| /** |
| * 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.fs.slive; |
| |
| import java.util.List; |
| |
| import org.apache.hadoop.fs.FileSystem; |
| |
| /** |
| * Operation which wraps a given operation and allows an observer to be notified |
| * when the operation is about to start and when the operation has finished |
| */ |
| class ObserveableOp extends Operation { |
| |
| /** |
| * The observation interface which class that wish to monitor starting and |
| * ending events must implement. |
| */ |
| interface Observer { |
| void notifyStarting(Operation op); |
| void notifyFinished(Operation op); |
| } |
| |
| private Operation op; |
| private Observer observer; |
| |
| ObserveableOp(Operation op, Observer observer) { |
| super(op.getType(), op.getConfig(), op.getRandom()); |
| this.op = op; |
| this.observer = observer; |
| } |
| |
| /** |
| * Proxy to underlying operation toString() |
| */ |
| public String toString() { |
| return op.toString(); |
| } |
| |
| @Override // Operation |
| List<OperationOutput> run(FileSystem fs) { |
| List<OperationOutput> result = null; |
| try { |
| if (observer != null) { |
| observer.notifyStarting(op); |
| } |
| result = op.run(fs); |
| } finally { |
| if (observer != null) { |
| observer.notifyFinished(op); |
| } |
| } |
| return result; |
| } |
| |
| } |