get_read_stream('foo'), * 'bar' => get_read_stream('bar'), * ]; * * foreach(IO\streaming($handles) as $type => $chunk) { * IO\write_line('received chunk "%s" from "%s" stream', $chunk, $type); * } * * @template T of array-key * * @param iterable $handles * * @throws Exception\AlreadyClosedException If one of the handles has been already closed. * @throws Exception\RuntimeException If an error occurred during the operation. * @throws Exception\TimeoutException If $timeout is reached before being able to read all the handles until the end. * * @return Generator */ function streaming(iterable $handles, ?float $timeout = null): Generator { /** * @psalm-suppress UnnecessaryVarAnnotation * * @var Channel\ReceiverInterface}> $receiver * @var Channel\SenderInterface}> $sender */ [$receiver, $sender] = Channel\unbounded(); /** @var Psl\Ref> $watchers */ $watchers = new Psl\Ref([]); foreach ($handles as $index => $handle) { $stream = $handle->getStream(); if ($stream === null) { throw new Exception\AlreadyClosedException(Str\format('Handle "%s" is already closed.', (string) $index)); } $watchers->value[$index] = EventLoop::onReadable($stream, static function (string $watcher) use ($index, $handle, $sender, $watchers): void { try { $result = Result\wrap($handle->tryRead(...)); if ($result->isFailed() || ($result->isSucceeded() && $result->getResult() === '')) { EventLoop::cancel($watcher); unset($watchers->value[$index]); } $sender->send([$index, $result]); } finally { if ($watchers->value === []) { $sender->close(); } } }); } $timeout_watcher = null; if ($timeout !== null) { $timeout_watcher = EventLoop::delay($timeout, static function () use ($sender): void { /** @var Result\ResultInterface $failure */ $failure = new Result\Failure( new Exception\TimeoutException('Reached timeout before being able to read all the handles until the end.') ); $sender->send([null, $failure]); }); } try { while (true) { [$index, $result] = $receiver->receive(); if (null === $index || $result->isFailed()) { throw $result->getThrowable(); } yield $index => $result->getResult(); } } catch (Channel\Exception\ClosedChannelException) { // completed. return; } finally { if ($timeout_watcher !== null) { EventLoop::cancel($timeout_watcher); } foreach ($watchers->value as $watcher) { EventLoop::cancel($watcher); } } }