content: /*
   * 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
   *
   *     https://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.avro.mapred.tether;
  
  import java.io.IOException;
  
  import org.apache.hadoop.io.NullWritable;
  import org.apache.hadoop.mapred.JobConf;
  import org.apache.hadoop.mapred.FileSplit;
  import org.apache.hadoop.mapred.RecordReader;
  
  import org.apache.avro.Schema;
  import org.apache.avro.file.DataFileReader;
  import org.apache.avro.generic.GenericDatumReader;
  import org.apache.avro.mapred.AvroJob;
  import org.apache.avro.mapred.FsInput;
  
  class TetherRecordReader implements RecordReader<TetherData, NullWritable> {
  
    private FsInput in;
    private DataFileReader reader;
    private long start;
    private long end;
  
    public TetherRecordReader(JobConf job, FileSplit split) throws IOException {
      this.in = new FsInput(split.getPath(), job);
      this.reader = new DataFileReader<>(in, new GenericDatumReader<>());
  
      reader.sync(split.getStart()); // sync to start
      this.start = in.tell();
      this.end = split.getStart() + split.getLength();
  
      job.set(AvroJob.INPUT_SCHEMA, reader.getSchema().toString());
    }
  
    public Schema getSchema() {
      return reader.getSchema();
    }
  
    @Override
    public TetherData createKey() {
      return new TetherData();
    }
  
    @Override
    public NullWritable createValue() {
      return NullWritable.get();
    }
  
    @Override
    public boolean next(TetherData data, NullWritable ignore) throws IOException {
      if (!reader.hasNext() || reader.pastSync(end))
        return false;
      data.buffer(reader.nextBlock());
      data.count((int) reader.getBlockCount());
      return true;
    }
  
    @Override
    public float getProgress() throws IOException {
      if (end == start) {
        return 0.0f;
      } else {
        return Math.min(1.0f, (in.tell() - start) / (float) (end - start));
      }
    }
  
    @Override
    public long getPos() throws IOException {
      return in.tell();
    }
  
    @Override
    public void close() throws IOException {
      reader.close();
    }
  }
  