org.apache.druid.indexer.SortableBytes.java Source code

Introduction

Here is the source code for org.apache.druid.indexer.SortableBytes.java

Source

/*
 * 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.druid.indexer;

import org.apache.druid.java.util.common.StringUtils;
import org.apache.hadoop.io.BytesWritable;
import org.apache.hadoop.io.WritableComparator;
import org.apache.hadoop.mapreduce.Job;
import org.apache.hadoop.mapreduce.Partitioner;

import java.nio.ByteBuffer;
import java.util.Arrays;

/**
 */
public class SortableBytes {
    private final byte[] groupKey;
    private final byte[] sortKey;

    public SortableBytes(byte[] groupKey, byte[] sortKey) {
        this.groupKey = groupKey;
        this.sortKey = sortKey;
    }

    public byte[] getGroupKey() {
        return groupKey;
    }

    public byte[] getSortKey() {
        return sortKey;
    }

    public byte[] toBytes() {
        ByteBuffer outBytes = ByteBuffer.wrap(new byte[4 + groupKey.length + sortKey.length]);
        outBytes.putInt(groupKey.length);
        outBytes.put(groupKey);
        outBytes.put(sortKey);
        return outBytes.array();
    }

    public BytesWritable toBytesWritable() {
        return new BytesWritable(toBytes());
    }

    @Override
    public String toString() {
        return "SortableBytes{" + "groupKey='" + StringUtils.fromUtf8(groupKey) + '\'' + ", sortKey='"
                + StringUtils.fromUtf8(sortKey) + '\'' + '}';
    }

    public static SortableBytes fromBytesWritable(BytesWritable bytes) {
        return fromBytes(bytes.getBytes(), 0, bytes.getLength());
    }

    public static SortableBytes fromBytes(byte[] bytes, int offset, int length) {
        int groupKeySize = ByteBuffer.wrap(bytes, offset, length).getInt();

        int sortKeyOffset = offset + 4 + groupKeySize;
        return new SortableBytes(Arrays.copyOfRange(bytes, offset + 4, sortKeyOffset),
                Arrays.copyOfRange(bytes, sortKeyOffset, offset + length));
    }

    public static void useSortableBytesAsMapOutputKey(Job job, Class<? extends Partitioner> partitionerClass) {
        job.setMapOutputKeyClass(BytesWritable.class);
        job.setGroupingComparatorClass(SortableBytesGroupingComparator.class);
        job.setSortComparatorClass(SortableBytesSortingComparator.class);
        job.setPartitionerClass(partitionerClass);
    }

    public static class SortableBytesGroupingComparator extends WritableComparator {

        protected SortableBytesGroupingComparator() {
            super(BytesWritable.class);
        }

        @Override
        public int compare(byte[] b1, int s1, int l1, byte[] b2, int s2, int l2) {
            int b1Length = ByteBuffer.wrap(b1, s1 + 4, l1 - 4).getInt();
            int b2Length = ByteBuffer.wrap(b2, s2 + 4, l2 - 4).getInt();

            final int retVal = compareBytes(b1, s1 + 8, b1Length, b2, s2 + 8, b2Length);

            return retVal;
        }
    }

    public static class SortableBytesSortingComparator extends WritableComparator {

        protected SortableBytesSortingComparator() {
            super(BytesWritable.class);
        }

        @Override
        public int compare(byte[] b1, int s1, int l1, byte[] b2, int s2, int l2) {
            int b1Length = ByteBuffer.wrap(b1, s1 + 4, l1 - 4).getInt();
            int b2Length = ByteBuffer.wrap(b2, s2 + 4, l2 - 4).getInt();

            int retVal = compareBytes(b1, s1 + 8, b1Length, b2, s2 + 8, b2Length);

            if (retVal == 0) {
                retVal = compareBytes(b1, s1 + 8 + b1Length, l1 - 8 - b1Length, b2, s2 + 8 + b2Length,
                        l2 - 8 - b2Length);
            }

            return retVal;
        }
    }
}