Part of the multiget() operation.

git-svn-id: https://svn.apache.org/repos/asf/incubator/cassandra/trunk@759194 13f79535-47bb-0310-9956-ffa450edef68

src/org/apache/cassandra/net/MultiAsyncResult.java

@@ -0,0 +1,133 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF 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 org.apache.cassandra.net;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.TimeoutException;
+import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.concurrent.locks.Condition;
+import java.util.concurrent.locks.Lock;
+import java.util.concurrent.locks.ReentrantLock;
+import org.apache.cassandra.utils.LogUtil;
+import org.apache.log4j.Logger;
+
+public class MultiAsyncResult implements IAsyncResult
+{
+    private static Logger logger_ = Logger.getLogger( AsyncResult.class );
+    private int expectedResults_;
+    private List<Object[]> result_ = new ArrayList<Object[]>();    
+    private AtomicBoolean done_ = new AtomicBoolean(false);
+    private Lock lock_ = new ReentrantLock();
+    private Condition condition_;
+    
+    MultiAsyncResult(int expectedResults)
+    {
+        expectedResults_ = expectedResults;
+        condition_ = lock_.newCondition();
+    }
+    
+    public Object[] get()
+    {
+        throw new UnsupportedOperationException("This operation is not supported in the AsyncResult abstraction.");
+    }
+    
+    public Object[] get(long timeout, TimeUnit tu) throws TimeoutException
+    {
+        throw new UnsupportedOperationException("This operation is not supported in the AsyncResult abstraction.");
+    }
+    
+    public List<Object[]> multiget()
+    {
+        lock_.lock();
+        try
+        {
+            if ( !done_.get() )
+            {
+                condition_.await();                    
+            }
+        }
+        catch ( InterruptedException ex )
+        {
+            logger_.warn( LogUtil.throwableToString(ex) );
+        }
+        finally
+        {
+            lock_.unlock();            
+        }        
+        return result_;
+    }
+    
+    public boolean isDone()
+    {
+        return done_.get();
+    }
+    
+    public List<Object[]> multiget(long timeout, TimeUnit tu) throws TimeoutException
+    {
+        lock_.lock();
+        try
+        {            
+            boolean bVal = true;
+            try
+            {
+                if ( !done_.get() )
+                {                    
+                    bVal = condition_.await(timeout, tu);
+                }
+            }
+            catch ( InterruptedException ex )
+            {
+                logger_.warn( LogUtil.throwableToString(ex) );
+            }
+            
+            if ( !bVal && !done_.get() )
+            {                                           
+                throw new TimeoutException("Operation timed out.");
+            }
+        }
+        finally
+        {
+            lock_.unlock();      
+        }
+        return result_;
+    }
+    
+    public void result(Message result)
+    {        
+        try
+        {
+            lock_.lock();
+            if ( !done_.get() )
+            {
+                result_.add(result.getMessageBody());
+                if ( result_.size() == expectedResults_ )
+                {
+                    done_.set(true);
+                    condition_.signal();
+                }
+            }
+        }
+        finally
+        {
+            lock_.unlock();
+        }        
+    }    
+}