added websocket backend, removed thrift

1 files changed, 755 insertions, 0 deletions

diff --git a/module/lib/mod_pywebsocket/_stream_hybi.py b/module/lib/mod_pywebsocket/_stream_hybi.py
new file mode 100644
index 000000000..34fa7a60e
--- /dev/null
+++ b/module/lib/mod_pywebsocket/_stream_hybi.py
@@ -0,0 +1,755 @@
+# Copyright 2012, Google Inc.
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+
+"""This file provides classes and helper functions for parsing/building frames
+of the WebSocket protocol (RFC 6455).
+
+Specification:
+http://tools.ietf.org/html/rfc6455
+"""
+
+
+from collections import deque
+import os
+import struct
+import time
+
+from mod_pywebsocket import common
+from mod_pywebsocket import util
+from mod_pywebsocket._stream_base import BadOperationException
+from mod_pywebsocket._stream_base import ConnectionTerminatedException
+from mod_pywebsocket._stream_base import InvalidFrameException
+from mod_pywebsocket._stream_base import InvalidUTF8Exception
+from mod_pywebsocket._stream_base import StreamBase
+from mod_pywebsocket._stream_base import UnsupportedFrameException
+
+
+_NOOP_MASKER = util.NoopMasker()
+
+
+class Frame(object):
+
+    def __init__(self, fin=1, rsv1=0, rsv2=0, rsv3=0,
+                 opcode=None, payload=''):
+        self.fin = fin
+        self.rsv1 = rsv1
+        self.rsv2 = rsv2
+        self.rsv3 = rsv3
+        self.opcode = opcode
+        self.payload = payload
+
+
+# Helper functions made public to be used for writing unittests for WebSocket
+# clients.
+
+
+def create_length_header(length, mask):
+    """Creates a length header.
+
+    Args:
+        length: Frame length. Must be less than 2^63.
+        mask: Mask bit. Must be boolean.
+
+    Raises:
+        ValueError: when bad data is given.
+    """
+
+    if mask:
+        mask_bit = 1 << 7
+    else:
+        mask_bit = 0
+
+    if length < 0:
+        raise ValueError('length must be non negative integer')
+    elif length <= 125:
+        return chr(mask_bit | length)
+    elif length < (1 << 16):
+        return chr(mask_bit | 126) + struct.pack('!H', length)
+    elif length < (1 << 63):
+        return chr(mask_bit | 127) + struct.pack('!Q', length)
+    else:
+        raise ValueError('Payload is too big for one frame')
+
+
+def create_header(opcode, payload_length, fin, rsv1, rsv2, rsv3, mask):
+    """Creates a frame header.
+
+    Raises:
+        Exception: when bad data is given.
+    """
+
+    if opcode < 0 or 0xf < opcode:
+        raise ValueError('Opcode out of range')
+
+    if payload_length < 0 or (1 << 63) <= payload_length:
+        raise ValueError('payload_length out of range')
+
+    if (fin | rsv1 | rsv2 | rsv3) & ~1:
+        raise ValueError('FIN bit and Reserved bit parameter must be 0 or 1')
+
+    header = ''
+
+    first_byte = ((fin << 7)
+                  | (rsv1 << 6) | (rsv2 << 5) | (rsv3 << 4)
+                  | opcode)
+    header += chr(first_byte)
+    header += create_length_header(payload_length, mask)
+
+    return header
+
+
+def _build_frame(header, body, mask):
+    if not mask:
+        return header + body
+
+    masking_nonce = os.urandom(4)
+    masker = util.RepeatedXorMasker(masking_nonce)
+
+    return header + masking_nonce + masker.mask(body)
+
+
+def _filter_and_format_frame_object(frame, mask, frame_filters):
+    for frame_filter in frame_filters:
+        frame_filter.filter(frame)
+
+    header = create_header(
+        frame.opcode, len(frame.payload), frame.fin,
+        frame.rsv1, frame.rsv2, frame.rsv3, mask)
+    return _build_frame(header, frame.payload, mask)
+
+
+def create_binary_frame(
+    message, opcode=common.OPCODE_BINARY, fin=1, mask=False, frame_filters=[]):
+    """Creates a simple binary frame with no extension, reserved bit."""
+
+    frame = Frame(fin=fin, opcode=opcode, payload=message)
+    return _filter_and_format_frame_object(frame, mask, frame_filters)
+
+
+def create_text_frame(
+    message, opcode=common.OPCODE_TEXT, fin=1, mask=False, frame_filters=[]):
+    """Creates a simple text frame with no extension, reserved bit."""
+
+    encoded_message = message.encode('utf-8')
+    return create_binary_frame(encoded_message, opcode, fin, mask,
+                               frame_filters)
+
+
+class FragmentedFrameBuilder(object):
+    """A stateful class to send a message as fragments."""
+
+    def __init__(self, mask, frame_filters=[]):
+        """Constructs an instance."""
+
+        self._mask = mask
+        self._frame_filters = frame_filters
+
+        self._started = False
+
+        # Hold opcode of the first frame in messages to verify types of other
+        # frames in the message are all the same.
+        self._opcode = common.OPCODE_TEXT
+
+    def build(self, message, end, binary):
+        if binary:
+            frame_type = common.OPCODE_BINARY
+        else:
+            frame_type = common.OPCODE_TEXT
+        if self._started:
+            if self._opcode != frame_type:
+                raise ValueError('Message types are different in frames for '
+                                 'the same message')
+            opcode = common.OPCODE_CONTINUATION
+        else:
+            opcode = frame_type
+            self._opcode = frame_type
+
+        if end:
+            self._started = False
+            fin = 1
+        else:
+            self._started = True
+            fin = 0
+
+        if binary:
+            return create_binary_frame(
+                message, opcode, fin, self._mask, self._frame_filters)
+        else:
+            return create_text_frame(
+                message, opcode, fin, self._mask, self._frame_filters)
+
+
+def _create_control_frame(opcode, body, mask, frame_filters):
+    frame = Frame(opcode=opcode, payload=body)
+
+    for frame_filter in frame_filters:
+        frame_filter.filter(frame)
+
+    if len(frame.payload) > 125:
+        raise BadOperationException(
+            'Payload data size of control frames must be 125 bytes or less')
+
+    header = create_header(
+        frame.opcode, len(frame.payload), frame.fin,
+        frame.rsv1, frame.rsv2, frame.rsv3, mask)
+    return _build_frame(header, frame.payload, mask)
+
+
+def create_ping_frame(body, mask=False, frame_filters=[]):
+    return _create_control_frame(common.OPCODE_PING, body, mask, frame_filters)
+
+
+def create_pong_frame(body, mask=False, frame_filters=[]):
+    return _create_control_frame(common.OPCODE_PONG, body, mask, frame_filters)
+
+
+def create_close_frame(body, mask=False, frame_filters=[]):
+    return _create_control_frame(
+        common.OPCODE_CLOSE, body, mask, frame_filters)
+
+
+class StreamOptions(object):
+    """Holds option values to configure Stream objects."""
+
+    def __init__(self):
+        """Constructs StreamOptions."""
+
+        # Enables deflate-stream extension.
+        self.deflate_stream = False
+
+        # Filters applied to frames.
+        self.outgoing_frame_filters = []
+        self.incoming_frame_filters = []
+
+        self.mask_send = False
+        self.unmask_receive = True
+
+
+class Stream(StreamBase):
+    """A class for parsing/building frames of the WebSocket protocol
+    (RFC 6455).
+    """
+
+    def __init__(self, request, options):
+        """Constructs an instance.
+
+        Args:
+            request: mod_python request.
+        """
+
+        StreamBase.__init__(self, request)
+
+        self._logger = util.get_class_logger(self)
+
+        self._options = options
+
+        if self._options.deflate_stream:
+            self._logger.debug('Setup filter for deflate-stream')
+            self._request = util.DeflateRequest(self._request)
+
+        self._request.client_terminated = False
+        self._request.server_terminated = False
+
+        # Holds body of received fragments.
+        self._received_fragments = []
+        # Holds the opcode of the first fragment.
+        self._original_opcode = None
+
+        self._writer = FragmentedFrameBuilder(
+            self._options.mask_send, self._options.outgoing_frame_filters)
+
+        self._ping_queue = deque()
+
+    def _receive_frame(self):
+        """Receives a frame and return data in the frame as a tuple containing
+        each header field and payload separately.
+
+        Raises:
+            ConnectionTerminatedException: when read returns empty
+                string.
+            InvalidFrameException: when the frame contains invalid data.
+        """
+
+        self._logger.log(common.LOGLEVEL_FINE,
+                         'Receive the first 2 octets of a frame')
+
+        received = self.receive_bytes(2)
+
+        first_byte = ord(received[0])
+        fin = (first_byte >> 7) & 1
+        rsv1 = (first_byte >> 6) & 1
+        rsv2 = (first_byte >> 5) & 1
+        rsv3 = (first_byte >> 4) & 1
+        opcode = first_byte & 0xf
+
+        second_byte = ord(received[1])
+        mask = (second_byte >> 7) & 1
+        payload_length = second_byte & 0x7f
+
+        self._logger.log(common.LOGLEVEL_FINE,
+                         'FIN=%s, RSV1=%s, RSV2=%s, RSV3=%s, opcode=%s, '
+                         'Mask=%s, Payload_length=%s',
+                         fin, rsv1, rsv2, rsv3, opcode, mask, payload_length)
+
+        if (mask == 1) != self._options.unmask_receive:
+            raise InvalidFrameException(
+                'Mask bit on the received frame did\'nt match masking '
+                'configuration for received frames')
+
+        # The Hybi-13 and later specs disallow putting a value in 0x0-0xFFFF
+        # into the 8-octet extended payload length field (or 0x0-0xFD in
+        # 2-octet field).
+        valid_length_encoding = True
+        length_encoding_bytes = 1
+        if payload_length == 127:
+            self._logger.log(common.LOGLEVEL_FINE,
+                             'Receive 8-octet extended payload length')
+
+            extended_payload_length = self.receive_bytes(8)
+            payload_length = struct.unpack(
+                '!Q', extended_payload_length)[0]
+            if payload_length > 0x7FFFFFFFFFFFFFFF:
+                raise InvalidFrameException(
+                    'Extended payload length >= 2^63')
+            if self._request.ws_version >= 13 and payload_length < 0x10000:
+                valid_length_encoding = False
+                length_encoding_bytes = 8
+
+            self._logger.log(common.LOGLEVEL_FINE,
+                             'Decoded_payload_length=%s', payload_length)
+        elif payload_length == 126:
+            self._logger.log(common.LOGLEVEL_FINE,
+                             'Receive 2-octet extended payload length')
+
+            extended_payload_length = self.receive_bytes(2)
+            payload_length = struct.unpack(
+                '!H', extended_payload_length)[0]
+            if self._request.ws_version >= 13 and payload_length < 126:
+                valid_length_encoding = False
+                length_encoding_bytes = 2
+
+            self._logger.log(common.LOGLEVEL_FINE,
+                             'Decoded_payload_length=%s', payload_length)
+
+        if not valid_length_encoding:
+            self._logger.warning(
+                'Payload length is not encoded using the minimal number of '
+                'bytes (%d is encoded using %d bytes)',
+                payload_length,
+                length_encoding_bytes)
+
+        if mask == 1:
+            self._logger.log(common.LOGLEVEL_FINE, 'Receive mask')
+
+            masking_nonce = self.receive_bytes(4)
+            masker = util.RepeatedXorMasker(masking_nonce)
+
+            self._logger.log(common.LOGLEVEL_FINE, 'Mask=%r', masking_nonce)
+        else:
+            masker = _NOOP_MASKER
+
+        self._logger.log(common.LOGLEVEL_FINE, 'Receive payload data')
+        if self._logger.isEnabledFor(common.LOGLEVEL_FINE):
+            receive_start = time.time()
+
+        raw_payload_bytes = self.receive_bytes(payload_length)
+
+        if self._logger.isEnabledFor(common.LOGLEVEL_FINE):
+            self._logger.log(
+                common.LOGLEVEL_FINE,
+                'Done receiving payload data at %s MB/s',
+                payload_length / (time.time() - receive_start) / 1000 / 1000)
+        self._logger.log(common.LOGLEVEL_FINE, 'Unmask payload data')
+
+        if self._logger.isEnabledFor(common.LOGLEVEL_FINE):
+            unmask_start = time.time()
+
+        bytes = masker.mask(raw_payload_bytes)
+
+        if self._logger.isEnabledFor(common.LOGLEVEL_FINE):
+            self._logger.log(
+                common.LOGLEVEL_FINE,
+                'Done unmasking payload data at %s MB/s',
+                payload_length / (time.time() - unmask_start) / 1000 / 1000)
+
+        return opcode, bytes, fin, rsv1, rsv2, rsv3
+
+    def _receive_frame_as_frame_object(self):
+        opcode, bytes, fin, rsv1, rsv2, rsv3 = self._receive_frame()
+
+        return Frame(fin=fin, rsv1=rsv1, rsv2=rsv2, rsv3=rsv3,
+                     opcode=opcode, payload=bytes)
+
+    def send_message(self, message, end=True, binary=False):
+        """Send message.
+
+        Args:
+            message: text in unicode or binary in str to send.
+            binary: send message as binary frame.
+
+        Raises:
+            BadOperationException: when called on a server-terminated
+                connection or called with inconsistent message type or
+                binary parameter.
+        """
+
+        if self._request.server_terminated:
+            raise BadOperationException(
+                'Requested send_message after sending out a closing handshake')
+
+        if binary and isinstance(message, unicode):
+            raise BadOperationException(
+                'Message for binary frame must be instance of str')
+
+        try:
+            self._write(self._writer.build(message, end, binary))
+        except ValueError, e:
+            raise BadOperationException(e)
+
+    def receive_message(self):
+        """Receive a WebSocket frame and return its payload as a text in
+        unicode or a binary in str.
+
+        Returns:
+            payload data of the frame
+            - as unicode instance if received text frame
+            - as str instance if received binary frame
+            or None iff received closing handshake.
+        Raises:
+            BadOperationException: when called on a client-terminated
+                connection.
+            ConnectionTerminatedException: when read returns empty
+                string.
+            InvalidFrameException: when the frame contains invalid
+                data.
+            UnsupportedFrameException: when the received frame has
+                flags, opcode we cannot handle. You can ignore this
+                exception and continue receiving the next frame.
+        """
+
+        if self._request.client_terminated:
+            raise BadOperationException(
+                'Requested receive_message after receiving a closing '
+                'handshake')
+
+        while True:
+            # mp_conn.read will block if no bytes are available.
+            # Timeout is controlled by TimeOut directive of Apache.
+
+            frame = self._receive_frame_as_frame_object()
+
+            # Check the constraint on the payload size for control frames
+            # before extension processes the frame.
+            # See also http://tools.ietf.org/html/rfc6455#section-5.5
+            if (common.is_control_opcode(frame.opcode) and
+                len(frame.payload) > 125):
+                raise InvalidFrameException(
+                    'Payload data size of control frames must be 125 bytes or '
+                    'less')
+
+            for frame_filter in self._options.incoming_frame_filters:
+                frame_filter.filter(frame)
+
+            if frame.rsv1 or frame.rsv2 or frame.rsv3:
+                raise UnsupportedFrameException(
+                    'Unsupported flag is set (rsv = %d%d%d)' %
+                    (frame.rsv1, frame.rsv2, frame.rsv3))
+
+            if frame.opcode == common.OPCODE_CONTINUATION:
+                if not self._received_fragments:
+                    if frame.fin:
+                        raise InvalidFrameException(
+                            'Received a termination frame but fragmentation '
+                            'not started')
+                    else:
+                        raise InvalidFrameException(
+                            'Received an intermediate frame but '
+                            'fragmentation not started')
+
+                if frame.fin:
+                    # End of fragmentation frame
+                    self._received_fragments.append(frame.payload)
+                    message = ''.join(self._received_fragments)
+                    self._received_fragments = []
+                else:
+                    # Intermediate frame
+                    self._received_fragments.append(frame.payload)
+                    continue
+            else:
+                if self._received_fragments:
+                    if frame.fin:
+                        raise InvalidFrameException(
+                            'Received an unfragmented frame without '
+                            'terminating existing fragmentation')
+                    else:
+                        raise InvalidFrameException(
+                            'New fragmentation started without terminating '
+                            'existing fragmentation')
+
+                if frame.fin:
+                    # Unfragmented frame
+
+                    self._original_opcode = frame.opcode
+                    message = frame.payload
+                else:
+                    # Start of fragmentation frame
+
+                    if common.is_control_opcode(frame.opcode):
+                        raise InvalidFrameException(
+                            'Control frames must not be fragmented')
+
+                    self._original_opcode = frame.opcode
+                    self._received_fragments.append(frame.payload)
+                    continue
+
+            if self._original_opcode == common.OPCODE_TEXT:
+                # The WebSocket protocol section 4.4 specifies that invalid
+                # characters must be replaced with U+fffd REPLACEMENT
+                # CHARACTER.
+                try:
+                    return message.decode('utf-8')
+                except UnicodeDecodeError, e:
+                    raise InvalidUTF8Exception(e)
+            elif self._original_opcode == common.OPCODE_BINARY:
+                return message
+            elif self._original_opcode == common.OPCODE_CLOSE:
+                self._request.client_terminated = True
+
+                # Status code is optional. We can have status reason only if we
+                # have status code. Status reason can be empty string. So,
+                # allowed cases are
+                # - no application data: no code no reason
+                # - 2 octet of application data: has code but no reason
+                # - 3 or more octet of application data: both code and reason
+                if len(message) == 0:
+                    self._logger.debug('Received close frame (empty body)')
+                    self._request.ws_close_code = (
+                        common.STATUS_NO_STATUS_RECEIVED)
+                elif len(message) == 1:
+                    raise InvalidFrameException(
+                        'If a close frame has status code, the length of '
+                        'status code must be 2 octet')
+                elif len(message) >= 2:
+                    self._request.ws_close_code = struct.unpack(
+                        '!H', message[0:2])[0]
+                    self._request.ws_close_reason = message[2:].decode(
+                        'utf-8', 'replace')
+                    self._logger.debug(
+                        'Received close frame (code=%d, reason=%r)',
+                        self._request.ws_close_code,
+                        self._request.ws_close_reason)
+
+                # Drain junk data after the close frame if necessary.
+                self._drain_received_data()
+
+                if self._request.server_terminated:
+                    self._logger.debug(
+                        'Received ack for server-initiated closing handshake')
+                    return None
+
+                self._logger.debug(
+                    'Received client-initiated closing handshake')
+
+                code = common.STATUS_NORMAL_CLOSURE
+                reason = ''
+                if hasattr(self._request, '_dispatcher'):
+                    dispatcher = self._request._dispatcher
+                    code, reason = dispatcher.passive_closing_handshake(
+                        self._request)
+                    if code is None and reason is not None and len(reason) > 0:
+                        self._logger.warning(
+                            'Handler specified reason despite code being None')
+                        reason = ''
+                    if reason is None:
+                        reason = ''
+                self._send_closing_handshake(code, reason)
+                self._logger.debug(
+                    'Sent ack for client-initiated closing handshake '
+                    '(code=%r, reason=%r)', code, reason)
+                return None
+            elif self._original_opcode == common.OPCODE_PING:
+                try:
+                    handler = self._request.on_ping_handler
+                    if handler:
+                        handler(self._request, message)
+                        continue
+                except AttributeError, e:
+                    pass
+                self._send_pong(message)
+            elif self._original_opcode == common.OPCODE_PONG:
+                # TODO(tyoshino): Add ping timeout handling.
+
+                inflight_pings = deque()
+
+                while True:
+                    try:
+                        expected_body = self._ping_queue.popleft()
+                        if expected_body == message:
+                            # inflight_pings contains pings ignored by the
+                            # other peer. Just forget them.
+                            self._logger.debug(
+                                'Ping %r is acked (%d pings were ignored)',
+                                expected_body, len(inflight_pings))
+                            break
+                        else:
+                            inflight_pings.append(expected_body)
+                    except IndexError, e:
+                        # The received pong was unsolicited pong. Keep the
+                        # ping queue as is.
+                        self._ping_queue = inflight_pings
+                        self._logger.debug('Received a unsolicited pong')
+                        break
+
+                try:
+                    handler = self._request.on_pong_handler
+                    if handler:
+                        handler(self._request, message)
+                        continue
+                except AttributeError, e:
+                    pass
+
+                continue
+            else:
+                raise UnsupportedFrameException(
+                    'Opcode %d is not supported' % self._original_opcode)
+
+    def _send_closing_handshake(self, code, reason):
+        body = ''
+        if code is not None:
+            if (code > common.STATUS_USER_PRIVATE_MAX or
+                code < common.STATUS_NORMAL_CLOSURE):
+                raise BadOperationException('Status code is out of range')
+            if (code == common.STATUS_NO_STATUS_RECEIVED or
+                code == common.STATUS_ABNORMAL_CLOSURE or
+                code == common.STATUS_TLS_HANDSHAKE):
+                raise BadOperationException('Status code is reserved pseudo '
+                    'code')
+            encoded_reason = reason.encode('utf-8')
+            body = struct.pack('!H', code) + encoded_reason
+
+        frame = create_close_frame(
+            body,
+            self._options.mask_send,
+            self._options.outgoing_frame_filters)
+
+        self._request.server_terminated = True
+
+        self._write(frame)
+
+    def close_connection(self, code=common.STATUS_NORMAL_CLOSURE, reason=''):
+        """Closes a WebSocket connection.
+
+        Args:
+            code: Status code for close frame. If code is None, a close
+                frame with empty body will be sent.
+            reason: string representing close reason.
+        Raises:
+            BadOperationException: when reason is specified with code None
+            or reason is not an instance of both str and unicode.
+        """
+
+        if self._request.server_terminated:
+            self._logger.debug(
+                'Requested close_connection but server is already terminated')
+            return
+
+        if code is None:
+            if reason is not None and len(reason) > 0:
+                raise BadOperationException(
+                    'close reason must not be specified if code is None')
+            reason = ''
+        else:
+            if not isinstance(reason, str) and not isinstance(reason, unicode):
+                raise BadOperationException(
+                    'close reason must be an instance of str or unicode')
+
+        self._send_closing_handshake(code, reason)
+        self._logger.debug(
+            'Sent server-initiated closing handshake (code=%r, reason=%r)',
+            code, reason)
+
+        if (code == common.STATUS_GOING_AWAY or
+            code == common.STATUS_PROTOCOL_ERROR):
+            # It doesn't make sense to wait for a close frame if the reason is
+            # protocol error or that the server is going away. For some of
+            # other reasons, it might not make sense to wait for a close frame,
+            # but it's not clear, yet.
+            return
+
+        # TODO(ukai): 2. wait until the /client terminated/ flag has been set,
+        # or until a server-defined timeout expires.
+        #
+        # For now, we expect receiving closing handshake right after sending
+        # out closing handshake.
+        message = self.receive_message()
+        if message is not None:
+            raise ConnectionTerminatedException(
+                'Didn\'t receive valid ack for closing handshake')
+        # TODO: 3. close the WebSocket connection.
+        # note: mod_python Connection (mp_conn) doesn't have close method.
+
+    def send_ping(self, body=''):
+        frame = create_ping_frame(
+            body,
+            self._options.mask_send,
+            self._options.outgoing_frame_filters)
+        self._write(frame)
+
+        self._ping_queue.append(body)
+
+    def _send_pong(self, body):
+        frame = create_pong_frame(
+            body,
+            self._options.mask_send,
+            self._options.outgoing_frame_filters)
+        self._write(frame)
+
+    def _drain_received_data(self):
+        """Drains unread data in the receive buffer to avoid sending out TCP
+        RST packet. This is because when deflate-stream is enabled, some
+        DEFLATE block for flushing data may follow a close frame. If any data
+        remains in the receive buffer of a socket when the socket is closed,
+        it sends out TCP RST packet to the other peer.
+
+        Since mod_python's mp_conn object doesn't support non-blocking read,
+        we perform this only when pywebsocket is running in standalone mode.
+        """
+
+        # If self._options.deflate_stream is true, self._request is
+        # DeflateRequest, so we can get wrapped request object by
+        # self._request._request.
+        #
+        # Only _StandaloneRequest has _drain_received_data method.
+        if (self._options.deflate_stream and
+            ('_drain_received_data' in dir(self._request._request))):
+            self._request._request._drain_received_data()
+
+
+# vi:sts=4 sw=4 et