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 * System independent wrapper for logging runtime information to file. 11 * Note: All log messages will be written to the same trace file. 12 * Note: If too many messages are written to file there will be a build up of 13 * messages. Apply filtering to avoid that. 14 */ 15 16 #ifndef WEBRTC_SYSTEM_WRAPPERS_INTERFACE_TRACE_H_ 17 #define WEBRTC_SYSTEM_WRAPPERS_INTERFACE_TRACE_H_ 18 19 #include "webrtc/common_types.h" 20 #include "webrtc/typedefs.h" 21 22 namespace webrtc { 23 24 #if defined(WEBRTC_RESTRICT_LOGGING) 25 // Disable all TRACE macros. The LOG macro is still functional. 26 #define WEBRTC_TRACE true ? (void) 0 : Trace::Add 27 #else 28 #define WEBRTC_TRACE Trace::Add 29 #endif 30 31 class Trace { 32 public: 33 // The length of the trace text preceeding the log message. 34 static const int kBoilerplateLength; 35 // The position of the timestamp text within a trace. 36 static const int kTimestampPosition; 37 // The length of the timestamp (without "delta" field). 38 static const int kTimestampLength; 39 40 // Increments the reference count to the trace. 41 static void CreateTrace(); 42 // Decrements the reference count to the trace. 43 static void ReturnTrace(); 44 // Note: any instance that writes to the trace file should increment and 45 // decrement the reference count on construction and destruction, 46 // respectively. 47 48 // Specifies what type of messages should be written to the trace file. The 49 // filter parameter is a bitmask where each message type is enumerated by the 50 // TraceLevel enumerator. TODO(hellner): why is the TraceLevel enumerator not 51 // defined in this file? 52 static void set_level_filter(uint32_t filter) { level_filter_ = filter; } 53 54 // Returns what type of messages are written to the trace file. 55 static uint32_t level_filter() { return level_filter_; } 56 57 // Sets the file name. If add_file_counter is false the same file will be 58 // reused when it fills up. If it's true a new file with incremented name 59 // will be used. 60 static int32_t SetTraceFile(const char* file_name, 61 const bool add_file_counter = false); 62 63 // Returns the name of the file that the trace is currently writing to. 64 static int32_t TraceFile(char file_name[1024]); 65 66 // Registers callback to receive trace messages. 67 // TODO(hellner): Why not use OutStream instead? Why is TraceCallback not 68 // defined in this file? 69 static int32_t SetTraceCallback(TraceCallback* callback); 70 71 // Adds a trace message for writing to file. The message is put in a queue 72 // for writing to file whenever possible for performance reasons. I.e. there 73 // is a crash it is possible that the last, vital logs are not logged yet. 74 // level is the type of message to log. If that type of messages is 75 // filtered it will not be written to file. module is an identifier for what 76 // part of the code the message is coming. 77 // id is an identifier that should be unique for that set of classes that 78 // are associated (e.g. all instances owned by an engine). 79 // msg and the ellipsis are the same as e.g. sprintf. 80 // TODO(hellner) Why is TraceModule not defined in this file? 81 static void Add(const TraceLevel level, 82 const TraceModule module, 83 const int32_t id, 84 const char* msg, ...); 85 86 private: 87 static uint32_t level_filter_; 88 }; 89 90 } // namespace webrtc 91 92 #endif // WEBRTC_SYSTEM_WRAPPERS_INTERFACE_TRACE_H_ 93
