Binary Share

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This group discusses the functions that allow you to store one copy of an object, and use it throughout your program.

This is a method to reduce the number of duplicated objects kept in the memory.

For more information, you can look at the Binary Share Tutorial.

Functions
const void *	eina_binshare_add_length (const void *obj, unsigned int olen)
	Retrieves an instance of an object for use in a program.
const void *	eina_binshare_ref (const void *obj)
	Increments references of the given shared object.
void	eina_binshare_del (const void *obj)
	Notes that the given object has lost an instance.
int	eina_binshare_length (const void *obj)
	Notes that the given object must be shared.
void	eina_binshare_dump (void)
	Dumps the contents of share_common.
Defines
#define	eina_binshare_add(ptr)   eina_binshare_add_length(ptr, sizeof(*ptr))
	Retrieves an instance of a blob for use in a program.

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Define Documentation

#define eina_binshare_add

(

ptr

)

eina_binshare_add_length(ptr, sizeof(*ptr))

Retrieves an instance of a blob for use in a program.

This macro retrieves an instance of obj. If obj is NULL, then NULL is returned. If obj is already stored, it is just returned and its reference counter is increased. Otherwise it is added to the blobs to be searched and a duplicated blob of obj is returned.

Parameters:

[in]

ptr

The binary blob to retrieve an instance of

Returns:

A pointer to an instance of the string on success, otherwise NULL on failure

Note:

This macro essentially calls eina_binshare_add_length with ptr and sizeof(*ptr) as the parameters. It's useful for pointers to structures.

See also:

eina_stringshare_add_length()

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Function Documentation

const void* eina_binshare_add_length	(	const void *	obj,
		unsigned int	olen
	)

Retrieves an instance of an object for use in a program.

Parameters:

[in]	obj	The binary object to retrieve an instance of
[in]	olen	The byte size

Returns:

A pointer to an instance of the object on success, otherwise NULL on failure

This function retrieves an instance of obj. If obj is NULL, then NULL is returned. If obj is already stored, it is just returned and its reference counter is increased. Otherwise it is added to the objects to be searched and a duplicated object of obj is returned.

Note:

This function does not check the object size, but uses the exact given size. This can be used to share a part of a larger object or subobject.

See also:

eina_binshare_add()

Since :

2.3

void eina_binshare_del

(

const void *

obj

)

Notes that the given object has lost an instance.

Parameters:

[in]

obj

The given object

This function decreases the reference counter associated to obj if it exists. If that counter reaches 0, the memory associated to obj is freed. If obj is NULL, the function returns immediately.

Warning:

If the given pointer is not shared, bad things happen, mostly a segmentation fault.

Since :

2.3

void eina_binshare_dump

(

void

)

Dumps the contents of share_common.

This function dumps all the objects from share_common to stdout with a DDD: prefix per line and a memory usage summary.

Since :

2.3

int eina_binshare_length

(

const void *

obj

)

Notes that the given object must be shared.

This function is a cheap way to know the length of a shared object.

Parameters:

[in]

obj

The shared object to know the length It is safe to give NULL, in which case -1 is returned

Returns:

The length of the shared object

Warning:

If the given pointer is not shared, bad things happen, mostly a segmentation fault. If in doubt, try strlen().

Since :

2.3

const void* eina_binshare_ref

(

const void *

obj

)

Increments references of the given shared object.

Parameters:

[in]

obj

The shared object

Returns:

A pointer to an instance of the object on success, otherwise NULL on failure

Note:

This is similar to eina_share_common_add(), but it's faster since it avoids lookups if possible, but on the down side it requires the parameter to be shared before, in other words, it must be the return of a previous eina_binshare_add().

There is no unref since this is the work of eina_binshare_del().

Since :

2.3