001/*
002 * Copyright (c) 2016-2017 Chris K Wensel <chris@wensel.net>. All Rights Reserved.
003 * Copyright (c) 2007-2017 Xplenty, Inc. All Rights Reserved.
004 *
005 * Project and contact information: http://www.cascading.org/
006 *
007 * This file is part of the Cascading project.
008 *
009 * Licensed under the Apache License, Version 2.0 (the "License");
010 * you may not use this file except in compliance with the License.
011 * You may obtain a copy of the License at
012 *
013 *     http://www.apache.org/licenses/LICENSE-2.0
014 *
015 * Unless required by applicable law or agreed to in writing, software
016 * distributed under the License is distributed on an "AS IS" BASIS,
017 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
018 * See the License for the specific language governing permissions and
019 * limitations under the License.
020 */
021
022package cascading.operation;
023
024import cascading.tuple.Fields;
025
026public interface OperationCall<Context>
027  {
028  /**
029   * Returns the user set context object, C.
030   *
031   * @return user defined object
032   */
033  Context getContext();
034
035  /**
036   * Sets the user defined 'context' object.
037   *
038   * @param context user defined object
039   */
040  void setContext( Context context );
041
042  /**
043   * Returns the {@link Fields} of the expected arguments {@link cascading.tuple.TupleEntry}.
044   *
045   * @return the argumentFields (type Fields) of this OperationCall object.
046   */
047  Fields getArgumentFields();
048
049  /**
050   * Returns the {@link Fields} declared by this operation.
051   * <p>
052   * If the original declared fields on the current operation defined a substitution, this value
053   * will be the actual resolved fields. That is, if the current operation declared {@link Fields#ARGS}
054   * this method will return the declared arguments on the operator pipe.
055   *
056   * @return the declaredFields (type Fields) of this OperationCall object.
057   */
058  Fields getDeclaredFields();
059  }