WebSocketClient::WebSocketClient Class Reference

the main websocket client class More...

Public Member Methods
	clearStats ()
	Clears performance statistics. More...
nothing	clearWarningQueue ()
	Removes any warning Queue object from the Socket. More...
hash	connect (*hash opts, *reference< hash > info)
	connects to the websocket server More...
	constructor (code cb, hash opts)
	creates the object and optionally sets logging targets More...
	destructor ()
	disconnects the connection and stops the event thread if connected
	disconnect (int cmd=WSCC_GoingAway)
	disconnect with the given close code
int	getConnectionId ()
	returns the unique connection ID
hash	getSchemes ()
	returns a hash of URL scheme information for URL schemes supported by this object
string	getUrl ()
	returns the URL given in the constructor
hash< auto >	getUsageInfo ()
	Returns performance statistics for the socket. More...
bool	isOpen ()
	returns True if the connection is currently open and active, False if not
	pong ()
	Sends a PONG message to the server as a unidirectional keep-alive message. More...
	send (string str)
	Sends string data over the web socket with timeout specified in options; if any errors occur, an exception is thrown. More...
	send (binary bin)
	Sends binary data over the web socket with timeout specified in options; if any errors occur, an exception is thrown. More...
	setEventQueue (Qore::Thread::Queue queue, auto arg, *bool with_data)
	Sets a Queue object to receive socket events. More...
	setEventQueue ()
	Removes any Queue object so that socket events are no longer added to the Queue. More...
nothing	setWarningQueue (int warning_ms, int warning_bs, Queue queue, auto arg, timeout min_ms=1s)
	Sets a Queue object to receive socket warnings. More...

Public Attributes
const	DefaultTimeout = 15s
	default socket I/O operation timeout: 15 seconds
const	DefaultUserAgent = sprintf("Qore-WebSocketClient/%s", WebSocketClient::Version)
	default user agent string for HTTP requests
const	Version = "1.6"
	module version

Private Attributes
int	cid = -1
	unique websocket connection ID; -1 when not connected
string	url
	URL string.
*code	yield
	callable object to yield the current thread's execution

Detailed Description

the main websocket client class

To use this class, create a WebSocketClient object and the call WebSocketClient::connect().

The WebSocketClient::connect() method starts a background thread to receive messages, which are then posted to the callback provided in the WebSocketClient::constructor().

To stop listening for web socket events, call WebSocketClient::disconnect().

The WebSocketClient class includes support for running in sandboxed Program objects with the following parse options set:

• PO_NO_PROCESS_CONTROL: in this case the "yield" option is required in WebSocketClient::constructor()

Member Function Documentation

clearStats()

WebSocketClient::WebSocketClient::clearStats

(

)

Clears performance statistics.

Example:

ws.clearStats();

Since

WebSocketClient 1.1

See also

WebSocketClient::getUsageInfo()

clearWarningQueue()

nothing WebSocketClient::WebSocketClient::clearWarningQueue

(

)

Removes any warning Queue object from the Socket.

Example:

ws.clearWarningQueue();

See also

WebSocketClient::setWarningQueue()

Since

WebSocketClient 1.1

connect()

hash WebSocketClient::WebSocketClient::connect	(	*hash	opts,
		*reference< hash >	info
	)

connects to the websocket server

Example:

sub event(*data msg) {
    if (!msg)
        printf("connection closed\n");
    else
        printf("%s msg: %y\n", now_us().format("YYYY-MM-DD HH:mm:SS.xx"), msg);
}
WebSocketClient ws(("url": "ws://example.com:8080/path", "callback": \event()));
ws.connect();

This method starts a background thread to receive messages, which are then posted to the callback closure or call reference given as an argument. If the server disconnects the web socket connection, the callback will be called with no argument (ie NOTHING). In this case the event thread also terminates and the WebSocketClient object will be in a disconnected state.

To stop listening for web socket events, call WebSocketClient::disconnect().

If this method is called while a connection is already in progress, then the existing connection is first implicitly disconnected with close code WSCC_GoingAway.

Parameters

opts	a hash with the following keys: hdr: (optional) a hash giving header values for the connection request to the web socket server
info	a reference to a hash which will be set to information about the call setup

Returns

a hash with information about the HTTP response from the webn socket server corresponding to the return value of Qore::Socket::readHTTPHeader()

Exceptions

WEBSOCKET-ERROR

the option hash is missing either the 'url' or 'callback' keys or type error in the option hash

constructor()

WebSocketClient::WebSocketClient::constructor	(	code	cb,
		hash	opts
	)

creates the object and optionally sets logging targets

Example:

sub event(*data msg) {
    if (!msg)
        printf("connection closed\n");
    else
        printf("%s msg: %y\n", now_us().format("YYYY-MM-DD HH:mm:SS.xx"), msg);
}
WebSocketClient ws(\event(), ("url": "ws://example.com:8080/path"));

Parameters

cb

the callback closure or call reference for received messages

opts

an option hash for the HTTPClient constructor plus the following keys: log: an optional closure or call reference for informational logging errlog: an optional closure or call reference for error logging debuglog: an optional closure or call reference for logging debugging/technical messages about the web socket connection yield: an options closure or call reference for yielding the current thread's execution to another thread (default value: Qore::Threads::thread_yield()); required if Qore::PO_NO_PROCESS_CONTROL is set in the current execution context

Exceptions

WEBSOCKET-ERROR

unknown scheme, missing 'url' key in option hash; invalid option value

Since

WebSocketClient 1.6 added the yield option

getUsageInfo()

hash<auto> WebSocketClient::WebSocketClient::getUsageInfo

(

)

Returns performance statistics for the socket.

Example:

hash<auto> h = ws.getUsageInfo();

Returns

a hash with the following keys:

• "bytes_sent": an integer giving the total amount of bytes sent
• "bytes_recv": an integer giving the total amount of bytes received
• "us_sent": an integer giving the total number of microseconds spent sending data
• "us_recv": an integer giving the total number of microseconds spent receiving data
• "arg": (only if warning values have been set with WebSocketClient::setWarningQueue()) the optional argument for warning hashes
• "timeout": (only if warning values have been set with WebSocketClient::setWarningQueue()) the warning timeout in microseconds
• "min_throughput": (only if warning values have been set with WebSocketClient::setWarningQueue()) the minimum warning throughput in bytes/sec

Since

WebSocketClient 1.1

See also

WebSocketClient::clearStats()

pong()

WebSocketClient::WebSocketClient::pong

(

)

Sends a PONG message to the server as a unidirectional keep-alive message.

Since

WebSocketClient 1.6.1

send() [1/2]

WebSocketClient::WebSocketClient::send

(

string

str

)

Sends string data over the web socket with timeout specified in options; if any errors occur, an exception is thrown.

Parameters

str	Sends the string data over the socket

See also

Socket::send()

send() [2/2]

WebSocketClient::WebSocketClient::send

(

binary

bin

)

Sends binary data over the web socket with timeout specified in options; if any errors occur, an exception is thrown.

Parameters

bin	Sends the binary data over the socket

See also

Socket::send()

setEventQueue() [1/2]

WebSocketClient::WebSocketClient::setEventQueue	(	Qore::Thread::Queue	queue,
		auto	arg,
		*bool	with_data
	)

Sets a Queue object to receive socket events.

Example:

ws.setEventQueue(queue);

Parameters

queue	the Queue object to receive socket events; note that the Queue passed cannot have any maximum size set or a QUEUE-ERROR will be thrown
arg	an argument that will be included in each event hash in the arg key
with_data	if True, then the actual raw data transferred / received is also included in the events

Exceptions

QUEUE-ERROR

the Queue passed has a maximum size set

See also

I/O Event Handling for more information

Since

WebSocketClient 1.8

setEventQueue() [2/2]

WebSocketClient::WebSocketClient::setEventQueue

(

)

Removes any Queue object so that socket events are no longer added to the Queue.

Example:

ws.setEventQueue();

See also

I/O Event Handling for more information

Since

WebSocketClient 1.8

setWarningQueue()

nothing WebSocketClient::WebSocketClient::setWarningQueue	(	int	warning_ms,
		int	warning_bs,
		Queue	queue,
		auto	arg,
		timeout	min_ms = 1s
	)

Sets a Queue object to receive socket warnings.

Example:

ws.setWarningQueue(5000, 5000, queue, "socket-1");

Parameters

warning_ms	the threshold in milliseconds for individual socket actions (send, receive, connect), if exceeded, a socket warning is placed on the warning queue with the following keys: "type": a string with the constant value "SOCKET-OPERATION-WARNING" "operation": a string giving the operation that caused the warning (ex: "connect") "us": an integer giving the number of microseconds for the operation "timeout": an integer giving the warning threshold in microseconds "arg": if any "arg" argument is passed to the WebSocketClient::setWarningQueue() method, it will be included in the warning hash here
warning_bs	value in bytes per second; if any call has performance below this threshold, a socket warning is placed on the warning queue with the following keys: "type": a string with the constant value "SOCKET-THROUGHPUT-WARNING" "dir": either "send" or "recv" depending on the direction of the data flow "bytes": the amount of bytes sent "us": an integer giving the number of microseconds for the operation "bytes_sec": a float giving the transfer speed in bytes per second "threshold": an integer giving the warning threshold in bytes per second "arg": if any "arg" argument is passed to the WebSocketClient::setWarningQueue() method, it will be included in the warning hash here
queue	the Queue object to receive warning events
arg	an optional argument to be placed in the "arg" key in each warning hash (could be used to identify the socket for example)
min_ms	the minimum transfer time with a resolution of milliseconds for a transfer to be eligible for triggering a warning; transfers that take less than this period of time are not eligible for raising a warning

Exceptions

QUEUE-ERROR	the Queue passed has a maximum size set
SOCKET-SETWARNINGQUEUE-ERROR	at least one of warning_ms and warning_bs must be > 0

See also

WebSocketClient::clearWarningQueue()

Since

WebSocketClient 1.1