KFL: Simplify the hash calculation

gongminmin · Dec 25, 2023 · 0462bc6 · 0462bc6
1 parent accfba2
commit 0462bc6
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Showing 28 changed files with 341 additions and 359 deletions.
diff --git a/KFL/include/KFL/Hash.hpp b/KFL/include/KFL/Hash.hpp
@@ -40,38 +40,28 @@
 
 namespace KlayGE
 {
-#define PRIME_NUM 0x9e3779b9
-
-#ifdef KLAYGE_COMPILER_MSVC
-#pragma warning(disable: 4307) // The hash here could cause integral constant overflow
-#endif
-
-	size_t constexpr CTHashImpl(char const* str, size_t seed) noexcept
+	constexpr size_t HashCombineImpl(size_t value, size_t seed) noexcept
 	{
-		return 0 == *str ? seed : CTHashImpl(str + 1, seed ^ (static_cast<size_t>(*str) + PRIME_NUM + (seed << 6) + (seed >> 2)));
+		size_t constexpr PRIME_NUM = 0x9e3779b9U;
+		return seed ^ (value + PRIME_NUM + (seed << 6) + (seed >> 2));
 	}
 
-	#define CT_HASH(x) (CTHashImpl(x, 0))
-
-	template <typename SizeT>
-	inline void HashCombineImpl(SizeT& seed, SizeT value) noexcept
+	constexpr size_t CtHash(char const* str, size_t seed = 0) noexcept
 	{
-		seed ^= value + PRIME_NUM + (seed << 6) + (seed >> 2);
+		return 0 == *str ? seed : CtHash(str + 1, HashCombineImpl(*str, seed));
 	}
 
-	inline size_t RT_HASH(char const* str) noexcept
+	inline size_t RtHash(char const* str) noexcept
 	{
 		size_t seed = 0;
 		while (*str != 0)
 		{
-			HashCombineImpl(seed, static_cast<size_t>(*str));
+			seed = HashCombineImpl(*str, seed);
 			++ str;
 		}
 		return seed;
 	}
 
-#undef PRIME_NUM
-
 	template <typename T>
 	inline size_t HashValue(T v) noexcept
 	{
@@ -87,7 +77,7 @@ namespace KlayGE
 	template <typename T>
 	inline void HashCombine(size_t& seed, T const& v) noexcept
 	{
-		return HashCombineImpl(seed, HashValue(v));
+		seed = HashCombineImpl(HashValue(v), seed);
 	}
 
 	template <typename T>

diff --git a/KlayGE/Core/Src/Base/Context.cpp b/KlayGE/Core/Src/Base/Context.cpp
@@ -389,34 +389,34 @@ namespace KlayGE
 					keep_screen_on = attr->ValueBool();
 				}
 
-				size_t const color_fmt_str_hash = RT_HASH(color_fmt_str.c_str());
-				if (CT_HASH("ARGB8") == color_fmt_str_hash)
+				size_t const color_fmt_str_hash = RtHash(color_fmt_str.c_str());
+				if (CtHash("ARGB8") == color_fmt_str_hash)
 				{
 					color_fmt = EF_ARGB8;
 				}
-				else if (CT_HASH("ABGR8") == color_fmt_str_hash)
+				else if (CtHash("ABGR8") == color_fmt_str_hash)
 				{
 					color_fmt = EF_ABGR8;
 				}
-				else if (CT_HASH("A2BGR10") == color_fmt_str_hash)
+				else if (CtHash("A2BGR10") == color_fmt_str_hash)
 				{
 					color_fmt = EF_A2BGR10;
 				}
-				else if (CT_HASH("ABGR16F") == color_fmt_str_hash)
+				else if (CtHash("ABGR16F") == color_fmt_str_hash)
 				{
 					color_fmt = EF_ABGR16F;
 				}
 
-				size_t const depth_stencil_fmt_str_hash = RT_HASH(depth_stencil_fmt_str.c_str());
-				if (CT_HASH("D16") == depth_stencil_fmt_str_hash)
+				size_t const depth_stencil_fmt_str_hash = RtHash(depth_stencil_fmt_str.c_str());
+				if (CtHash("D16") == depth_stencil_fmt_str_hash)
 				{
 					depth_stencil_fmt = EF_D16;
 				}
-				else if (CT_HASH("D24S8") == depth_stencil_fmt_str_hash)
+				else if (CtHash("D24S8") == depth_stencil_fmt_str_hash)
 				{
 					depth_stencil_fmt = EF_D24S8;
 				}
-				else if (CT_HASH("D32F") == depth_stencil_fmt_str_hash)
+				else if (CtHash("D32F") == depth_stencil_fmt_str_hash)
 				{
 					depth_stencil_fmt = EF_D32F;
 				}
@@ -477,43 +477,43 @@ namespace KlayGE
 				if (XMLAttribute const* attr = stereo_node->Attrib("method"))
 				{
 					size_t const method_str_hash = HashValue(attr->ValueString());
-					if (CT_HASH("none") == method_str_hash)
+					if (CtHash("none") == method_str_hash)
 					{
 						stereo_method = STM_None;
 					}
-					else if (CT_HASH("red_cyan") == method_str_hash)
+					else if (CtHash("red_cyan") == method_str_hash)
 					{
 						stereo_method = STM_ColorAnaglyph_RedCyan;
 					}
-					else if (CT_HASH("yellow_blue") == method_str_hash)
+					else if (CtHash("yellow_blue") == method_str_hash)
 					{
 						stereo_method = STM_ColorAnaglyph_YellowBlue;
 					}
-					else if (CT_HASH("green_red") == method_str_hash)
+					else if (CtHash("green_red") == method_str_hash)
 					{
 						stereo_method = STM_ColorAnaglyph_GreenRed;
 					}
-					else if (CT_HASH("lcd_shutter") == method_str_hash)
+					else if (CtHash("lcd_shutter") == method_str_hash)
 					{
 						stereo_method = STM_LCDShutter;
 					}
-					else if (CT_HASH("hor_interlacing") == method_str_hash)
+					else if (CtHash("hor_interlacing") == method_str_hash)
 					{
 						stereo_method = STM_HorizontalInterlacing;
 					}
-					else if (CT_HASH("ver_interlacing") == method_str_hash)
+					else if (CtHash("ver_interlacing") == method_str_hash)
 					{
 						stereo_method = STM_VerticalInterlacing;
 					}
-					else if (CT_HASH("horizontal") == method_str_hash)
+					else if (CtHash("horizontal") == method_str_hash)
 					{
 						stereo_method = STM_Horizontal;
 					}
-					else if (CT_HASH("vertical") == method_str_hash)
+					else if (CtHash("vertical") == method_str_hash)
 					{
 						stereo_method = STM_Vertical;
 					}
-					else if (CT_HASH("oculus_vr") == method_str_hash)
+					else if (CtHash("oculus_vr") == method_str_hash)
 					{
 						stereo_method = STM_OculusVR;
 					}
@@ -535,7 +535,7 @@ namespace KlayGE
 				if (XMLAttribute const* attr = output_node->Attrib("method"))
 				{
 					size_t const method_str_hash = HashValue(attr->ValueString());
-					if (CT_HASH("hdr10") == method_str_hash)
+					if (CtHash("hdr10") == method_str_hash)
 					{
 						display_output_method = DOM_HDR10;
 					}

diff --git a/KlayGE/Core/Src/Base/ResLoader.cpp b/KlayGE/Core/Src/Base/ResLoader.cpp
@@ -183,7 +183,7 @@ namespace KlayGE
 			local_path_ = exe_path_;
 #endif
 
-			paths_.emplace_back(PathInfo{CT_HASH(""), 0U, std::filesystem::path(), PackagePtr()});
+			paths_.emplace_back(PathInfo{CtHash(""), 0U, std::filesystem::path(), PackagePtr()});
 
 #if defined KLAYGE_PLATFORM_WINDOWS_STORE
 			this->AddPath("Assets/");

diff --git a/KlayGE/Core/Src/Render/CameraController.cpp b/KlayGE/Core/Src/Render/CameraController.cpp
@@ -807,19 +807,19 @@ namespace KlayGE
 		{
 			size_t const type_str_hash = HashValue(curve_node->Attrib("type")->ValueString());
 			CameraPathController::InterpolateType type;
-			if (CT_HASH("linear") == type_str_hash)
+			if (CtHash("linear") == type_str_hash)
 			{
 				type = CameraPathController::IT_Linear;
 			}
-			else if (CT_HASH("catmull_rom") == type_str_hash)
+			else if (CtHash("catmull_rom") == type_str_hash)
 			{
 				type = CameraPathController::IT_CatmullRom;
 			}
-			else if (CT_HASH("b_spline") == type_str_hash)
+			else if (CtHash("b_spline") == type_str_hash)
 			{
 				type = CameraPathController::IT_BSpline;
 			}
-			else if (CT_HASH("bezier") == type_str_hash)
+			else if (CtHash("bezier") == type_str_hash)
 			{
 				type = CameraPathController::IT_Bezier;
 			}

diff --git a/KlayGE/Core/Src/Render/Font.cpp b/KlayGE/Core/Src/Render/Font.cpp
@@ -728,8 +728,7 @@ namespace
 
 		uint64_t Type() const override
 		{
-			static uint64_t const type = CT_HASH("FontLoadingDesc");
-			return type;
+			return CtHash("FontLoadingDesc");
 		}
 
 		bool StateLess() const override

diff --git a/KlayGE/Core/Src/Render/Imposter.cpp b/KlayGE/Core/Src/Render/Imposter.cpp
@@ -69,8 +69,7 @@ namespace KlayGE
 
 		uint64_t Type() const override
 		{
-			static uint64_t const type = CT_HASH("ImposterLoadingDesc");
-			return type;
+			return CtHash("ImposterLoadingDesc");
 		}
 
 		bool StateLess() const override

diff --git a/KlayGE/Core/Src/Render/Mesh.cpp b/KlayGE/Core/Src/Render/Mesh.cpp
@@ -89,8 +89,7 @@ namespace
 
 		uint64_t Type() const override
 		{
-			static uint64_t const type = CT_HASH("RenderModelLoadingDesc");
-			return type;
+			return CtHash("RenderModelLoadingDesc");
 		}
 
 		bool StateLess() const override

diff --git a/KlayGE/Core/Src/Render/ParticleSystem.cpp b/KlayGE/Core/Src/Render/ParticleSystem.cpp
@@ -103,8 +103,7 @@ namespace
 
 		uint64_t Type() const override
 		{
-			static uint64_t const type = CT_HASH("ParticleSystemLoadingDesc");
-			return type;
+			return CtHash("ParticleSystemLoadingDesc");
 		}
 
 		bool StateLess() const override
@@ -290,15 +289,15 @@ namespace
 
 						XMLAttribute const* attr = node->Attrib("name");
 						size_t const name_hash = HashValue(attr->ValueString());
-						if (CT_HASH("size_over_life") == name_hash)
+						if (CtHash("size_over_life") == name_hash)
 						{
 							ps_desc_.ps_data->size_over_life_ctrl_pts = xys;
 						}
-						else if (CT_HASH("mass_over_life") == name_hash)
+						else if (CtHash("mass_over_life") == name_hash)
 						{
 							ps_desc_.ps_data->mass_over_life_ctrl_pts = xys;
 						}
-						else if (CT_HASH("opacity_over_life") == name_hash)
+						else if (CtHash("opacity_over_life") == name_hash)
 						{
 							ps_desc_.ps_data->opacity_over_life_ctrl_pts = xys;
 						}

diff --git a/KlayGE/Core/Src/Render/PostProcess.cpp b/KlayGE/Core/Src/Render/PostProcess.cpp
@@ -80,8 +80,7 @@ namespace
 
 		uint64_t Type() const override
 		{
-			static uint64_t const type = CT_HASH("PostProcessLoadingDesc");
-			return type;
+			return CtHash("PostProcessLoadingDesc");
 		}
 
 		bool StateLess() const override