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