--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/org/dancres/blitz/remote/nio/ControlBlock.java	Sat Mar 21 11:00:06 2009 +0000
@@ -0,0 +1,99 @@
+package org.dancres.blitz.remote.nio;
+
+import java.nio.channels.SelectionKey;
+import java.nio.channels.SocketChannel;
+import java.nio.ByteBuffer;
+import java.io.IOException;
+import java.util.ArrayList;
+
+/**
+ * Responsible for processing selector messages associated with a particular
+ * endpoint (socket) as defined by a SelectionKey.  Uses a dispatcher to
+ * actually process the data received (it may also invoke methods etc) and to
+ * generate responses to be transmitted back through the endpoint.
+ */
+public class ControlBlock {
+    private SelectionKey _key;
+    private ArrayList _outputBuffers = new ArrayList();
+    private Dispatcher _dispatcher;
+
+    ControlBlock(SelectionKey aKey, Dispatcher aDispatcher) {
+        _key = aKey;
+        _dispatcher = aDispatcher;
+    }
+
+    /**
+     * Processes the SelectionKey's events according to internal state machine
+     * and dispatches work to threads accordingly
+     */
+    public void process() throws IOException {
+        /*
+            Determine what flags are tripped
+
+            If write flag is set invoke a write using current list of
+            buffers.  Scan buffers for now done and remove them from the
+            list.  If there are no buffers, turn of the write interest flag
+            in selector
+
+            If read flag is set grab bytes and parse with state machine
+            which will then figure out whether we are ready to process
+            a request and dispatch it to the pool with a reference to us
+            so's we can post the response.
+        */
+        SocketChannel myChannel = (SocketChannel) _key.channel();
+
+        if (_key.isWritable()) {
+            synchronized(_outputBuffers) {
+
+                while (_outputBuffers.size() > 0) {
+                    ByteBuffer myBuffer = (ByteBuffer) _outputBuffers.get(0);
+
+                    myChannel.write(myBuffer);
+
+                    if (myBuffer.hasRemaining()) {
+                        break;
+                    } else
+                        _outputBuffers.remove(0);
+                }
+
+                if (_outputBuffers.size() == 0) {
+                    _key.interestOps(_key.interestOps() ^ SelectionKey.OP_WRITE);
+                }
+            }
+        }
+
+        if (_key.isReadable()) {
+            _dispatcher.process(this);
+        }
+    }
+
+    public SocketChannel getChannel() {
+        return (SocketChannel) _key.channel();
+    }
+
+    public void send(ByteBuffer[] aBuffers) {
+        /*
+            Lock current list of buffers add this one to the list
+
+            If this is the first new set of buffers we need to set
+            write interest on our selection key and then do
+            _key.selector().wakeup() so we get events
+        */
+        boolean enableWrites;
+
+        synchronized(_outputBuffers) {
+            enableWrites = (_outputBuffers.size() == 0);
+
+            for (int i = 0; i < aBuffers.length; i++) {
+                _outputBuffers.add(aBuffers[i]);
+            }
+        }
+
+        if (enableWrites) {
+            if (_key.isValid()) {
+                _key.interestOps(_key.interestOps() | SelectionKey.OP_WRITE);
+                _key.selector().wakeup();
+            }
+        }
+    }
+}