| /* |
| * 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 |
| * |
| * https://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.avro.ipc.stats; |
| |
| /** Encapsulates the passing of time. */ |
| class Stopwatch { |
| /** Encapsulates ticking time sources. */ |
| interface Ticks { |
| /** |
| * Returns a number of "ticks" in nanoseconds. This should be monotonically |
| * non-decreasing. |
| */ |
| long ticks(); |
| } |
| |
| /** Default System time source. */ |
| public final static Ticks SYSTEM_TICKS = new SystemTicks(); |
| |
| private Ticks ticks; |
| private long start; |
| private long elapsed = -1; |
| private boolean running; |
| |
| public Stopwatch(Ticks ticks) { |
| this.ticks = ticks; |
| } |
| |
| /** Returns seconds that have elapsed since start() */ |
| public long elapsedNanos() { |
| if (running) { |
| return this.ticks.ticks() - start; |
| } else { |
| if (elapsed == -1) |
| throw new IllegalStateException(); |
| return elapsed; |
| } |
| } |
| |
| /** Starts the stopwatch. */ |
| public void start() { |
| if (running) |
| throw new IllegalStateException(); |
| start = ticks.ticks(); |
| running = true; |
| } |
| |
| /** Stops the stopwatch and calculates the elapsed time. */ |
| public void stop() { |
| if (!running) |
| throw new IllegalStateException(); |
| elapsed = ticks.ticks() - start; |
| running = false; |
| } |
| |
| /** Implementation of Ticks using System.nanoTime(). */ |
| private static class SystemTicks implements Ticks { |
| @Override |
| public long ticks() { |
| return System.nanoTime(); |
| } |
| } |
| } |