1 /* 2 * Copyright (C) 2012 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package com.android.contacts.util; 18 19 import com.google.android.collect.Lists; 20 21 import android.util.Log; 22 23 import java.util.ArrayList; 24 25 /** 26 * A {@link StopWatch} records start, laps and stop, and print them to logcat. 27 */ 28 public class StopWatch { 29 30 private final String mLabel; 31 32 private final ArrayList<Long> mTimes = Lists.newArrayList(); 33 private final ArrayList<String> mLapLabels = Lists.newArrayList(); 34 35 private StopWatch(String label) { 36 mLabel = label; 37 lap(""); 38 } 39 40 /** 41 * Create a new instance and start it. 42 */ 43 public static StopWatch start(String label) { 44 return new StopWatch(label); 45 } 46 47 /** 48 * Record a lap. 49 */ 50 public void lap(String lapLabel) { 51 mTimes.add(System.currentTimeMillis()); 52 mLapLabels.add(lapLabel); 53 } 54 55 /** 56 * Stop it and log the result, if the total time >= {@code timeThresholdToLog}. 57 */ 58 public void stopAndLog(String TAG, int timeThresholdToLog) { 59 60 lap(""); 61 62 final long start = mTimes.get(0); 63 final long stop = mTimes.get(mTimes.size() - 1); 64 65 final long total = stop - start; 66 if (total < timeThresholdToLog) return; 67 68 final StringBuilder sb = new StringBuilder(); 69 sb.append(mLabel); 70 sb.append(","); 71 sb.append(total); 72 sb.append(": "); 73 74 long last = start; 75 for (int i = 1; i < mTimes.size(); i++) { 76 final long current = mTimes.get(i); 77 sb.append(mLapLabels.get(i)); 78 sb.append(","); 79 sb.append((current - last)); 80 sb.append(" "); 81 last = current; 82 } 83 Log.v(TAG, sb.toString()); 84 } 85 86 /** 87 * Return a dummy instance that does no operations. 88 */ 89 public static StopWatch getNullStopWatch() { 90 return NullStopWatch.INSTANCE; 91 } 92 93 private static class NullStopWatch extends StopWatch { 94 public static final NullStopWatch INSTANCE = new NullStopWatch(); 95 96 public NullStopWatch() { 97 super(null); 98 } 99 100 @Override 101 public void lap(String lapLabel) { 102 // noop 103 } 104 105 @Override 106 public void stopAndLog(String TAG, int timeThresholdToLog) { 107 // noop 108 } 109 } 110 } 111