tornavis/source/blender/blenlib/BLI_generic_value_map.hh

112 lines
3.7 KiB
C++

/* SPDX-FileCopyrightText: 2023 Blender Authors
*
* SPDX-License-Identifier: GPL-2.0-or-later */
#pragma once
#include "BLI_generic_pointer.hh"
#include "BLI_linear_allocator.hh"
#include "BLI_map.hh"
namespace blender {
/**
* This is a map that stores key-value-pairs. What makes it special is that the type of values does
* not have to be known at compile time. There just has to be a corresponding CPPType.
*/
template<typename Key> class GValueMap {
private:
/* Used to allocate values owned by this container. */
LinearAllocator<> &allocator_;
Map<Key, GMutablePointer> values_;
public:
GValueMap(LinearAllocator<> &allocator) : allocator_(allocator) {}
~GValueMap()
{
/* Destruct all values that are still in the map. */
for (GMutablePointer value : values_.values()) {
value.destruct();
}
}
/* Add a value to the container. The container becomes responsible for destructing the value that
* is passed in. The caller remains responsible for freeing the value after it has been
* destructed. */
template<typename ForwardKey> void add_new_direct(ForwardKey &&key, GMutablePointer value)
{
values_.add_new_as(std::forward<ForwardKey>(key), value);
}
/* Add a value to the container that is move constructed from the given value. The caller remains
* responsible for destructing and freeing the given value. */
template<typename ForwardKey> void add_new_by_move(ForwardKey &&key, GMutablePointer value)
{
const CPPType &type = *value.type();
void *buffer = allocator_.allocate(type.size(), type.alignment());
type.move_construct(value.get(), buffer);
values_.add_new_as(std::forward<ForwardKey>(key), GMutablePointer{type, buffer});
}
/* Add a value to the container that is copy constructed from the given value. The caller remains
* responsible for destructing and freeing the given value. */
template<typename ForwardKey> void add_new_by_copy(ForwardKey &&key, GPointer value)
{
const CPPType &type = *value.type();
void *buffer = allocator_.allocate(type.size(), type.alignment());
type.copy_construct(value.get(), buffer);
values_.add_new_as(std::forward<ForwardKey>(key), GMutablePointer{type, buffer});
}
/* Add a value to the container. */
template<typename ForwardKey, typename T> void add_new(ForwardKey &&key, T &&value)
{
if constexpr (std::is_rvalue_reference_v<T>) {
this->add_new_by_move(std::forward<ForwardKey>(key), &value);
}
else {
this->add_new_by_copy(std::forward<ForwardKey>(key), &value);
}
}
/* Remove the value for the given name from the container and remove it. The caller is
* responsible for freeing it. The lifetime of the referenced memory might be bound to lifetime
* of the container. */
template<typename ForwardKey> GMutablePointer extract(const ForwardKey &key)
{
return values_.pop_as(key);
}
template<typename ForwardKey> GPointer lookup(const ForwardKey &key) const
{
return values_.lookup_as(key);
}
/* Remove the value for the given name from the container and remove it. */
template<typename T, typename ForwardKey> T extract(const ForwardKey &key)
{
GMutablePointer value = values_.pop_as(key);
const CPPType &type = *value.type();
BLI_assert(type.is<T>());
T return_value;
type.relocate_assign(value.get(), &return_value);
return return_value;
}
template<typename T, typename ForwardKey> const T &lookup(const ForwardKey &key) const
{
GMutablePointer value = values_.lookup_as(key);
BLI_assert(value.is_type<T>());
BLI_assert(value.get() != nullptr);
return *(const T *)value.get();
}
template<typename ForwardKey> bool contains(const ForwardKey &key) const
{
return values_.contains_as(key);
}
};
} // namespace blender