samza-api/src/main/java/org/apache/samza/checkpoint/CheckpointedChangelogOffset.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.checkpoint;

import java.util.Objects;
import org.apache.commons.lang3.StringUtils;
import org.apache.samza.annotation.InterfaceStability;

/**
 * Checkpointed changelog offset has the format: [checkpointId, offset], separated by a colon.
 */
@InterfaceStability.Unstable
public class CheckpointedChangelogOffset {
  public static final String SEPARATOR = ":";

  private final CheckpointId checkpointId;
  private final String offset;

  public CheckpointedChangelogOffset(CheckpointId checkpointId, String offset) {
    this.checkpointId = checkpointId;
    this.offset = offset;
  }

  public static CheckpointedChangelogOffset fromString(String message) {
    if (StringUtils.isBlank(message)) {
      throw new IllegalArgumentException("Invalid checkpointed changelog message: " + message);
    }
    String[] checkpointIdAndOffset = message.split(":");
    if (checkpointIdAndOffset.length != 2) {
      throw new IllegalArgumentException("Invalid checkpointed changelog offset: " + message);
    }
    CheckpointId checkpointId = CheckpointId.fromString(checkpointIdAndOffset[0]);
    String offset = null;
    if (!"null".equals(checkpointIdAndOffset[1])) {
      offset = checkpointIdAndOffset[1];
    }
    return new CheckpointedChangelogOffset(checkpointId, offset);
  }

  public CheckpointId getCheckpointId() {
    return checkpointId;
  }

  public String getOffset() {
    return offset;
  }

  @Override
  public String toString() {
    return String.format("%s%s%s", checkpointId, SEPARATOR, offset);
  }

  @Override
  public boolean equals(Object o) {
    if (this == o) return true;
    if (o == null || getClass() != o.getClass()) return false;
    CheckpointedChangelogOffset that = (CheckpointedChangelogOffset) o;
    return Objects.equals(checkpointId, that.checkpointId) &&
        Objects.equals(offset, that.offset);
  }

  @Override
  public int hashCode() {
    return Objects.hash(checkpointId, offset);
  }
}