Add: Option to disable polymorphic allocator

The option will automatically activate if the code detects missing headers for these features. This option switches many of the types between their normal and their pmr versions.
spnda · Nov 2, 2023 · 8aaa89e · 8aaa89e
1 parent 66fbe38
commit 8aaa89e
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Showing 6 changed files with 124 additions and 82 deletions.
diff --git a/CMakeLists.txt b/CMakeLists.txt
@@ -15,6 +15,7 @@ option(FASTGLTF_ENABLE_EXAMPLES "Enables example targets for fastgltf" OFF)
 option(FASTGLTF_ENABLE_DOCS "Enables the configuration of targets that build/generate documentation" OFF)
 option(FASTGLTF_ENABLE_GLTF_RS "Enables the benchmark usage of gltf-rs" OFF)
 option(FASTGLTF_ENABLE_DEPRECATED_EXT "Enables support for deprecated extensions" OFF)
+option(FASTGLTF_DISABLE_CUSTOM_MEMORY_POOL "Disables the memory allocation algorithm based on polymorphic resources" OFF)
 
 include(${CMAKE_CURRENT_SOURCE_DIR}/cmake/add_source_directory.cmake)
 include(${CMAKE_CURRENT_SOURCE_DIR}/cmake/compiler_flags.cmake)
@@ -105,6 +106,7 @@ endif()
 
 target_compile_definitions(fastgltf PUBLIC "FASTGLTF_USE_CUSTOM_SMALLVECTOR=$<BOOL:${FASTGLTF_USE_CUSTOM_SMALLVECTOR}>")
 target_compile_definitions(fastgltf PUBLIC "FASTGLTF_ENABLE_DEPRECATED_EXT=$<BOOL:${FASTGLTF_ENABLE_DEPRECATED_EXT}>")
+target_compile_definitions(fastgltf PUBLIC "FASTGLTF_DISABLE_CUSTOM_MEMORY_POOL=$<BOOL:${FASTGLTF_DISABLE_CUSTOM_MEMORY_POOL}>")
 
 if (ANDROID)
     target_link_libraries(fastgltf PRIVATE android)

diff --git a/include/fastgltf/parser.hpp b/include/fastgltf/parser.hpp
@@ -355,6 +355,7 @@ namespace fastgltf {
 		return "";
 	}
 
+#if !FASTGLTF_DISABLE_CUSTOM_MEMORY_POOL
 	class ChunkMemoryResource : public std::pmr::memory_resource {
 		/**
 		 * The default size of the individual blocks we allocate.
@@ -415,6 +416,7 @@ namespace fastgltf {
 			return this == std::addressof(other);
 		}
 	};
+#endif
 
 	/**
 	 * A type that stores an error together with an expected value.
@@ -649,7 +651,9 @@ namespace fastgltf {
 
 		ParserInternalConfig config = {};
 		DataSource glbBuffer;
+#if !FASTGLTF_DISABLE_CUSTOM_MEMORY_POOL
 		std::shared_ptr<ChunkMemoryResource> resourceAllocator;
+#endif
 		std::filesystem::path directory;
 		Options options;
 

diff --git a/include/fastgltf/types.hpp b/include/fastgltf/types.hpp
@@ -31,7 +31,6 @@
 #include <cstring>
 #include <cstdint>
 #include <filesystem>
-#include <memory_resource>
 #include <optional>
 #include <utility>
 #include <variant>
@@ -40,6 +39,33 @@
 // Utils header already includes some headers, which we'll try and avoid including twice.
 #include "util.hpp"
 
+#ifndef FASTGLTF_DISABLE_CUSTOM_MEMORY_POOL
+#define FASTGLTF_DISABLE_CUSTOM_MEMORY_POOL 0
+#endif
+
+#if __has_include(<memory_resource>)
+#define FASTGLTF_MISSING_MEMORY_RESOURCE 0
+#else
+#define FASTGLTF_MISSING_MEMORY_RESOURCE 1
+#define FASTGLTF_DISABLE_CUSTOM_MEMORY_POOL 1
+#endif
+
+#if !FASTGLTF_DISABLE_CUSTOM_MEMORY_POOL
+#include <memory_resource>
+#endif
+
+#if FASTGLTF_DISABLE_CUSTOM_MEMORY_POOL
+#define FASTGLTF_STD_PMR_NS ::std
+#define FASTGLTF_FG_PMR_NS ::fastgltf
+
+#define FASTGLTF_CONSTRUCT_PMR_RESOURCE(type, memoryResource, ...) type(__VA_ARGS__)
+#else
+#define FASTGLTF_STD_PMR_NS ::std::pmr
+#define FASTGLTF_FG_PMR_NS ::fastgltf::pmr
+
+#define FASTGLTF_CONSTRUCT_PMR_RESOURCE(type, memoryResource, ...) type(__VA_ARGS__, memoryResource)
+#endif
+
 #if FASTGLTF_CPP_20
 #include <span>
 #endif
@@ -688,10 +714,12 @@ namespace fastgltf {
         }
     };
 
+#if !FASTGLTF_MISSING_MEMORY_RESOURCE
 	namespace pmr {
 		template<typename T, std::size_t N>
 		using SmallVector = SmallVector<T, N, std::pmr::polymorphic_allocator<T>>;
 	} // namespace pmr
+#endif
 
 #ifndef FASTGLTF_USE_CUSTOM_SMALLVECTOR
 #define FASTGLTF_USE_CUSTOM_SMALLVECTOR 0
@@ -705,6 +733,7 @@ namespace fastgltf {
 	using MaybeSmallVector = std::vector<T>;
 #endif
 
+#if !FASTGLTF_MISSING_MEMORY_RESOURCE
 	namespace pmr {
 #if FASTGLTF_USE_CUSTOM_SMALLVECTOR
 		template <typename T, std::size_t N = initialSmallVectorStorage>
@@ -714,6 +743,7 @@ namespace fastgltf {
 		using MaybeSmallVector = std::pmr::vector<T>;
 #endif
 	} // namespace pmr
+#endif
 
 	template<typename, typename = void>
 	struct OptionalFlagValue {
@@ -1066,7 +1096,7 @@ namespace fastgltf {
 	 * also decodes any percent-encoded characters.
 	 */
 	class URI {
-		std::pmr::string uri;
+		std::string uri;
 		URIView view;
 
 		void readjustViews(const URIView& other);
@@ -1088,7 +1118,7 @@ namespace fastgltf {
 
 		operator URIView() const noexcept;
 
-		static void decodePercents(std::pmr::string& x) noexcept;
+		static void decodePercents(std::string& x) noexcept;
 
 		[[nodiscard]] auto string() const noexcept -> std::string_view;
 
@@ -1224,16 +1254,16 @@ namespace fastgltf {
     };
 
     struct Animation {
-	    pmr::MaybeSmallVector<AnimationChannel> channels;
-	    pmr::MaybeSmallVector<AnimationSampler> samplers;
+	    FASTGLTF_FG_PMR_NS::MaybeSmallVector<AnimationChannel> channels;
+	    FASTGLTF_FG_PMR_NS::MaybeSmallVector<AnimationSampler> samplers;
 
-        std::pmr::string name;
+        FASTGLTF_STD_PMR_NS::string name;
     };
 
     struct AssetInfo {
-        std::pmr::string gltfVersion;
-        std::pmr::string copyright;
-        std::pmr::string generator;
+        FASTGLTF_STD_PMR_NS::string gltfVersion;
+        FASTGLTF_STD_PMR_NS::string copyright;
+        FASTGLTF_STD_PMR_NS::string generator;
     };
 
     struct Camera {
@@ -1256,15 +1286,15 @@ namespace fastgltf {
          * and/or std::get_if to figure out which camera type is being used.
          */
         std::variant<Perspective, Orthographic> camera;
-        std::pmr::string name;
+        FASTGLTF_STD_PMR_NS::string name;
     };
 
     struct Skin {
-	    pmr::MaybeSmallVector<std::size_t> joints;
+	    FASTGLTF_FG_PMR_NS::MaybeSmallVector<std::size_t> joints;
 	    Optional<std::size_t> skeleton;
 	    Optional<std::size_t> inverseBindMatrices;
 
-        std::pmr::string name;
+        FASTGLTF_STD_PMR_NS::string name;
     };
 
     struct Sampler {
@@ -1273,13 +1303,13 @@ namespace fastgltf {
         Wrap wrapS;
         Wrap wrapT;
 
-        std::pmr::string name;
+        FASTGLTF_STD_PMR_NS::string name;
     };
 
     struct Scene {
-	    pmr::MaybeSmallVector<std::size_t> nodeIndices;
+	    FASTGLTF_FG_PMR_NS::MaybeSmallVector<std::size_t> nodeIndices;
 
-        std::pmr::string name;
+        FASTGLTF_STD_PMR_NS::string name;
     };
 
     struct Node {
@@ -1292,8 +1322,8 @@ namespace fastgltf {
          */
         Optional<std::size_t> lightIndex;
 
-	    pmr::MaybeSmallVector<std::size_t> children;
-	    pmr::MaybeSmallVector<float> weights;
+	    FASTGLTF_FG_PMR_NS::MaybeSmallVector<std::size_t> children;
+	    FASTGLTF_FG_PMR_NS::MaybeSmallVector<float> weights;
 
         struct TRS {
             std::array<float, 3> translation;
@@ -1312,9 +1342,9 @@ namespace fastgltf {
         /**
          * Only ever non-empty when EXT_mesh_gpu_instancing is enabled and used by the asset.
          */
-        std::pmr::vector<std::pair<std::pmr::string, std::size_t>> instancingAttributes;
+        FASTGLTF_STD_PMR_NS::vector<std::pair<FASTGLTF_STD_PMR_NS::string, std::size_t>> instancingAttributes;
 
-        std::pmr::string name;
+        FASTGLTF_STD_PMR_NS::string name;
 
         [[nodiscard]] auto findInstancingAttribute(std::string_view attributeName) noexcept {
             for (auto it = instancingAttributes.begin(); it != instancingAttributes.end(); ++it) {
@@ -1334,14 +1364,14 @@ namespace fastgltf {
    };
 
     struct Primitive {
-		using attribute_type = std::pair<std::pmr::string, std::size_t>;
+		using attribute_type = std::pair<FASTGLTF_STD_PMR_NS::string, std::size_t>;
 
 		// Instead of a map, we have a list of attributes here. Each pair contains
 		// the name of the attribute and the corresponding accessor index.
-		pmr::SmallVector<attribute_type, 4> attributes;
+		FASTGLTF_FG_PMR_NS::SmallVector<attribute_type, 4> attributes;
         PrimitiveType type;
 
-        std::pmr::vector<pmr::SmallVector<attribute_type, 4>> targets;
+        FASTGLTF_STD_PMR_NS::vector<FASTGLTF_FG_PMR_NS::SmallVector<attribute_type, 4>> targets;
 
         Optional<std::size_t> indicesAccessor;
         Optional<std::size_t> materialIndex;
@@ -1382,10 +1412,10 @@ namespace fastgltf {
 	};
 
     struct Mesh {
-		pmr::MaybeSmallVector<Primitive, 2> primitives;
-		pmr::MaybeSmallVector<float> weights;
+		FASTGLTF_FG_PMR_NS::MaybeSmallVector<Primitive, 2> primitives;
+	    FASTGLTF_FG_PMR_NS::MaybeSmallVector<float> weights;
 
-        std::pmr::string name;
+        FASTGLTF_STD_PMR_NS::string name;
     };
 
     /**
@@ -1606,7 +1636,7 @@ namespace fastgltf {
          */
         bool unlit;
 
-        std::pmr::string name;
+        FASTGLTF_STD_PMR_NS::string name;
     };
 
     struct Texture {
@@ -1637,13 +1667,13 @@ namespace fastgltf {
 		 */
 		Optional<std::size_t> webpImageIndex;
 
-        std::pmr::string name;
+        FASTGLTF_STD_PMR_NS::string name;
     };
 
     struct Image {
         DataSource data;
 
-        std::pmr::string name;
+        FASTGLTF_STD_PMR_NS::string name;
     };
 
     struct SparseAccessor {
@@ -1662,15 +1692,15 @@ namespace fastgltf {
         ComponentType componentType;
         bool normalized;
 
-        std::variant<std::monostate, std::pmr::vector<double>, std::pmr::vector<std::int64_t>> max;
-        std::variant<std::monostate, std::pmr::vector<double>, std::pmr::vector<std::int64_t>> min;
+        std::variant<std::monostate, FASTGLTF_STD_PMR_NS::vector<double>, FASTGLTF_STD_PMR_NS::vector<std::int64_t>> max;
+        std::variant<std::monostate, FASTGLTF_STD_PMR_NS::vector<double>, FASTGLTF_STD_PMR_NS::vector<std::int64_t>> min;
 
         // Could have no value for sparse morph targets
         Optional<std::size_t> bufferViewIndex;
 
         Optional<SparseAccessor> sparse;
 
-        std::pmr::string name;
+        FASTGLTF_STD_PMR_NS::string name;
     };
 
     struct CompressedBufferView {
@@ -1697,15 +1727,15 @@ namespace fastgltf {
          */
         std::unique_ptr<CompressedBufferView> meshoptCompression;
 
-        std::pmr::string name;
+        FASTGLTF_STD_PMR_NS::string name;
     };
 
     struct Buffer {
         std::size_t byteLength;
 
         DataSource data;
 
-        std::pmr::string name;
+        FASTGLTF_STD_PMR_NS::string name;
     };
 
     struct Light {
@@ -1721,7 +1751,7 @@ namespace fastgltf {
         Optional<float> innerConeAngle;
         Optional<float> outerConeAngle;
 
-        std::pmr::string name;
+        FASTGLTF_STD_PMR_NS::string name;
     };
 
 	class ChunkMemoryResource;
@@ -1730,17 +1760,19 @@ namespace fastgltf {
 	class Asset {
 		friend class Parser;
 
+#if !FASTGLTF_DISABLE_CUSTOM_MEMORY_POOL
 		// This has to be first in this struct so that it gets destroyed last, leaving all allocations
 		// alive until the end.
 		std::shared_ptr<ChunkMemoryResource> memoryResource;
+#endif
 
 	public:
         /**
          * This will only ever have no value if #Options::DontRequireValidAssetMember was specified.
          */
         Optional<AssetInfo> assetInfo;
-		std::pmr::vector<std::pmr::string> extensionsUsed;
-		std::pmr::vector<std::pmr::string> extensionsRequired;
+		FASTGLTF_STD_PMR_NS::vector<FASTGLTF_STD_PMR_NS::string> extensionsUsed;
+		FASTGLTF_STD_PMR_NS::vector<FASTGLTF_STD_PMR_NS::string> extensionsRequired;
 
         Optional<std::size_t> defaultScene;
         std::vector<Accessor> accessors;
@@ -1764,7 +1796,9 @@ namespace fastgltf {
         explicit Asset() = default;
         explicit Asset(const Asset& other) = delete;
         Asset(Asset&& other) noexcept :
+#if !FASTGLTF_DISABLE_CUSTOM_MEMORY_POOL
 				memoryResource(std::move(other.memoryResource)),
+#endif
 				assetInfo(std::move(other.assetInfo)),
 				extensionsUsed(std::move(other.extensionsUsed)),
 				extensionsRequired(std::move(other.extensionsRequired)),
@@ -1787,7 +1821,9 @@ namespace fastgltf {
 
 		Asset& operator=(const Asset& other) = delete;
 		Asset& operator=(Asset&& other) noexcept {
+#if !FASTGLTF_DISABLE_CUSTOM_MEMORY_POOL
 			memoryResource = std::move(other.memoryResource);
+#endif
 			assetInfo = std::move(other.assetInfo);
 			extensionsUsed = std::move(other.extensionsUsed);
 			extensionsRequired = std::move(other.extensionsRequired);