Thu, 22 Jan 2015 13:21:57 +0100
Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6
michael@0 | 1 | # Copyright 2011, Google Inc. |
michael@0 | 2 | # All rights reserved. |
michael@0 | 3 | # |
michael@0 | 4 | # Redistribution and use in source and binary forms, with or without |
michael@0 | 5 | # modification, are permitted provided that the following conditions are |
michael@0 | 6 | # met: |
michael@0 | 7 | # |
michael@0 | 8 | # * Redistributions of source code must retain the above copyright |
michael@0 | 9 | # notice, this list of conditions and the following disclaimer. |
michael@0 | 10 | # * Redistributions in binary form must reproduce the above |
michael@0 | 11 | # copyright notice, this list of conditions and the following disclaimer |
michael@0 | 12 | # in the documentation and/or other materials provided with the |
michael@0 | 13 | # distribution. |
michael@0 | 14 | # * Neither the name of Google Inc. nor the names of its |
michael@0 | 15 | # contributors may be used to endorse or promote products derived from |
michael@0 | 16 | # this software without specific prior written permission. |
michael@0 | 17 | # |
michael@0 | 18 | # THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
michael@0 | 19 | # "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
michael@0 | 20 | # LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
michael@0 | 21 | # A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
michael@0 | 22 | # OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
michael@0 | 23 | # SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
michael@0 | 24 | # LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
michael@0 | 25 | # DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
michael@0 | 26 | # THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
michael@0 | 27 | # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
michael@0 | 28 | # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
michael@0 | 29 | |
michael@0 | 30 | |
michael@0 | 31 | """Message related utilities. |
michael@0 | 32 | |
michael@0 | 33 | Note: request.connection.write/read are used in this module, even though |
michael@0 | 34 | mod_python document says that they should be used only in connection |
michael@0 | 35 | handlers. Unfortunately, we have no other options. For example, |
michael@0 | 36 | request.write/read are not suitable because they don't allow direct raw |
michael@0 | 37 | bytes writing/reading. |
michael@0 | 38 | """ |
michael@0 | 39 | |
michael@0 | 40 | |
michael@0 | 41 | import Queue |
michael@0 | 42 | import threading |
michael@0 | 43 | |
michael@0 | 44 | |
michael@0 | 45 | # Export Exception symbols from msgutil for backward compatibility |
michael@0 | 46 | from mod_pywebsocket._stream_base import ConnectionTerminatedException |
michael@0 | 47 | from mod_pywebsocket._stream_base import InvalidFrameException |
michael@0 | 48 | from mod_pywebsocket._stream_base import BadOperationException |
michael@0 | 49 | from mod_pywebsocket._stream_base import UnsupportedFrameException |
michael@0 | 50 | |
michael@0 | 51 | |
michael@0 | 52 | # An API for handler to send/receive WebSocket messages. |
michael@0 | 53 | def close_connection(request): |
michael@0 | 54 | """Close connection. |
michael@0 | 55 | |
michael@0 | 56 | Args: |
michael@0 | 57 | request: mod_python request. |
michael@0 | 58 | """ |
michael@0 | 59 | request.ws_stream.close_connection() |
michael@0 | 60 | |
michael@0 | 61 | |
michael@0 | 62 | def send_message(request, message, end=True, binary=False): |
michael@0 | 63 | """Send message. |
michael@0 | 64 | |
michael@0 | 65 | Args: |
michael@0 | 66 | request: mod_python request. |
michael@0 | 67 | message: unicode text or str binary to send. |
michael@0 | 68 | end: False to send message as a fragment. All messages until the |
michael@0 | 69 | first call with end=True (inclusive) will be delivered to the |
michael@0 | 70 | client in separate frames but as one WebSocket message. |
michael@0 | 71 | binary: send message as binary frame. |
michael@0 | 72 | Raises: |
michael@0 | 73 | BadOperationException: when server already terminated. |
michael@0 | 74 | """ |
michael@0 | 75 | request.ws_stream.send_message(message, end, binary) |
michael@0 | 76 | |
michael@0 | 77 | |
michael@0 | 78 | def receive_message(request): |
michael@0 | 79 | """Receive a WebSocket frame and return its payload as a text in |
michael@0 | 80 | unicode or a binary in str. |
michael@0 | 81 | |
michael@0 | 82 | Args: |
michael@0 | 83 | request: mod_python request. |
michael@0 | 84 | Raises: |
michael@0 | 85 | InvalidFrameException: when client send invalid frame. |
michael@0 | 86 | UnsupportedFrameException: when client send unsupported frame e.g. some |
michael@0 | 87 | of reserved bit is set but no extension can |
michael@0 | 88 | recognize it. |
michael@0 | 89 | InvalidUTF8Exception: when client send a text frame containing any |
michael@0 | 90 | invalid UTF-8 string. |
michael@0 | 91 | ConnectionTerminatedException: when the connection is closed |
michael@0 | 92 | unexpectedly. |
michael@0 | 93 | BadOperationException: when client already terminated. |
michael@0 | 94 | """ |
michael@0 | 95 | return request.ws_stream.receive_message() |
michael@0 | 96 | |
michael@0 | 97 | |
michael@0 | 98 | def send_ping(request, body=''): |
michael@0 | 99 | request.ws_stream.send_ping(body) |
michael@0 | 100 | |
michael@0 | 101 | |
michael@0 | 102 | class MessageReceiver(threading.Thread): |
michael@0 | 103 | """This class receives messages from the client. |
michael@0 | 104 | |
michael@0 | 105 | This class provides three ways to receive messages: blocking, |
michael@0 | 106 | non-blocking, and via callback. Callback has the highest precedence. |
michael@0 | 107 | |
michael@0 | 108 | Note: This class should not be used with the standalone server for wss |
michael@0 | 109 | because pyOpenSSL used by the server raises a fatal error if the socket |
michael@0 | 110 | is accessed from multiple threads. |
michael@0 | 111 | """ |
michael@0 | 112 | |
michael@0 | 113 | def __init__(self, request, onmessage=None): |
michael@0 | 114 | """Construct an instance. |
michael@0 | 115 | |
michael@0 | 116 | Args: |
michael@0 | 117 | request: mod_python request. |
michael@0 | 118 | onmessage: a function to be called when a message is received. |
michael@0 | 119 | May be None. If not None, the function is called on |
michael@0 | 120 | another thread. In that case, MessageReceiver.receive |
michael@0 | 121 | and MessageReceiver.receive_nowait are useless |
michael@0 | 122 | because they will never return any messages. |
michael@0 | 123 | """ |
michael@0 | 124 | |
michael@0 | 125 | threading.Thread.__init__(self) |
michael@0 | 126 | self._request = request |
michael@0 | 127 | self._queue = Queue.Queue() |
michael@0 | 128 | self._onmessage = onmessage |
michael@0 | 129 | self._stop_requested = False |
michael@0 | 130 | self.setDaemon(True) |
michael@0 | 131 | self.start() |
michael@0 | 132 | |
michael@0 | 133 | def run(self): |
michael@0 | 134 | try: |
michael@0 | 135 | while not self._stop_requested: |
michael@0 | 136 | message = receive_message(self._request) |
michael@0 | 137 | if self._onmessage: |
michael@0 | 138 | self._onmessage(message) |
michael@0 | 139 | else: |
michael@0 | 140 | self._queue.put(message) |
michael@0 | 141 | finally: |
michael@0 | 142 | close_connection(self._request) |
michael@0 | 143 | |
michael@0 | 144 | def receive(self): |
michael@0 | 145 | """ Receive a message from the channel, blocking. |
michael@0 | 146 | |
michael@0 | 147 | Returns: |
michael@0 | 148 | message as a unicode string. |
michael@0 | 149 | """ |
michael@0 | 150 | return self._queue.get() |
michael@0 | 151 | |
michael@0 | 152 | def receive_nowait(self): |
michael@0 | 153 | """ Receive a message from the channel, non-blocking. |
michael@0 | 154 | |
michael@0 | 155 | Returns: |
michael@0 | 156 | message as a unicode string if available. None otherwise. |
michael@0 | 157 | """ |
michael@0 | 158 | try: |
michael@0 | 159 | message = self._queue.get_nowait() |
michael@0 | 160 | except Queue.Empty: |
michael@0 | 161 | message = None |
michael@0 | 162 | return message |
michael@0 | 163 | |
michael@0 | 164 | def stop(self): |
michael@0 | 165 | """Request to stop this instance. |
michael@0 | 166 | |
michael@0 | 167 | The instance will be stopped after receiving the next message. |
michael@0 | 168 | This method may not be very useful, but there is no clean way |
michael@0 | 169 | in Python to forcefully stop a running thread. |
michael@0 | 170 | """ |
michael@0 | 171 | self._stop_requested = True |
michael@0 | 172 | |
michael@0 | 173 | |
michael@0 | 174 | class MessageSender(threading.Thread): |
michael@0 | 175 | """This class sends messages to the client. |
michael@0 | 176 | |
michael@0 | 177 | This class provides both synchronous and asynchronous ways to send |
michael@0 | 178 | messages. |
michael@0 | 179 | |
michael@0 | 180 | Note: This class should not be used with the standalone server for wss |
michael@0 | 181 | because pyOpenSSL used by the server raises a fatal error if the socket |
michael@0 | 182 | is accessed from multiple threads. |
michael@0 | 183 | """ |
michael@0 | 184 | |
michael@0 | 185 | def __init__(self, request): |
michael@0 | 186 | """Construct an instance. |
michael@0 | 187 | |
michael@0 | 188 | Args: |
michael@0 | 189 | request: mod_python request. |
michael@0 | 190 | """ |
michael@0 | 191 | threading.Thread.__init__(self) |
michael@0 | 192 | self._request = request |
michael@0 | 193 | self._queue = Queue.Queue() |
michael@0 | 194 | self.setDaemon(True) |
michael@0 | 195 | self.start() |
michael@0 | 196 | |
michael@0 | 197 | def run(self): |
michael@0 | 198 | while True: |
michael@0 | 199 | message, condition = self._queue.get() |
michael@0 | 200 | condition.acquire() |
michael@0 | 201 | send_message(self._request, message) |
michael@0 | 202 | condition.notify() |
michael@0 | 203 | condition.release() |
michael@0 | 204 | |
michael@0 | 205 | def send(self, message): |
michael@0 | 206 | """Send a message, blocking.""" |
michael@0 | 207 | |
michael@0 | 208 | condition = threading.Condition() |
michael@0 | 209 | condition.acquire() |
michael@0 | 210 | self._queue.put((message, condition)) |
michael@0 | 211 | condition.wait() |
michael@0 | 212 | |
michael@0 | 213 | def send_nowait(self, message): |
michael@0 | 214 | """Send a message, non-blocking.""" |
michael@0 | 215 | |
michael@0 | 216 | self._queue.put((message, threading.Condition())) |
michael@0 | 217 | |
michael@0 | 218 | |
michael@0 | 219 | # vi:sts=4 sw=4 et |