map

This section documents the map object of the GPAC framework. More...

Collaboration diagram for map:

Data Structures
struct	GF_Pair
	Pair structure. More...
struct	GF_It_Map
struct	GF_Map
	Map Object. More...
struct	GF_Iterator
	Map iterator Object. More...

Typedefs
typedef struct _tag_map	GF_Map

Functions
GF_Map *	gf_map_new (u32 hash_capacity)
	map constructor More...
void	gf_map_del (GF_Map *ptr)
	map destructor More...
GF_Err	gf_map_iter_set (GF_Map *map, GF_It_Map *it)
	Set a new map iterator. More...
void *	gf_map_iter_has_next (GF_It_Map *it)
	return the next value in the map More...
GF_Err	gf_map_iter_reset (GF_It_Map *it)
	Reset the iterator in the map. More...
u32	gf_map_count (const GF_Map *ptr)
	get count More...
GF_Err	gf_map_insert (GF_Map *ptr, const char *key, void *item)
	add item More...
Bool	gf_map_rem (GF_Map *ptr, const char *key)
	removes the couple key/item from the map More...
void *	gf_map_find (GF_Map *ptr, const char *key)
	finds item More...
Bool	gf_map_has_key (GF_Map *ptr, const char *key)
	Check if map contains key. More...
void	gf_map_reset (GF_Map *ptr)
	resets map More...

Detailed Description

Note

The map use a random function for hashing. Collisions are resolved by using a GF_List on each slot.

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Data Structure Documentation

struct GF_Pair

Define the association Key/value.

Data Fields
char *	key
void *	value

struct GF_It_Map

Collaboration diagram for GF_It_Map:

Data Fields
GF_Map *	map
GF_Pair *	pair
u32	ilist
u32	hash

struct GF_Map

A GF_Map associate key to values.

struct GF_Iterator

Allows to go through each pair key/value in the map.

Typedef Documentation

typedef struct _tag_map GF_Map

Function Documentation

GF_Map* gf_map_new

(

u32

hash_capacity

)

Constructs a new map object

Parameters

hash_capacity

the number of slot in the hash table

Note

a zero hash_capacity is not allowed, a hash_capacity of 1 is equivalent to a gf_list_find from GF_List with a complexity search in o(n)

Returns

new map object

void gf_map_del

(

GF_Map *

ptr

)

Destructs a map object

Parameters

ptr	map object to destruct

Note

The caller is only responsible to destroy the content of the map, not the key

GF_Err gf_map_iter_set	(	GF_Map *	map,
		GF_It_Map *	it
	)

Associate a map iterator to a map

Parameters

map	the map associated to the iterator
it	the resulting iterator

Returns

GF_OK if iterator has been set properly, otherwise a GF_Err

void* gf_map_iter_has_next

(

GF_It_Map *

it

)

Return the next value of a GF_Pair in the map
\param it  the map iterator object

Returns

the next value of the map if exists, otherwise NULL

GF_Err gf_map_iter_reset

(

GF_It_Map *

it

)

Reinitalize the iterator to the beginning of the map
\param it  the map iterator object

Returns

GF_OK if the iterator has been correctly reinitialize, otherwise a GF_Err

u32 gf_map_count

(

const GF_Map *

ptr

)

Returns number of items in the map

Parameters

ptr	target map object

Returns

number of items in the map

GF_Err gf_map_insert	(	GF_Map *	ptr,
		const char *	key,
		void *	item
	)

Adds an item in the map with an associated key

Parameters

ptr	target map object
key	the identified key
item	item to add

Returns

GF_OF if insertion occurs properly, GF_NOT_SUPPORTED if the key already exists, a GF_Err in other cases

Note

the caller is responsible for the deallocation of the key as it is copyied in the map

Bool gf_map_rem	(	GF_Map *	ptr,
		const char *	key
	)

Removes an item from the map given to its key if exists

Parameters

ptr	target map object
key	the key of the item.

Returns

GF_TRUE if the key has been delete, otherwise GF_FALSE

Note

It is the caller responsability to destroy the content of the list if needed

void* gf_map_find	(	GF_Map *	ptr,
		const char *	key
	)

Finds a key in the map

Parameters

ptr	target map object.
key	the key to find.

Returns

a pointer to the corresponding value if found, otherwise NULL.

Bool gf_map_has_key	(	GF_Map *	ptr,
		const char *	key
	)

Parameters

ptr	target map object.
key	the key to check.

Returns

GF_TRUE if map contains keys, otherwise GF_FALSE

void gf_map_reset

(

GF_Map *

ptr

)

Resets the content of the map

Parameters

ptr	target map object.

Note

It is the caller responsability to destroy the content of the list if needed