BSC-3397 Add IOFSwitch.writeThrottled() and make OFMessageDamper call it

src/main/java/net/floodlightcontroller/core/IOFSwitch.java

@@ -107,7 +107,17 @@ public interface IOFSwitch {
     public void setChannel(Channel channel);
 
     /**
-     * Writes to the OFMessage to the output stream.
+     * Write OFMessage to the output stream, subject to switch rate limiting.
+     * The message will be handed to the floodlightProvider for possible filtering
+     * and processing by message listeners
+     * @param msg
+     * @param cntx
+     * @throws IOException
+     */
+    public void writeThrottled(OFMessage msg, FloodlightContext cntx) throws IOException;
+
+    /**
+     * Writes to the OFMessage to the output stream, bypassing rate limiting.
      * The message will be handed to the floodlightProvider for possible filtering
      * and processing by message listeners
      * @param m   

src/main/java/net/floodlightcontroller/core/OFSwitchBase.java

@@ -183,6 +183,13 @@ public abstract class OFSwitchBase implements IOFSwitch {
         this.channel = channel;
     }
     
+    @Override
+    public void writeThrottled(OFMessage m, FloodlightContext bc)
+            throws IOException {
+        // By default, there is no throttling
+        write(m, bc);
+    }
+
     @Override
     public void write(OFMessage m, FloodlightContext bc)
             throws IOException {

src/main/java/net/floodlightcontroller/util/OFMessageDamper.java

@@ -134,7 +134,7 @@ public class OFMessageDamper {
                         FloodlightContext cntx, boolean flush) 
             throws IOException {
         if (! msgTypesToCache.contains(msg.getType())) {
-            sw.write(msg, cntx);
+            sw.writeThrottled(msg, cntx);
             if (flush) {
                 sw.flush();
             }
@@ -146,7 +146,7 @@ public class OFMessageDamper {
             // entry exists in cache. Dampening.
             return false; 
         } else {
-            sw.write(msg, cntx);
+            sw.writeThrottled(msg, cntx);
             if (flush) {
                 sw.flush();
             }