1 files changed, 124 insertions, 0 deletions
diff --git a/python/qpid/framer.py b/python/qpid/framer.py
new file mode 100644
index 0000000000..adc52cc3bd
--- /dev/null
+++ b/python/qpid/framer.py
@@ -0,0 +1,124 @@
+#
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+#
+
+import struct, socket
+from packer import Packer
+
+FIRST_SEG = 0x08
+LAST_SEG = 0x04
+FIRST_FRM = 0x02
+LAST_FRM = 0x01
+
+class Frame:
+
+  HEADER = "!2BHxBH4x"
+  MAX_PAYLOAD = 65535 - struct.calcsize(HEADER)
+
+  def __init__(self, flags, type, track, channel, payload):
+    if len(payload) > Frame.MAX_PAYLOAD:
+      raise ValueError("max payload size exceeded: %s" % len(payload))
+    self.flags = flags
+    self.type = type
+    self.track = track
+    self.channel = channel
+    self.payload = payload
+
+  def isFirstSegment(self):
+    return bool(FIRST_SEG & self.flags)
+
+  def isLastSegment(self):
+    return bool(LAST_SEG & self.flags)
+
+  def isFirstFrame(self):
+    return bool(FIRST_FRM & self.flags)
+
+  def isLastFrame(self):
+    return bool(LAST_FRM & self.flags)
+
+  def __str__(self):
+    return "%s%s%s%s %s %s %s %r" % (int(self.isFirstSegment()),
+                                     int(self.isLastSegment()),
+                                     int(self.isFirstFrame()),
+                                     int(self.isLastFrame()),
+                                     self.type,
+                                     self.track,
+                                     self.channel,
+                                     self.payload)
+
+class Closed(Exception): pass
+
+class Framer(Packer):
+
+  HEADER="!4s4B"
+
+  def __init__(self, sock):
+    self.sock = sock
+
+  def aborted(self):
+    return False
+
+  def write(self, buf):
+#    print "OUT: %r" % buf
+    while buf:
+      try:
+        n = self.sock.send(buf)
+      except socket.timeout:
+        if self.aborted():
+          raise Closed()
+        else:
+          continue
+      buf = buf[n:]
+
+  def read(self, n):
+    data = ""
+    while len(data) < n:
+      try:
+        s = self.sock.recv(n - len(data))
+      except socket.timeout:
+        if self.aborted():
+          raise Closed()
+        else:
+          continue
+      except socket.error, e:
+        if data != "":
+          raise e
+        else:
+          raise Closed()
+      if len(s) == 0:
+        raise Closed()
+#      print "IN: %r" % s
+      data += s
+    return data
+
+  def read_header(self):
+    return self.unpack(Framer.HEADER)
+
+  def write_header(self, major, minor):
+    self.pack(Framer.HEADER, "AMQP", 1, 1, major, minor)
+
+  def write_frame(self, frame):
+    size = len(frame.payload) + struct.calcsize(Frame.HEADER)
+    track = frame.track & 0x0F
+    self.pack(Frame.HEADER, frame.flags, frame.type, size, track, frame.channel)
+    self.write(frame.payload)
+
+  def read_frame(self):
+    flags, type, size, track, channel = self.unpack(Frame.HEADER)
+    payload = self.read(size - struct.calcsize(Frame.HEADER))
+    return Frame(flags, type, track, channel, payload)