Binary Share
[Data types.]

These functions allow you to store one copy of an object, and use it throughout your program. More...

Defines

#define eina_binshare_add(ptr)   eina_binshare_add_length(ptr, sizeof(*ptr))
 Retrieve an instance of a blob for use in a program.

Functions

const void * eina_binshare_add_length (const void *obj, unsigned int olen)
 Retrieve an instance of an object for use in a program.
const void * eina_binshare_ref (const void *obj)
 Increment references of the given shared object.
void eina_binshare_del (const void *obj)
 Note that the given object has lost an instance.
int eina_binshare_length (const void *obj)
 Note that the given object must be shared.
void eina_binshare_dump (void)
 Dump the contents of the share_common.

Detailed Description

These functions 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 memory.

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

Define Documentation

#define eina_binshare_add ( ptr   )     eina_binshare_add_length(ptr, sizeof(*ptr))

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

Parameters:
ptr The binary blob to retrieve an instance of.
Returns:
A pointer to an instance of the string on success. NULL on failure.

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.

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()

Function Documentation

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

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

Parameters:
obj The binary object to retrieve an instance of.
olen The byte size
Returns:
A pointer to an instance of the object on success. 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.

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

See also:
eina_binshare_add()
const void * eina_binshare_ref ( const void *  obj  ) 

Increment references of the given shared object.

Parameters:
obj The shared object.
Returns:
A pointer to an instance of the object on success. NULL on failure.

This is similar to eina_share_common_add(), but it's faster since it will avoid 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().

void eina_binshare_del ( const void *  obj  ) 

Note that the given object has lost an instance.

Parameters:
obj object 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.

Note that if the given pointer is not shared or NULL, bad things will happen, likely a segmentation fault.

int eina_binshare_length ( const void *  obj  ) 

Note that the given object must be shared.

Parameters:
obj the shared object to know the length. It is safe to give NULL, in that case -1 is returned.
Returns:
The length of the shared object.

This function is a cheap way to known the length of a shared object. Note that if the given pointer is not shared, bad things will happen, likely a segmentation fault. If in doubt, try strlen().

void eina_binshare_dump ( void   ) 

Dump the contents of the share_common.

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