samza-api/src/main/java/org/apache/samza/job/model/TaskModel.java

/*
 * 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.samza.job.model;

import java.util.Collections;
import java.util.Set;
import org.apache.samza.Partition;
import org.apache.samza.container.TaskName;
import org.apache.samza.system.SystemStreamPartition;


/**
 * This contains metadata about a Samza task, such as the stream partitions that it is consuming.
 * <p>
 * The hierarchy for a Samza's job data model is that jobs have containers, and containers have tasks.
 */
public class TaskModel implements Comparable<TaskModel> {
  private final TaskName taskName;
  private final Set<SystemStreamPartition> systemStreamPartitions;
  private final Partition changelogPartition;
  private final TaskMode taskMode;

  /**
   *  Create a TaskModel for an active task with the given taskName, SSPs, and changelogPartition.
   * @param taskName The desired taskName
   * @param systemStreamPartitions SSPs assigned to this task.
   * @param changelogPartition The changelog SSP for this task.
   * @param taskMode The mode of the task
   */
  public TaskModel(TaskName taskName, Set<SystemStreamPartition> systemStreamPartitions, Partition changelogPartition, TaskMode taskMode) {
    this.taskName = taskName;
    this.systemStreamPartitions = Collections.unmodifiableSet(systemStreamPartitions);
    this.changelogPartition = changelogPartition;
    this.taskMode = taskMode;
  }


  /**
   *  Create a TaskModel for an active task with the given taskName, SSPs, and changelogPartition.
   * @param taskName The desired taskName
   * @param systemStreamPartitions SSPs assigned to this task.
   * @param changelogPartition The changelog SSP for this task.
   */
  public TaskModel(TaskName taskName, Set<SystemStreamPartition> systemStreamPartitions, Partition changelogPartition) {
    this(taskName, systemStreamPartitions, changelogPartition, TaskMode.Active);
  }

  /**
   * Returns the name of the task.
   * @return name of the task
   */
  public TaskName getTaskName() {
    return taskName;
  }

  /**
   * Returns the {@link SystemStreamPartition}s that this task is responsible for consuming.
   * @return {@link SystemStreamPartition}s for this task
   */
  public Set<SystemStreamPartition> getSystemStreamPartitions() {
    return systemStreamPartitions;
  }

  /**
   * Returns the {@link Partition} used for all changelogs for this task.
   * @return changelog partition for this task
   */
  public Partition getChangelogPartition() {
    return changelogPartition;
  }

  public TaskMode getTaskMode() {
    return this.taskMode;
  }

  @Override
  public boolean equals(Object o) {
    if (this == o) {
      return true;
    }
    if (o == null || getClass() != o.getClass()) {
      return false;
    }

    TaskModel taskModel = (TaskModel) o;

    if (!changelogPartition.equals(taskModel.changelogPartition)) {
      return false;
    }
    if (!systemStreamPartitions.equals(taskModel.systemStreamPartitions)) {
      return false;
    }
    if (!taskName.equals(taskModel.taskName)) {
      return false;
    }

    if (!taskMode.equals(taskModel.taskMode)) {
      return false;
    }

    return true;
  }

  @Override
  public int hashCode() {
    int result = taskName.hashCode();
    result = 31 * result + systemStreamPartitions.hashCode();
    result = 31 * result + changelogPartition.hashCode();
    result = 31 * result + taskMode.hashCode();
    return result;
  }

  @Override
  public String toString() {
    return "TaskModel [taskName=" + taskName + ", systemStreamPartitions=" + systemStreamPartitions
        + ", changeLogPartition=" + changelogPartition + ", taskMode=" + this.taskMode + "]";
  }

  public int compareTo(TaskModel other) {
    return taskName.compareTo(other.getTaskName());
  }
}