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Generalize non-define registration with MEDIAPIPE_STATIC_REGISTRATOR_TEMPLATE

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PiperOrigin-RevId: 547929982
This commit is contained in:
MediaPipe Team 2023-07-13 14:50:41 -07:00 committed by Copybara-Service
parent c2c67c20fa
commit 723e91cec1
2 changed files with 85 additions and 62 deletions
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72
mediapipe/framework/api2/node.h
View File

@ -64,57 +64,13 @@ class CalculatorBaseFactoryFor<
namespace api2 {
namespace internal {
// Defining a member of this type causes P to be ODR-used, which forces its
// instantiation if it's a static member of a template.
// Previously we depended on the pointer's value to determine whether the size
// of a character array is 0 or 1, forcing it to be instantiated so the
// compiler can determine the object's layout. But using it as a template
// argument is more compact.
template <auto* P>
struct ForceStaticInstantiation {
#ifdef _MSC_VER
// Just having it as the template argument does not count as a use for
// MSVC.
static constexpr bool Use() { return P != nullptr; }
char force_static[Use()];
#endif // _MSC_VER
};
MEDIAPIPE_STATIC_REGISTRATOR_TEMPLATE(
NodeRegistrator, mediapipe::CalculatorBaseRegistry, T::kCalculatorName,
absl::make_unique<mediapipe::internal::CalculatorBaseFactoryFor<T>>)
// Helper template for forcing the definition of a static registration token.
template <typename T>
struct NodeRegistrationStatic {
static NoDestructor<mediapipe::RegistrationToken> registration;
static mediapipe::RegistrationToken Make() {
return mediapipe::CalculatorBaseRegistry::Register(
T::kCalculatorName,
absl::make_unique<mediapipe::internal::CalculatorBaseFactoryFor<T>>);
}
using RequireStatics = ForceStaticInstantiation<&registration>;
};
// Static members of template classes can be defined in the header.
template <typename T>
NoDestructor<mediapipe::RegistrationToken>
NodeRegistrationStatic<T>::registration(NodeRegistrationStatic<T>::Make());
template <typename T>
struct SubgraphRegistrationImpl {
static NoDestructor<mediapipe::RegistrationToken> registration;
static mediapipe::RegistrationToken Make() {
return mediapipe::SubgraphRegistry::Register(T::kCalculatorName,
absl::make_unique<T>);
}
using RequireStatics = ForceStaticInstantiation<&registration>;
};
template <typename T>
NoDestructor<mediapipe::RegistrationToken>
SubgraphRegistrationImpl<T>::registration(
SubgraphRegistrationImpl<T>::Make());
MEDIAPIPE_STATIC_REGISTRATOR_TEMPLATE(SubgraphRegistrator,
mediapipe::SubgraphRegistry,
T::kCalculatorName, absl::make_unique<T>)
} // namespace internal
@ -127,14 +83,7 @@ template <class Impl = void>
class RegisteredNode;
template <class Impl>
class RegisteredNode : public Node {
private:
// The member below triggers instantiation of the registration static.
// Note that the constructor of calculator subclasses is only invoked through
// the registration token, and so we cannot simply use the static in the
// constructor.
typename internal::NodeRegistrationStatic<Impl>::RequireStatics register_;
};
class RegisteredNode : public Node, private internal::NodeRegistrator<Impl> {};
// No-op version for backwards compatibility.
template <>
@ -216,10 +165,9 @@ class NodeImpl : public RegisteredNode<Impl>, public Intf {
// TODO: verify that the subgraph config fully implements the
// declared interface.
template <class Intf, class Impl>
class SubgraphImpl : public Subgraph, public Intf {
private:
typename internal::SubgraphRegistrationImpl<Impl>::RequireStatics register_;
};
class SubgraphImpl : public Subgraph,
public Intf,
private internal::SubgraphRegistrator<Impl> {};
// This macro is used to register a calculator that does not use automatic
// registration. Deprecated.

75
mediapipe/framework/deps/registration.h
View File

@ -144,6 +144,23 @@ template <typename T>
struct WrapStatusOr<absl::StatusOr<T>> {
using type = absl::StatusOr<T>;
};
// Defining a member of this type causes P to be ODR-used, which forces its
// instantiation if it's a static member of a template.
// Previously we depended on the pointer's value to determine whether the size
// of a character array is 0 or 1, forcing it to be instantiated so the
// compiler can determine the object's layout. But using it as a template
// argument is more compact.
template <auto* P>
struct ForceStaticInstantiation {
#ifdef _MSC_VER
// Just having it as the template argument does not count as a use for
// MSVC.
static constexpr bool Use() { return P != nullptr; }
char force_static[Use()];
#endif // _MSC_VER
};
} // namespace registration_internal
class NamespaceAllowlist {
@ -408,6 +425,64 @@ class GlobalFactoryRegistry {
new mediapipe::RegistrationToken( \
RegistryType::Register(#name, __VA_ARGS__))
// Defines a utility registrator class which can be used to automatically
// register factory functions.
//
// Example:
// === Defining a registry ================================================
//
// class Component {};
//
// using ComponentRegistry = GlobalFactoryRegistry<std::unique_ptr<Component>>;
//
// === Defining a registrator =============================================
//
// MEDIAPIPE_STATIC_REGISTRATOR_TEMPLATE(ComponentRegistrator,
// ComponentRegistry, T::kName,
// absl::make_unique<T>);
//
// === Defining and registering a new component. ==========================
//
// class MyComponent : public Component,
// private ComponentRegistrator<MyComponent> {
// public:
// static constexpr char kName[] = "MyComponent";
// ...
// };
//
// NOTE:
// - MyComponent is automatically registered in ComponentRegistry by
// "MyComponent" name.
// - Every component is require to provide its name (T::kName here.)
#define MEDIAPIPE_STATIC_REGISTRATOR_TEMPLATE(RegistratorName, RegistryType, \
name, ...) \
template <typename T> \
struct Internal##RegistratorName { \
static NoDestructor<mediapipe::RegistrationToken> registration; \
\
static mediapipe::RegistrationToken Make() { \
return RegistryType::Register(name, __VA_ARGS__); \
} \
\
using RequireStatics = \
registration_internal::ForceStaticInstantiation<&registration>; \
}; \
/* Static members of template classes can be defined in the header. */ \
template <typename T> \
NoDestructor<mediapipe::RegistrationToken> \
Internal##RegistratorName<T>::registration( \
Internal##RegistratorName<T>::Make()); \
\
template <typename T> \
class RegistratorName { \
private: \
/* The member below triggers instantiation of the registration static. */ \
/* Note that the constructor of calculator subclasses is only invoked */ \
/* through the registration token, and so we cannot simply use the */ \
/* static in theconstructor. */ \
typename Internal##RegistratorName<T>::RequireStatics register_; \
};
} // namespace mediapipe
#endif // MEDIAPIPE_DEPS_REGISTRATION_H_