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.kafka.jmh.metadata;
  
  import org.apache.kafka.common.Uuid;
  import org.apache.kafka.common.metadata.PartitionRecord;
  import org.apache.kafka.common.metadata.TopicRecord;
  import org.apache.kafka.image.TopicsDelta;
  import org.apache.kafka.image.TopicsImage;
  
  import org.openjdk.jmh.annotations.Benchmark;
  import org.openjdk.jmh.annotations.BenchmarkMode;
  import org.openjdk.jmh.annotations.Fork;
  import org.openjdk.jmh.annotations.Level;
  import org.openjdk.jmh.annotations.Measurement;
  import org.openjdk.jmh.annotations.Mode;
  import org.openjdk.jmh.annotations.OutputTimeUnit;
  import org.openjdk.jmh.annotations.Param;
  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 java.util.ArrayList;
  import java.util.Collections;
  import java.util.concurrent.TimeUnit;
  import java.util.concurrent.atomic.AtomicInteger;
  import java.util.stream.IntStream;
  
  @State(Scope.Benchmark)
  @Fork(value = 1)
  @Warmup(iterations = 3)
  @Measurement(iterations = 5)
  @BenchmarkMode(Mode.AverageTime)
  @OutputTimeUnit(TimeUnit.MILLISECONDS)
  public class TopicsImageSnapshotLoadBenchmark {
      @Param({"12500", "25000", "50000", "100000"})
      private int totalTopicCount;
      @Param({"10"})
      private int partitionsPerTopic;
      @Param({"3"})
      private int replicationFactor;
      @Param({"10000"})
      private int numReplicasPerBroker;
  
      private TopicsDelta topicsDelta;
  
  
      @Setup(Level.Trial)
      public void setup() {
          // build a delta to apply within the benchmark code
          // that consists of all the topics and partitions that would get loaded in a snapshot
          topicsDelta = getInitialTopicsDelta(totalTopicCount, partitionsPerTopic, replicationFactor, numReplicasPerBroker);
          System.out.print("(Loading a snapshot containing " + totalTopicCount + " total topics) ");
      }
  
      static TopicsDelta getInitialTopicsDelta(int totalTopicCount, int partitionsPerTopic, int replicationFactor, int numReplicasPerBroker) {
          int numBrokers = getNumBrokers(totalTopicCount, partitionsPerTopic, replicationFactor, numReplicasPerBroker);
          TopicsDelta buildupTopicsDelta = new TopicsDelta(TopicsImage.EMPTY);
          final AtomicInteger currentLeader = new AtomicInteger(0);
          IntStream.range(0, totalTopicCount).forEach(topicNumber -> {
              Uuid topicId = Uuid.randomUuid();
              buildupTopicsDelta.replay(new TopicRecord().setName("topic" + topicNumber).setTopicId(topicId));
              IntStream.range(0, partitionsPerTopic).forEach(partitionNumber -> {
                  ArrayList<Integer> replicas = getReplicas(totalTopicCount, partitionsPerTopic, replicationFactor, numReplicasPerBroker, currentLeader.get());
                  ArrayList<Integer> isr = new ArrayList<>(replicas);
                  buildupTopicsDelta.replay(new PartitionRecord().
                      setPartitionId(partitionNumber).
                      setTopicId(topicId).
                      setReplicas(replicas).
                      setIsr(isr).
                      setRemovingReplicas(Collections.emptyList()).
                      setAddingReplicas(Collections.emptyList()).
                      setLeader(currentLeader.get()));
                  currentLeader.set((1 + currentLeader.get()) % numBrokers);
              });
          });
          return buildupTopicsDelta;
      }
  
      static ArrayList<Integer> getReplicas(int totalTopicCount, int partitionsPerTopic, int replicationFactor, int numReplicasPerBroker, int currentLeader) {
          ArrayList<Integer> replicas = new ArrayList<>();
          int numBrokers = getNumBrokers(totalTopicCount, partitionsPerTopic, replicationFactor, numReplicasPerBroker);
          IntStream.range(0, replicationFactor).forEach(replicaNumber ->
              replicas.add((replicaNumber + currentLeader) % numBrokers));
          return replicas;
      }
  
      static int getNumBrokers(int totalTopicCount, int partitionsPerTopic, int replicationFactor, int numReplicasPerBroker) {
          int numBrokers = totalTopicCount * partitionsPerTopic * replicationFactor / numReplicasPerBroker;
          return numBrokers - numBrokers % 3;
      }
  
      @Benchmark
      public void testTopicsDeltaSnapshotLoad() {
          topicsDelta.apply();
      }
  }
  