Internal methods for working with json_type_object objects. Although this is exposed by the json_object_get_object() function and within the json_object_iter type, it is not recommended for direct use. More...

Data Structures
struct	lh_entry

struct	lh_table

Macros
#define	LH_PRIME 0x9e370001UL

#define	LH_LOAD_FACTOR 0.66

#define	LH_EMPTY (void *)-1

#define	LH_FREED (void *)-2

#define	JSON_C_STR_HASH_DFLT 0

#define	JSON_C_STR_HASH_PERLLIKE 1

#define	lh_foreach(table, entry) for (entry = table->head; entry; entry = entry->next)

#define	lh_foreach_safe(table, entry, tmp) for (entry = table->head; entry && ((tmp = entry->next) \|\| 1); entry = tmp)

#define	_LH_INLINE inline

#define	_LH_UNCONST(a) ((void )(uintptr_t)(const void )(a))

#define	lh_entry_k(entry) _LH_UNCONST((entry)->k)

#define	lh_entry_v(entry) _LH_UNCONST((entry)->v)

Typedefs
typedef void(	lh_entry_free_fn )(struct lh_entry *e)

typedef unsigned long(	lh_hash_fn )(const void *k)

typedef int(	lh_equal_fn )(const void k1, const void k2)

typedef struct lh_table	lh_table

Functions
int	json_global_set_string_hash (const int h)

struct lh_table *	lh_table_new (int size, lh_entry_free_fn free_fn, lh_hash_fn hash_fn, lh_equal_fn *equal_fn)

struct lh_table *	lh_kchar_table_new (int size, lh_entry_free_fn *free_fn)

struct lh_table *	lh_kptr_table_new (int size, lh_entry_free_fn *free_fn)

void	lh_table_free (struct lh_table *t)

int	lh_table_insert (struct lh_table t, const void k, const void *v)

int	lh_table_insert_w_hash (struct lh_table t, const void k, const void *v, const unsigned long h, const unsigned opts)

struct lh_entry *	lh_table_lookup_entry (struct lh_table t, const void k)

struct lh_entry *	lh_table_lookup_entry_w_hash (struct lh_table t, const void k, const unsigned long h)

json_bool	lh_table_lookup_ex (struct lh_table t, const void k, void **v)

int	lh_table_delete_entry (struct lh_table t, struct lh_entry e)

int	lh_table_delete (struct lh_table t, const void k)

int	lh_table_length (struct lh_table *t)

int	lh_table_resize (struct lh_table *t, int new_size)

Detailed Description

Internal methods for working with json_type_object objects. Although this is exposed by the json_object_get_object() function and within the json_object_iter type, it is not recommended for direct use.

Macro Definition Documentation

#define _LH_INLINE inline

Deprecated:: Don't use this outside of linkhash.h:

#define _LH_UNCONST ( a ) ((void *)(uintptr_t)(const void *)(a))

Deprecated:: Don't use this outside of linkhash.h:

#define JSON_C_STR_HASH_DFLT 0

default string hash function

#define JSON_C_STR_HASH_PERLLIKE 1

perl-like string hash function

#define LH_EMPTY (void *)-1

sentinel pointer value for empty slots

#define lh_entry_k ( entry ) _LH_UNCONST((entry)->k)

Return a non-const version of lh_entry.k.

lh_entry.k is const to indicate and help ensure that linkhash itself doesn't modify it, but callers are allowed to do what they want with it. See also lh_entry.k_is_constant

#define lh_entry_v ( entry ) _LH_UNCONST((entry)->v)

Return a non-const version of lh_entry.v.

v is const to indicate and help ensure that linkhash itself doesn't modify it, but callers are allowed to do what they want with it.

#define lh_foreach	(	table,
		entry
	)	for (entry = table->head; entry; entry = entry->next)

Convenience list iterator.

#define lh_foreach_safe	(	table,
		entry,
		tmp
	)	for (entry = table->head; entry && ((tmp = entry->next) \|\| 1); entry = tmp)

lh_foreach_safe allows calling of deletion routine while iterating.

Parameters

table	a struct lh_table * to iterate over
entry	a struct lh_entry * variable to hold each element
tmp	a struct lh_entry * variable to hold a temporary pointer to the next element

#define LH_FREED (void *)-2

sentinel pointer value for freed slots

#define LH_LOAD_FACTOR 0.66

The fraction of filled hash buckets until an insert will cause the table to be resized. This can range from just above 0 up to 1.0.

#define LH_PRIME 0x9e370001UL

golden prime used in hash functions

Typedef Documentation

typedef void( lh_entry_free_fn)(struct lh_entry *e)

callback function prototypes

typedef int( lh_equal_fn)(const void *k1, const void *k2)

callback function prototypes

typedef unsigned long( lh_hash_fn)(const void *k)

callback function prototypes

typedef struct lh_table lh_table

Function Documentation

int json_global_set_string_hash ( const int h )

This function sets the hash function to be used for strings. Must be one of the JSON_C_STR_HASH_* values.

Returns: 0 - ok, -1 if parameter was invalid

struct lh_table* lh_kchar_table_new	(	int	size,
		lh_entry_free_fn *	free_fn
	)

read

Convenience function to create a new linkhash table with char keys.

Parameters

size	initial table size.
free_fn	callback function used to free memory for entries.

Returns: On success, a pointer to the new linkhash table is returned. On error, a null pointer is returned.

struct lh_table* lh_kptr_table_new	(	int	size,
		lh_entry_free_fn *	free_fn
	)

read

Convenience function to create a new linkhash table with ptr keys.

Parameters

size	initial table size.
free_fn	callback function used to free memory for entries.

Returns: On success, a pointer to the new linkhash table is returned. On error, a null pointer is returned.

int lh_table_delete	(	struct lh_table *	t,
		const void *	k
	)

Delete a record from the table.

If a callback free function is provided then it is called for the for the item being deleted.

Parameters

t	the table to delete from.
k	a pointer to the key to delete.

Returns: 0 if the item was deleted.; -1 if it was not found.

int lh_table_delete_entry	(	struct lh_table *	t,
		struct lh_entry *	e
	)

Delete a record from the table.

If a callback free function is provided then it is called for the for the item being deleted.

Parameters

t	the table to delete from.
e	a pointer to the entry to delete.

Returns: 0 if the item was deleted.; -1 if it was not found.

void lh_table_free ( struct lh_table * t )

Free a linkhash table.

If a lh_entry_free_fn callback free function was provided then it is called for all entries in the table.

Parameters

t	table to free.

int lh_table_insert	(	struct lh_table *	t,
		const void *	k,
		const void *	v
	)

Insert a record into the table.

Parameters

t	the table to insert into.
k	a pointer to the key to insert.
v	a pointer to the value to insert.

Returns: On success, 0 is returned. On error, a negative value is returned.

int lh_table_insert_w_hash	(	struct lh_table *	t,
		const void *	k,
		const void *	v,
		const unsigned long	h,
		const unsigned	opts
	)

Insert a record into the table using a precalculated key hash.

The hash h, which should be calculated with lh_get_hash() on k, is provided by the caller, to allow for optimization when multiple operations with the same key are known to be needed.

Parameters

t	the table to insert into.
k	a pointer to the key to insert.
v	a pointer to the value to insert.
h	hash value of the key to insert
opts	if set to JSON_C_OBJECT_KEY_IS_CONSTANT, sets lh_entry.k_is_constant so t's free function knows to avoid freeing the key.

int lh_table_length ( struct lh_table * t )

struct lh_entry* lh_table_lookup_entry	(	struct lh_table *	t,
		const void *	k
	)

read

Lookup a record in the table.

Parameters

t	the table to lookup
k	a pointer to the key to lookup

Returns: a pointer to the record structure of the value or NULL if it does not exist.

struct lh_entry* lh_table_lookup_entry_w_hash	(	struct lh_table *	t,
		const void *	k,
		const unsigned long	h
	)

read

Lookup a record in the table using a precalculated key hash.

The hash h, which should be calculated with lh_get_hash() on k, is provided by the caller, to allow for optimization when multiple operations with the same key are known to be needed.

Parameters

t	the table to lookup
k	a pointer to the key to lookup
h	hash value of the key to lookup

Returns: a pointer to the record structure of the value or NULL if it does not exist.

json_bool lh_table_lookup_ex	(	struct lh_table *	t,
		const void *	k,
		void **	v
	)

Lookup a record in the table.

Parameters

t	the table to lookup
k	a pointer to the key to lookup
v	a pointer to a where to store the found value (set to NULL if it doesn't exist).

Returns: whether or not the key was found

struct lh_table* lh_table_new	(	int	size,
		lh_entry_free_fn *	free_fn,
		lh_hash_fn *	hash_fn,
		lh_equal_fn *	equal_fn
	)

read

Create a new linkhash table.

Parameters

size	initial table size. The table is automatically resized although this incurs a performance penalty.
free_fn	callback function used to free memory for entries when lh_table_free or lh_table_delete is called. If NULL is provided, then memory for keys and values must be freed by the caller.
hash_fn	function used to hash keys. 2 standard ones are defined: lh_ptr_hash and lh_char_hash for hashing pointer values and C strings respectively.
equal_fn	comparison function to compare keys. 2 standard ones defined: lh_ptr_hash and lh_char_hash for comparing pointer values and C strings respectively.

Returns: On success, a pointer to the new linkhash table is returned. On error, a null pointer is returned.

int lh_table_resize	(	struct lh_table *	t,
		int	new_size
	)

Resizes the specified table.

Parameters

t	Pointer to table to resize.
new_size	New table size. Must be positive.

Returns: On success, 0 is returned. On error, a negative value is returned.

Data Structures

Macros

Typedefs

Functions

Detailed Description

Macro Definition Documentation

Typedef Documentation

Function Documentation