CobarMRBase.java

/**
 * Copyright 1999-2011 Alibaba Group
 *
 * Licensed 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 com.alibaba.cobar.client.support.vo;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;

import com.alibaba.cobar.client.support.utils.CollectionUtils;
/**
 * 
 * TODO Comment of CobarHive
 * @author fujohnwang
 *
 */
public class CobarMRBase {

    private Map<String, List<Object>> resources = new HashMap<String, List<Object>>();
    private Map<String, Lock>         locks     = new HashMap<String, Lock>();
    private Set<String>               keys      = new HashSet<String>();

    public CobarMRBase(String[] keys) {
        this(Arrays.asList(keys));
    }

    public CobarMRBase(List<String> keys) {
        if (CollectionUtils.isEmpty(keys)) {
            throw new IllegalArgumentException(
                    "empty collection is invalid for hive to spawn data holders.");
        }
        this.keys.addAll(keys);
        initResourceHolders();
        initResourceLocks();
    }

    public CobarMRBase(Set<String> keys) {
        if (CollectionUtils.isEmpty(keys)) {
            throw new IllegalArgumentException(
                    "empty collection is invalid for hive to spawn data holders.");
        }
        this.keys.addAll(keys);
        initResourceHolders();
        initResourceLocks();
    }

    private void initResourceLocks() {
        for (String key : keys) {
            locks.put(key, new ReentrantLock());
        }
    }

    private void initResourceHolders() {
        for (String key : keys) {
            resources.put(key, new ArrayList<Object>());
        }
    }

    public Map<String, List<Object>> getResources()
    {
        return this.resources;
    }
    
    public <T> void emit(String key, T entity)
    {
        Lock lock = locks.get(key);
        lock.lock();
        try{
            resources.get(key).add(entity);
        }
        finally
        {
            lock.unlock();
        }
    }
}