Trace category groups and category filter.

base/debug/trace_event_impl.h

Index: base/debug/trace_event_impl.h
diff --git a/base/debug/trace_event_impl.h b/base/debug/trace_event_impl.h
index f152b0a413b4302e51191518b2c3993252d15d70..16361b1eedac4d3f01e5326bb57a06177d251007 100644
--- a/base/debug/trace_event_impl.h
+++ b/base/debug/trace_event_impl.h
@@ -157,6 +157,55 @@ class BASE_EXPORT TraceResultBuffer {
   bool append_comma_;
 };
 
+class BASE_EXPORT CategoryFilter {
+  // The default category filter, used when none is provided.
+  // Allows all categories through, except if they end in the suffix 'Debug' or
+  // 'Test'.
+  static const char* kDefaultCategoryFilterString;
+
+  public:
+  // Constructs the default category filter. This is equivalent to
+  // CategoryFilter(CategoryFilter::kDefaultCategoryFilterString);
+  CategoryFilter();
+
+  // |filter_string| is a comma-delimited list of category wildcards.
+  // A category can have an optional '-' prefix to make it an excluded category.
+  // All the same rules apply above, so for example, having both included and
+  // excluded categories in the same list would not be supported.
+  //
+  // Example: SetEnabled("test_MyTest*");
+  // Example: SetEnabled("test_MyTest*,test_OtherStuff");
+  // Example: SetEnabled("-excluded_category1,-excluded_category2");
+  CategoryFilter(const std::string& filter_string);
+
+  // Writes the string representation of the CategoryFilter. This is a comma
+  // separated string, similar in nature to the one used to determine
+  // enabled/disabled category patterns, except here there is an arbitrary
+  // order, included categories go first, then excluded categories. Excluded
+  // categories are distinguished from included categories by the prefix '-'.
+  void ToString(std::string* filter_string) const;
+
+  // Determines whether category group would be enabled or
+  // disabled by this filter.
+  bool IsCategoryGroupEnabled(const char* category_group) const;
+
+  // Merges nested_filter with the current CategoryFilter
+  void Merge(const CategoryFilter& nested_filter);
+
+  // Determines whether or not we have included category patterns.
+  bool HasIncludedCategories() const;
+
+  // Clears both included/excluded pattern lists.
+  void Clear();
+
+private:
+  void Initialize(const std::string& filter_string);
+  void WriteString(std::string* out, bool included) const;
+
+  std::vector<std::string> included_;
+  std::vector<std::string> excluded_;
+
+};
 
 class BASE_EXPORT TraceLog {
  public:
@@ -172,40 +221,22 @@ class BASE_EXPORT TraceLog {
 
   static TraceLog* GetInstance();
 
-  // Get set of known categories. This can change as new code paths are reached.
-  // The known categories are inserted into |categories|.
-  void GetKnownCategories(std::vector<std::string>* categories);
-
-  // Enable tracing for provided list of categories. If tracing is already
-  // enabled, this method does nothing -- changing categories during trace is
-  // not supported.
-  // If both included_categories and excluded_categories are empty,
-  //   all categories are traced.
-  // Else if included_categories is non-empty, only those are traced.
-  // Else if excluded_categories is non-empty, everything but those are traced.
-  // Wildcards * and ? are supported (see MatchPattern in string_util.h).
-  void SetEnabled(const std::vector<std::string>& included_categories,
-                  const std::vector<std::string>& excluded_categories);
-
-  // |categories| is a comma-delimited list of category wildcards.
-  // A category can have an optional '-' prefix to make it an excluded category.
-  // All the same rules apply above, so for example, having both included and
-  // excluded categories in the same list would not be supported.
-  //
-  // Example: SetEnabled("test_MyTest*");
-  // Example: SetEnabled("test_MyTest*,test_OtherStuff");
-  // Example: SetEnabled("-excluded_category1,-excluded_category2");
-  void SetEnabled(const std::string& categories);
+  // Get set of known category groups. This can change as new code paths are
+  // reached. The known category groups are inserted into |category_groups|.
+  void GetKnownCategories(std::vector<std::string>* category_groups);
 
-  // Retieves the categories set via a prior call to SetEnabled(). Only
-  // meaningful if |IsEnabled()| is true.
-  void GetEnabledTraceCategories(std::vector<std::string>* included_out,
-                                 std::vector<std::string>* excluded_out);
+  // Enables tracing. See CategoryFilter comments for details
+  // on how to control what categories will be traced.
+  void SetEnabled(const CategoryFilter& category_filter);
 
   // Disable tracing for all categories.
   void SetDisabled();
+
+  // Retieves the current filter used to enable categories. Only
+  // meaningful if |IsEnabled()| is true.
+  CategoryFilter& GetCurrentCategoryFilter();
+
   // Helper method to enable/disable tracing for all categories.
-  void SetEnabled(bool enabled);
   bool IsEnabled() { return !!enable_count_; }
 
 #if defined(OS_ANDROID)
@@ -251,6 +282,8 @@ class BASE_EXPORT TraceLog {
   void Flush(const OutputCallback& cb);
 
   // Called by TRACE_EVENT* macros, don't call this directly.
+  // The name parameter is a category group for example:
+  // TRACE_EVENT0("renderer,webkit", "WebViewImpl::HandleInputEvent")
   static const unsigned char* GetCategoryEnabled(const char* name);
   static const char* GetCategoryName(const unsigned char* category_enabled);
 
@@ -325,8 +358,16 @@ class BASE_EXPORT TraceLog {
   // by the Singleton class.
   friend struct StaticMemorySingletonTraits<TraceLog>;
 
-  // The pointer returned from GetCategoryEnabledInternal() points to a value
-  // with zero or more of the following bits. Used in this class only.
+  // Enable/disable each category group based on the given |category_filter|.
+  // If the category group contains a category that matches an included category
+  // pattern, that category group will be enabled.
+  static void EnableIncludedCategoryGroups(
+                                         const CategoryFilter& category_filter);
+  static void EnableIncludedCategoryGroup(int category_index,
+                                         const CategoryFilter& category_filter);
+
+  // The pointer returned from GetCategoryGroupEnabledInternal() points to a
+  // value with zero or more of the following bits. Used in this class only.
   // The TRACE_EVENT macros should only use the value as a bool.
   enum CategoryEnabledFlags {
     // Normal enabled flag for categories enabled with Enable().
@@ -382,8 +423,7 @@ class BASE_EXPORT TraceLog {
   int enable_count_;
   NotificationCallback notification_callback_;
   std::vector<TraceEvent> logged_events_;
-  std::vector<std::string> included_categories_;
-  std::vector<std::string> excluded_categories_;
+  CategoryFilter category_filter_;
   bool dispatching_to_observer_list_;
   ObserverList<EnabledStateChangedObserver> enabled_state_observer_list_;