Add basic support for log contexts.

Source/Engine/Core/Types/LogContexts.cpp

@@ -0,0 +1,43 @@
+#include "LogContexts.h"
+#include "Engine/Core/Types/Guid.h"
+#include "Engine/Core/Types/String.h"
+#include "Engine/Core/Collections/Array.h"
+
+ThreadLocal<LogContextStack> LogContexts::CurrentLogContext;
+
+String LogContextFormatter::Format()
+{
+    LogContextData context = LogContexts::Get();
+    if (context.ObjectID != Guid::Empty)
+        return String::Format(TEXT("(Loading source was {0})"), context.ObjectID);
+
+    return String("");
+}
+
+void LogContexts::Set(const Guid& id)
+{
+    LogContextData context = LogContextData();
+    context.ObjectID = id;
+
+    LogContextStack contextStack = LogContexts::CurrentLogContext.Get();
+    contextStack.Stack.Push(context);
+
+    LogContexts::CurrentLogContext.Set(contextStack);
+}
+
+void LogContexts::Clear()
+{
+    LogContextStack contextStack = LogContexts::CurrentLogContext.Get();
+    contextStack.Stack.Pop();
+
+    LogContexts::CurrentLogContext.Set(contextStack);
+}
+
+LogContextData LogContexts::Get()
+{
+    LogContextStack contextStack = LogContexts::CurrentLogContext.Get();
+    if (contextStack.Stack.Count() == 0)
+        return LogContextData();
+
+    return contextStack.Stack.Last();
+}

Source/Engine/Core/Types/LogContexts.h

@@ -0,0 +1,91 @@
+#pragma once
+#include "Engine/Core/Config.h"
+#include "Engine/Scripting/ScriptingType.h"
+#include "Engine/Threading/ThreadLocal.h"
+
+class String;
+struct Guid;
+
+/// <summary>
+/// Log context data structure. Contains different kinds of context data for different situtations.
+/// </summary>
+API_STRUCT() struct FLAXENGINE_API LogContextData
+{
+    DECLARE_SCRIPTING_TYPE_STRUCTURE(LogContextData)
+
+    /// <summary>
+    /// A GUID for an object which this context applies to.
+    /// </summary>
+    API_FIELD() Guid ObjectID;
+};
+
+template<>
+struct TIsPODType<LogContextData>
+{
+    enum { Value = true };
+};
+
+/// <summary>
+/// Stores a stack of log contexts.
+/// </summary>
+API_STRUCT() struct FLAXENGINE_API LogContextStack
+{
+    DECLARE_SCRIPTING_TYPE_STRUCTURE(LogContextStack)
+
+    /// <summary>
+    /// Log context stack.
+    /// </summary>
+    Array<LogContextData> Stack;
+};
+
+template<>
+struct TIsPODType<LogContextStack>
+{
+    enum { Value = true };
+};
+
+/// <summary>
+/// Log context interaction class. Methods are thread local, and as such, the context is as well.
+/// This system is used to pass down important information to be logged through large callstacks
+/// which don't have any reason to be passing down the information otherwise.
+/// </summary>
+API_CLASS(Static) class FLAXENGINE_API LogContexts
+{
+    DECLARE_SCRIPTING_TYPE_MINIMAL(LogContexts)
+
+    /// <summary>
+    /// Adds a log context element to the stack to be displayed in warning and error logs.
+    /// </summary>
+    /// <param name="id">The GUID of the object this context applies to.</param>
+    API_FUNCTION() static void Set(const Guid& id);
+
+    /// <summary>
+    /// Pops a log context element off of the stack and discards it.
+    /// </summary>
+    API_FUNCTION() static void Clear();
+
+    /// <summary>
+    /// Gets the log context element off the top of stack.
+    /// </summary>
+    /// <returns>The log context element at the top of the stack.</returns>
+    API_FUNCTION() static LogContextData Get();
+
+private:
+    static ThreadLocal<LogContextStack> CurrentLogContext;
+};
+
+/// <summary>
+/// Formatting class which will provide a string to apply
+/// the current log context to an error or warning.
+/// </summary>
+API_CLASS(Static) class FLAXENGINE_API LogContextFormatter
+{
+    DECLARE_SCRIPTING_TYPE_MINIMAL(LogContextFormatter)
+
+public:
+    /// <summary>
+    /// Returns a string which represents the current log context on the stack.
+    /// </summary>
+    /// <returns>The formatted string representing the current log context.</returns>
+    API_FUNCTION() static String Format();
+};