diff options
author | Jacques Lucke <jacques@blender.org> | 2022-03-19 12:57:40 +0300 |
---|---|---|
committer | Jacques Lucke <jacques@blender.org> | 2022-03-19 12:57:40 +0300 |
commit | 8711483632823524019a6cc95575c5a4ba5aa831 (patch) | |
tree | 76c2f8355d0fce66f4f9e35b5ec1282960e51209 /source/blender/blenlib | |
parent | 3e16f3b3ef4b8f385b30fe4a1e00860620f610ee (diff) |
BLI: generalize converting CPPType to static type
Previously, the conversion was done manually for a fixed set of types.
Now, there is a more general utility that can be used in other contexts
(outside of geometry nodes attribute processing) as well.
Diffstat (limited to 'source/blender/blenlib')
-rw-r--r-- | source/blender/blenlib/BLI_cpp_type.hh | 73 | ||||
-rw-r--r-- | source/blender/blenlib/intern/cpp_type.cc | 9 | ||||
-rw-r--r-- | source/blender/blenlib/tests/BLI_cpp_type_test.cc | 24 |
3 files changed, 104 insertions, 2 deletions
diff --git a/source/blender/blenlib/BLI_cpp_type.hh b/source/blender/blenlib/BLI_cpp_type.hh index ae6a87b4b68..881408f460b 100644 --- a/source/blender/blenlib/BLI_cpp_type.hh +++ b/source/blender/blenlib/BLI_cpp_type.hh @@ -22,6 +22,7 @@ * - If the code is not performance sensitive, it usually makes sense to use #CPPType instead. * - Sometimes a combination can make sense. Optimized code can be be generated at compile-time for * some types, while there is a fallback code path using #CPPType for all other types. + * #CPPType::to_static_type allows dispatching between both versions based on the type. * * Under some circumstances, #CPPType serves a similar role as #std::type_info. However, #CPPType * has much more utility because it contains methods for actually working with instances of the @@ -71,6 +72,7 @@ #include "BLI_hash.hh" #include "BLI_index_mask.hh" +#include "BLI_map.hh" #include "BLI_math_base.h" #include "BLI_string_ref.hh" #include "BLI_utility_mixins.hh" @@ -643,6 +645,77 @@ class CPPType : NonCopyable, NonMovable { { return this == &CPPType::get<std::decay_t<T>>(); } + + /** + * Convert a #CPPType that is only known at run-time, to a static type that is known at + * compile-time. This allows the compiler to optimize a function for specific types, while all + * other types can still use a generic fallback function. + * + * \param Types The types that code should be generated for. + * \param fn The function object to call. This is expected to have a templated `operator()` and a + * non-templated `operator()`. The templated version will be called if the current #CPPType + * matches any of the given types. Otherwise, the non-templated function is called. + */ + template<typename... Types, typename Fn> void to_static_type(const Fn &fn) const + { + using Callback = void (*)(const Fn &fn); + + /* Build a lookup table to avoid having to compare the current #CPPType with every type in + * #Types one after another. */ + static const Map<const CPPType *, Callback> callback_map = []() { + Map<const CPPType *, Callback> callback_map; + /* This adds an entry in the map for every type in #Types. */ + (callback_map.add_new(&CPPType::get<Types>(), + [](const Fn &fn) { + /* Call the templated `operator()` of the given function object. */ + fn.template operator()<Types>(); + }), + ...); + return callback_map; + }(); + + const Callback callback = callback_map.lookup_default(this, nullptr); + if (callback != nullptr) { + callback(fn); + } + else { + /* Call the non-templated `operator()` of the given function object. */ + fn(); + } + } + + template<typename T> struct type_tag { + using type = T; + }; + + private: + template<typename Fn> struct TypeTagExecutor { + const Fn &fn; + + template<typename T> void operator()() const + { + fn(type_tag<T>{}); + } + + void operator()() const + { + fn(type_tag<void>{}); + } + }; + + public: + /** + * Similar to #to_static_type but is easier to use with a lambda function. The function is + * expected to take a single `auto type_tag` parameter. To extract the static type, use: + * `using T = typename decltype(type_tag)::type;` + * + * If the current #CPPType is not in #Types, the type tag is `void`. + */ + template<typename... Types, typename Fn> void to_static_type_tag(const Fn &fn) const + { + TypeTagExecutor<Fn> executor{fn}; + this->to_static_type<Types...>(executor); + } }; } // namespace blender diff --git a/source/blender/blenlib/intern/cpp_type.cc b/source/blender/blenlib/intern/cpp_type.cc index 72ccc54e552..d6a087cf175 100644 --- a/source/blender/blenlib/intern/cpp_type.cc +++ b/source/blender/blenlib/intern/cpp_type.cc @@ -12,10 +12,15 @@ BLI_CPP_TYPE_MAKE(float2, blender::float2, CPPTypeFlags::BasicType) BLI_CPP_TYPE_MAKE(float3, blender::float3, CPPTypeFlags::BasicType) BLI_CPP_TYPE_MAKE(float4x4, blender::float4x4, CPPTypeFlags::BasicType) -BLI_CPP_TYPE_MAKE(int32, int32_t, CPPTypeFlags::BasicType) BLI_CPP_TYPE_MAKE(int8, int8_t, CPPTypeFlags::BasicType) -BLI_CPP_TYPE_MAKE(uint32, uint32_t, CPPTypeFlags::BasicType) +BLI_CPP_TYPE_MAKE(int16, int16_t, CPPTypeFlags::BasicType) +BLI_CPP_TYPE_MAKE(int32, int32_t, CPPTypeFlags::BasicType) +BLI_CPP_TYPE_MAKE(int64, int64_t, CPPTypeFlags::BasicType) + BLI_CPP_TYPE_MAKE(uint8, uint8_t, CPPTypeFlags::BasicType) +BLI_CPP_TYPE_MAKE(uint16, uint16_t, CPPTypeFlags::BasicType) +BLI_CPP_TYPE_MAKE(uint32, uint32_t, CPPTypeFlags::BasicType) +BLI_CPP_TYPE_MAKE(uint64, uint64_t, CPPTypeFlags::BasicType) BLI_CPP_TYPE_MAKE(ColorGeometry4f, blender::ColorGeometry4f, CPPTypeFlags::BasicType) BLI_CPP_TYPE_MAKE(ColorGeometry4b, blender::ColorGeometry4b, CPPTypeFlags::BasicType) diff --git a/source/blender/blenlib/tests/BLI_cpp_type_test.cc b/source/blender/blenlib/tests/BLI_cpp_type_test.cc index c7e6ed47b24..94456e1ee28 100644 --- a/source/blender/blenlib/tests/BLI_cpp_type_test.cc +++ b/source/blender/blenlib/tests/BLI_cpp_type_test.cc @@ -323,4 +323,28 @@ TEST(cpp_type, DebugPrint) EXPECT_EQ(text, "42"); } +TEST(cpp_type, ToStaticType) +{ + Vector<const CPPType *> types; + bool found_unsupported_type = false; + auto fn = [&](auto type_tag) { + using T = typename decltype(type_tag)::type; + if constexpr (!std::is_same_v<T, void>) { + types.append(&CPPType::get<T>()); + } + else { + found_unsupported_type = true; + } + }; + CPPType::get<std::string>().to_static_type_tag<int, float, std::string>(fn); + CPPType::get<float>().to_static_type_tag<int, float, std::string>(fn); + EXPECT_FALSE(found_unsupported_type); + CPPType::get<int64_t>().to_static_type_tag<int, float, std::string>(fn); + EXPECT_TRUE(found_unsupported_type); + + EXPECT_EQ(types.size(), 2); + EXPECT_EQ(types[0], &CPPType::get<std::string>()); + EXPECT_EQ(types[1], &CPPType::get<float>()); +} + } // namespace blender::tests |