com.datasalt.pangool.tuplemr.avro.AvroInputFormat.java Source code

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Here is the source code for com.datasalt.pangool.tuplemr.avro.AvroInputFormat.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.datasalt.pangool.tuplemr.avro;

import java.io.IOException;
import java.io.Serializable;
import java.util.ArrayList;
import java.util.List;

import org.apache.avro.Schema;
import org.apache.avro.mapred.AvroWrapper;
import org.apache.avro.mapreduce.lib.output.AvroOutputFormat;
import org.apache.hadoop.fs.FileStatus;
import org.apache.hadoop.io.NullWritable;
import org.apache.hadoop.mapreduce.InputSplit;
import org.apache.hadoop.mapreduce.JobContext;
import org.apache.hadoop.mapreduce.RecordReader;
import org.apache.hadoop.mapreduce.TaskAttemptContext;
import org.apache.hadoop.mapreduce.lib.input.FileInputFormat;
import org.apache.hadoop.mapreduce.lib.input.FileSplit;

/** 
 * This is a Pangool's implementation of {@link org.apache.avro.mapred.AvroInputFormat}.
 * Instead of being configured via {@link Configuration}, its state is defined via 
 * instantiation using Java-serialization.    
 */
@SuppressWarnings("serial")
public class AvroInputFormat<T> extends FileInputFormat<AvroWrapper<T>, NullWritable> implements Serializable {

    private transient Schema schema;
    private String schemaStr;
    private boolean isReflect;

    public AvroInputFormat(Schema schema) {
        this.schema = schema;
        this.schemaStr = schema.toString();
    }

    public AvroInputFormat(Schema schema, boolean isReflect) {
        this(schema);
        this.isReflect = isReflect;
    }

    private Schema getSchema() {
        if (schema == null) {
            schema = new Schema.Parser().parse(schemaStr);
        }
        return schema;
    }

    @Override
    public RecordReader<AvroWrapper<T>, NullWritable> createRecordReader(InputSplit inputSplit,
            TaskAttemptContext context) throws IOException, InterruptedException {
        context.setStatus(inputSplit.toString());
        return new AvroRecordReader<T>(getSchema(), isReflect, context.getConfiguration(), (FileSplit) inputSplit);
    }

    @Override
    protected List<FileStatus> listStatus(JobContext job) throws IOException {
        List<FileStatus> result = new ArrayList<FileStatus>();
        for (FileStatus file : super.listStatus(job)) {
            String fileName = file.getPath().getName();
            if (fileName.endsWith(AvroOutputFormat.EXT)) {
                result.add(file);
            }
        }
        return result;
    }
}