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.beam.sdk.transforms.windowing;
  
  import com.google.auto.value.AutoValue;
  import java.io.Serializable;
  import org.apache.beam.sdk.annotations.Internal;
  import org.joda.time.Duration;
  import org.joda.time.Instant;
  
  /**
   * <b><i>For internal use only; no backwards-compatibility guarantees.</i></b>
   *
   * <p>An abstract description of a standardized transformation on timestamps.
   */
  @Internal
  public abstract class TimestampTransform implements Serializable {
  
    TimestampTransform() {}
  
    /**
     * <b><i>For internal use only; no backwards-compatibility guarantees.</i></b>
     *
     * <p>Returns a transform that shifts a timestamp later by {@code delay}.
     */
    @Internal
    public static TimestampTransform delay(Duration delay) {
      return new AutoValue_TimestampTransform_Delay(delay);
    }
  
    /**
     * <b><i>For internal use only; no backwards-compatibility guarantees.</i></b>
     *
     * <p>Returns a transform that aligns a timestamp to the next boundary of {@code period}, starting
     * from {@code offset}.
     */
    @Internal
    public static TimestampTransform alignTo(Duration period, Instant offset) {
      return new AutoValue_TimestampTransform_AlignTo(period, offset);
    }
  
    /**
     * <b><i>For internal use only; no backwards-compatibility guarantees.</i></b>
     *
     * <p>Returns a transform that aligns a timestamp to the next boundary of {@code period}, starting
     * from the start of the epoch.
     */
    @Internal
    public static TimestampTransform alignTo(Duration period) {
      return alignTo(period, new Instant(0));
    }
  
    /**
     * <b><i>For internal use only; no backwards-compatibility guarantees.</i></b>
     *
     * <p>Represents the transform that aligns a timestamp to the next boundary of {@link
     * #getPeriod()} start at {@link #getOffset()}.
     */
    @Internal
    @AutoValue
    public abstract static class AlignTo extends TimestampTransform {
      public abstract Duration getPeriod();
  
      public abstract Instant getOffset();
    }
  
    /**
     * <b><i>For internal use only; no backwards-compatibility guarantees.</i></b>
     *
     * <p>Represents the transform that delays a timestamp by {@link #getDelay()}.
     */
    @Internal
    @AutoValue
    public abstract static class Delay extends TimestampTransform {
      public abstract Duration getDelay();
    }
  }
  