OVR_Log.h
Go to the documentation of this file.
00001 /************************************************************************************
00002 
00003 PublicHeader:   OVR
00004 Filename    :   OVR_Log.h
00005 Content     :   Logging support
00006 Created     :   September 19, 2012
00007 Notes       : 
00008 
00009 Copyright   :   Copyright 2012 Oculus VR, Inc. All Rights reserved.
00010 
00011 Use of this software is subject to the terms of the Oculus license
00012 agreement provided at the time of installation or download, or which
00013 otherwise accompanies this software in either electronic or hard copy form.
00014 
00015 ************************************************************************************/
00016 
00017 #ifndef OVR_Log_h
00018 #define OVR_Log_h
00019 
00020 #include "OVR_Types.h"
00021 #include <stdarg.h>
00022 
00023 namespace OVR {
00024 
00025 //-----------------------------------------------------------------------------------
00026 // ***** Logging Constants
00027 
00028 // LogMaskConstants defined bit mask constants that describe what log messages
00029 // should be displayed.
00030 enum LogMaskConstants
00031 {
00032     LogMask_Regular = 0x100,
00033     LogMask_Debug   = 0x200,
00034     LogMask_None    = 0,
00035     LogMask_All     = LogMask_Regular|LogMask_Debug
00036 };
00037 
00038 
00039 // LogMessageType describes the type of the log message, controls when it is
00040 // displayed and what prefix/suffix is given to it. Messages are subdivided into
00041 // regular and debug logging types. Debug logging is only generated in debug builds.
00042 //
00043 // Log_Text         - General output text displayed without prefix or new-line.
00044 //                    Used in OVR libraries for general log flow messages
00045 //                    such as "Device Initialized".
00046 //
00047 // Log_Error        - Error message output with "Error: %s\n", intended for
00048 //                    application/sample-level use only, in cases where an expected
00049 //                    operation failed. OVR libraries should not use this internally,
00050 //                    reporting status codes instead.
00051 //
00052 // Log_DebugText    - Message without prefix or new lines; output in Debug build only.
00053 //
00054 // Log_Debug        - Debug-build only message, formatted with "Debug: %s\n".
00055 //                    Intended to comment on incorrect API usage that doesn't lead
00056 //                    to crashes but can be avoided with proper use.
00057 //                    There is no Debug Error on purpose, since real errors should
00058 //                    be handled by API user.
00059 //
00060 // Log_Assert      -  Debug-build only message, formatted with "Assert: %s\n".
00061 //                    Intended for severe unrecoverable conditions in library
00062 //                    source code. Generated though OVR_ASSERT_MSG(c, "Text").
00063 
00064 enum LogMessageType
00065 {    
00066     // General Logging
00067     Log_Text        = LogMask_Regular | 0,    
00068     Log_Error       = LogMask_Regular | 1, // "Error: %s\n".
00069     
00070     // Debug-only messages (not generated in release build)
00071     Log_DebugText   = LogMask_Debug | 0,
00072     Log_Debug       = LogMask_Debug | 1,   // "Debug: %s\n".
00073     Log_Assert      = LogMask_Debug | 2,   // "Assert: %s\n".
00074 };
00075 
00076 
00077 // LOG_VAARG_ATTRIBUTE macro, enforces printf-style fromatting for message types
00078 #ifdef __GNUC__
00079 #  define OVR_LOG_VAARG_ATTRIBUTE(a,b) __attribute__((format (printf, a, b)))
00080 #else
00081 #  define OVR_LOG_VAARG_ATTRIBUTE(a,b)
00082 #endif
00083 
00084 
00085 //-----------------------------------------------------------------------------------
00086 // ***** Log
00087 
00088 // Log defines a base class interface that can be implemented to catch both
00089 // debug and runtime messages.
00090 // Debug logging can be overridden by calling Log::SetGlobalLog.
00091 
00092 class Log
00093 {
00094     friend class System;
00095 public: 
00096     Log(unsigned logMask = LogMask_Debug) : LoggingMask(logMask) { }
00097     virtual ~Log();
00098 
00099     // Log formating buffer size used by default LogMessageVarg. Longer strings are truncated.
00100     enum { MaxLogBufferMessageSize = 2048 };
00101 
00102     unsigned        GetLoggingMask() const            { return LoggingMask; }
00103     void            SetLoggingMask(unsigned logMask)  { LoggingMask = logMask; }
00104 
00105     // This virtual function receives all the messages,
00106     // developers should override this function in order to do custom logging
00107     virtual void    LogMessageVarg(LogMessageType messageType, const char* fmt, va_list argList);
00108 
00109     // Call the logging function with specific message type, with no type filtering.
00110     void            LogMessage(LogMessageType messageType,
00111                                const char* fmt, ...) OVR_LOG_VAARG_ATTRIBUTE(3,4);
00112 
00113 
00114     // Helper used by LogMessageVarg to format the log message, writing the resulting
00115     // string into buffer. It formats text based on fmt and appends prefix/new line
00116     // based on LogMessageType.
00117     static void     FormatLog(char* buffer, unsigned bufferSize, LogMessageType messageType,
00118                               const char* fmt, va_list argList);
00119 
00120     // Default log output implementation used by by LogMessageVarg.
00121     // Debug flag may be used to re-direct output on some platforms, but doesn't
00122     // necessarily disable it in release builds; that is the job of the called.    
00123     static void     DefaultLogOutput(const char* textBuffer, bool debug);
00124 
00125     // Determines if the specified message type is for debugging only.
00126     static bool     IsDebugMessage(LogMessageType messageType)
00127     {
00128         return (messageType & LogMask_Debug) != 0;
00129     }
00130 
00131     // *** Global APIs
00132 
00133     // Global Log registration APIs.
00134     //  - Global log is used for OVR_DEBUG messages. Set global log to null (0)
00135     //    to disable all logging.
00136     static void     SetGlobalLog(Log *log);
00137     static Log*     GetGlobalLog();
00138 
00139     // Returns default log singleton instance.
00140     static Log*     GetDefaultLog();
00141 
00142     // Applies logMask to the default log and returns a pointer to it.
00143     // By default, only Debug logging is enabled, so to avoid SDK generating console
00144     // messages in user app (those are always disabled in release build,
00145     // even if the flag is set). This function is useful in System constructor.
00146     static Log*     ConfigureDefaultLog(unsigned logMask = LogMask_Debug)
00147     {
00148         Log* log = GetDefaultLog();
00149         log->SetLoggingMask(logMask);
00150         return log;
00151     }
00152 
00153 private:
00154     // Logging mask described by LogMaskConstants.
00155     unsigned    LoggingMask;
00156 };
00157 
00158 
00159 //-----------------------------------------------------------------------------------
00160 // ***** Global Logging Functions and Debug Macros
00161 
00162 // These functions will output text to global log with semantics described by
00163 // their LogMessageType.
00164 void LogText(const char* fmt, ...) OVR_LOG_VAARG_ATTRIBUTE(1,2);
00165 void LogError(const char* fmt, ...) OVR_LOG_VAARG_ATTRIBUTE(1,2);
00166 
00167 #ifdef OVR_BUILD_DEBUG
00168 
00169     // Debug build only logging.
00170     void LogDebugText(const char* fmt, ...) OVR_LOG_VAARG_ATTRIBUTE(1,2);
00171     void LogDebug(const char* fmt, ...) OVR_LOG_VAARG_ATTRIBUTE(1,2);
00172     void LogAssert(const char* fmt, ...) OVR_LOG_VAARG_ATTRIBUTE(1,2);
00173 
00174     // Macro to do debug logging, printf-style.
00175     // An extra set of set of parenthesis must be used around arguments,
00176     // as in: OVR_LOG_DEBUG(("Value %d", 2)).
00177     #define OVR_DEBUG_LOG(args)       do { OVR::LogDebug args; } while(0)
00178     #define OVR_DEBUG_LOG_TEXT(args)  do { OVR::LogDebugText args; } while(0)
00179 
00180     #define OVR_ASSERT_LOG(c, args)   do { if (!(c)) { OVR::LogAssert args; OVR_DEBUG_BREAK; } } while(0)
00181 
00182 #else
00183 
00184     // If not in debug build, macros do nothing.
00185     #define OVR_DEBUG_LOG(args)         ((void)0)
00186     #define OVR_DEBUG_LOG_TEXT(args)    ((void)0)
00187     #define OVR_ASSERT_LOG(c, args)     ((void)0)
00188 
00189 #endif
00190 
00191 } // OVR 
00192 
00193 #endif


oculus_sdk
Author(s):
autogenerated on Fri Aug 28 2015 11:53:11