StopWatch.java revision 7687f05f7bd02a4400e340eeb05cd296c34da42a 
1/*
2 * Copyright (C) 2010 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
17package com.android.email;
18
19import android.os.SystemClock;
20import android.util.Log;
21
22/**
23 * A simple class to measure elapsed time.
24 *
25 * <code>
26 *   StopWatch s = StopWatch.start();
27 *   // Do your stuff
28 *   s.split();
29 *   // More stuff
30 *   s.split();
31 *   // More stuff
32 *   s.stop();
33 * </code>
34 */
35public class StopWatch {
36    private final String mName;
37    private final long mStart;
38    private long mLastSplit;
39
40    private StopWatch(String name) {
41        mName = name;
42        mStart = getCurrentTime();
43        mLastSplit = mStart;
44        Log.w(Email.LOG_TAG, "StopWatch(" + mName + ") start");
45    }
46
47    public static StopWatch start(String name) {
48        return new StopWatch(name);
49    }
50
51    public void split(String label) {
52        long now = getCurrentTime() ;
53        long elapse = now - mLastSplit;
54        Log.w(Email.LOG_TAG, "StopWatch(" + mName + ") split(" + label + ") " + elapse);
55        mLastSplit = now;
56    }
57
58    public void stop() {
59        long now = getCurrentTime();
60        long elapse = now - mLastSplit;
61        Log.w(Email.LOG_TAG, "StopWatch(" + mName + ") stop: "
62                + (now - mLastSplit)
63                + "  (total " + (now - mStart) + ")");
64    }
65
66    private static long getCurrentTime() {
67        // We might want to use other counters, such as currentThreadTimeMillis().
68        // TODO add option for that?
69        return SystemClock.elapsedRealtime();
70    }
71}
72