ReversingOperationSink.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.waveprotocol.wave.model.operation;

import org.waveprotocol.wave.model.operation.Operation;
import org.waveprotocol.wave.model.operation.OperationException;
import org.waveprotocol.wave.model.operation.OperationSink;

/**
 * As per {@link OperationSink} but provides an ability to return the reverse
 * operation.
 *
 * @author thorogood@google.com (Sam Thorogood)
 */
public interface ReversingOperationSink<T extends Operation<?>> {

  /**
   * Consumes an operation and returns the single reverse operation.
   */
  T consumeAndReturnReverse(T op) throws OperationException;

}