resolve($value);
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});
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}
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return $deferred->getAwaitable();
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}
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/**
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* Maps the callback to each awaitable as it succeeds. Returns an array of awaitables resolved by the return
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* callback value of the callback function. The callback may return awaitables or throw exceptions to fail
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* awaitables in the array. If a awaitable in the passed array fails, the callback will not be called and the
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* awaitable in the array fails for the same reason. Tip: Use all() or any() to determine when all
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* awaitables in the array have been resolved.
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*
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* @param callable(mixed $value): mixed $callback
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* @param Awaitable[] ...$awaitables
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*
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* @return \Interop\Async\Awaitable[] Array of awaitables resolved with the result of the mapped function.
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*/
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function map(callable $callback /* array ...$awaitables */) {
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$args = \func_get_args();
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$count = \count($args);
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$args[0] = lift($callback);
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for ($i = 1; $i < $count; ++$i) {
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foreach ($args[$i] as $awaitable) {
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if (!$awaitable instanceof Awaitable) {
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throw new \InvalidArgumentException('Non-awaitable provided');
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}
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}
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}
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return \call_user_func_array("array_map", $args);
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}
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/**
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* @param \Amp\Observable $observable
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* @param callable(mixed $value): mixed $onNext
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* @param callable(mixed $value): mixed|null $onComplete
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*
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* @return \Amp\Observable
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*/
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function each(Observable $observable, callable $onNext, callable $onComplete = null) {
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return new Emitter(function (callable $emit) use ($observable, $onNext, $onComplete) {
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$observable->subscribe(function ($value) use ($emit, $onNext) {
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return $emit($onNext($value));
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});
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$result = (yield $observable);
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if ($onComplete === null) {
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yield Coroutine::result($result);
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return;
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}
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yield Coroutine::result($onComplete($result));
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});
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}
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/**
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* @param \Amp\Observable $observable
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* @param callable(mixed $value): bool $filter
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*
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* @return \Amp\Observable
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*/
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function filter(Observable $observable, callable $filter) {
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return new Emitter(function (callable $emit) use ($observable, $filter) {
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$observable->subscribe(function ($value) use ($emit, $filter) {
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if (!$filter($value)) {
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return null;
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}
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return $emit($value);
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});
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yield Coroutine::result(yield $observable);
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});
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}
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/**
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* Creates an observable that emits values emitted from any observable in the array of observables. Values in the
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* array are passed through the from() function, so they may be observables, arrays of values to emit, awaitables,
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* or any other value.
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*
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* @param \Amp\Observable[] $observables
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*
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* @return \Amp\Observable
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*/
|
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function merge(array $observables) {
|
|
foreach ($observables as $observable) {
|
|
if (!$observable instanceof Observable) {
|
|
throw new \InvalidArgumentException("Non-observable provided");
|
|
}
|
|
}
|
|
|
|
return new Emitter(function (callable $emit) use ($observables) {
|
|
$subscriptions = [];
|
|
|
|
foreach ($observables as $observable) {
|
|
$subscriptions[] = $observable->subscribe($emit);
|
|
}
|
|
|
|
try {
|
|
$result = (yield all($observables));
|
|
} finally {
|
|
foreach ($subscriptions as $subscription) {
|
|
$subscription->unsubscribe();
|
|
}
|
|
}
|
|
|
|
yield Coroutine::result($result);
|
|
});
|
|
}
|
|
|
|
|
|
/**
|
|
* Creates an observable from the given array of awaitables, emitting the success value of each provided awaitable or
|
|
* failing if any awaitable fails.
|
|
*
|
|
* @param \Interop\Async\Awaitable[] $awaitables
|
|
*
|
|
* @return \Amp\Observable
|
|
*/
|
|
function stream(array $awaitables) {
|
|
$postponed = new Postponed;
|
|
|
|
if (empty($awaitables)) {
|
|
$postponed->resolve();
|
|
return $postponed->getObservable();
|
|
}
|
|
|
|
$pending = \count($awaitables);
|
|
$onResolved = function ($exception, $value) use (&$pending, $postponed) {
|
|
if ($pending <= 0) {
|
|
return;
|
|
}
|
|
|
|
if ($exception) {
|
|
$pending = 0;
|
|
$postponed->fail($exception);
|
|
return;
|
|
}
|
|
|
|
$postponed->emit($value);
|
|
|
|
if (--$pending === 0) {
|
|
$postponed->complete();
|
|
}
|
|
};
|
|
|
|
foreach ($awaitables as $awaitable) {
|
|
if (!$awaitable instanceof Awaitable) {
|
|
throw new \InvalidArgumentException("Non-awaitable provided");
|
|
}
|
|
|
|
$awaitable->when($onResolved);
|
|
}
|
|
|
|
return $postponed->getObservable();
|
|
}
|
|
|
|
/**
|
|
* Concatenates the given observables into a single observable, emitting values from a single observable at a time. The
|
|
* prior observable must complete before values are emitted from any subsequent observable. Observables are concatenated
|
|
* in the order given (iteration order of the array).
|
|
*
|
|
* @param array $observables
|
|
*
|
|
* @return \Amp\Observable
|
|
*/
|
|
function concat(array $observables) {
|
|
foreach ($observables as $observable) {
|
|
if (!$observable instanceof Observable) {
|
|
throw new \InvalidArgumentException("Non-observable provided");
|
|
}
|
|
}
|
|
|
|
return new Emitter(function (callable $emit) use ($observables) {
|
|
$subscriptions = [];
|
|
$previous = [];
|
|
$awaitable = all($previous);
|
|
|
|
foreach ($observables as $observable) {
|
|
$subscriptions[] = $observable->subscribe(coroutine(function ($value) use ($emit, $awaitable) {
|
|
try {
|
|
yield $awaitable;
|
|
} catch (\Throwable $exception) {
|
|
// Ignore exception in this context.
|
|
} catch (\Exception $exception) {
|
|
// Ignore exception in this context.
|
|
}
|
|
|
|
yield Coroutine::result(yield $emit($value));
|
|
}));
|
|
$previous[] = $observable;
|
|
$awaitable = all($previous);
|
|
}
|
|
|
|
try {
|
|
$result = (yield $awaitable);
|
|
} finally {
|
|
foreach ($subscriptions as $subscription) {
|
|
$subscription->unsubscribe();
|
|
}
|
|
}
|
|
|
|
yield Coroutine::result($result);
|
|
});
|
|
}
|
|
|
|
/**
|
|
* Returns an observable that emits a value every $interval milliseconds after (up to $count times). The value emitted
|
|
* is an integer of the number of times the observable emitted a value.
|
|
*
|
|
* @param int $interval Time interval between emitted values in milliseconds.
|
|
* @param int $count Number of values to emit. PHP_INT_MAX by default.
|
|
*
|
|
* @return \Amp\Observable
|
|
*/
|
|
function interval($interval, $count = PHP_INT_MAX) {
|
|
$count = (int) $count;
|
|
if (0 >= $count) {
|
|
throw new \InvalidArgumentException("The number of times to emit must be a positive value");
|
|
}
|
|
|
|
$postponed = new Postponed;
|
|
|
|
Loop::repeat($interval, function ($watcher) use (&$i, $postponed, $count) {
|
|
$postponed->emit(++$i);
|
|
|
|
if ($i === $count) {
|
|
Loop::cancel($watcher);
|
|
$postponed->resolve();
|
|
}
|
|
});
|
|
|
|
return $postponed->getObservable();
|
|
}
|
|
|
|
/**
|
|
* @param int $start
|
|
* @param int $end
|
|
* @param int $step
|
|
*
|
|
* @return \Amp\Observable
|
|
*/
|
|
function range($start, $end, $step = 1) {
|
|
$start = (int) $start;
|
|
$end = (int) $end;
|
|
$step = (int) $step;
|
|
|
|
if (0 === $step) {
|
|
throw new \InvalidArgumentException("Step must be a non-zero integer");
|
|
}
|
|
|
|
if ((($end - $start) ^ $step) < 0) {
|
|
throw new \InvalidArgumentException("Step is not of the correct sign");
|
|
}
|
|
|
|
return new Emitter(function (callable $emit) use ($start, $end, $step) {
|
|
for ($i = $start; $i <= $end; $i += $step) {
|
|
yield $emit($i);
|
|
}
|
|
});
|
|
}
|