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 14 namespace base { 15 16 // This module provides some helper functions for logging actions tracked by 17 // the user metrics system. 18 19 // Record that the user performed an action. 20 // This method *must* be called from the main thread. 21 // 22 // "Action" here means a user-generated event: 23 // good: "Reload", "CloseTab", and "IMEInvoked" 24 // not good: "SSLDialogShown", "PageLoaded", "DiskFull" 25 // We use this to gather anonymized information about how users are 26 // interacting with the browser. 27 // WARNING: In calls to this function, UserMetricsAction and a 28 // string literal parameter must be on the same line, e.g. 29 // RecordAction(UserMetricsAction("my extremely long action name")); 30 // This ensures that our processing scripts can associate this action's hash 31 // with its metric name. Therefore, it will be possible to retrieve the metric 32 // name from the hash later on. 33 // 34 // Once a new recorded action is added, run 35 // tools/metrics/actions/extract_actions.py 36 // to add the metric to actions.xml, then update the <owner>s and <description> 37 // sections. Make sure to include the actions.xml file when you upload your code 38 // for review! 39 // 40 // For more complicated situations (like when there are many different 41 // possible actions), see RecordComputedAction. 42 BASE_EXPORT void RecordAction(const UserMetricsAction& action); 43 44 // This function has identical input and behavior to RecordAction, but is 45 // not automatically found by the action-processing scripts. It can be used 46 // when it's a pain to enumerate all possible actions, but if you use this 47 // you need to also update the rules for extracting known actions in 48 // tools/metrics/actions/extract_actions.py. 49 BASE_EXPORT void RecordComputedAction(const std::string& action); 50 51 // Called with the action string. 52 typedef base::Callback<void(const std::string&)> ActionCallback; 53 54 // Add/remove action callbacks (see above). 55 BASE_EXPORT void AddActionCallback(const ActionCallback& callback); 56 BASE_EXPORT void RemoveActionCallback(const ActionCallback& callback); 57 58 } // namespace base 59 60 #endif // BASE_METRICS_USER_METRICS_H_ 61