/*
    * 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.maven.buildcache.hash;
  
  import java.io.IOException;
  import java.nio.file.Files;
  import java.nio.file.Path;
  import java.nio.file.Paths;
  import java.util.List;
  import java.util.concurrent.TimeUnit;
  import java.util.stream.Collectors;
  import java.util.stream.Stream;
  
  import org.openjdk.jmh.annotations.Benchmark;
  import org.openjdk.jmh.annotations.BenchmarkMode;
  import org.openjdk.jmh.annotations.Level;
  import org.openjdk.jmh.annotations.Mode;
  import org.openjdk.jmh.annotations.OutputTimeUnit;
  import org.openjdk.jmh.annotations.Scope;
  import org.openjdk.jmh.annotations.Setup;
  import org.openjdk.jmh.annotations.State;
  import org.openjdk.jmh.annotations.Warmup;
  import org.openjdk.jmh.runner.Runner;
  import org.openjdk.jmh.runner.RunnerException;
  import org.openjdk.jmh.runner.options.Options;
  import org.openjdk.jmh.runner.options.OptionsBuilder;
  import org.openjdk.jmh.runner.options.TimeValue;
  
  @BenchmarkMode(Mode.Throughput)
  @OutputTimeUnit(TimeUnit.MILLISECONDS)
  @Warmup(iterations = 3, time = 3, timeUnit = TimeUnit.SECONDS)
  public class PerfTest {
  
      @State(Scope.Benchmark)
      public static class HashState {
          List<Path> paths;
  
          @Setup(Level.Iteration)
          public void setUp() throws IOException {
              try (Stream<Path> stream = Files.walk(Paths.get(System.getProperty("user.dir")))) {
                  paths = stream.filter(p -> p.getFileName().toString().endsWith(".java"))
                          .collect(Collectors.toList());
              }
          }
      }
  
      String doTest(HashFactory hashFactory, HashState state) throws IOException {
          HashAlgorithm hash = hashFactory.createAlgorithm();
          StringBuilder sb = new StringBuilder();
          for (Path path : state.paths) {
              if (sb.length() > 0) {
                  sb.append("\n");
              }
              sb.append(hash.hash(path));
          }
          return sb.toString();
      }
  
      @Benchmark
      public String SHA1(HashState state) throws IOException {
          return doTest(HashFactory.SHA1, state);
      }
  
      @Benchmark
      public String SHA256(HashState state) throws IOException {
          return doTest(HashFactory.SHA256, state);
      }
  
      @Benchmark
      public String XX(HashState state) throws IOException {
          return doTest(HashFactory.XX, state);
      }
  
      @Benchmark
      public String XXMM(HashState state) throws IOException {
          return doTest(HashFactory.XXMM, state);
      }
  
      @Benchmark
      public String METRO(HashState state) throws IOException {
          return doTest(HashFactory.METRO, state);
      }
  
     @Benchmark
     public String METRO_MM(HashState state) throws IOException {
         return doTest(HashFactory.METRO_MM, state);
     }
 
     /*
      * <p>main.</p>
      *
      * @param args a {@link java.lang.String} object.
      * @throws org.openjdk.jmh.runner.RunnerException if any.
      */
     public static void main(String... args) throws RunnerException {
         Options opts = new OptionsBuilder()
                 .measurementIterations(3)
                 .measurementTime(TimeValue.milliseconds(3000))
                 .forks(1)
                 .build();
         new Runner(opts).run();
     }
 }