Removed `full-drain` event from Buffer

[akadlec]

Hello. I have a small problem after upgrade to latest version of reactphp/socket an event on buffer is missing. In previous version there was event full-drain. I use this event to fire handlers after data are completly sent to stream.

So is there some other way how to listen on simillar event? Right now i have patched actual buffer class React\Stream\Buffer:

    public function handleWrite()
    {
        $error = null;
        set_error_handler(function ($errno, $errstr, $errfile, $errline) use (&$error) {
            $error = array(
                'message' => $errstr,
                'number' => $errno,
                'file' => $errfile,
                'line' => $errline
            );
        });

        $sent = fwrite($this->stream, $this->data);

        restore_error_handler();

        // Only report errors if *nothing* could be sent.
        // Any hard (permanent) error will fail to send any data at all.
        // Sending excessive amounts of data will only flush *some* data and then
        // report a temporary error (EAGAIN) which we do not raise here in order
        // to keep the stream open for further tries to write.
        // Should this turn out to be a permanent error later, it will eventually
        // send *nothing* and we can detect this.
        if ($sent === 0 || $sent === false) {
            if ($error === null) {
                $error = new \RuntimeException('Send failed');
            } else {
                $error = new \ErrorException(
                    $error['message'],
                    0,
                    $error['number'],
                    $error['file'],
                    $error['line']
                );
            }

            $this->emit('error', array(new \RuntimeException('Unable to write to stream: ' . $error->getMessage(), 0, $error)));
            $this->close();

            return;
        }

        $exceeded = isset($this->data[$this->softLimit - 1]);
        $this->data = (string) substr($this->data, $sent);

        // buffer has been above limit and is now below limit
        if ($exceeded && !isset($this->data[$this->softLimit - 1])) {
            $this->emit('drain');
        }

        // buffer is now completely empty => stop trying to write
        if ($this->data === '') {
            // stop waiting for resource to be writable
            if ($this->listening) {
                $this->loop->removeWriteStream($this->stream);
                $this->listening = false;

                $this->emit('full-drain', array($this));
            }

            // buffer is end()ing and now completely empty => close buffer
            if (!$this->writable) {
                $this->close();
            }
        }
    }

added $this->emit('full-drain', array($this));

[clue]

Thanks for reporting this!

The full-drain event has been removed via reactphp/stream#63 recently.

Can you give us some background (gist?) on what you need this event for? Thanks!

[akadlec]

So, i'm implementing package binsoul/net-mqtt-client-react and this package create client connection to server: https://github.com/binsoul/net-mqtt-client-react/blob/master/src/ReactMqttClient.php

The flow is:
connect to server - send data (socket:write) - after data transfer finished wait for response

[akadlec]

I could solve it on my side, but there will be edgecases when transfering data will took too long.

[clue]

The flow is:
connect to server - send data (socket:write) - after data transfer finished wait for response

Can you show a very simple gist of this and why this requires a full-drain event? It's my understanding that data can be received at ANY time, i.e. the data event could also be emitted while your buffer is flushing, in case it contains multiple pipelined higher-level "messages".

[…] there will be edgecases when transfering data will took too long.

Care to elaborate?

[clue]

I'm closing this for now as it hasn't received any input in a while and I believe this has been answered. Please come back with more details if this problem persists and we can reopen this 👍

[akadlec]

Hi @clue i am back to work on this issue :/ I have upgraded to latest version of reactphp/socket and reactphp/strem but still have no idea how to solve missing event full-drain

My example of usage:

$this->establishConnection()
	->then(function (Socket\ConnectionInterface $connectionStream) {
	...
	$connectionStream->write($packet);
	...
	$connectionStream->on('full-drain', function () {
		$this->streamListening = FALSE;

		$this->handleSend();
	});
	...
	});

In my case, full-drain event is used to notify script that all data has been sent (packet) and newly received packet is the right one

[akadlec]

lets keep it closed, i solved it :)

[WyriHaximus]

@akadlec for future reference for others, what was the cause of your issue and what was the solution?

[akadlec]

As was written earlier, my script needed to know when transfer of packet to server was finished. So i solved on my side with easy check, so now i could operate without buffer event