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#
# 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 util import Buffer, parse
AMQP_FRAME = 0x00
SASL_FRAME = 0x01
FRAME_HDR_FMT = "!I2BH"
FRAME_HDR_SIZE = struct.calcsize(FRAME_HDR_FMT)
assert FRAME_HDR_SIZE == 8
class Frame:
def __init__(self, type, channel, extended, payload):
self.type = type
self.channel = channel
self.extended = extended
self.payload = payload
def __repr__(self):
return "Frame(%s, %s, %r, %r)" % \
(self.type, self.channel, self.extended, self.payload)
def encode(frame):
extended = frame.extended or ""
padd = len(extended) % 4
if padd: extended += "\x00"*(4-padd)
size = FRAME_HDR_SIZE + len(extended) + len(frame.payload)
doff = (FRAME_HDR_SIZE + len(extended))/4
header = struct.pack(FRAME_HDR_FMT, size, doff, frame.type, frame.channel)
return "%s%s%s" % (header, extended, frame.payload)
def decode(bytes):
if len(bytes) >= FRAME_HDR_SIZE:
hdr = bytes[:FRAME_HDR_SIZE]
size, doff, type, channel = struct.unpack(FRAME_HDR_FMT, hdr)
if len(bytes) >= size:
extended = bytes[FRAME_HDR_SIZE:doff*4]
payload = bytes[doff*4:size]
return Frame(type, channel, extended, payload), size
return None, 0