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
   *
   *     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 org.apache.beam.sdk.jmh.io;
  
  import java.io.BufferedWriter;
  import java.io.FileInputStream;
  import java.nio.charset.StandardCharsets;
  import java.nio.file.Files;
  import java.nio.file.Path;
  import java.util.Arrays;
  import java.util.concurrent.ThreadLocalRandom;
  import org.apache.beam.sdk.io.FileBasedSource;
  import org.apache.beam.sdk.io.Source;
  import org.apache.beam.sdk.io.TextIOReadTest;
  import org.apache.beam.sdk.options.PipelineOptionsFactory;
  import org.apache.hadoop.io.Text;
  import org.apache.hadoop.util.LineReader;
  import org.openjdk.jmh.annotations.Benchmark;
  import org.openjdk.jmh.annotations.Scope;
  import org.openjdk.jmh.annotations.Setup;
  import org.openjdk.jmh.annotations.State;
  import org.openjdk.jmh.annotations.TearDown;
  
  public class TextSourceBenchmark {
    private static final int NUM_LINES = 10_000_000;
    private static char[] data = new char[120];
  
    static {
      Arrays.fill(data, 'a');
    }
  
    @State(Scope.Benchmark)
    public static class Data {
      public Path path;
      public String pathString;
      public int length;
  
      /** Generates a random file with {@code NUM_LINES} between 60 and 120 characters each. */
      @Setup
      public void createFile() throws Exception {
        path = Files.createTempFile("benchmark", null).toAbsolutePath();
        pathString = path.toString();
        BufferedWriter writer = Files.newBufferedWriter(path, StandardCharsets.UTF_8);
        for (int i = 0; i < NUM_LINES; ++i) {
          String valueToAppend =
              String.valueOf(data, 0, ThreadLocalRandom.current().nextInt(60, 120));
          length += valueToAppend.length();
          writer.write(valueToAppend);
          writer.write('\n');
        }
        writer.close();
      }
  
      @TearDown
      public void deleteFile() throws Exception {
        Files.deleteIfExists(path);
      }
    }
  
    @Benchmark
    public void benchmarkTextSource(Data data) throws Exception {
      Source.Reader<String> reader =
          ((FileBasedSource<String>) TextIOReadTest.getTextSource(data.pathString, null))
              .createReader(PipelineOptionsFactory.create());
      int length = 0;
      int linesRead = 0;
      if (reader.start()) {
        linesRead += 1;
        length += reader.getCurrent().length();
      }
      while (reader.advance()) {
        linesRead += 1;
        length += reader.getCurrent().length();
      }
      if (linesRead != NUM_LINES) {
        throw new IllegalStateException();
      }
      if (length != data.length) {
        throw new IllegalStateException();
      }
      reader.close();
    }
  
    @Benchmark
    public void benchmarkHadoopLineReader(Data data) throws Exception {
      LineReader reader = new LineReader(new FileInputStream(data.pathString));
      int length = 0;
      int linesRead = 0;
      do {
        Text text = new Text();
        reader.readLine(text);
        // It is important to convert toString() here so that we force the decoding to UTF8 otherwise
        // Text keeps the encoded byte[] version in memory.
        length += text.toString().length();
        linesRead += 1;
      } while (length < data.length);
      if (linesRead != NUM_LINES) {
        throw new IllegalStateException();
      }
      reader.close();
    }
  }
  