com.twitter.elephanttwin.io.ListLongWritable.java Source code

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Here is the source code for com.twitter.elephanttwin.io.ListLongWritable.java

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/**
 * Copyright 2012 Twitter, Inc.
 *
 * 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.twitter.elephanttwin.io;

import java.io.DataInput;
import java.io.DataOutput;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.io.Writable;

/**
 * A Writable class to write a list of LongWritable values.
 */
public class ListLongWritable implements Writable {

    private List<LongWritable> list;

    public ListLongWritable() {
        list = new ArrayList<LongWritable>();
    }

    public ListLongWritable(List<LongWritable> l) {
        list = l;
    }

    public ListLongWritable(int initialCapacity) {
        list = new ArrayList<LongWritable>(initialCapacity);
    }

    public int size() {
        return list.size();
    }

    public void add(LongWritable value) {
        LongWritable a = new LongWritable(value.get());
        list.add(a);
    }

    public void add(ListLongWritable listLongWritable) {
        list.addAll(listLongWritable.get());
    }

    @Override
    public void write(DataOutput out) throws IOException {
        out.writeInt(list.size());
        Iterator<LongWritable> itr = list.iterator();

        while (itr.hasNext()) {
            LongWritable element = itr.next();
            element.write(out);
        }
    }

    @Override
    public String toString() {
        Iterator<LongWritable> it = list.listIterator();
        StringBuilder str = new StringBuilder();
        while (it.hasNext()) {
            str.append(" " + it.next());
        }
        return str.toString();
    }

    @Override
    public void readFields(DataInput in) throws IOException {
        int numElements = in.readInt();
        list = new ArrayList<LongWritable>(numElements);

        for (int cnt = 0; cnt < numElements; cnt++) {
            LongWritable l = new LongWritable();
            l.readFields(in);
            list.add(l);
        }
    }

    public static List<LongWritable> readLongList(DataInput in) throws IOException {
        int numElements = in.readInt();
        List<LongWritable> retlist = new ArrayList<LongWritable>(numElements);

        for (int cnt = 0; cnt < numElements; cnt++) {
            LongWritable l = new LongWritable();
            l.readFields(in);
            retlist.add(l);
        }
        return retlist;
    }

    public List<LongWritable> get() {
        return list;
    }
}