StreamConsumerState.java

/*
 * Copyright © 2014 Cask Data, Inc.
 *
 * Licensed 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 co.cask.cdap.data2.transaction.stream;

import co.cask.cdap.data.stream.StreamFileOffset;
import com.google.common.base.Objects;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.Iterables;

/**
 * Represents the consumer state of a {@link StreamConsumer}.
 */
public final class StreamConsumerState implements ConsumerState<Iterable<StreamFileOffset>> {

  private final long groupId;
  private final int instanceId;
  private Iterable<StreamFileOffset> state;

  public StreamConsumerState(StreamConsumerState other) {
    this(other.getGroupId(), other.getInstanceId(), other.getState());
  }

  public StreamConsumerState(long groupId, int instanceId) {
    this(groupId, instanceId, ImmutableList.<StreamFileOffset>of());
  }

  public StreamConsumerState(long groupId, int instanceId, Iterable<StreamFileOffset> state) {
    this.groupId = groupId;
    this.instanceId = instanceId;
    this.state = ImmutableList.copyOf(state);
  }

  @Override
  public long getGroupId() {
    return groupId;
  }

  @Override
  public int getInstanceId() {
    return instanceId;
  }

  @Override
  public Iterable<StreamFileOffset> getState() {
    return state;
  }

  @Override
  public void setState(Iterable<StreamFileOffset> state) {
    this.state = ImmutableList.copyOf(state);
  }

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

    StreamConsumerState other = (StreamConsumerState) o;

    return (groupId == other.groupId)
      && (instanceId == other.instanceId)
      && Iterables.elementsEqual(state, other.state);
  }

  @Override
  public int hashCode() {
    return Objects.hashCode(groupId, instanceId, state);
  }

  @Override
  public String toString() {
    return Objects.toStringHelper(this)
      .add("groupId", groupId)
      .add("instanceId", instanceId)
      .add("states", state)
      .toString();
  }
}