src/java/org/apache/cassandra/service/AbstractWriteResponseHandler.java

package org.apache.cassandra.service;
/*
 *
 * 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.
 *
 */


import java.net.InetAddress;
import java.util.Collection;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;

import org.apache.cassandra.config.DatabaseDescriptor;
import org.apache.cassandra.net.Message;
import org.apache.cassandra.thrift.ConsistencyLevel;
import org.apache.cassandra.thrift.UnavailableException;
import org.apache.cassandra.utils.SimpleCondition;

public abstract class AbstractWriteResponseHandler implements IWriteResponseHandler
{
    private final SimpleCondition condition = new SimpleCondition();
    protected final long startTime;
    protected final Collection<InetAddress> writeEndpoints;
    protected final ConsistencyLevel consistencyLevel;
    protected final Runnable callback;

    /**
     * @param callback A callback to be called when the write is successful.
     * Note that this callback will *not* be called in case of an exception (timeout or unavailable).
     */
    protected AbstractWriteResponseHandler(Collection<InetAddress> writeEndpoints, ConsistencyLevel consistencyLevel, Runnable callback)
    {
        startTime = System.currentTimeMillis();
        this.consistencyLevel = consistencyLevel;
        this.writeEndpoints = writeEndpoints;
        this.callback = callback;
    }

    public void get() throws TimeoutException
    {
        long timeout = DatabaseDescriptor.getRpcTimeout() - (System.currentTimeMillis() - startTime);
        boolean success;
        try
        {
            success = condition.await(timeout, TimeUnit.MILLISECONDS);
        }
        catch (InterruptedException ex)
        {
            throw new AssertionError(ex);
        }

        if (!success)
        {
            throw new TimeoutException();
        }
    }

    /** null message means "response from local write" */
    public abstract void response(Message msg);

    public abstract void assureSufficientLiveNodes() throws UnavailableException;

    protected void signal()
    {
        condition.signal();
        if (callback != null)
            callback.run();
    }
}