/*
* 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.locator;

import org.apache.cassandra.dht.Token;
import org.cliffc.high_scale_lib.NonBlockingHashMap;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.net.InetAddress;
import java.util.ArrayList;
import java.util.Collection;
import java.util.List;
import java.util.Map;
import java.util.concurrent.CopyOnWriteArrayList;

public abstract class AbstractEndpointSnitch implements IEndpointSnitch
{
    private static final Logger logger = LoggerFactory.getLogger(AbstractEndpointSnitch.class);
    
    /* list of subscribers that are notified when cached values from this snitch are invalidated */
    protected List<AbstractReplicationStrategy> subscribers = new CopyOnWriteArrayList<AbstractReplicationStrategy>();
    
    private final Map<Token, ArrayList<InetAddress>> cachedEndpoints = new NonBlockingHashMap<Token, ArrayList<InetAddress>>();
    
    public ArrayList<InetAddress> getCachedEndpoints(Token t)
    {
        return cachedEndpoints.get(t);
    }

    public void cacheEndpoint(Token t, ArrayList<InetAddress> addr)
    {
        cachedEndpoints.put(t, addr);
    }

    public void clearEndpointCache()
    {
        logger.debug("clearing cached endpoints");
        cachedEndpoints.clear();
    }

    public abstract List<InetAddress> getSortedListByProximity(InetAddress address, Collection<InetAddress> unsortedAddress);
    public abstract List<InetAddress> sortByProximity(InetAddress address, List<InetAddress> addresses);

    public int compareEndpoints(InetAddress target, InetAddress a1, InetAddress a2)
    {
        return a1.getHostAddress().compareTo(a2.getHostAddress());
    }
}