How to create an infinite loop for Clients?

[cristian-dan-f]

Hi,
please tell me how to keep the websocket client open and listening forever?

I ask this because I can only find $client->receive() which closes the socket.

I need something to keep getting data from the socket.

Thank you.

BTW: this is the first script that actually makes it easy to use websockets.

[arthurkushman]

Hi, I suppose, that the receiveFragment function only closes the socket connection iff there are close opcode frame sent from server, e.g.:

        if ($opcode === CommonsContract::EVENT_TYPE_CLOSE) {
            // Get the close status.
            if ($payloadLength >= 2) {
                $statusBin = $payload[0] . $payload[1];
                $status = bindec(sprintf('%08b%08b', ord($payload[0]), ord($payload[1])));
                $this->closeStatus = $status;
                $payload = substr($payload, 2);

                if (!$this->isClosing) {
                    $this->send($statusBin . 'Close acknowledged: ' . $status,
                        CommonsContract::EVENT_TYPE_CLOSE); // Respond.
                }
            }

            if ($this->isClosing) {
                $this->isClosing = false; // A close response, all done.
            }

            fclose($this->socket);
            $this->isConnected = false;
        }

when the messages is proceeding to send from server, then the client is still reading them, so the main point not only the client can initiate close connection, but either a server.

PS Please, if u claim something to discuss technically attach some examples, it will be faster and more efficiently.

[cristian-dan-f]

Thanks for answering. I have very litle knowledge about websockets.

This is what I do:

		set_time_limit(0);
		ob_implicit_flush();

		echo 'Initiating new websocket';

		$config = new ClientConfig();
		$config->setFragmentSize(8096);
		$config->setTimeout(15);

		$client = new WebSocketClient('wss://zkillboard.com/websocket/', $config);

		try{
			$client->send('{"action":"sub","channel":"killstream"}');
		}catch( \BadOpcodeException $e ){
            echo 'Couldn`t sent: ' . $e->getMessage();
        }

		echo $client->receive();

It works perfectly, but I only receive one message, and I do the same on:
https://websocketking.com/

wss://zkillboard.com/websocket/

{"action":"sub","channel":"killstream"}

and if you try it you will see is sending messages every few seconds.

What should I do to receive messages continuosly, not only one?

[cristian-dan-f]

if I try to put it in a loop like this:

$x = 0;
$status = true;
while( $status ){
	$x++;

	$json = $client->receive();
	//$json = $client->receiveFragment();// is protected
			
	$data = json_decode( $json, true);
			
	echo '<pre>';
	print_r( $data );
	echo '</pre>';
	echo '<br/>';
	echo 'End packet: '.$x.'<br/>';
			
	unset($json);
	unset($data);
			
	$status = $client->isConnected();

}

It will get me the first response, but it throws an error afterwards:

Fatal error: Uncaught WSSC\Exceptions\ConnectionException: Broken frame, read 0 of stated 2 bytes. Stream state: 
{
	"crypto":
	{
		"protocol":"TLSv1.2",
		"cipher_name":"ECDHE-ECDSA-AES128-GCM-SHA256",
		"cipher_bits":128,
		"cipher_version":"TLSv1.2"
	},
	"timed_out":true,
	"blocked":true,
	"eof":false,
	"stream_type":"tcp_socket\/ssl",
	"mode":"r+",
	"unread_bytes":0,
	"seekable":false
}
in /.../includes/php-wss/vendor/arthurkushman/php-wss/src/Components/WscMain.php:412 
Stack trace: 
#0 /.../includes/php-wss/vendor/arthurkushman/php-wss/src/Components/WSClientTrait.php(125): WSSC\Components\WscMain->read(2) 
#1 /.../includes/php-wss/vendor/arthurkushman/php-wss/src/Components/WscMain.php(350): WSSC\Components\WscMain->receiveFragment() 
#2 /.../abc.php(89): WSSC\Components\ in /.../includes/php-wss/vendor/arthurkushman/php-wss/src/Components/WscMain.php on line 412

Not sure what I am doing wrong.

[cristian-dan-f]

it says
"timed_out":true,
"blocked":true,
but is neither timed_out nor blocked, because is usualy arround 5 to 7 seconds and if I reload script it always gets the first message.

Is something else.

[cristian-dan-f]

I solved it. It is ugly and surely it can be improven.

I modified the read method in WcsMain.php line 404

    protected function read(int $len): string
    {
        $data = '';
	$start = time();
        while (($dataLen = strlen($data)) < $len) {
            $buff = fread($this->socket, $len - $dataLen);

            if ($buff === false ) {
                 if ( time() - $start > $this->config->getTimeout() ) {
                     $metadata = stream_get_meta_data($this->socket);
                     throw new ConnectionException(
                         'Broken frame, read ' . strlen($data) . ' of stated '
                         . $len . ' bytes.  Stream state: '
                         . json_encode($metadata),
                         CommonsContract::CLIENT_BROKEN_FRAME
                     );
                 }
            }else{
                 $start = time();
            }

            if ($buff === '') {
                 if ( time() - $start > $this->config->getTimeout() ) {
                      $metadata = stream_get_meta_data($this->socket);
                      throw new ConnectionException(
                          'Empty read; connection dead?  Stream state: ' . json_encode($metadata),
                          CommonsContract::CLIENT_EMPTY_READ
                      );
                 }
            }else{
                 $start = time();
            }
            $data .= $buff;
        }
        return $data;
    }

I added a timer
$start = time();
And if buffer is empty it will check against the specified timeout before throwing an Exception:
if ( time() - $start > $this->config->getTimeout() ) {

The counterpart is that it consumes 100% of CPU resources. I am on a AMD Ryzen 9 5950X 16-Core Processor and CPU goes to 100%

Hope this can be improven.