OLD | NEW |
(Empty) | |
| 1 // Copyright 2016 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_TRACE_EVENT_TRACE_EVENT_FILTER_H_ |
| 6 #define BASE_TRACE_EVENT_TRACE_EVENT_FILTER_H_ |
| 7 |
| 8 #include <memory> |
| 9 |
| 10 #include "base/base_export.h" |
| 11 #include "base/macros.h" |
| 12 |
| 13 namespace base { |
| 14 namespace trace_event { |
| 15 |
| 16 class TraceEvent; |
| 17 |
| 18 // TraceEventFilter is like iptables for TRACE_EVENT macros. Filters can be |
| 19 // enabled on a per-category basis, hence a single filter instance can serve |
| 20 // more than a TraceCategory. There are two use cases for filters: |
| 21 // 1. Snooping TRACE_EVENT macros without adding them to the TraceLog. This is |
| 22 // possible by setting the ENABLED_FOR_FILTERING flag on a category w/o |
| 23 // ENABLED_FOR_RECORDING (see TraceConfig for user-facing configuration). |
| 24 // 2. Filtering TRACE_EVENT macros before they are added to the TraceLog. This |
| 25 // requires both the ENABLED_FOR_FILTERING and ENABLED_FOR_RECORDING flags |
| 26 // on the category. |
| 27 // More importantly, filters must be thread-safe. The FilterTraceEvent and |
| 28 // EndEvent methods can be called concurrently as trace macros are hit on |
| 29 // different threads. |
| 30 class BASE_EXPORT TraceEventFilter { |
| 31 public: |
| 32 TraceEventFilter(); |
| 33 virtual ~TraceEventFilter(); |
| 34 |
| 35 // If the category is ENABLED_FOR_RECORDING, the event is added iff all the |
| 36 // filters enabled for the category return true. false causes the event to be |
| 37 // discarded. |
| 38 virtual bool FilterTraceEvent(const TraceEvent& trace_event) const = 0; |
| 39 |
| 40 // Notifies the end of a duration event when the RAII macro goes out of scope. |
| 41 virtual void EndEvent(const char* category_name, |
| 42 const char* event_name) const; |
| 43 |
| 44 private: |
| 45 DISALLOW_COPY_AND_ASSIGN(TraceEventFilter); |
| 46 }; |
| 47 |
| 48 } // namespace trace_event |
| 49 } // namespace base |
| 50 |
| 51 #endif // BASE_TRACE_EVENT_TRACE_EVENT_FILTER_H_ |
OLD | NEW |