SleekXMPP/sleekxmpp/test/livesocket.py

"""
    SleekXMPP: The Sleek XMPP Library
    Copyright (C) 2010 Nathanael C. Fritz, Lance J.T. Stout
    This file is part of SleekXMPP.

    See the file LICENSE for copying permission.
"""

import socket
import threading
try:
    import queue
except ImportError:
    import Queue as queue


class TestLiveSocket(object):

    """
    A live test socket that reads and writes to queues in
    addition to an actual networking socket.

    Methods:
        next_sent -- Return the next sent stanza.
        next_recv -- Return the next received stanza.
        recv_data -- Dummy method to have same interface as TestSocket.
        recv      -- Read the next stanza from the socket.
        send      -- Write a stanza to the socket.
        makefile  -- Dummy call, returns self.
        read      -- Read the next stanza from the socket.
    """

    def __init__(self, *args, **kwargs):
        """
        Create a new, live test socket.

        Arguments:
            Same as arguments for socket.socket
        """
        self.socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        self.recv_buffer = []
        self.recv_queue = queue.Queue()
        self.send_queue = queue.Queue()
        self.send_queue_lock = threading.Lock()
        self.recv_queue_lock = threading.Lock()
        self.is_live = True

    def __getattr__(self, name):
        """
        Return attribute values of internal, live socket.

        Arguments:
            name -- Name of the attribute requested.
        """

        return getattr(self.socket, name)

    # ------------------------------------------------------------------
    # Testing Interface

    def disconnect_errror(self):
        """
        Used to simulate a socket disconnection error.

        Not used by live sockets.
        """
        try:
            self.socket.shutdown()
            self.socket.close()
        except:
            pass

    def next_sent(self, timeout=None):
        """
        Get the next stanza that has been sent.

        Arguments:
            timeout -- Optional timeout for waiting for a new value.
        """
        args = {'block': False}
        if timeout is not None:
            args = {'block': True, 'timeout': timeout}
        try:
            return self.send_queue.get(**args)
        except:
            return None

    def next_recv(self, timeout=None):
        """
        Get the next stanza that has been received.

        Arguments:
            timeout -- Optional timeout for waiting for a new value.
        """
        args = {'block': False}
        if timeout is not None:
            args = {'block': True, 'timeout': timeout}
        try:
            if self.recv_buffer:
                return self.recv_buffer.pop(0)
            else:
                return self.recv_queue.get(**args)
        except:
            return None

    def recv_data(self, data):
        """
        Add data to a receive buffer for cases when more than a single stanza
        was received.
        """
        self.recv_buffer.append(data)

    # ------------------------------------------------------------------
    # Socket Interface

    def recv(self, *args, **kwargs):
        """
        Read data from the socket.

        Store a copy in the receive queue.

        Arguments:
            Placeholders. Same as for socket.recv.
        """
        data = self.socket.recv(*args, **kwargs)
        with self.recv_queue_lock:
            self.recv_queue.put(data)
        return data

    def send(self, data):
        """
        Send data on the socket.

        Store a copy in the send queue.

        Arguments:
            data -- String value to write.
        """
        with self.send_queue_lock:
            self.send_queue.put(data)
        self.socket.send(data)

    # ------------------------------------------------------------------
    # File Socket

    def makefile(self, *args, **kwargs):
        """
        File socket version to use with ElementTree.

        Arguments:
            Placeholders, same as socket.makefile()
        """
        return self

    def read(self, *args, **kwargs):
        """
        Implement the file socket read interface.

        Arguments:
            Placeholders, same as socket.recv()
        """
        return self.recv(*args, **kwargs)

    def clear(self):
        """
        Empty the send queue, typically done once the session has started to
        remove the feature negotiation and log in stanzas.
        """
        with self.send_queue_lock:
            for i in range(0, self.send_queue.qsize()):
                self.send_queue.get(block=False)
        with self.recv_queue_lock:
            for i in range(0, self.recv_queue.qsize()):
                self.recv_queue.get(block=False)