[ONOS-2337,ONOS-2338,ONOS-2339]Pcep Controller

Change-Id: I27fee4669ec923a55d83993b493699c1c46a1b36
diff --git a/pcep/ctl/src/main/java/org/onosproject/pcep/controller/impl/PcepMessageDecoder.java b/pcep/ctl/src/main/java/org/onosproject/pcep/controller/impl/PcepMessageDecoder.java
new file mode 100644
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+++ b/pcep/ctl/src/main/java/org/onosproject/pcep/controller/impl/PcepMessageDecoder.java
@@ -0,0 +1,68 @@
+/*
+ * Copyright 2015 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.pcep.controller.impl;
+
+import java.util.LinkedList;
+import java.util.List;
+
+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.onosproject.pcepio.protocol.PcepFactories;
+import org.onosproject.pcepio.protocol.PcepMessage;
+import org.onosproject.pcepio.protocol.PcepMessageReader;
+import org.onosproject.pcepio.util.HexDump;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * Decode an pcep message from a Channel, for use in a netty pipeline.
+ */
+public class PcepMessageDecoder extends FrameDecoder {
+
+    protected static final Logger log = LoggerFactory.getLogger(PcepMessageDecoder.class);
+
+    @Override
+    protected Object decode(ChannelHandlerContext ctx, Channel channel,
+            ChannelBuffer buffer) throws Exception {
+        log.debug("Message received.");
+        if (!channel.isConnected()) {
+            log.info("Channel is not connected.");
+            // In testing, I see decode being called AFTER decode last.
+            // This check avoids that from reading corrupted frames
+            return null;
+        }
+
+        HexDump.pcepHexDump(buffer);
+
+        // Note that a single call to decode results in reading a single
+        // PcepMessage from the channel buffer, which is passed on to, and processed
+        // by, the controller (in PcepChannelHandler).
+        // This is different from earlier behavior (with the original pcepIO),
+        // 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.
+        PcepMessageReader<PcepMessage> reader = PcepFactories.getGenericReader();
+        List<PcepMessage> msgList = new LinkedList<PcepMessage>();
+
+        while (buffer.readableBytes() > 0) {
+            PcepMessage message = reader.readFrom(buffer);
+            msgList.add(message);
+        }
+        return msgList;
+    }
+}