1 files changed, 55 insertions, 0 deletions
diff --git a/framework/src/onos/protocols/openflow/ctl/src/main/java/org/onosproject/openflow/controller/impl/OFMessageDecoder.java b/framework/src/onos/protocols/openflow/ctl/src/main/java/org/onosproject/openflow/controller/impl/OFMessageDecoder.java
new file mode 100644
index 00000000..f52d27e5
--- /dev/null
+++ b/framework/src/onos/protocols/openflow/ctl/src/main/java/org/onosproject/openflow/controller/impl/OFMessageDecoder.java
@@ -0,0 +1,55 @@
+/*
+ * Copyright 2014 Open Networking Laboratory
+ *
+ * Licensed 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.
+ */
+
+package org.onosproject.openflow.controller.impl;
+
+
+import org.jboss.netty.buffer.ChannelBuffer;
+import org.jboss.netty.channel.Channel;
+import org.jboss.netty.channel.ChannelHandlerContext;
+import org.jboss.netty.handler.codec.frame.FrameDecoder;
+import org.projectfloodlight.openflow.protocol.OFFactories;
+import org.projectfloodlight.openflow.protocol.OFMessage;
+import org.projectfloodlight.openflow.protocol.OFMessageReader;
+
+/**
+ * Decode an openflow message from a Channel, for use in a netty pipeline.
+ */
+public class OFMessageDecoder extends FrameDecoder {
+
+    @Override
+    protected Object decode(ChannelHandlerContext ctx, Channel channel,
+            ChannelBuffer buffer) throws Exception {
+        if (!channel.isConnected()) {
+            // In testing, I see decode being called AFTER decode last.
+            // This check avoids that from reading corrupted frames
+            return null;
+        }
+
+        // Note that a single call to decode results in reading a single
+        // OFMessage from the channel buffer, which is passed on to, and processed
+        // by, the controller (in OFChannelHandler).
+        // This is different from earlier behavior (with the original openflowj),
+        // where we parsed all the messages in the buffer, before passing on
+        // a list of the parsed messages to the controller.
+        // The performance *may or may not* not be as good as before.
+        OFMessageReader<OFMessage> reader = OFFactories.getGenericReader();
+        OFMessage message = reader.readFrom(buffer);
+
+        return message;
+    }
+
+}