FTS hashtable
[FTS Utilitiy Data Structures]

---

Detailed Description

The FTS hashtable.

An FTS hashtable maps keys to values, where both keys and values are FTS atoms.

FTS hashtable performs automatic rehashing when the ration between number of inserted keys and the capacity is greater than a "load factor" (typically 0.75).

The initial capacity of the hashtable can be given by an argument at the initialisation (FTS_HASHTABLE_SMALL, FTS_HASHTABLE_MEDIUM or FTS_HASHTABLE_BIG). To work with a big hashtable, it is more efficient to create the hashtable with a big capacity to avoid intermediate automatic rehashing.

Defines
#define	FTS_HASHTABLE_SMALL   1
	Initialisation argument constant for small hashtables.
#define	FTS_HASHTABLE_MEDIUM   2
	Initialisation argument constant for medium hashtables.
#define	FTS_HASHTABLE_BIG   3
	Initialisation argument constant for big hashtables.
Typedefs
typedef struct fts_hashtable	fts_hashtable_t
	FTS hashtable data type.
Functions
int	fts_hashtable_get_size (fts_hashtable_t *ht)
	Get size of a hashtable.
FTS_API void	fts_hashtable_init (fts_hashtable_t *h, int initial_capacity)
	Initialise a hashtable.
FTS_API void	fts_hashtable_destroy (fts_hashtable_t *h)
	Destroy (deinitialise) a hashtable.
FTS_API fts_hashtable_t *	fts_hashtable_new (int initial_capacity)
	Allocate and initialise a hashtable.
FTS_API void	fts_hashtable_free (fts_hashtable_t *h)
	Free a hashtable that was obtained by fts_hashtable_new().
FTS_API void	fts_hashtable_clear (fts_hashtable_t *h)
	Clear the content of a hashtable.
FTS_API void	fts_hashtable_copy (fts_hashtable_t *from, fts_hashtable_t *to)
	Copy the content of a hashtable to another.
FTS_API int	fts_hashtable_equals (fts_hashtable_t *a, fts_hashtable_t *b)
	Compare a hashtable content to another.
FTS_API int	fts_hashtable_get (const fts_hashtable_t *h, const fts_atom_t *key, fts_atom_t *value)
	Retrieve the value associated to a given key from a hashtable.
FTS_API int	fts_hashtable_put (fts_hashtable_t *h, const fts_atom_t *key, const fts_atom_t *value)
	Insert or set a value associated to teh given key to a hashtable.
FTS_API int	fts_hashtable_remove (fts_hashtable_t *h, const fts_atom_t *key)
	Remove a given key from a hashtable.
FTS_API void	fts_hashtable_get_keys (const fts_hashtable_t *h, fts_iterator_t *i)
	Get an iterator to enumerate the keys contained in the hashtable.
FTS_API void	fts_hashtable_get_values (const fts_hashtable_t *h, fts_iterator_t *i)
	Get an iterator to enumerate the values contained in the hashtable.

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Function Documentation

FTS_API void fts_hashtable_clear

(

fts_hashtable_t *

h

)

Clear the content of a hashtable.

After calling fts_hashtable_clear(), the hashtable will contain no keys, but will keep its allocation state (i.e. its capacity will be its capacity before call).

Parameters:

h

the hashtable

FTS_API void fts_hashtable_copy	(	fts_hashtable_t *	from,
		fts_hashtable_t *	to
	)

Copy the content of a hashtable to another.

Parameters:

	from	the hashtable
	to	the copied hashtable

FTS_API void fts_hashtable_destroy

(

fts_hashtable_t *

h

)

Destroy (deinitialise) a hashtable.

Parameters:

h

the hashtable

FTS_API int fts_hashtable_equals	(	fts_hashtable_t *	a,
		fts_hashtable_t *	b
	)

Compare a hashtable content to another.

Parameters:

	a	the hashtable
	b	the hashtable to compare with

Returns:

1 if hashtables have equal content, else 0

FTS_API void fts_hashtable_free

(

fts_hashtable_t *

h

)

Free a hashtable that was obtained by fts_hashtable_new().

Parameters:

h

the hashtable

FTS_API int fts_hashtable_get	(	const fts_hashtable_t *	h,
		const fts_atom_t *	key,
		fts_atom_t *	value
	)

Retrieve the value associated to a given key from a hashtable.

Parameters:

	h	the hashtable
	key	a pointer to the key to be inserted
	value	a pointer for returning the retrieved value

Returns:

1 if key is mapped, 0 if not

FTS_API void fts_hashtable_get_keys	(	const fts_hashtable_t *	h,
		fts_iterator_t *	i
	)

Get an iterator to enumerate the keys contained in the hashtable.

Parameters:

	h	the hashtable
	i	the iterator

int fts_hashtable_get_size

(

fts_hashtable_t *

ht

)

Get size of a hashtable.

Parameters:

ht

hashtable

Returns:

hashtable size

FTS_API void fts_hashtable_get_values	(	const fts_hashtable_t *	h,
		fts_iterator_t *	i
	)

Get an iterator to enumerate the values contained in the hashtable.

Parameters:

	h	the hashtable
	i	the iterator

FTS_API void fts_hashtable_init	(	fts_hashtable_t *	h,
		int	initial_capacity
	)

Initialise a hashtable.

Parameters:

	h	the hashtable
	initial_capacity	the initial capacity of the hashtable.

FTS_API fts_hashtable_t* fts_hashtable_new

(

int

initial_capacity

)

Allocate and initialise a hashtable.

Parameters:

initial_capacity

the initial capacity of the hashtable.

Returns:

the allocated hashtable

FTS_API int fts_hashtable_put	(	fts_hashtable_t *	h,
		const fts_atom_t *	key,
		const fts_atom_t *	value
	)

Insert or set a value associated to teh given key to a hashtable.

Parameters:

	h	the hashtable
	key	a pointer to the key to be inserted
	value	a pointer to the value to be inserted

Returns:

1 if entry was already mapped, 0 if not

FTS_API int fts_hashtable_remove	(	fts_hashtable_t *	h,
		const fts_atom_t *	key
	)

Remove a given key from a hashtable.

Parameters:

	h	the hashtable
	key	a pointer to the key to be removed

Returns:

1 if entry was mapped, 0 if not