com.uber.hoodie.hadoop.realtime.HoodieRealtimeRecordReader.java Source code

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Here is the source code for com.uber.hoodie.hadoop.realtime.HoodieRealtimeRecordReader.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 com.uber.hoodie.hadoop.realtime;

import com.uber.hoodie.exception.HoodieException;
import java.io.IOException;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.io.ArrayWritable;
import org.apache.hadoop.io.NullWritable;
import org.apache.hadoop.mapred.JobConf;
import org.apache.hadoop.mapred.RecordReader;

/**
 * Realtime Record Reader which can do compacted (merge-on-read) record reading or
 * unmerged reading (parquet and log files read in parallel) based on job configuration.
 */
public class HoodieRealtimeRecordReader implements RecordReader<NullWritable, ArrayWritable> {

    // Property to enable parallel reading of parquet and log files without merging.
    public static final String REALTIME_SKIP_MERGE_PROP = "hoodie.realtime.merge.skip";
    // By default, we do merged-reading
    public static final String DEFAULT_REALTIME_SKIP_MERGE = "false";
    public static final Log LOG = LogFactory.getLog(HoodieRealtimeRecordReader.class);
    private final RecordReader<NullWritable, ArrayWritable> reader;

    public HoodieRealtimeRecordReader(HoodieRealtimeFileSplit split, JobConf job,
            RecordReader<NullWritable, ArrayWritable> realReader) {
        this.reader = constructRecordReader(split, job, realReader);
    }

    public static boolean canSkipMerging(JobConf jobConf) {
        return Boolean.valueOf(jobConf.get(REALTIME_SKIP_MERGE_PROP, DEFAULT_REALTIME_SKIP_MERGE));
    }

    /**
     * Construct record reader based on job configuration
     *
     * @param split      File Split
     * @param jobConf    Job Configuration
     * @param realReader Parquet Record Reader
     * @return Realtime Reader
     */
    private static RecordReader<NullWritable, ArrayWritable> constructRecordReader(HoodieRealtimeFileSplit split,
            JobConf jobConf, RecordReader<NullWritable, ArrayWritable> realReader) {
        try {
            if (canSkipMerging(jobConf)) {
                LOG.info("Enabling un-merged reading of realtime records");
                return new RealtimeUnmergedRecordReader(split, jobConf, realReader);
            }
            return new RealtimeCompactedRecordReader(split, jobConf, realReader);
        } catch (IOException ex) {
            LOG.error("Got exception when constructing record reader", ex);
            throw new HoodieException(ex);
        }
    }

    @Override
    public boolean next(NullWritable key, ArrayWritable value) throws IOException {
        return this.reader.next(key, value);
    }

    @Override
    public NullWritable createKey() {
        return this.reader.createKey();
    }

    @Override
    public ArrayWritable createValue() {
        return this.reader.createValue();
    }

    @Override
    public long getPos() throws IOException {
        return this.reader.getPos();
    }

    @Override
    public void close() throws IOException {
        this.reader.close();
    }

    @Override
    public float getProgress() throws IOException {
        return this.reader.getProgress();
    }
}