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Diffstat (limited to 'vendor/react/stream/src/ThroughStream.php')
-rw-r--r-- | vendor/react/stream/src/ThroughStream.php | 190 |
1 files changed, 190 insertions, 0 deletions
diff --git a/vendor/react/stream/src/ThroughStream.php b/vendor/react/stream/src/ThroughStream.php new file mode 100644 index 0000000..6f73fb8 --- /dev/null +++ b/vendor/react/stream/src/ThroughStream.php @@ -0,0 +1,190 @@ +<?php + +namespace React\Stream; + +use Evenement\EventEmitter; +use InvalidArgumentException; + +/** + * The `ThroughStream` implements the + * [`DuplexStreamInterface`](#duplexstreaminterface) and will simply pass any data + * you write to it through to its readable end. + * + * ```php + * $through = new ThroughStream(); + * $through->on('data', $this->expectCallableOnceWith('hello')); + * + * $through->write('hello'); + * ``` + * + * Similarly, the [`end()` method](#end) will end the stream and emit an + * [`end` event](#end-event) and then [`close()`](#close-1) the stream. + * The [`close()` method](#close-1) will close the stream and emit a + * [`close` event](#close-event). + * Accordingly, this is can also be used in a [`pipe()`](#pipe) context like this: + * + * ```php + * $through = new ThroughStream(); + * $source->pipe($through)->pipe($dest); + * ``` + * + * Optionally, its constructor accepts any callable function which will then be + * used to *filter* any data written to it. This function receives a single data + * argument as passed to the writable side and must return the data as it will be + * passed to its readable end: + * + * ```php + * $through = new ThroughStream('strtoupper'); + * $source->pipe($through)->pipe($dest); + * ``` + * + * Note that this class makes no assumptions about any data types. This can be + * used to convert data, for example for transforming any structured data into + * a newline-delimited JSON (NDJSON) stream like this: + * + * ```php + * $through = new ThroughStream(function ($data) { + * return json_encode($data) . PHP_EOL; + * }); + * $through->on('data', $this->expectCallableOnceWith("[2, true]\n")); + * + * $through->write(array(2, true)); + * ``` + * + * The callback function is allowed to throw an `Exception`. In this case, + * the stream will emit an `error` event and then [`close()`](#close-1) the stream. + * + * ```php + * $through = new ThroughStream(function ($data) { + * if (!is_string($data)) { + * throw new \UnexpectedValueException('Only strings allowed'); + * } + * return $data; + * }); + * $through->on('error', $this->expectCallableOnce())); + * $through->on('close', $this->expectCallableOnce())); + * $through->on('data', $this->expectCallableNever())); + * + * $through->write(2); + * ``` + * + * @see WritableStreamInterface::write() + * @see WritableStreamInterface::end() + * @see DuplexStreamInterface::close() + * @see WritableStreamInterface::pipe() + */ +final class ThroughStream extends EventEmitter implements DuplexStreamInterface +{ + private $readable = true; + private $writable = true; + private $closed = false; + private $paused = false; + private $drain = false; + private $callback; + + public function __construct($callback = null) + { + if ($callback !== null && !\is_callable($callback)) { + throw new InvalidArgumentException('Invalid transformation callback given'); + } + + $this->callback = $callback; + } + + public function pause() + { + $this->paused = true; + } + + public function resume() + { + if ($this->drain) { + $this->drain = false; + $this->emit('drain'); + } + $this->paused = false; + } + + public function pipe(WritableStreamInterface $dest, array $options = array()) + { + return Util::pipe($this, $dest, $options); + } + + public function isReadable() + { + return $this->readable; + } + + public function isWritable() + { + return $this->writable; + } + + public function write($data) + { + if (!$this->writable) { + return false; + } + + if ($this->callback !== null) { + try { + $data = \call_user_func($this->callback, $data); + } catch (\Exception $e) { + $this->emit('error', array($e)); + $this->close(); + + return false; + } + } + + $this->emit('data', array($data)); + + if ($this->paused) { + $this->drain = true; + return false; + } + + return true; + } + + public function end($data = null) + { + if (!$this->writable) { + return; + } + + if (null !== $data) { + $this->write($data); + + // return if write() already caused the stream to close + if (!$this->writable) { + return; + } + } + + $this->readable = false; + $this->writable = false; + $this->paused = true; + $this->drain = false; + + $this->emit('end'); + $this->close(); + } + + public function close() + { + if ($this->closed) { + return; + } + + $this->readable = false; + $this->writable = false; + $this->closed = true; + $this->paused = true; + $this->drain = false; + $this->callback = null; + + $this->emit('close'); + $this->removeAllListeners(); + } +} |