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.state;
  
  import org.apache.beam.sdk.annotations.Internal;
  
  /**
   * {@link TimeDomain} specifies whether an operation is based on timestamps of elements or current
   * "real-world" time as reported while processing.
   */
  public enum TimeDomain {
    /**
     * The {@link #EVENT_TIME} domain corresponds to the timestamps on the elements. Time advances on
     * the system watermark advances.
     */
    EVENT_TIME,
  
    /**
     * The {@link #PROCESSING_TIME} domain corresponds to the current (system) time. This is advanced
     * during execution of the pipeline.
     */
    PROCESSING_TIME,
  
    /**
     * <b>For internal use only; no backwards compatibility guarantees.</b>
     *
     * <p>Same as the {@link #PROCESSING_TIME} domain, except it won't fire a timer set for time
     * <i>t</i> until all timers from earlier stages set for a time earlier than <i>t</i> have fired.
     */
    @Internal
    SYNCHRONIZED_PROCESSING_TIME
  }
  