1 /* 2 * Copyright (C) 2007 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 android.util; 18 19 import java.util.ArrayList; 20 21 import android.os.SystemClock; 22 23 /** 24 * A utility class to help log timings splits throughout a method call. 25 * Typical usage is: 26 * 27 * <pre> 28 * TimingLogger timings = new TimingLogger(TAG, "methodA"); 29 * // ... do some work A ... 30 * timings.addSplit("work A"); 31 * // ... do some work B ... 32 * timings.addSplit("work B"); 33 * // ... do some work C ... 34 * timings.addSplit("work C"); 35 * timings.dumpToLog(); 36 * </pre> 37 * 38 * <p>The dumpToLog call would add the following to the log:</p> 39 * 40 * <pre> 41 * D/TAG ( 3459): methodA: begin 42 * D/TAG ( 3459): methodA: 9 ms, work A 43 * D/TAG ( 3459): methodA: 1 ms, work B 44 * D/TAG ( 3459): methodA: 6 ms, work C 45 * D/TAG ( 3459): methodA: end, 16 ms 46 * </pre> 47 */ 48 public class TimingLogger { 49 50 /** 51 * The Log tag to use for checking Log.isLoggable and for 52 * logging the timings. 53 */ 54 private String mTag; 55 56 /** A label to be included in every log. */ 57 private String mLabel; 58 59 /** Used to track whether Log.isLoggable was enabled at reset time. */ 60 private boolean mDisabled; 61 62 /** Stores the time of each split. */ 63 ArrayList<Long> mSplits; 64 65 /** Stores the labels for each split. */ 66 ArrayList<String> mSplitLabels; 67 68 /** 69 * Create and initialize a TimingLogger object that will log using 70 * the specific tag. If the Log.isLoggable is not enabled to at 71 * least the Log.VERBOSE level for that tag at creation time then 72 * the addSplit and dumpToLog call will do nothing. 73 * @param tag the log tag to use while logging the timings 74 * @param label a string to be displayed with each log 75 */ 76 public TimingLogger(String tag, String label) { 77 reset(tag, label); 78 } 79 80 /** 81 * Clear and initialize a TimingLogger object that will log using 82 * the specific tag. If the Log.isLoggable is not enabled to at 83 * least the Log.VERBOSE level for that tag at creation time then 84 * the addSplit and dumpToLog call will do nothing. 85 * @param tag the log tag to use while logging the timings 86 * @param label a string to be displayed with each log 87 */ 88 public void reset(String tag, String label) { 89 mTag = tag; 90 mLabel = label; 91 reset(); 92 } 93 94 /** 95 * Clear and initialize a TimingLogger object that will log using 96 * the tag and label that was specified previously, either via 97 * the constructor or a call to reset(tag, label). If the 98 * Log.isLoggable is not enabled to at least the Log.VERBOSE 99 * level for that tag at creation time then the addSplit and 100 * dumpToLog call will do nothing. 101 */ 102 public void reset() { 103 mDisabled = !Log.isLoggable(mTag, Log.VERBOSE); 104 if (mDisabled) return; 105 if (mSplits == null) { 106 mSplits = new ArrayList<Long>(); 107 mSplitLabels = new ArrayList<String>(); 108 } else { 109 mSplits.clear(); 110 mSplitLabels.clear(); 111 } 112 addSplit(null); 113 } 114 115 /** 116 * Add a split for the current time, labeled with splitLabel. If 117 * Log.isLoggable was not enabled to at least the Log.VERBOSE for 118 * the specified tag at construction or reset() time then this 119 * call does nothing. 120 * @param splitLabel a label to associate with this split. 121 */ 122 public void addSplit(String splitLabel) { 123 if (mDisabled) return; 124 long now = SystemClock.elapsedRealtime(); 125 mSplits.add(now); 126 mSplitLabels.add(splitLabel); 127 } 128 129 /** 130 * Dumps the timings to the log using Log.d(). If Log.isLoggable was 131 * not enabled to at least the Log.VERBOSE for the specified tag at 132 * construction or reset() time then this call does nothing. 133 */ 134 public void dumpToLog() { 135 if (mDisabled) return; 136 Log.d(mTag, mLabel + ": begin"); 137 final long first = mSplits.get(0); 138 long now = first; 139 for (int i = 1; i < mSplits.size(); i++) { 140 now = mSplits.get(i); 141 final String splitLabel = mSplitLabels.get(i); 142 final long prev = mSplits.get(i - 1); 143 144 Log.d(mTag, mLabel + ": " + (now - prev) + " ms, " + splitLabel); 145 } 146 Log.d(mTag, mLabel + ": end, " + (now - first) + " ms"); 147 } 148 } 149
