entt::resource_cache< Resource > Struct Template Reference

Simple cache for resources of a given type. More...

#include <cache.hpp>

Public Types
using	size_type = std::size_t
	Unsigned integer type.
using	resource_type = Resource
	Type of resources managed by a cache.

Public Member Functions
	resource_cache ()=default
	Default constructor.
	resource_cache (resource_cache &&)=default
	Default move constructor.
resource_cache &	operator= (resource_cache &&)=default
	Default move assignment operator. More...
size_type	size () const noexcept
	Number of resources managed by a cache. More...
bool	empty () const noexcept
	Returns true if a cache contains no resources, false otherwise. More...
void	clear () noexcept
	Clears a cache and discards all its resources. More...
template<typename Loader , typename... Args>
resource_handle< Resource >	load (const id_type id, Args &&... args)
	Loads the resource that corresponds to a given identifier. More...
template<typename Loader , typename... Args>
resource_handle< Resource >	reload (const id_type id, Args &&... args)
	Reloads a resource or loads it for the first time if not present. More...
template<typename Loader , typename... Args>
resource_handle< Resource >	temp (Args &&... args) const
	Creates a temporary handle for a resource. More...
resource_handle< Resource >	handle (const id_type id) const
	Creates a handle for a given resource identifier. More...
bool	contains (const id_type id) const
	Checks if a cache contains a given identifier. More...
void	discard (const id_type id)
	Discards the resource that corresponds to a given identifier. More...
template<typename Func >
void	each (Func func) const
	Iterates all resources. More...

Detailed Description

template<typename Resource>
struct entt::resource_cache< Resource >

Simple cache for resources of a given type.

Minimal implementation of a cache for resources of a given type. It doesn't offer much functionalities but it's suitable for small or medium sized applications and can be freely inherited to add targeted functionalities for large sized applications.

Template Parameters

Resource

Type of resources managed by a cache.

Definition at line 30 of file cache.hpp.

Member Function Documentation

clear()

template<typename Resource >

void entt::resource_cache< Resource >::clear ( )

inlinenoexcept

Clears a cache and discards all its resources.

Handles are not invalidated and the memory used by a resource isn't freed as long as at least a handle keeps the resource itself alive.

Definition at line 67 of file cache.hpp.

contains()

template<typename Resource >

bool entt::resource_cache< Resource >::contains ( const id_type  id ) const

inline

Checks if a cache contains a given identifier.

Parameters

id	Unique resource identifier.

Returns

True if the cache contains the resource, false otherwise.

Definition at line 178 of file cache.hpp.

discard()

template<typename Resource >

void entt::resource_cache< Resource >::discard ( const id_type  id )

inline

Discards the resource that corresponds to a given identifier.

Handles are not invalidated and the memory used by the resource isn't freed as long as at least a handle keeps the resource itself alive.

Parameters

id	Unique resource identifier.

Definition at line 190 of file cache.hpp.

each()

template<typename Resource >

template<typename Func >

void entt::resource_cache< Resource >::each ( Func  func ) const

inline

Iterates all resources.

The function object is invoked for each element. It is provided with either the resource identifier, the resource handle or both of them.
The signature of the function must be equivalent to one of the following forms:

void(const entt::id_type);
void(entt::resource_handle<Resource>);
void(const entt::id_type, entt::resource_handle<Resource>);

Template Parameters

Func	Type of the function object to invoke.

Parameters

func	A valid function object.

Definition at line 214 of file cache.hpp.

empty()

template<typename Resource >

bool entt::resource_cache< Resource >::empty ( ) const

inlinenoexcept

Returns true if a cache contains no resources, false otherwise.

Returns

True if the cache contains no resources, false otherwise.

Definition at line 57 of file cache.hpp.

handle()

template<typename Resource >

resource_handle<Resource> entt::resource_cache< Resource >::handle ( const id_type  id ) const

inline

Creates a handle for a given resource identifier.

A resource handle can be in a either valid or invalid state. In other terms, a resource handle is properly initialized with a resource if the cache contains the resource itself. Otherwise the returned handle is uninitialized and accessing it results in undefined behavior.

See also

resource_handle

Parameters

id	Unique resource identifier.

Returns

A handle for the given resource.

Definition at line 168 of file cache.hpp.

load()

template<typename Resource >

template<typename Loader , typename... Args>

resource_handle<Resource> entt::resource_cache< Resource >::load ( const id_type  id, Args &&...  args  )

inline

Loads the resource that corresponds to a given identifier.

In case an identifier isn't already present in the cache, it loads its resource and stores it aside for future uses. Arguments are forwarded directly to the loader in order to construct properly the requested resource.

Note

If the identifier is already present in the cache, this function does nothing and the arguments are simply discarded.

Warning

If the resource cannot be loaded correctly, the returned handle will be invalid and any use of it will result in undefined behavior.

Template Parameters

Loader	Type of loader to use to load the resource if required.
Args	Types of arguments to use to load the resource if required.

Parameters

id	Unique resource identifier.
args	Arguments to use to load the resource if required.

Returns

A handle for the given resource.

Definition at line 94 of file cache.hpp.

operator=()

template<typename Resource >

resource_cache& entt::resource_cache< Resource >::operator= ( resource_cache< Resource > &&  )

default

Default move assignment operator.

Returns

This cache.

reload()

template<typename Resource >

template<typename Loader , typename... Args>

resource_handle<Resource> entt::resource_cache< Resource >::reload ( const id_type  id, Args &&...  args  )

inline

Reloads a resource or loads it for the first time if not present.

Equivalent to the following snippet (pseudocode):

cache.discard(id);
cache.load(id, args...);

Arguments are forwarded directly to the loader in order to construct properly the requested resource.

Warning

If the resource cannot be loaded correctly, the returned handle will be invalid and any use of it will result in undefined behavior.

Template Parameters

Loader	Type of loader to use to load the resource.
Args	Types of arguments to use to load the resource.

Parameters

id	Unique resource identifier.
args	Arguments to use to load the resource.

Returns

A handle for the given resource.

Definition at line 134 of file cache.hpp.

size()

template<typename Resource >

size_type entt::resource_cache< Resource >::size ( ) const

inlinenoexcept

Number of resources managed by a cache.

Returns

Number of resources currently stored.

Definition at line 49 of file cache.hpp.

temp()

template<typename Resource >

template<typename Loader , typename... Args>

resource_handle<Resource> entt::resource_cache< Resource >::temp ( Args &&...  args ) const

inline

Creates a temporary handle for a resource.

Arguments are forwarded directly to the loader in order to construct properly the requested resource. The handle isn't stored aside and the cache isn't in charge of the lifetime of the resource itself.

Template Parameters

Loader	Type of loader to use to load the resource.
Args	Types of arguments to use to load the resource.

Parameters

args	Arguments to use to load the resource.

Returns

A handle for the given resource.

Definition at line 151 of file cache.hpp.

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The documentation for this struct was generated from the following file:

• src/entt/resource/cache.hpp