1 files changed, 142 insertions, 0 deletions
diff --git a/python/qpid/framing.py b/python/qpid/framing.py
new file mode 100644
index 0000000000..7c5f68fbcc
--- /dev/null
+++ b/python/qpid/framing.py
@@ -0,0 +1,142 @@
+#
+# 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
+from qpid.framer import Frame, FIRST_SEG, LAST_SEG, FIRST_FRM, LAST_FRM
+from qpid.assembler import Segment
+
+class FrameDecoder:
+
+  def __init__(self):
+    self.input = ""
+    self.output = []
+    self.parse = self.__frame_header
+
+  def write(self, bytes):
+    self.input += bytes
+    while True:
+      next = self.parse()
+      if next is None:
+        break
+      else:
+        self.parse = next
+
+  def __consume(self, n):
+    result = self.input[:n]
+    self.input = self.input[n:]
+    return result
+
+  def __frame_header(self):
+    if len(self.input) >= Frame.HEADER_SIZE:
+      st = self.__consume(Frame.HEADER_SIZE)
+      self.flags, self.type, self.size, self.track, self.channel = \
+          struct.unpack(Frame.HEADER, st)
+      return self.__frame_body
+
+  def __frame_body(self):
+    size = self.size - Frame.HEADER_SIZE
+    if len(self.input) >= size:
+      payload = self.__consume(size)
+      frame = Frame(self.flags, self.type, self.track, self.channel, payload)
+      self.output.append(frame)
+      return self.__frame_header
+
+  def read(self):
+    result = self.output
+    self.output = []
+    return result
+
+class FrameEncoder:
+
+  def __init__(self):
+    self.output = ""
+
+  def write(self, *frames):
+    for frame in frames:
+      size = len(frame.payload) + Frame.HEADER_SIZE
+      track = frame.track & 0x0F
+      self.output += struct.pack(Frame.HEADER, frame.flags, frame.type, size,
+                                 track, frame.channel)
+      self.output += frame.payload
+
+  def read(self):
+    result = self.output
+    self.output = ""
+    return result
+
+class SegmentDecoder:
+
+  def __init__(self):
+    self.fragments = {}
+    self.segments = []
+
+  def write(self, *frames):
+    for frm in frames:
+      key = (frm.channel, frm.track)
+      seg = self.fragments.get(key)
+
+      if seg == None:
+        seg = Segment(frm.isFirstSegment(), frm.isLastSegment(),
+                      frm.type, frm.track, frm.channel, "")
+        self.fragments[key] = seg
+
+      seg.payload += frm.payload
+
+      if frm.isLastFrame():
+        self.fragments.pop(key)
+        self.segments.append(seg)
+
+  def read(self):
+    result = self.segments
+    self.segments = []
+    return result
+
+class SegmentEncoder:
+
+  def __init__(self, max_payload=Frame.MAX_PAYLOAD):
+    self.max_payload = max_payload
+    self.frames = []
+
+  def write(self, *segments):
+    for seg in segments:
+      remaining = seg.payload
+
+      first = True
+      while first or remaining:
+        payload = remaining[:self.max_payload]
+        remaining = remaining[self.max_payload:]
+
+        flags = 0
+        if first:
+          flags |= FIRST_FRM
+          first = False
+        if not remaining:
+          flags |= LAST_FRM
+        if seg.first:
+          flags |= FIRST_SEG
+        if seg.last:
+          flags |= LAST_SEG
+
+        frm = Frame(flags, seg.type, seg.track, seg.channel, payload)
+        self.frames.append(frm)
+
+  def read(self):
+    result = self.frames
+    self.frames = []
+    return result