1 files changed, 155 insertions, 0 deletions
diff --git a/qpid/dotnet/Qpid.Common/Framing/AMQDataBlockDecoder.cs b/qpid/dotnet/Qpid.Common/Framing/AMQDataBlockDecoder.cs
new file mode 100644
index 0000000000..7867650e50
--- /dev/null
+++ b/qpid/dotnet/Qpid.Common/Framing/AMQDataBlockDecoder.cs
@@ -0,0 +1,155 @@
+/*
+ *
+ * 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.
+ *
+ */
+using System;
+using System.Collections;
+using log4net;
+using Apache.Qpid.Buffer;
+using Apache.Qpid.Codec;
+using Apache.Qpid.Codec.Demux;
+
+namespace Apache.Qpid.Framing
+{
+    public class AMQDataBlockDecoder : IMessageDecoder
+    {
+        private static ILog _logger = LogManager.GetLogger(typeof(AMQDataBlockDecoder));
+
+        private Hashtable _supportedBodies = new Hashtable();
+
+        private bool _disabled = false;
+
+        public AMQDataBlockDecoder()
+        {
+            _supportedBodies[AMQMethodBody.TYPE] = AMQMethodBodyFactory.GetInstance();
+            _supportedBodies[ContentHeaderBody.TYPE] = ContentHeaderBodyFactory.GetInstance();
+            _supportedBodies[ContentBody.TYPE] = ContentBodyFactory.GetInstance();
+            _supportedBodies[HeartbeatBody.TYPE] = new HeartbeatBodyFactory();
+        }
+        
+        public MessageDecoderResult Decodable(ByteBuffer input)
+        {
+            if (_disabled)
+            {
+                return MessageDecoderResult.NOT_OK;
+            }
+            // final +1 represents the command end which we know we must require even
+            // if there is an empty body
+            if (input.Remaining < 1)
+            {
+                return MessageDecoderResult.NEED_DATA;
+            }
+            byte type = input.GetByte();
+
+            // we have to check this isn't a protocol initiation frame here - we can't tell later on and we end up
+            // waiting for more data. This could be improved if MINA supported some kind of state awareness when decoding
+            if ((char)type == 'A')
+            {
+                _logger.Error("Received what appears to be a protocol initiation frame");
+                return MessageDecoderResult.NOT_OK;
+            }
+            // zero, channel, body size and end byte
+            if (input.Remaining < (1 + 2 + 4 + 1))
+            {
+                return MessageDecoderResult.NEED_DATA;
+            }
+
+            int channel = input.GetUInt16();
+            long bodySize = input.GetUInt32();            
+
+            // bodySize can be zero
+            if (type <= 0 || channel < 0 || bodySize < 0)
+            {
+                _logger.Error(String.Format("Error decoding frame: Type={0}, Channel={1}, BodySize={2}", type, channel, bodySize));                
+                return MessageDecoderResult.NOT_OK;
+            }
+
+            if (input.Remaining < (bodySize + 1))
+            {
+                return MessageDecoderResult.NEED_DATA;
+            }
+
+            if (IsSupportedFrameType(type))
+            {
+                if (_logger.IsDebugEnabled)
+                {
+                    // we have read 7 bytes so far, so output 7 + bodysize + 1 (for end byte) to get complete data block size
+                    // this logging statement is useful when looking at exactly what size of data is coming in/out
+                    // the broker
+                    _logger.Debug("Able to decode data block of size " + (bodySize + 8));
+                }
+                return MessageDecoderResult.OK;
+            }
+            else
+            {
+                return MessageDecoderResult.NOT_OK;
+            }
+        }
+
+        private bool IsSupportedFrameType(byte frameType)
+        {
+            bool result = _supportedBodies.ContainsKey(frameType);
+
+            if (!result)
+            {
+                _logger.Warn("AMQDataBlockDecoder does not handle frame type " + frameType);
+            }
+
+            return result;
+        }
+
+        protected Object CreateAndPopulateFrame(ByteBuffer input)
+        {
+            byte type = input.GetByte();
+            ushort channel = input.GetUInt16();
+            uint bodySize = input.GetUInt32();
+
+            IBodyFactory bodyFactory = (IBodyFactory)_supportedBodies[type];
+            if (bodyFactory == null)
+            {
+                throw new AMQFrameDecodingException("Unsupported body type: " + type);
+            }
+            AMQFrame frame = new AMQFrame();
+
+            frame.PopulateFromBuffer(input, channel, bodySize, bodyFactory);
+
+            byte marker = input.GetByte();
+            if (marker != 0xCE) {
+           		throw new FormatException("marker is not 0xCE"); 	
+            }
+            return frame;
+        }
+
+        public MessageDecoderResult Decode(ByteBuffer input, IProtocolDecoderOutput output)
+        {
+
+            output.Write(CreateAndPopulateFrame(input));
+
+            return MessageDecoderResult.OK;
+        }
+
+        public bool Disabled
+        {
+            set
+            {
+                _disabled = value;
+            }
+        }
+    }
+}