1 // Copyright 2014 The Chromium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #ifndef BASE_METRICS_USER_METRICS_H_ 6 #define BASE_METRICS_USER_METRICS_H_ 7 8 #include <string> 9 10 #include "base/base_export.h" 11 #include "base/callback.h" 12 #include "base/metrics/user_metrics_action.h" 13 #include "base/single_thread_task_runner.h" 14 15 namespace base { 16 17 // This module provides some helper functions for logging actions tracked by 18 // the user metrics system. 19 20 // Record that the user performed an action. 21 // This function must be called after the task runner has been set with 22 // SetRecordActionTaskRunner(). 23 // 24 // "Action" here means a user-generated event: 25 // good: "Reload", "CloseTab", and "IMEInvoked" 26 // not good: "SSLDialogShown", "PageLoaded", "DiskFull" 27 // We use this to gather anonymized information about how users are 28 // interacting with the browser. 29 // WARNING: In calls to this function, UserMetricsAction should be followed by a 30 // string literal parameter and not a variable e.g. 31 // RecordAction(UserMetricsAction("my action name")); 32 // This ensures that our processing scripts can associate this action's hash 33 // with its metric name. Therefore, it will be possible to retrieve the metric 34 // name from the hash later on. 35 // 36 // Once a new recorded action is added, run 37 // tools/metrics/actions/extract_actions.py 38 // to add the metric to actions.xml, then update the <owner>s and <description> 39 // sections. Make sure to include the actions.xml file when you upload your code 40 // for review! 41 // 42 // For more complicated situations (like when there are many different 43 // possible actions), see RecordComputedAction(). 44 BASE_EXPORT void RecordAction(const UserMetricsAction& action); 45 46 // This function has identical input and behavior to RecordAction(), but is 47 // not automatically found by the action-processing scripts. It can be used 48 // when it's a pain to enumerate all possible actions, but if you use this 49 // you need to also update the rules for extracting known actions in 50 // tools/metrics/actions/extract_actions.py. 51 // This function must be called after the task runner has been set with 52 // SetRecordActionTaskRunner(). 53 BASE_EXPORT void RecordComputedAction(const std::string& action); 54 55 // Called with the action string. 56 typedef Callback<void(const std::string&)> ActionCallback; 57 58 // Add/remove action callbacks (see above). 59 // These functions must be called after the task runner has been set with 60 // SetRecordActionTaskRunner(). 61 BASE_EXPORT void AddActionCallback(const ActionCallback& callback); 62 BASE_EXPORT void RemoveActionCallback(const ActionCallback& callback); 63 64 // Set the task runner on which to record actions. 65 BASE_EXPORT void SetRecordActionTaskRunner( 66 scoped_refptr<SingleThreadTaskRunner> task_runner); 67 68 } // namespace base 69 70 #endif // BASE_METRICS_USER_METRICS_H_ 71