fm.last.feathers.output.IndexedPlainTypedBytes.java Source code

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Here is the source code for fm.last.feathers.output.IndexedPlainTypedBytes.java

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/**
 * 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 fm.last.feathers.output;

import java.io.DataOutputStream;
import java.io.IOException;
import java.util.Arrays;

import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.fs.FSDataOutputStream;
import org.apache.hadoop.mapred.FileOutputFormat;
import org.apache.hadoop.mapred.JobConf;
import org.apache.hadoop.mapred.RecordWriter;
import org.apache.hadoop.mapred.Reporter;
import org.apache.hadoop.typedbytes.TypedBytesOutput;
import org.apache.hadoop.typedbytes.TypedBytesWritable;
import org.apache.hadoop.util.*;

public class IndexedPlainTypedBytes extends PlainTypedBytes {

    protected static class IndexingPairWriter extends PlainTypedBytes.PairWriter {

        private DataOutputStream indexOut;
        private TypedBytesOutput indexTbOut;

        private byte[] prevKey = new byte[0];
        private long written = 0;

        public IndexingPairWriter(DataOutputStream out, DataOutputStream indexOut) {
            super(out);
            this.indexOut = indexOut;
            indexTbOut = new TypedBytesOutput(indexOut);
        }

        @Override
        public synchronized void write(TypedBytesWritable key, TypedBytesWritable value) throws IOException {
            super.write(key, value);
            int keyLength = key.getSize();
            byte[] keyBytes = new byte[keyLength];
            System.arraycopy(key.get(), 0, keyBytes, 0, keyLength);
            if (!Arrays.equals(prevKey, keyBytes)) {
                indexOut.write(keyBytes);
                indexTbOut.writeLong(written);
            }
            prevKey = keyBytes;
            written += keyLength + value.getSize();
        }

        public synchronized void close(Reporter reporter) throws IOException {
            super.close(reporter);
            indexOut.close();
        }
    }

    @Override
    public RecordWriter<TypedBytesWritable, TypedBytesWritable> getRecordWriter(FileSystem ignored, JobConf job,
            String name, Progressable progress) throws IOException {
        Path file = FileOutputFormat.getTaskOutputPath(job, name);
        Path index = file.suffix("-index");
        FileSystem fs = file.getFileSystem(job);
        FSDataOutputStream fileOut = fs.create(file, progress);
        FSDataOutputStream indexOut = fs.create(index);
        return new IndexingPairWriter(fileOut, indexOut);
    }
}