| /** |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package org.apache.hadoop.mapreduce; |
| |
| import java.io.IOException; |
| import java.util.Iterator; |
| |
| import org.apache.hadoop.classification.InterfaceAudience; |
| import org.apache.hadoop.classification.InterfaceStability; |
| |
| /** |
| * <code>MarkableIteratorInterface</code> is an interface for a iterator that |
| * supports mark-reset functionality. |
| * |
| * <p>Mark can be called at any point during the iteration process and a reset |
| * will go back to the last record before the call to the previous mark. |
| * |
| */ |
| @InterfaceAudience.Public |
| @InterfaceStability.Evolving |
| interface MarkableIteratorInterface<VALUE> extends Iterator<VALUE> { |
| /** |
| * Mark the current record. A subsequent call to reset will rewind |
| * the iterator to this record. |
| * @throws IOException |
| */ |
| void mark() throws IOException; |
| |
| /** |
| * Reset the iterator to the last record before a call to the previous mark |
| * @throws IOException |
| */ |
| void reset() throws IOException; |
| |
| /** |
| * Clear any previously set mark |
| * @throws IOException |
| */ |
| void clearMark() throws IOException; |
| } |