These functions provide some helper for a pseudo Copy-On-Write mechanism. More...
Macros | |
| #define | EINA_COW_WRITE_BEGIN(Cow, Read, Write_Type, Write) |
| Definition for the macro to setup a writeable pointer from a const one. More... | |
| #define | EINA_COW_WRITE_END(Cow, Read, Write) |
| Definition for the macro to close the writeable pointer. More... | |
| #define | EINA_COW_WRITE_END_NOGC(Cow, Read, Write) |
| Definition for the macro to close the writeable pointer without triggering the GC. More... | |
Typedefs | |
| typedef struct _Eina_Cow | Eina_Cow |
| Type for Eina_Cow pool. | |
| typedef void | Eina_Cow_Data |
| Type of the returned pointer to simplify some reading. | |
Functions | |
| Eina_Cow * | eina_cow_add (const char *name, unsigned int struct_size, unsigned int step, const void *default_value, Eina_Bool gc) |
| Instantiates a new Eina_Cow pool. More... | |
| void | eina_cow_del (Eina_Cow *cow) |
| Destroys an Eina_Cow pool and all the allocated memory. More... | |
| const Eina_Cow_Data * | eina_cow_alloc (Eina_Cow *cow) |
| Returns an initialized pointer from the pool. More... | |
| void | eina_cow_free (Eina_Cow *cow, const Eina_Cow_Data **data) |
| Frees a pointer from the pool. More... | |
| void * | eina_cow_write (Eina_Cow *cow, const Eina_Cow_Data *const *src) |
| Gets a writeable pointer from a const pointer. More... | |
| void | eina_cow_done (Eina_Cow *cow, const Eina_Cow_Data *const *dst, const void *data, Eina_Bool needed_gc) |
| Sets back a pointer into read only. More... | |
| void | eina_cow_memcpy (Eina_Cow *cow, const Eina_Cow_Data *const *dst, const Eina_Cow_Data *src) |
| Makes the destination contain the same thing as the source pointer. More... | |
| Eina_Bool | eina_cow_gc (Eina_Cow *cow) |
| Tries to find entries that have the same content and update them. More... | |
These functions provide some helper for a pseudo Copy-On-Write mechanism.
Eina_Cow will return a const memory pointer to some default value that you will be able to change only by requesting a writable pointer. Later on a garbage collector can come online and try to merge back some of those pointers.
| #define EINA_COW_WRITE_BEGIN | ( | Cow, | |
| Read, | |||
| Write_Type, | |||
| Write | |||
| ) |
Definition for the macro to setup a writeable pointer from a const one.
| [in,out] | Cow | The Eina_Cow where the const pointer came from. |
| [in] | Read | The const pointer to get a writable handler from. |
| [in] | Write_Type | The type of the pointer you want to write to. |
| [in] | Write | The name of the variable where to put the writeable pointer to. |
| #define EINA_COW_WRITE_END | ( | Cow, | |
| Read, | |||
| Write | |||
| ) |
Definition for the macro to close the writeable pointer.
| [in,out] | Cow | The Eina_Cow where the const pointer came from. |
| [in] | Read | The const pointer to get a writable handler from. |
| [in] | Write | The name of the variable where to put the writeable pointer to. |
| #define EINA_COW_WRITE_END_NOGC | ( | Cow, | |
| Read, | |||
| Write | |||
| ) |
Definition for the macro to close the writeable pointer without triggering the GC.
| [in,out] | Cow | The Eina_Cow where the const pointer came from. |
| [in] | Read | The const pointer to get a writable handler from. |
| [in] | Write | The name of the variable where to put the writeable pointer to. |
| Eina_Cow* eina_cow_add | ( | const char * | name, |
| unsigned int | struct_size, | ||
| unsigned int | step, | ||
| const void * | default_value, | ||
| Eina_Bool | gc | ||
| ) |
Instantiates a new Eina_Cow pool.
| [in] | name | The name of this pool, used for debugging. |
| [in] | struct_size | The size of the object from this pool. |
| [in] | step | How many objects to allocate when the pool gets empty. |
| [in] | default_value | The default value returned by this pool. |
| [in] | gc | Is it possible to run garbage collection on this pool. |
NULL on error. References eina_hash_new(), eina_hash_pointer_new(), EINA_MAGIC_SET, eina_mempool_add(), eina_mempool_alignof(), EINA_SAFETY_ON_FALSE_RETURN_VAL, EINA_SAFETY_ON_NULL_RETURN_VAL, ERR, and INF.
| void eina_cow_del | ( | Eina_Cow * | cow | ) |
Destroys an Eina_Cow pool and all the allocated memory.
| [in] | cow | The pool to destroy |
References eina_hash_free(), and eina_mempool_del().
Referenced by evas_shutdown().
| const Eina_Cow_Data* eina_cow_alloc | ( | Eina_Cow * | cow | ) |
Returns an initialized pointer from the pool.
| [in] | cow | The pool to take things from. |
| void eina_cow_free | ( | Eina_Cow * | cow, |
| const Eina_Cow_Data ** | data | ||
| ) |
Frees a pointer from the pool.
| [in,out] | cow | The pool to gave back memory to. |
| [in] | data | The data to give back. |
References EINA_MAGIC_NONE, EINA_MAGIC_SET, and eina_mempool_free().
Referenced by eina_cow_memcpy().
| void* eina_cow_write | ( | Eina_Cow * | cow, |
| const Eina_Cow_Data *const * | src | ||
| ) |
Gets a writeable pointer from a const pointer.
| [in,out] | cow | The pool the pointer came from. |
| [in] | src | The pointer you want to write to. |
References EINA_FALSE, EINA_MAGIC_SET, eina_mempool_malloc(), and ERR.
| void eina_cow_done | ( | Eina_Cow * | cow, |
| const Eina_Cow_Data *const * | dst, | ||
| const void * | data, | ||
| Eina_Bool | needed_gc | ||
| ) |
Sets back a pointer into read only.
| [in,out] | cow | The pool the pointer came from. |
| [in] | dst | The read only version of the pointer. |
| [in] | data | The pointer to which data was written to. |
| [in] | needed_gc | Does this pool need to be garbage collected? |
References ERR.
| void eina_cow_memcpy | ( | Eina_Cow * | cow, |
| const Eina_Cow_Data *const * | dst, | ||
| const Eina_Cow_Data * | src | ||
| ) |
Makes the destination contain the same thing as the source pointer.
| [in,out] | cow | The pool the pointers came from. |
| [in] | dst | The destination to update. |
| [in] | src | The source of information to copy. |
References eina_cow_free().
Tries to find entries that have the same content and update them.
| [in,out] | cow | The cow to try to compact. |
There is no guaranty in the time it will require, but should remain low. It does run a hash function on all possible common structures trying to find the one that matches and merge them into one pointer.
References EINA_FALSE, eina_hash_iterator_data_new(), eina_hash_population(), eina_iterator_free(), eina_iterator_next(), and EINA_TRUE.