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      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  */
     16 package com.android.mail.analytics;
     17 
     18 import android.os.SystemClock;
     19 
     20 import com.google.common.collect.Maps;
     21 
     22 import 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  */
     33 public 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