/*
 * Copyright 2012 The Netty Project
 *
 * The Netty Project licenses this file to you 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 io.netty.channel;

import java.util.HashSet;
import java.util.Set;


/**
 * Class which is used to consolidate multiple channel futures into one, by
 * listening to the individual futures and producing an aggregated result
 * (success/failure) when all futures have completed.
 */
public final class ChannelPromiseAggregator implements ChannelFutureListener {

    private final ChannelPromise aggregatePromise;

    private Set<ChannelPromise> pendingPromises;

    public ChannelPromiseAggregator(ChannelPromise aggregatePromise) {
        this.aggregatePromise = aggregatePromise;
    }

    public ChannelPromiseAggregator add(ChannelPromise... promises) {
        if (promises == null) {
            throw new NullPointerException("promises");
        }
        synchronized (this) {
            if (pendingPromises == null) {
                pendingPromises = new HashSet<ChannelPromise>();
            }
            for (ChannelPromise p: promises) {
                if (p == null) {
                    continue;
                }
                pendingPromises.add(p);
                p.addListener(this);
            }
        }
        return this;
    }

    @Override
    public synchronized void operationComplete(ChannelFuture future) throws Exception {
        if (pendingPromises == null) {
            aggregatePromise.setSuccess();
        } else {
            pendingPromises.remove(future);
            if (!future.isSuccess()) {
                aggregatePromise.setFailure(future.cause());
                for (ChannelPromise pendingFuture : pendingPromises) {
                    pendingFuture.setFailure(future.cause());
                }
            } else {
                if (pendingPromises.isEmpty()) {
                    aggregatePromise.setSuccess();
                }
            }
        }
    }
}

@@ -1183,56 +1183,250 @@
     
-this.aggregatePromise = aggregatePromise;%0A    %7D%0A
+if (aggregatePromise == null) %7B%0A            throw new NullPointerException(%22aggregatePromise%22);%0A        %7D%0A        this.aggregatePromise = aggregatePromise;%0A    %7D%0A%0A    /**%0A     * Add the given %7B@link ChannelPromise%7Ds to the aggregator.%0A     */
 %0A   
@@ -1582,32 +1582,103 @@
 es%22);%0A        %7D%0A
+        if (promises.length == 0) %7B%0A            return this;%0A        %7D%0A
         synchron
@@ -1726,32 +1726,218 @@
 ises == null) %7B%0A
+                int size;%0A                if (promises.length %3E 1) %7B%0A                    size = promises.length;%0A                %7D else %7B%0A                    size = 2;%0A                %7D%0A
                 
@@ -1982,16 +1982,20 @@
 romise%3E(
+size
 );%0A     

Check for NPE and also optimze HashSet allocation