Class DuplexResourceStream

The DuplexStreamInterface is responsible for providing an interface for duplex streams (both readable and writable).

It builds on top of the existing interfaces for readable and writable streams and follows the exact same method and event semantics. If you're new to this concept, you should look into the ReadableStreamInterface and WritableStreamInterface first.

Besides defining a few methods, this interface also implements the EventEmitterInterface which allows you to react to the same events defined on the ReadbleStreamInterface and WritableStreamInterface.

Evenement\EventEmitter implements Evenement\EventEmitterInterface uses Evenement\EventEmitterTrait

React\Stream\DuplexResourceStream implements React\Stream\DuplexStreamInterface

Namespace: React\Stream
See: React\Stream\ReadableStreamInterface
See: React\Stream\WritableStreamInterface
Located at DuplexResourceStream.php

Methods summary
`public`	# `__construct( mixed $stream, React\EventLoop\LoopInterface $loop, React\Stream\WritableStreamInterface $buffer = null )`
`public boolean`	# `isReadable( )` Checks whether this stream is in a readable state (not closed already). Checks whether this stream is in a readable state (not closed already). This method can be used to check if the stream still accepts incoming data events or if it is ended or closed already. Once the stream is non-readable, no further `data` or `end` events SHOULD be emitted. `php assert($stream->isReadable() === false); $stream->on('data', assertNeverCalled()); $stream->on('end', assertNeverCalled()); ` A successfully opened stream always MUST start in readable mode. Once the stream ends or closes, it MUST switch to non-readable mode. This can happen any time, explicitly through `close()` or implicitly due to a remote close or an unrecoverable transmission error. Once a stream has switched to non-readable mode, it MUST NOT transition back to readable mode. If this stream is a `DuplexStreamInterface`, you should also notice how the writable side of the stream also implements an `isWritable()` method. Unless this is a half-open duplex stream, they SHOULD usually have the same return value. Returns `boolean` Implementation of `React\Stream\ReadableStreamInterface::isReadable()`
`public boolean`	# `isWritable( )` Checks whether this stream is in a writable state (not closed already). Checks whether this stream is in a writable state (not closed already). This method can be used to check if the stream still accepts writing any data or if it is ended or closed already. Writing any data to a non-writable stream is a NO-OP: `php assert($stream->isWritable() === false); $stream->write('end'); // NO-OP $stream->end('end'); // NO-OP ` A successfully opened stream always MUST start in writable mode. Once the stream ends or closes, it MUST switch to non-writable mode. This can happen any time, explicitly through `end()` or `close()` or implicitly due to a remote close or an unrecoverable transmission error. Once a stream has switched to non-writable mode, it MUST NOT transition back to writable mode. If this stream is a `DuplexStreamInterface`, you should also notice how the readable side of the stream also implements an `isReadable()` method. Unless this is a half-open duplex stream, they SHOULD usually have the same return value. Returns `boolean` Implementation of `React\Stream\WritableStreamInterface::isWritable()`
`public`	# `pause( )` Pauses reading incoming data events. Pauses reading incoming data events. Removes the data source file descriptor from the event loop. This allows you to throttle incoming data. Unless otherwise noted, a successfully opened stream SHOULD NOT start in paused state. Once the stream is paused, no futher `data` or `end` events SHOULD be emitted. `php $stream->pause(); $stream->on('data', assertShouldNeverCalled()); $stream->on('end', assertShouldNeverCalled()); ` This method is advisory-only, though generally not recommended, the stream MAY continue emitting `data` events. You can continue processing events by calling `resume()` again. Note that both methods can be called any number of times, in particular calling `pause()` more than once SHOULD NOT have any effect. See `React\Stream\DuplexResourceStream::resume()` Implementation of `React\Stream\ReadableStreamInterface::pause()`
`public`	# `resume( )` Resumes reading incoming data events. Resumes reading incoming data events. Re-attach the data source after a previous `pause()`. `php $stream->pause(); $loop->addTimer(1.0, function () use ($stream) { $stream->resume(); }); ` Note that both methods can be called any number of times, in particular calling `resume()` without a prior `pause()` SHOULD NOT have any effect. See `React\Stream\DuplexResourceStream::pause()` Implementation of `React\Stream\ReadableStreamInterface::resume()`
`public boolean`	# `write( mixed\|string $data )` Write some data into the stream. Write some data into the stream. A successful write MUST be confirmed with a boolean `true`, which means that either the data was written (flushed) immediately or is buffered and scheduled for a future write. Note that this interface gives you no control over explicitly flushing the buffered data, as finding the appropriate time for this is beyond the scope of this interface and left up to the implementation of this interface. Many common streams (such as a TCP/IP connection or file-based stream) may choose to buffer all given data and schedule a future flush by using an underlying EventLoop to check when the resource is actually writable. If a stream cannot handle writing (or flushing) the data, it SHOULD emit an `error` event and MAY `close()` the stream if it can not recover from this error. If the internal buffer is full after adding `$data`, then `write()` SHOULD return `false`, indicating that the caller should stop sending data until the buffer drains. The stream SHOULD send a `drain` event once the buffer is ready to accept more data. Similarly, if the the stream is not writable (already in a closed state) it MUST NOT process the given `$data` and SHOULD return `false`, indicating that the caller should stop sending data. The given `$data` argument MAY be of mixed type, but it's usually recommended it SHOULD be a `string` value or MAY use a type that allows representation as a `string` for maximum compatibility. Many common streams (such as a TCP/IP connection or a file-based stream) will only accept the raw (binary) payload data that is transferred over the wire as chunks of `string` values. Due to the stream-based nature of this, the sender may send any number of chunks with varying sizes. There are no guarantees that these chunks will be received with the exact same framing the sender intended to send. In other words, many lower-level protocols (such as TCP/IP) transfer the data in chunks that may be anywhere between single-byte values to several dozens of kilobytes. You may want to apply a higher-level protocol to these low-level data chunks in order to achieve proper message framing. Parameters `$data` `mixed\|string` $data Returns `boolean` Implementation of `React\Stream\WritableStreamInterface::write()`
`public`	# `close( )` Closes the stream (forcefully). Closes the stream (forcefully). This method can be used to (forcefully) close the stream. `php $stream->close(); ` Once the stream is closed, it SHOULD emit a `close` event. Note that this event SHOULD NOT be emitted more than once, in particular if this method is called multiple times. After calling this method, the stream MUST switch into a non-readable mode, see also `isReadable()`. This means that no further `data` or `end` events SHOULD be emitted. `php $stream->close(); assert($stream->isReadable() === false); $stream->on('data', assertNeverCalled()); $stream->on('end', assertNeverCalled()); ` If this stream is a `DuplexStreamInterface`, you should also notice how the writable side of the stream also implements a `close()` method. In other words, after calling this method, the stream MUST switch into non-writable AND non-readable mode, see also `isWritable()`. Note that this method should not be confused with the `end()` method. See `React\Stream\WritableStreamInterface::close()` Implementation of `React\Stream\ReadableStreamInterface::close()`
`public`	# `end( mixed\|string\|null $data = null )` Successfully ends the stream (after optionally sending some final data). Successfully ends the stream (after optionally sending some final data). This method can be used to successfully end the stream, i.e. close the stream after sending out all data that is currently buffered. `php $stream->write('hello'); $stream->write('world'); $stream->end(); ` If there's no data currently buffered and nothing to be flushed, then this method MAY `close()` the stream immediately. If there's still data in the buffer that needs to be flushed first, then this method SHOULD try to write out this data and only then `close()` the stream. Once the stream is closed, it SHOULD emit a `close` event. Note that this interface gives you no control over explicitly flushing the buffered data, as finding the appropriate time for this is beyond the scope of this interface and left up to the implementation of this interface. Many common streams (such as a TCP/IP connection or file-based stream) may choose to buffer all given data and schedule a future flush by using an underlying EventLoop to check when the resource is actually writable. You can optionally pass some final data that is written to the stream before ending the stream. If a non-`null` value is given as `$data`, then this method will behave just like calling `write($data)` before ending with no data. `php // shorter version $stream->end('bye'); // same as longer version $stream->write('bye'); $stream->end(); ` After calling this method, the stream MUST switch into a non-writable mode, see also `isWritable()`. This means that no further writes are possible, so any additional `write()` or `end()` calls have no effect. `php $stream->end(); assert($stream->isWritable() === false); $stream->write('nope'); // NO-OP $stream->end(); // NO-OP ` If this stream is a `DuplexStreamInterface`, calling this method SHOULD also end its readable side, unless the stream supports half-open mode. In other words, after calling this method, these streams SHOULD switch into non-writable AND non-readable mode, see also `isReadable()`. This implies that in this case, the stream SHOULD NOT emit any `data` or `end` events anymore. Streams MAY choose to use the `pause()` method logic for this, but special care may have to be taken to ensure a following call to the `resume()` method SHOULD NOT continue emitting readable events. Note that this method should not be confused with the `close()` method. Parameters `$data` `mixed\|string\|null` $data Implementation of `React\Stream\WritableStreamInterface::end()`
`public React\Stream\WritableStreamInterface`	# `pipe( React\Stream\WritableStreamInterface $dest, array $options = array() )` Pipes all the data from this readable source into the given writable destination. Pipes all the data from this readable source into the given writable destination. Automatically sends all incoming data to the destination. Automatically throttles the source based on what the destination can handle. `php $source->pipe($dest); ` Similarly, you can also pipe an instance implementing `DuplexStreamInterface` into itself in order to write back all the data that is received. This may be a useful feature for a TCP/IP echo service: `php $connection->pipe($connection); ` This method returns the destination stream as-is, which can be used to set up chains of piped streams: `php $source->pipe($decodeGzip)->pipe($filterBadWords)->pipe($dest); ` By default, this will call `end()` on the destination stream once the source stream emits an `end` event. This can be disabled like this: `php $source->pipe($dest, array('end' => false)); ` Note that this only applies to the `end` event. If an `error` or explicit `close` event happens on the source stream, you'll have to manually close the destination stream: `php $source->pipe($dest); $source->on('close', function () use ($dest) { $dest->end('BYE!'); }); ` If the source stream is not readable (closed state), then this is a NO-OP. `php $source->close(); $source->pipe($dest); // NO-OP ` If the destinantion stream is not writable (closed state), then this will simply throttle (pause) the source stream: `php $dest->close(); $source->pipe($dest); // calls $source->pause() ` Similarly, if the destination stream is closed while the pipe is still active, it will also throttle (pause) the source stream: `php $source->pipe($dest); $dest->close(); // calls $source->pause() ` Once the pipe is set up successfully, the destination stream MUST emit a `pipe` event with this source stream an event argument. Parameters `$dest` `React\Stream\WritableStreamInterface` $dest `$options` `array` $options Returns `React\Stream\WritableStreamInterface` $dest stream as-is Implementation of `React\Stream\ReadableStreamInterface::pipe()`
`public`	# `handleData( mixed $stream )`
`public`	# `handleClose( )`
`public React\Stream\WritableStreamInterface`	# `getBuffer( )` Returns `React\Stream\WritableStreamInterface`

Methods inherited from Evenement\EventEmitterInterface
`emit(), listeners(), on(), once(), removeAllListeners(), removeListener()`

Methods used from Evenement\EventEmitterTrait
`(), (), (), (), (), ()`

Properties summary
`public integer\|null`	`$bufferSize`	`65536`	# Controls the maximum buffer size in bytes to read at once from the stream. Controls the maximum buffer size in bytes to read at once from the stream. This can be a positive number which means that up to X bytes will be read at once from the underlying stream resource. Note that the actual number of bytes read may be lower if the stream resource has less than X bytes currently available. This can be `null` which means read everything available from the underlying stream resource. This should read until the stream resource is not readable anymore (i.e. underlying buffer drained), note that this does not neccessarily mean it reached EOF.
`public mixed`	`$stream`		#
`protected boolean`	`$readable`	`true`	#
`protected boolean`	`$writable`	`true`	#
`protected boolean`	`$closing`	`false`	#
`protected mixed`	`$loop`		#
`protected mixed`	`$buffer`		#

Properties used from Evenement\EventEmitterTrait
`$listeners`

Namespaces

Classes

Interfaces

Class DuplexResourceStream

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