com.facebook.hiveio.input.RecordReaderImpl.java Source code

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Here is the source code for com.facebook.hiveio.input.RecordReaderImpl.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.facebook.hiveio.input;

import org.apache.hadoop.io.Writable;
import org.apache.hadoop.io.WritableComparable;
import org.apache.hadoop.mapreduce.InputSplit;
import org.apache.hadoop.mapreduce.RecordReader;
import org.apache.hadoop.mapreduce.TaskAttemptContext;

import com.facebook.hiveio.input.parser.RecordParser;
import com.facebook.hiveio.record.HiveReadableRecord;

import java.io.IOException;

/**
 * RecordReader for Hive data
 */
public class RecordReaderImpl extends RecordReader<WritableComparable, HiveReadableRecord> {
    // CHECKSTYLE: stop LineLength
    /** Base record reader */
    private final org.apache.hadoop.mapred.RecordReader<WritableComparable, Writable> baseRecordReader;
    // CHECKSTYLE: resume LineLength
    /** Current key read */
    private final WritableComparable key;
    /** Current value read */
    private final Writable value;
    /** Parser to use */
    private final RecordParser<Writable> parser;

    /** Holds current record */
    private HiveReadableRecord record;

    /** Observer for operations here */
    private HiveApiInputObserver observer;

    /**
     * Constructor
     *
     * @param baseRecordReader Base record reader
     * @param parser RecordParser
     */
    public RecordReaderImpl(org.apache.hadoop.mapred.RecordReader<WritableComparable, Writable> baseRecordReader,
            RecordParser parser) {
        this.baseRecordReader = baseRecordReader;
        this.key = baseRecordReader.createKey();
        this.value = baseRecordReader.createValue();
        this.observer = HiveApiInputObserver.Empty.get();
        this.parser = parser;
    }

    public HiveApiInputObserver getObserver() {
        return observer;
    }

    /**
     * Set observer to call back to
     *
     * @param observer Observer to callback to
     */
    public void setObserver(HiveApiInputObserver observer) {
        if (observer != null) {
            this.observer = observer;
        }
    }

    @Override
    public void initialize(InputSplit inputSplit, TaskAttemptContext taskAttemptContext)
            throws IOException, InterruptedException {
        record = parser.createRecord();
    }

    @Override
    public boolean nextKeyValue() throws IOException, InterruptedException {
        observer.beginReadRow();
        boolean result = baseRecordReader.next(key, value);
        observer.endReadRow(key, value);

        if (!result) {
            observer.hiveReadRowFailed();
            return false;
        }

        observer.beginParse();
        record = parser.parse(value, record);
        observer.endParse(record);

        return true;
    }

    @Override
    public WritableComparable getCurrentKey() throws IOException, InterruptedException {
        return key;
    }

    @Override
    public HiveReadableRecord getCurrentValue() throws IOException, InterruptedException {
        return record;
    }

    @Override
    public float getProgress() throws IOException, InterruptedException {
        return baseRecordReader.getProgress();
    }

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