/*
* Copyright (C) 2007 The Android Open Source Project
*
* Licensed 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.
*/
package android.util;
import java.util.ArrayList;
import android.os.SystemClock;
/**
* A utility class to help log timings splits throughout a method call.
* Typical usage is:
*
* <pre>
* TimingLogger timings = new TimingLogger(TAG, "methodA");
* // ... do some work A ...
* timings.addSplit("work A");
* // ... do some work B ...
* timings.addSplit("work B");
* // ... do some work C ...
* timings.addSplit("work C");
* timings.dumpToLog();
* </pre>
*
* <p>The dumpToLog call would add the following to the log:</p>
*
* <pre>
* D/TAG ( 3459): methodA: begin
* D/TAG ( 3459): methodA: 9 ms, work A
* D/TAG ( 3459): methodA: 1 ms, work B
* D/TAG ( 3459): methodA: 6 ms, work C
* D/TAG ( 3459): methodA: end, 16 ms
* </pre>
*/
public class TimingLogger {
/**
* The Log tag to use for checking Log.isLoggable and for
* logging the timings.
*/
private String mTag;
/** A label to be included in every log. */
private String mLabel;
/** Used to track whether Log.isLoggable was enabled at reset time. */
private boolean mDisabled;
/** Stores the time of each split. */
ArrayList<Long> mSplits;
/** Stores the labels for each split. */
ArrayList<String> mSplitLabels;
/**
* Create and initialize a TimingLogger object that will log using
* the specific tag. If the Log.isLoggable is not enabled to at
* least the Log.VERBOSE level for that tag at creation time then
* the addSplit and dumpToLog call will do nothing.
* @param tag the log tag to use while logging the timings
* @param label a string to be displayed with each log
*/
public TimingLogger(String tag, String label) {
reset(tag, label);
}
/**
* Clear and initialize a TimingLogger object that will log using
* the specific tag. If the Log.isLoggable is not enabled to at
* least the Log.VERBOSE level for that tag at creation time then
* the addSplit and dumpToLog call will do nothing.
* @param tag the log tag to use while logging the timings
* @param label a string to be displayed with each log
*/
public void reset(String tag, String label) {
mTag = tag;
mLabel = label;
reset();
}
/**
* Clear and initialize a TimingLogger object that will log using
* the tag and label that was specified previously, either via
* the constructor or a call to reset(tag, label). If the
* Log.isLoggable is not enabled to at least the Log.VERBOSE
* level for that tag at creation time then the addSplit and
* dumpToLog call will do nothing.
*/
public void reset() {
mDisabled = !Log.isLoggable(mTag, Log.VERBOSE);
if (mDisabled) return;
if (mSplits == null) {
mSplits = new ArrayList<Long>();
mSplitLabels = new ArrayList<String>();
} else {
mSplits.clear();
mSplitLabels.clear();
}
addSplit(null);
}
/**
* Add a split for the current time, labeled with splitLabel. If
* Log.isLoggable was not enabled to at least the Log.VERBOSE for
* the specified tag at construction or reset() time then this
* call does nothing.
* @param splitLabel a label to associate with this split.
*/
public void addSplit(String splitLabel) {
if (mDisabled) return;
long now = SystemClock.elapsedRealtime();
mSplits.add(now);
mSplitLabels.add(splitLabel);
}
/**
* Dumps the timings to the log using Log.d(). If Log.isLoggable was
* not enabled to at least the Log.VERBOSE for the specified tag at
* construction or reset() time then this call does nothing.
*/
public void dumpToLog() {
if (mDisabled) return;
Log.d(mTag, mLabel + ": begin");
final long first = mSplits.get(0);
long now = first;
for (int i = 1; i < mSplits.size(); i++) {
now = mSplits.get(i);
final String splitLabel = mSplitLabels.get(i);
final long prev = mSplits.get(i - 1);
Log.d(mTag, mLabel + ": " + (now - prev) + " ms, " + splitLabel);
}
Log.d(mTag, mLabel + ": end, " + (now - first) + " ms");
}
}