| /******************************************************************************** |
| * 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. |
| * |
| * Performance timers. |
| * |
| * $Header:$ |
| */ |
| |
| package org.apache.pig.tools.timer; |
| |
| import java.io.PrintStream; |
| import java.lang.String; |
| |
| public class PerformanceTimer |
| { |
| |
| /** |
| * Start the timer. |
| */ |
| public void start() |
| { |
| mStartedAt = System.nanoTime(); |
| mStarts++; |
| mState = State.RUNNING; |
| } |
| |
| /** |
| * Stop the timer. |
| */ |
| public void stop() |
| { |
| mState = State.STOPPED; |
| mNanosecs += System.nanoTime() - mStartedAt; |
| } |
| |
| /** |
| * Dump the total time, total number of starts and stops, and average run time of the |
| * timer to an output stream. |
| * @param out output stream to write info to. |
| */ |
| public void print(PrintStream out) |
| { |
| if (mStarts == 0) { |
| out.println(mName + " never started."); |
| return; |
| } |
| |
| if (mState == State.RUNNING) out.print("WARNING: timer still running! "); |
| out.print(mName + ": "); |
| double t = mNanosecs / 1000000000.0; |
| out.print(t); |
| out.print(". Run "); |
| out.print(mStarts); |
| out.print(" times, average run time "); |
| long avg = mNanosecs / mStarts; |
| t = avg / 1000000000.0; |
| out.print(t); |
| out.println("."); |
| } |
| |
| /** |
| * @param name Name of this timer. |
| */ |
| PerformanceTimer(String name) |
| { |
| mNanosecs = 0; |
| mStarts = 0; |
| mName = name; |
| mState = State.STOPPED; |
| } |
| |
| |
| private enum State { RUNNING, STOPPED }; |
| |
| private State mState; |
| private long mNanosecs; |
| private long mStartedAt; |
| private int mStarts; |
| private String mName; |
| |
| } |