001/*
002 * Copyright (c) 2007-2017 Xplenty, Inc. All Rights Reserved.
003 *
004 * Project and contact information: http://www.cascading.org/
005 *
006 * This file is part of the Cascading project.
007 *
008 * Licensed under the Apache License, Version 2.0 (the "License");
009 * you may not use this file except in compliance with the License.
010 * You may obtain a copy of the License at
011 *
012 *     http://www.apache.org/licenses/LICENSE-2.0
013 *
014 * Unless required by applicable law or agreed to in writing, software
015 * distributed under the License is distributed on an "AS IS" BASIS,
016 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
017 * See the License for the specific language governing permissions and
018 * limitations under the License.
019 */
020
021package cascading.scheme;
022
023import cascading.tuple.TupleEntry;
024
025/**
026 * SinkCall provides access to the current {@link Scheme#sink(cascading.flow.FlowProcess, SinkCall)} invocation
027 * arguments.
028 * <p/>
029 * Use the Context to store thread local values.
030 *
031 * @param <Context>
032 * @param <Output>
033 */
034public interface SinkCall<Context, Output>
035  {
036  /**
037   * Method getContext returns the context of this SinkCall object.
038   *
039   * @return the context (type C) of this SinkCall object.
040   */
041  Context getContext();
042
043  /**
044   * Method setContext sets the context of this SinkCall object.
045   *
046   * @param context the context of this SinkCall object.
047   */
048  void setContext( Context context );
049
050  /**
051   * Method getOutgoingEntry returns the final {@link TupleEntry} to be passed to the
052   * {@link #getOutput()} output handler.
053   * <p/>
054   * That is, the result of calling getOutgoingEntry() should be passed directly to the
055   * platform specific output handler returned by getOutput().
056   * <p/>
057   * Note the returned value from this method cannot be modified.
058   *
059   * @return TupleEntry
060   */
061  TupleEntry getOutgoingEntry();
062
063  Output getOutput();
064  }