* Fixed issue: NETTY-125 (Backward incompatible) Use an integer as a Channel ID instead of UUID

* More concise Channel.toString() and ChannelEvent.toString() implementations

src/main/java/org/jboss/netty/channel/AbstractChannel.java

@@ -23,9 +23,9 @@
 package org.jboss.netty.channel;
 
 import java.net.SocketAddress;
-import java.util.UUID;
+import java.util.concurrent.ConcurrentMap;
 
-import org.jboss.netty.util.TimeBasedUuidGenerator;
+import org.jboss.netty.util.ConcurrentHashMap;
 
 /**
  * A skeletal {@link Channel} implementation.
@@ -38,7 +38,35 @@ import org.jboss.netty.util.TimeBasedUuidGenerator;
  */
 public abstract class AbstractChannel implements Channel {
 
-    private final UUID id = TimeBasedUuidGenerator.generate();
+    static final ConcurrentMap<Integer, Channel> allChannels = new ConcurrentHashMap<Integer, Channel>();
+    private static final IdDeallocator ID_DEALLOCATOR = new IdDeallocator();
+
+    private static Integer allocateId(Channel channel) {
+        Integer id = Integer.valueOf(System.identityHashCode(channel));
+        for (;;) {
+            // Loop until a unique ID is acquired.
+            // It should be found in one loop practically.
+            if (allChannels.putIfAbsent(id, channel) == null) {
+                // Successfully acquired.
+                return id;
+            } else {
+                // Taken by other channel at almost the same moment.
+                id = Integer.valueOf(id.intValue() + 1);
+            }
+        }
+    }
+
+    private static final class IdDeallocator implements ChannelFutureListener {
+        IdDeallocator() {
+            super();
+        }
+
+        public void operationComplete(ChannelFuture future) throws Exception {
+            allChannels.remove(future.getChannel().getId());
+        }
+    }
+
+    private final Integer id = allocateId(this);
     private final Channel parent;
     private final ChannelFactory factory;
     private final ChannelPipeline pipeline;
@@ -69,10 +97,11 @@ public abstract class AbstractChannel implements Channel {
         this.parent = parent;
         this.factory = factory;
         this.pipeline = pipeline;
+        closeFuture.addListener(ID_DEALLOCATOR);
         pipeline.attach(this, sink);
     }
 
-    public final UUID getId() {
+    public final Integer getId() {
         return id;
     }
 
@@ -225,9 +254,8 @@ public abstract class AbstractChannel implements Channel {
         }
 
         StringBuilder buf = new StringBuilder(128);
-        buf.append(getClass().getSimpleName());
+        buf.append("[id: 0x");
-        buf.append("(id: ");
+        buf.append(Integer.toHexString(id.intValue()));
-        buf.append(id.toString());
 
         if (connected) {
             buf.append(", ");
@@ -245,7 +273,7 @@ public abstract class AbstractChannel implements Channel {
             buf.append(getLocalAddress());
         }
 
-        buf.append(')');
+        buf.append(']');
 
         String strVal = buf.toString();
         if (connected) {

src/main/java/org/jboss/netty/channel/Channel.java

@@ -24,7 +24,6 @@ package org.jboss.netty.channel;
 
 import java.net.InetSocketAddress;
 import java.net.SocketAddress;
-import java.util.UUID;
 
 
 /**
@@ -92,9 +91,9 @@ public interface Channel extends Comparable<Channel>{
     static int OP_READ_WRITE = OP_READ | OP_WRITE;
 
     /**
-     * Returns the {@link UUID} of this channel.
+     * Returns the unique integer ID of this channel.
      */
-    UUID getId();
+    Integer getId();
 
     /**
      * Returns the {@link ChannelFactory} which created this channel.

src/main/java/org/jboss/netty/channel/DefaultChildChannelStateEvent.java

@@ -69,11 +69,8 @@ public class DefaultChildChannelStateEvent implements ChildChannelStateEvent {
         String channelString = getChannel().toString();
         StringBuilder buf = new StringBuilder(channelString.length() + 32);
         buf.append(channelString);
-        buf.append(" - (");
+        buf.append(getChildChannel().isOpen()? " CHILD_OPEN: " : " CHILD_CLOSED: ");
-        buf.append(getChildChannel().isOpen()? "CHILD_OPEN" : "CHILD_CLOSED");
-        buf.append(": ");
         buf.append(getChildChannel().getId());
-        buf.append(')');
         return buf.toString();
     }
 }

src/main/java/org/jboss/netty/channel/DefaultExceptionEvent.java

@@ -69,6 +69,6 @@ public class DefaultExceptionEvent implements ExceptionEvent {
 
     @Override
     public String toString() {
-        return getChannel().toString() + " - (EXCEPTION: " + cause + ')';
+        return getChannel().toString() + " EXCEPTION: " + cause;
     }
 }

src/main/java/org/jboss/netty/channel/DefaultWriteCompletionEvent.java

@@ -70,9 +70,8 @@ public class DefaultWriteCompletionEvent implements WriteCompletionEvent {
         String channelString = getChannel().toString();
         StringBuilder buf = new StringBuilder(channelString.length() + 32);
         buf.append(channelString);
-        buf.append(" - (WRITTEN_AMOUNT: ");
+        buf.append(" WRITTEN_AMOUNT: ");
         buf.append(getWrittenAmount());
-        buf.append(')');
         return buf.toString();
     }
 }

src/main/java/org/jboss/netty/channel/DownstreamChannelStateEvent.java

@@ -81,41 +81,40 @@ public class DownstreamChannelStateEvent implements ChannelStateEvent {
         String channelString = getChannel().toString();
         StringBuilder buf = new StringBuilder(channelString.length() + 64);
         buf.append(channelString);
-        buf.append(" - (");
         switch (getState()) {
         case OPEN:
             if (Boolean.TRUE.equals(getValue())) {
-                buf.append("OPEN");
+                buf.append(" OPEN");
             } else {
-                buf.append("CLOSE");
+                buf.append(" CLOSE");
             }
             break;
         case BOUND:
             if (getValue() != null) {
-                buf.append("BIND: ");
+                buf.append(" BIND: ");
                 buf.append(getValue());
             } else {
-                buf.append("UNBIND");
+                buf.append(" UNBIND");
             }
             break;
         case CONNECTED:
             if (getValue() != null) {
-                buf.append("CONNECT: ");
+                buf.append(" CONNECT: ");
                 buf.append(getValue());
             } else {
-                buf.append("DISCONNECT");
+                buf.append(" DISCONNECT");
             }
             break;
         case INTEREST_OPS:
-            buf.append("CHANGE_INTEREST: ");
+            buf.append(" CHANGE_INTEREST: ");
             buf.append(getValue());
             break;
         default:
+            buf.append(' ');
             buf.append(getState().name());
             buf.append(": ");
             buf.append(getValue());
         }
-        buf.append(')');
         return buf.toString();
     }
 }

src/main/java/org/jboss/netty/channel/DownstreamMessageEvent.java

@@ -83,12 +83,12 @@ public class DownstreamMessageEvent implements MessageEvent {
     @Override
     public String toString() {
         if (getRemoteAddress() == null) {
-            return getChannel().toString() + " - (WRITE: " +
+            return getChannel().toString() + " WRITE: " +
-                   StringUtil.stripControlCharacters(getMessage()) + ')';
+                   StringUtil.stripControlCharacters(getMessage());
         } else {
-            return getChannel().toString() + " - (WRITE: " +
+            return getChannel().toString() + " WRITE: " +
                    StringUtil.stripControlCharacters(getMessage()) + ", " +
-                   getRemoteAddress() + ')';
+                   getRemoteAddress();
         }
     }
 }

src/main/java/org/jboss/netty/channel/UpstreamChannelStateEvent.java

@@ -78,40 +78,38 @@ public class UpstreamChannelStateEvent implements ChannelStateEvent {
         String channelString = getChannel().toString();
         StringBuilder buf = new StringBuilder(channelString.length() + 64);
         buf.append(channelString);
-        buf.append(" - (");
         switch (getState()) {
         case OPEN:
             if (Boolean.TRUE.equals(getValue())) {
-                buf.append("OPEN");
+                buf.append(" OPEN");
             } else {
-                buf.append("CLOSED");
+                buf.append(" CLOSED");
             }
             break;
         case BOUND:
             if (getValue() != null) {
-                buf.append("BOUND: ");
+                buf.append(" BOUND: ");
                 buf.append(getValue());
             } else {
-                buf.append("UNBOUND");
+                buf.append(" UNBOUND");
             }
             break;
         case CONNECTED:
             if (getValue() != null) {
-                buf.append("CONNECTED: ");
+                buf.append(" CONNECTED: ");
                 buf.append(getValue());
             } else {
-                buf.append("DISCONNECTED");
+                buf.append(" DISCONNECTED");
             }
             break;
         case INTEREST_OPS:
-            buf.append("INTEREST_CHANGED");
+            buf.append(" INTEREST_CHANGED");
             break;
         default:
             buf.append(getState().name());
             buf.append(": ");
             buf.append(getValue());
         }
-        buf.append(')');
         return buf.toString();
     }
 }

src/main/java/org/jboss/netty/channel/UpstreamMessageEvent.java

@@ -79,12 +79,12 @@ public class UpstreamMessageEvent implements MessageEvent {
     @Override
     public String toString() {
         if (getRemoteAddress() == null) {
-            return getChannel().toString() + " - (RECEIVED: " +
+            return getChannel().toString() + " RECEIVED: " +
-                   StringUtil.stripControlCharacters(getMessage()) + ')';
+                   StringUtil.stripControlCharacters(getMessage());
         } else {
-            return getChannel().toString() + " - (RECEIVED: " +
+            return getChannel().toString() + " RECEIVED: " +
                    StringUtil.stripControlCharacters(getMessage()) + ", " +
-                   getRemoteAddress() + ')';
+                   getRemoteAddress();
         }
     }
 }

src/main/java/org/jboss/netty/channel/group/ChannelGroup.java

@@ -24,7 +24,6 @@ package org.jboss.netty.channel.group;
 
 import java.net.SocketAddress;
 import java.util.Set;
-import java.util.UUID;
 
 import org.jboss.netty.channel.Channel;
 
@@ -38,7 +37,7 @@ import org.jboss.netty.channel.Channel;
  */
 public interface ChannelGroup extends Set<Channel>, Comparable<ChannelGroup> {
     String getName();
-    Channel find(UUID id);
+    Channel find(Integer id);
     ChannelGroupFuture setInterestOps(int interestOps);
     ChannelGroupFuture setReadable(boolean readable);
     ChannelGroupFuture write(Object message);

src/main/java/org/jboss/netty/channel/group/ChannelGroupFuture.java

@@ -22,7 +22,6 @@
  */
 package org.jboss.netty.channel.group;
 
-import java.util.UUID;
 import java.util.concurrent.TimeUnit;
 
 import org.jboss.netty.channel.Channel;
@@ -39,7 +38,7 @@ public interface ChannelGroupFuture extends Iterable<ChannelFuture>{
 
     ChannelGroup getGroup();
 
-    ChannelFuture find(UUID channelId);
+    ChannelFuture find(Integer channelId);
     ChannelFuture find(Channel channel);
 
     /**

src/main/java/org/jboss/netty/channel/group/DefaultChannelGroup.java

@@ -50,8 +50,8 @@ public class DefaultChannelGroup extends AbstractSet<Channel> implements Channel
     private static final AtomicInteger nextId = new AtomicInteger();
 
     private final String name;
-    private final ConcurrentMap<UUID, Channel> serverChannels = new ConcurrentHashMap<UUID, Channel>();
+    private final ConcurrentMap<Integer, Channel> serverChannels = new ConcurrentHashMap<Integer, Channel>();
-    private final ConcurrentMap<UUID, Channel> nonServerChannels = new ConcurrentHashMap<UUID, Channel>();
+    private final ConcurrentMap<Integer, Channel> nonServerChannels = new ConcurrentHashMap<Integer, Channel>();
     private final ChannelFutureListener remover = new ChannelFutureListener() {
         public void operationComplete(ChannelFuture future) throws Exception {
             remove(future.getChannel());
@@ -83,7 +83,7 @@ public class DefaultChannelGroup extends AbstractSet<Channel> implements Channel
         return nonServerChannels.size() + serverChannels.size();
     }
 
-    public Channel find(UUID id) {
+    public Channel find(Integer id) {
         Channel c = nonServerChannels.get(id);
         if (c != null) {
             return c;
@@ -110,7 +110,7 @@ public class DefaultChannelGroup extends AbstractSet<Channel> implements Channel
 
     @Override
     public boolean add(Channel channel) {
-        ConcurrentMap<UUID, Channel> map =
+        ConcurrentMap<Integer, Channel> map =
             channel instanceof ServerChannel? serverChannels : nonServerChannels;
 
         boolean added = map.putIfAbsent(channel.getId(), channel) == null;
@@ -175,8 +175,8 @@ public class DefaultChannelGroup extends AbstractSet<Channel> implements Channel
     }
 
     public ChannelGroupFuture close() {
-        Map<UUID, ChannelFuture> futures =
+        Map<Integer, ChannelFuture> futures =
-            new HashMap<UUID, ChannelFuture>(size());
+            new HashMap<Integer, ChannelFuture>(size());
 
         for (Channel c: serverChannels.values()) {
             futures.put(c.getId(), c.close().awaitUninterruptibly());
@@ -189,8 +189,8 @@ public class DefaultChannelGroup extends AbstractSet<Channel> implements Channel
     }
 
     public ChannelGroupFuture disconnect() {
-        Map<UUID, ChannelFuture> futures =
+        Map<Integer, ChannelFuture> futures =
-            new HashMap<UUID, ChannelFuture>(size());
+            new HashMap<Integer, ChannelFuture>(size());
 
         for (Channel c: serverChannels.values()) {
             futures.put(c.getId(), c.disconnect().awaitUninterruptibly());
@@ -203,8 +203,8 @@ public class DefaultChannelGroup extends AbstractSet<Channel> implements Channel
     }
 
     public ChannelGroupFuture setInterestOps(int interestOps) {
-        Map<UUID, ChannelFuture> futures =
+        Map<Integer, ChannelFuture> futures =
-            new HashMap<UUID, ChannelFuture>(size());
+            new HashMap<Integer, ChannelFuture>(size());
 
         for (Channel c: serverChannels.values()) {
             futures.put(c.getId(), c.setInterestOps(interestOps).awaitUninterruptibly());
@@ -217,8 +217,8 @@ public class DefaultChannelGroup extends AbstractSet<Channel> implements Channel
     }
 
     public ChannelGroupFuture setReadable(boolean readable) {
-        Map<UUID, ChannelFuture> futures =
+        Map<Integer, ChannelFuture> futures =
-            new HashMap<UUID, ChannelFuture>(size());
+            new HashMap<Integer, ChannelFuture>(size());
 
         for (Channel c: serverChannels.values()) {
             futures.put(c.getId(), c.setReadable(readable).awaitUninterruptibly());
@@ -231,8 +231,8 @@ public class DefaultChannelGroup extends AbstractSet<Channel> implements Channel
     }
 
     public ChannelGroupFuture unbind() {
-        Map<UUID, ChannelFuture> futures =
+        Map<Integer, ChannelFuture> futures =
-            new HashMap<UUID, ChannelFuture>(size());
+            new HashMap<Integer, ChannelFuture>(size());
 
         for (Channel c: serverChannels.values()) {
             futures.put(c.getId(), c.unbind().awaitUninterruptibly());
@@ -245,8 +245,8 @@ public class DefaultChannelGroup extends AbstractSet<Channel> implements Channel
     }
 
     public ChannelGroupFuture write(Object message) {
-        Map<UUID, ChannelFuture> futures =
+        Map<Integer, ChannelFuture> futures =
-            new HashMap<UUID, ChannelFuture>(size());
+            new HashMap<Integer, ChannelFuture>(size());
         for (Channel c: this) {
             futures.put(c.getId(), c.write(message));
         }
@@ -254,8 +254,8 @@ public class DefaultChannelGroup extends AbstractSet<Channel> implements Channel
     }
 
     public ChannelGroupFuture write(Object message, SocketAddress remoteAddress) {
-        Map<UUID, ChannelFuture> futures =
+        Map<Integer, ChannelFuture> futures =
-            new HashMap<UUID, ChannelFuture>(size());
+            new HashMap<Integer, ChannelFuture>(size());
         for (Channel c: this) {
             futures.put(c.getId(), c.write(message, remoteAddress));
         }

src/main/java/org/jboss/netty/channel/group/DefaultChannelGroupFuture.java

@@ -31,7 +31,6 @@ import java.util.HashMap;
 import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
-import java.util.UUID;
 import java.util.concurrent.TimeUnit;
 
 import org.jboss.netty.channel.Channel;
@@ -54,7 +53,7 @@ public class DefaultChannelGroupFuture implements ChannelGroupFuture {
         InternalLoggerFactory.getInstance(DefaultChannelGroupFuture.class);
 
     private final ChannelGroup group;
-    final Map<UUID, ChannelFuture> futures;
+    final Map<Integer, ChannelFuture> futures;
     private volatile ChannelGroupFutureListener firstListener;
     private volatile List<ChannelGroupFutureListener> otherListeners;
     private boolean done;
@@ -96,7 +95,7 @@ public class DefaultChannelGroupFuture implements ChannelGroupFuture {
 
         this.group = group;
 
-        Map<UUID, ChannelFuture> futureMap = new HashMap<UUID, ChannelFuture>();
+        Map<Integer, ChannelFuture> futureMap = new HashMap<Integer, ChannelFuture>();
         for (ChannelFuture f: futures) {
             futureMap.put(f.getChannel().getId(), f);
         }
@@ -113,7 +112,7 @@ public class DefaultChannelGroupFuture implements ChannelGroupFuture {
         }
     }
 
-    DefaultChannelGroupFuture(ChannelGroup group, Map<UUID, ChannelFuture> futures) {
+    DefaultChannelGroupFuture(ChannelGroup group, Map<Integer, ChannelFuture> futures) {
         this.group = group;
         this.futures = Collections.unmodifiableMap(futures);
         for (ChannelFuture f: this.futures.values()) {
@@ -130,7 +129,7 @@ public class DefaultChannelGroupFuture implements ChannelGroupFuture {
         return group;
     }
 
-    public ChannelFuture find(UUID channelId) {
+    public ChannelFuture find(Integer channelId) {
         return futures.get(channelId);
     }
 

src/main/java/org/jboss/netty/handler/timeout/DefaultIdleStateEvent.java

@@ -73,9 +73,9 @@ public class DefaultIdleStateEvent implements IdleStateEvent {
 
     @Override
     public String toString() {
-        return getChannel().toString() + " - (" + getState() + " since " +
+        return getChannel().toString() + ' ' + getState() + " since " +
                DateFormat.getDateTimeInstance(
                        DateFormat.SHORT, DateFormat.SHORT, Locale.US).format(
-                               new Date(getLastActivityTimeMillis())) + ')';
+                               new Date(getLastActivityTimeMillis()));
     }
 }