001/*
002 * Copyright (c) 2007-2016 Concurrent, 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.operation;
022
023import cascading.tuple.TupleEntry;
024
025/**
026 * Interface GroupAssertionCall provides access to the current {@link GroupAssertion} invocation arguments.
027 * <p/>
028 * This interface is generic, allowing the user to set a custom 'context' object when {@link GroupAssertion#start(cascading.flow.FlowProcess, GroupAssertionCall)}
029 * is called. The {@link OperationCall#setContext(Object)} and {@link OperationCall#getContext()} methods are
030 * inherited from {@link OperationCall}.
031 *
032 * @see GroupAssertion
033 * @see OperationCall
034 */
035public interface GroupAssertionCall<C> extends OperationCall<C>
036  {
037  /**
038   * Returns the current grouping {@link TupleEntry}.
039   *
040   * @return TupleEntry
041   */
042  TupleEntry getGroup();
043
044  /**
045   * Returns {@link TupleEntry} of argument values.
046   * <p/>
047   * Note that the returned TupleEntry should not be cached (stored in a Collection), nor should the underlying Tuple
048   * instance. Where possible Cascading will re-use both TupleEntry and Tuple instances.
049   * <p/>
050   * To get a safe copy that can be cached, use {@link TupleEntry#getTupleCopy()}.
051   *
052   * @return TupleEntry
053   */
054  TupleEntry getArguments();
055  }