1 /*
2  *  Copyright (c) 2012 The WebRTC project authors. All Rights Reserved.
3  *
4  *  Use of this source code is governed by a BSD-style license
5  *  that can be found in the LICENSE file in the root of the source
6  *  tree. An additional intellectual property rights grant can be found
7  *  in the file PATENTS.  All contributing project authors may
8  *  be found in the AUTHORS file in the root of the source tree.
9  */
10 
11 // This file defines the interface for event tracing in WebRTC.
12 //
13 // Event log handlers are set through SetupEventTracer(). User of this API will
14 // provide two function pointers to handle event tracing calls.
15 //
16 // * GetCategoryEnabledPtr
17 //   Event tracing system calls this function to determine if a particular
18 //   event category is enabled.
19 //
20 // * AddTraceEventPtr
21 //   Adds a tracing event. It is the user's responsibility to log the data
22 //   provided.
23 //
24 // Parameters for the above two functions are described in trace_event.h.
25 
26 #ifndef RTC_BASE_EVENT_TRACER_H_
27 #define RTC_BASE_EVENT_TRACER_H_
28 
29 #include <stdio.h>
30 
31 namespace webrtc {
32 
33 typedef const unsigned char* (*GetCategoryEnabledPtr)(const char* name);
34 typedef void (*AddTraceEventPtr)(char phase,
35                                  const unsigned char* category_enabled,
36                                  const char* name,
37                                  unsigned long long id,
38                                  int num_args,
39                                  const char** arg_names,
40                                  const unsigned char* arg_types,
41                                  const unsigned long long* arg_values,
42                                  unsigned char flags);
43 
44 // User of WebRTC can call this method to setup event tracing.
45 //
46 // This method must be called before any WebRTC methods. Functions
47 // provided should be thread-safe.
48 void SetupEventTracer(GetCategoryEnabledPtr get_category_enabled_ptr,
49                       AddTraceEventPtr add_trace_event_ptr);
50 
51 // This class defines interface for the event tracing system to call
52 // internally. Do not call these methods directly.
53 class EventTracer {
54  public:
55   static const unsigned char* GetCategoryEnabled(const char* name);
56 
57   static void AddTraceEvent(char phase,
58                             const unsigned char* category_enabled,
59                             const char* name,
60                             unsigned long long id,
61                             int num_args,
62                             const char** arg_names,
63                             const unsigned char* arg_types,
64                             const unsigned long long* arg_values,
65                             unsigned char flags);
66 };
67 
68 }  // namespace webrtc
69 
70 namespace rtc {
71 namespace tracing {
72 // Set up internal event tracer.
73 void SetupInternalTracer();
74 bool StartInternalCapture(const char* filename);
75 void StartInternalCaptureToFile(FILE* file);
76 void StopInternalCapture();
77 // Make sure we run this, this will tear down the internal tracing.
78 void ShutdownInternalTracer();
79 }  // namespace tracing
80 }  // namespace rtc
81 
82 #endif  // RTC_BASE_EVENT_TRACER_H_
83