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Diffstat (limited to 'testing/mochitest/pywebsocket/mod_pywebsocket/_stream_base.py')
| -rw-r--r-- | testing/mochitest/pywebsocket/mod_pywebsocket/_stream_base.py | 181 |
1 files changed, 181 insertions, 0 deletions
diff --git a/testing/mochitest/pywebsocket/mod_pywebsocket/_stream_base.py b/testing/mochitest/pywebsocket/mod_pywebsocket/_stream_base.py new file mode 100644 index 000000000..8235666bb --- /dev/null +++ b/testing/mochitest/pywebsocket/mod_pywebsocket/_stream_base.py @@ -0,0 +1,181 @@ +# Copyright 2011, 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. + + +"""Base stream class. +""" + + +# Note: request.connection.write/read are used in this module, even though +# mod_python document says that they should be used only in connection +# handlers. Unfortunately, we have no other options. For example, +# request.write/read are not suitable because they don't allow direct raw bytes +# writing/reading. + + +import socket + +from mod_pywebsocket import util + + +# Exceptions + + +class ConnectionTerminatedException(Exception): + """This exception will be raised when a connection is terminated + unexpectedly. + """ + + pass + + +class InvalidFrameException(ConnectionTerminatedException): + """This exception will be raised when we received an invalid frame we + cannot parse. + """ + + pass + + +class BadOperationException(Exception): + """This exception will be raised when send_message() is called on + server-terminated connection or receive_message() is called on + client-terminated connection. + """ + + pass + + +class UnsupportedFrameException(Exception): + """This exception will be raised when we receive a frame with flag, opcode + we cannot handle. Handlers can just catch and ignore this exception and + call receive_message() again to continue processing the next frame. + """ + + pass + + +class InvalidUTF8Exception(Exception): + """This exception will be raised when we receive a text frame which + contains invalid UTF-8 strings. + """ + + pass + + +class StreamBase(object): + """Base stream class.""" + + def __init__(self, request): + """Construct an instance. + + Args: + request: mod_python request. + """ + + self._logger = util.get_class_logger(self) + + self._request = request + + def _read(self, length): + """Reads length bytes from connection. In case we catch any exception, + prepends remote address to the exception message and raise again. + + Raises: + ConnectionTerminatedException: when read returns empty string. + """ + + try: + read_bytes = self._request.connection.read(length) + if not read_bytes: + raise ConnectionTerminatedException( + 'Receiving %d byte failed. Peer (%r) closed connection' % + (length, (self._request.connection.remote_addr,))) + return read_bytes + except socket.error, e: + # Catch a socket.error. Because it's not a child class of the + # IOError prior to Python 2.6, we cannot omit this except clause. + # Use %s rather than %r for the exception to use human friendly + # format. + raise ConnectionTerminatedException( + 'Receiving %d byte failed. socket.error (%s) occurred' % + (length, e)) + except IOError, e: + # Also catch an IOError because mod_python throws it. + raise ConnectionTerminatedException( + 'Receiving %d byte failed. IOError (%s) occurred' % + (length, e)) + + def _write(self, bytes_to_write): + """Writes given bytes to connection. In case we catch any exception, + prepends remote address to the exception message and raise again. + """ + + try: + self._request.connection.write(bytes_to_write) + except Exception, e: + util.prepend_message_to_exception( + 'Failed to send message to %r: ' % + (self._request.connection.remote_addr,), + e) + raise + + def receive_bytes(self, length): + """Receives multiple bytes. Retries read when we couldn't receive the + specified amount. + + Raises: + ConnectionTerminatedException: when read returns empty string. + """ + + read_bytes = [] + while length > 0: + new_read_bytes = self._read(length) + read_bytes.append(new_read_bytes) + length -= len(new_read_bytes) + return ''.join(read_bytes) + + def _read_until(self, delim_char): + """Reads bytes until we encounter delim_char. The result will not + contain delim_char. + + Raises: + ConnectionTerminatedException: when read returns empty string. + """ + + read_bytes = [] + while True: + ch = self._read(1) + if ch == delim_char: + break + read_bytes.append(ch) + return ''.join(read_bytes) + + +# vi:sts=4 sw=4 et |