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.TupleEntry;
025
026/**
027 * Interface GroupAssertionCall provides access to the current {@link GroupAssertion} invocation arguments.
028 * <p>
029 * This interface is generic, allowing the user to set a custom 'context' object when {@link GroupAssertion#start(cascading.flow.FlowProcess, GroupAssertionCall)}
030 * is called. The {@link OperationCall#setContext(Object)} and {@link OperationCall#getContext()} methods are
031 * inherited from {@link OperationCall}.
032 *
033 * @see GroupAssertion
034 * @see OperationCall
035 */
036public interface GroupAssertionCall<C> extends OperationCall<C>
037  {
038  /**
039   * Returns the current grouping {@link TupleEntry}.
040   *
041   * @return TupleEntry
042   */
043  TupleEntry getGroup();
044
045  /**
046   * Returns {@link TupleEntry} of argument values.
047   * <p>
048   * Note that the returned TupleEntry should not be cached (stored in a Collection), nor should the underlying Tuple
049   * instance. Where possible Cascading will re-use both TupleEntry and Tuple instances.
050   * <p>
051   * To get a safe copy that can be cached, use {@link TupleEntry#getTupleCopy()}.
052   *
053   * @return TupleEntry
054   */
055  TupleEntry getArguments();
056  }