speed up logging by only creating formatted log messages when the log level is appropriate (#2685)

Source/Urho3D/IO/Log.cpp

@@ -22,6 +22,7 @@
 
 #include "../Precompiled.h"
 
+#include "../Container/Str.h"
 #include "../Core/Context.h"
 #include "../Core/CoreEvents.h"
 #include "../Core/ProcessUtils.h"
@@ -135,6 +136,21 @@ void Log::SetQuiet(bool quiet)
     quiet_ = quiet;
 }
 
+void Log::WriteFormat(int level, const char* format, ...)
+{
+    if (!logInstance || logInstance->level_ > level)
+        return;
+
+    // Forward to normal Write() after formatting the input
+    String message;
+    va_list args;
+    va_start(args, format);
+    message.AppendWithFormatArgs(format, args);
+    va_end(args);
+
+    Write(level, message);
+}
+
 void Log::Write(int level, const String& message)
 {
     // Special case for LOG_RAW level

Source/Urho3D/IO/Log.h

@@ -113,6 +113,8 @@ public:
     /// Write to the log. If logging level is higher than the level of the message, the message is ignored.
     /// @nobind
     static void Write(int level, const String& message);
+    /// Write formatted message to the log. If logging level is higher than the level of the message, the message is ignored.
+    static void WriteFormat(int level, const char* format, ...);
     /// Write raw output to the log.
     static void WriteRaw(const String& message, bool error = false);
 
@@ -139,25 +141,32 @@ private:
 };
 
 #ifdef URHO3D_LOGGING
+#define URHO3D_LOG(level, message) Urho3D::Log::Write(level, message)
 #define URHO3D_LOGTRACE(message) Urho3D::Log::Write(Urho3D::LOG_TRACE, message)
 #define URHO3D_LOGDEBUG(message) Urho3D::Log::Write(Urho3D::LOG_DEBUG, message)
 #define URHO3D_LOGINFO(message) Urho3D::Log::Write(Urho3D::LOG_INFO, message)
 #define URHO3D_LOGWARNING(message) Urho3D::Log::Write(Urho3D::LOG_WARNING, message)
 #define URHO3D_LOGERROR(message) Urho3D::Log::Write(Urho3D::LOG_ERROR, message)
-#define URHO3D_LOGRAW(message) Urho3D::Log::WriteRaw(message)
-#define URHO3D_LOGTRACEF(format, ...) Urho3D::Log::Write(Urho3D::LOG_TRACE, Urho3D::ToString(format, ##__VA_ARGS__))
-#define URHO3D_LOGDEBUGF(format, ...) Urho3D::Log::Write(Urho3D::LOG_DEBUG, Urho3D::ToString(format, ##__VA_ARGS__))
-#define URHO3D_LOGINFOF(format, ...) Urho3D::Log::Write(Urho3D::LOG_INFO, Urho3D::ToString(format, ##__VA_ARGS__))
-#define URHO3D_LOGWARNINGF(format, ...) Urho3D::Log::Write(Urho3D::LOG_WARNING, Urho3D::ToString(format, ##__VA_ARGS__))
-#define URHO3D_LOGERRORF(format, ...) Urho3D::Log::Write(Urho3D::LOG_ERROR, Urho3D::ToString(format, ##__VA_ARGS__))
-#define URHO3D_LOGRAWF(format, ...) Urho3D::Log::WriteRaw(Urho3D::ToString(format, ##__VA_ARGS__))
+#define URHO3D_LOGRAW(message) Urho3D::Log::Write(Urho3D::LOG_RAW, message)
+
+#define URHO3D_LOGF(level, format, ...) Urho3D::Log::WriteFormat(level, format, ##__VA_ARGS__)
+#define URHO3D_LOGTRACEF(format, ...) Urho3D::Log::WriteFormat(Urho3D::LOG_TRACE, format, ##__VA_ARGS__)
+#define URHO3D_LOGDEBUGF(format, ...) Urho3D::Log::WriteFormat(Urho3D::LOG_DEBUG, format, ##__VA_ARGS__)
+#define URHO3D_LOGINFOF(format, ...) Urho3D::Log::WriteFormat(Urho3D::LOG_INFO, format, ##__VA_ARGS__)
+#define URHO3D_LOGWARNINGF(format, ...) Urho3D::Log::WriteFormat(Urho3D::LOG_WARNING, format, ##__VA_ARGS__)
+#define URHO3D_LOGERRORF(format, ...) Urho3D::Log::WriteFormat(Urho3D::LOG_ERROR, format, ##__VA_ARGS__)
+#define URHO3D_LOGRAWF(format, ...) Urho3D::Log::WriteFormat(Urho3D::LOG_RAW, format, ##__VA_ARGS__)
+
 #else
+#define URHO3D_LOG(message) ((void)0)
 #define URHO3D_LOGTRACE(message) ((void)0)
 #define URHO3D_LOGDEBUG(message) ((void)0)
 #define URHO3D_LOGINFO(message) ((void)0)
 #define URHO3D_LOGWARNING(message) ((void)0)
 #define URHO3D_LOGERROR(message) ((void)0)
 #define URHO3D_LOGRAW(message) ((void)0)
+
+#define URHO3D_LOGF(...) ((void)0)
 #define URHO3D_LOGTRACEF(...) ((void)0)
 #define URHO3D_LOGDEBUGF(...) ((void)0)
 #define URHO3D_LOGINFOF(...) ((void)0)