[WebSocket] Add tests for permessage deflate split frames.

Tools/Scripts/webkitpy/thirdparty/mod_pywebsocket/util.py

 # 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
@@ skipping 313 matching lines @@
     flushes using the algorithm described in the RFC1979 section 2.1.
     """
 
     def __init__(self, window_bits, no_context_takeover):
         self._deflater = None
         if window_bits is None:
             window_bits = zlib.MAX_WBITS
         self._window_bits = window_bits
         self._no_context_takeover = no_context_takeover
 
-    def filter(self, bytes, flush=True, bfinal=False):
-        if self._deflater is None or (self._no_context_takeover and flush):
+    def filter(self, bytes, end=True, bfinal=False):
+        if self._deflater is None:
             self._deflater = _Deflater(self._window_bits)
 
         if bfinal:
             result = self._deflater.compress_and_finish(bytes)
             # Add a padding block with BFINAL = 0 and BTYPE = 0.
             result = result + chr(0)
             self._deflater = None
             return result
-        if flush:
+
+        result = self._deflater.compress_and_flush(bytes)
+        if end:
             # Strip last 4 octets which is LEN and NLEN field of a
             # non-compressed block added for Z_SYNC_FLUSH.
-            return self._deflater.compress_and_flush(bytes)[:-4]
-        return self._deflater.compress(bytes)
+            result = result[:-4]
+
+        if self._no_context_takeover and end:
+            self._deflater = None
+
+        return result
 
 
 class _RFC1979Inflater(object):
     """A decompressor class for byte sequence compressed and flushed following
     the algorithm described in the RFC1979 section 2.1.
     """
 
     def __init__(self, window_bits=zlib.MAX_WBITS):
         self._inflater = _Inflater(window_bits)
 
@@ skipping 42 matching lines @@
 
     def sendall(self, bytes):
         self.send(bytes)
 
     def send(self, bytes):
         self._socket.sendall(self._deflater.compress_and_flush(bytes))
         return len(bytes)
 
 
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