AnalyticsTimer.java revision 392ed2a4db3bb1c330ba0e31621446b0192ca96f 
1/*
2 * Copyright (C) 2014 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 */
16package com.android.mail.analytics;
17
18import android.os.SystemClock;
19
20import com.google.common.collect.Maps;
21
22import java.util.Map;
23
24/**
25 * Generic static singleton timer that keeps track of start time of various events. It  logs the
26 * event's duration into Analytics using the provided naming information.
27 * This timer class supports multiple data points per event ("lapping").
28 *
29 * This class also holds some defaults constant IDs that we log. This provides an easy way to check
30 * what data we are logging as well as ensuring that the IDs are consistent when accessed by
31 * different classes.
32 */
33public class AnalyticsTimer {
34    public static final String OPEN_CONV_VIEW_FROM_LIST = "open_conv_from_list";
35    public static final String COLD_START_LAUNCHER = "cold_start_to_list";
36    public static final String SEARCH_TO_LIST = "search_to_list";
37    public static final String COMPOSE_HTML_TO_SPAN = "compose_html_to_span";
38    public static final String COMPOSE_SPAN_TO_HTML = "compose_span_to_html";
39
40    private final Map<String, Long> mStartTimes = Maps.newConcurrentMap();
41
42    // Static singleton class to ensure that you can access the timer from anywhere in the code
43    private static final AnalyticsTimer mInstance = new AnalyticsTimer();
44
45    private AnalyticsTimer() {}
46
47    public static AnalyticsTimer getInstance() {
48        return mInstance;
49    }
50
51    /**
52     * Record the current time as the start time of the provided id. If the id has a previously
53     * recorded start time, that time is overwritten.
54     * @param id
55     */
56    public void trackStart(String id) {
57        mStartTimes.put(id, SystemClock.uptimeMillis());
58    }
59
60    /**
61     * Logs the duration of the event with the provided category, name, and label.
62     * This method can be destructive, meaning that any additional calls without calling
63     * {@link AnalyticsTimer#trackStart(String)} will do nothing
64     * We allow the method to be destructive to prevent the following cases from happening:
65     *   - recurring methods that call this with irrelevant mapped start times.
66     *   - multiple entry ways to the method that calls this, thus misusing the
67     *     start time.
68     * With destructive read, we ensure that we only log the event that we care about and only once.
69     * @param id id of the event
70     * @param isDestructive if you are done with this tag (used for multiple data points per tag)
71     * @param category category for analytics logging
72     * @param name name for analytics logging
73     * @param label label for analytics logging
74     */
75    public void logDuration(String id, boolean isDestructive, String category, String name,
76            String label) {
77        try {
78            logDurationAndReturn(id, isDestructive, category, name, label);
79        } catch (IllegalStateException e) { }
80    }
81
82
83    /**
84     * Same as logDuration except with the logged time returned (or exception thrown)
85     * @return logged time in millis
86     * @throws java.lang.IllegalStateException
87     */
88    public long logDurationAndReturn(String id, boolean isDestructive, String category, String name,
89            String label) throws IllegalStateException {
90        final Long value = isDestructive ? mStartTimes.remove(id) : mStartTimes.get(id);
91        if (value == null) {
92            throw new IllegalStateException("Trying to log id that doesn't exist: " + id);
93        }
94        final long time = SystemClock.uptimeMillis() - value;
95        Analytics.getInstance().sendTiming(category, time, name, label);
96        return time;
97    }
98
99    /**
100     * Removes a previously recorded start time of the provided id, if it exists.
101     */
102    public void stopTracking(String id) {
103        mStartTimes.remove(id);
104    }
105}
106