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.operation; 022 023import cascading.tuple.Fields; 024import cascading.tuple.TupleEntry; 025import cascading.tuple.TupleEntryCollector; 026 027/** Interface FunctionCall provides access to the current {@link Function} invocation arguments. */ 028public interface FunctionCall<C> extends OperationCall<C> 029 { 030 /** 031 * Returns {@link TupleEntry} of argument values. 032 * <p/> 033 * Note that the returned TupleEntry should not be cached (stored in a Collection), nor should the underlying Tuple 034 * instance. Where possible Cascading will re-use both TupleEntry and Tuple instances. 035 * <p/> 036 * To get a safe copy that can be cached, use {@link TupleEntry#getTupleCopy()}. 037 * 038 * @return TupleEntry 039 */ 040 TupleEntry getArguments(); 041 042 /** 043 * Return the resolved {@link Fields} declared by the current {@link Operation}. 044 * 045 * @return Fields 046 */ 047 Fields getDeclaredFields(); 048 049 /** 050 * Returns the {@link cascading.tuple.TupleEntryCollector} used to emit result values. 051 * 052 * @return TupleCollector 053 */ 054 TupleEntryCollector getOutputCollector(); 055 }