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 // For best practices on deciding when to emit a user action, see 21 // https://chromium.googlesource.com/chromium/src.git/+/HEAD/tools/metrics/actions/README.md 22 23 // Record that the user performed an action. 24 // This function must be called after the task runner has been set with 25 // SetRecordActionTaskRunner(). 26 // 27 // "Action" here means a user-generated event: 28 // good: "Reload", "CloseTab", and "IMEInvoked" 29 // not good: "SSLDialogShown", "PageLoaded", "DiskFull" 30 // We use this to gather anonymized information about how users are 31 // interacting with the browser. 32 // WARNING: In calls to this function, UserMetricsAction should be followed by a 33 // string literal parameter and not a variable e.g. 34 // RecordAction(UserMetricsAction("my action name")); 35 // This ensures that our processing scripts can associate this action's hash 36 // with its metric name. Therefore, it will be possible to retrieve the metric 37 // name from the hash later on. 38 // 39 // Once a new recorded action is added, run 40 // tools/metrics/actions/extract_actions.py 41 // to add the metric to actions.xml, then update the <owner>s and <description> 42 // sections. Make sure to include the actions.xml file when you upload your code 43 // for review! 44 // 45 // For more complicated situations (like when there are many different 46 // possible actions), see RecordComputedAction(). 47 BASE_EXPORT void RecordAction(const UserMetricsAction& action); 48 49 // This function has identical input and behavior to RecordAction(), but is 50 // not automatically found by the action-processing scripts. It can be used 51 // when it's a pain to enumerate all possible actions, but if you use this 52 // you need to also update the rules for extracting known actions in 53 // tools/metrics/actions/extract_actions.py. 54 // This function must be called after the task runner has been set with 55 // SetRecordActionTaskRunner(). 56 BASE_EXPORT void RecordComputedAction(const std::string& action); 57 58 // Called with the action string. 59 typedef Callback<void(const std::string&)> ActionCallback; 60 61 // Add/remove action callbacks (see above). 62 // These functions must be called after the task runner has been set with 63 // SetRecordActionTaskRunner(). 64 BASE_EXPORT void AddActionCallback(const ActionCallback& callback); 65 BASE_EXPORT void RemoveActionCallback(const ActionCallback& callback); 66 67 // Set the task runner on which to record actions. 68 BASE_EXPORT void SetRecordActionTaskRunner( 69 scoped_refptr<SingleThreadTaskRunner> task_runner); 70 71 } // namespace base 72 73 #endif // BASE_METRICS_USER_METRICS_H_ 74