LogTrace.h

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// Copyright Epic Games, Inc. All Rights Reserved.
 
#pragma once
 
#include "CoreTypes.h"
#include "Containers/Array.h"
#include "HAL/PreprocessorHelpers.h"
#include "Logging/LogVerbosity.h"
#include "Misc/Build.h"
#include "Templates/IsArrayOrRefOfTypeByPredicate.h"
#include "Trace/Config.h"
#include "Trace/Trace.h"
#include "Traits/IsCharEncodingCompatibleWith.h"
 
#if !defined(LOGTRACE_ENABLED)
#if UE_TRACE_ENABLED && !UE_BUILD_SHIPPING
#define LOGTRACE_ENABLED 1
#else
#define LOGTRACE_ENABLED 0
#endif
#endif
 
#if LOGTRACE_ENABLED
#include "ProfilingDebugging/FormatArgsTrace.h"
 
#if !defined(LOGTRACE_RUNTIME_FORMATTING_ENABLED)
#define LOGTRACE_RUNTIME_FORMATTING_ENABLED 1
#endif
 
UE_TRACE_CHANNEL_EXTERN(LogChannel, CORE_API)
 
struct FLogCategoryBase;
namespace UE { namespace Trace { class FChannel; } }
 
struct FLogTrace
{
    CORE_API static void OutputLogCategory(const FLogCategoryBase* Category, const TCHAR* Name, ELogVerbosity::Type DefaultVerbosity);
    CORE_API static void OutputLogMessageSpec(const void* LogPoint, const FLogCategoryBase* Category, ELogVerbosity::Type Verbosity, const ANSICHAR* File, int32 Line, const TCHAR* Format);
    CORE_API static void OutputLogMessageSimple(const void* LogPoint, const TCHAR* Fmt, ...);
 
    template <typename... Types>
    FORCENOINLINE static void OutputLogMessage(const void* LogPoint, Types... FormatArgs)
    {
        // This inline size covers 99.96% of log messages in sampled traces
        FFormatArgsTrace::TBufferWithOverflow<1600> Buffer;
        const int32 FormatArgsSize = FFormatArgsTrace::EncodeArgumentsWithArray(Buffer, FormatArgs...);
        const uint8* FormatArgsBuffer = Buffer.GetData();
        if (FormatArgsSize && FormatArgsSize < INT32_MAX)
        {
            OutputLogMessageInternal(LogPoint, FormatArgsSize, FormatArgsBuffer);
        }
    }
 
private:
    CORE_API static void OutputLogMessageInternal(const void* LogPoint, int32 EncodedFormatArgsSize, const uint8* EncodedFormatArgs);
};
 
#define TRACE_LOG_CATEGORY(Category, Name, DefaultVerbosity) \
    FLogTrace::OutputLogCategory(Category, Name, DefaultVerbosity);
 
#if LOGTRACE_RUNTIME_FORMATTING_ENABLED
#define TRACE_LOG_MESSAGE(Category, Verbosity, Format, ...) \
    if (UE_TRACE_CHANNELEXPR_IS_ENABLED(LogChannel)) \
    { \
        static bool PREPROCESSOR_JOIN(__LogPoint, __LINE__); \
        if (!PREPROCESSOR_JOIN(__LogPoint, __LINE__)) \
        { \
            FLogTrace::OutputLogMessageSpec(&PREPROCESSOR_JOIN(__LogPoint, __LINE__), &Category, ELogVerbosity::Verbosity, __FILE__, __LINE__, TEXT("%s")); \
            PREPROCESSOR_JOIN(__LogPoint, __LINE__) = true; \
        } \
        FLogTrace::OutputLogMessageSimple(&PREPROCESSOR_JOIN(__LogPoint, __LINE__), Format, ##__VA_ARGS__); \
    }
#else
#define TRACE_LOG_MESSAGE(Category, Verbosity, Format, ...) \
    static_assert(TIsArrayOrRefOfTypeByPredicate<decltype(Format), TIsCharEncodingCompatibleWithTCHAR>::Value, "Formatting string must be a TCHAR array."); \
    if (UE_TRACE_CHANNELEXPR_IS_ENABLED(LogChannel)) \
    { \
        static bool PREPROCESSOR_JOIN(__LogPoint, __LINE__); \
        if (!PREPROCESSOR_JOIN(__LogPoint, __LINE__)) \
        { \
            FLogTrace::OutputLogMessageSpec(&PREPROCESSOR_JOIN(__LogPoint, __LINE__), &Category, ELogVerbosity::Verbosity, __FILE__, __LINE__, (const TCHAR*)Format); \
            PREPROCESSOR_JOIN(__LogPoint, __LINE__) = true; \
        } \
        FLogTrace::OutputLogMessage(&PREPROCESSOR_JOIN(__LogPoint, __LINE__), ##__VA_ARGS__); \
    }
#endif
 
#else
#define TRACE_LOG_CATEGORY(Category, Name, DefaultVerbosity)
#define TRACE_LOG_MESSAGE(Category, Verbosity, Format, ...)
#endif