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.runners.samza.runtime;
  
  import java.util.Collection;
  import java.util.concurrent.CompletionStage;
  import org.apache.beam.sdk.values.WindowedValue;
  import org.joda.time.Instant;
  
  /** Output emitter for Samza {@link Op}. */
  public interface OpEmitter<OutT> {
  
    void emitFuture(CompletionStage<Collection<WindowedValue<OutT>>> resultFuture);
  
    void emitElement(WindowedValue<OutT> element);
  
    void emitWatermark(Instant watermark);
  
    <T> void emitView(String id, WindowedValue<Iterable<T>> elements);
  
    Collection<OpMessage<OutT>> collectOutput();
  
    CompletionStage<Collection<OpMessage<OutT>>> collectFuture();
  
    Long collectWatermark();
  }
  