arg_hashtable.c File Reference

#include "argtable3_private.h"
#include <math.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

Functions
arg_hashtable_t *	arg_hashtable_create (unsigned int minsize, unsigned int(*hashfn)(const void *), int(*eqfn)(const void *, const void *))
	Create a hash table.
unsigned int	arg_hashtable_count (arg_hashtable_t *h)
	Return the number of keys in the hash table.
void	arg_hashtable_insert (arg_hashtable_t *h, void *k, void *v)
	This function will cause the table to expand if the insertion would take the ratio of entries to table size over the maximum load factor.
void *	arg_hashtable_search (arg_hashtable_t *h, const void *k)
	Search the specified key in the hash table.
void	arg_hashtable_remove (arg_hashtable_t *h, const void *k)
	Remove the specified key from the hash table.
void	arg_hashtable_destroy (arg_hashtable_t *h, int free_values)
	Free the hash table and the memory allocated for each key-value pair.
arg_hashtable_itr_t *	arg_hashtable_itr_create (arg_hashtable_t *h)
void	arg_hashtable_itr_destroy (arg_hashtable_itr_t *itr)
void *	arg_hashtable_itr_key (arg_hashtable_itr_t *i)
	Return the value of the (key,value) pair at the current position.
void *	arg_hashtable_itr_value (arg_hashtable_itr_t *i)
	Return the value of the (key,value) pair at the current position.
int	arg_hashtable_itr_advance (arg_hashtable_itr_t *itr)
	Advance the iterator to the next element. Returns zero if advanced to end of table.
int	arg_hashtable_itr_remove (arg_hashtable_itr_t *itr)
	Remove current element and advance the iterator to the next element.
int	arg_hashtable_itr_search (arg_hashtable_itr_t *itr, arg_hashtable_t *h, void *k)
	Search and overwrite the supplied iterator, to point to the entry matching the supplied key.
int	arg_hashtable_change (arg_hashtable_t *h, void *k, void *v)

Variables
const unsigned int	prime_table_length = sizeof(primes) / sizeof(primes[0])
const float	max_load_factor = (float)0.65

Function Documentation

arg_hashtable_create()

arg_hashtable_t * arg_hashtable_create	(	unsigned int	minsize,
		unsigned int(*)(const void *)	hashfn,
		int(*)(const void *, const void *)	eqfn
	)

Create a hash table.

Parameters

minsize	minimum initial size of hash table
hashfn	function for hashing keys
eqfn	function for determining key equality

Returns

newly created hash table or NULL on failure

arg_hashtable_count()

unsigned int arg_hashtable_count

(

arg_hashtable_t *

h

)

Return the number of keys in the hash table.

Parameters

h	the hash table

Returns

the number of items stored in the hash table

arg_hashtable_insert()

void arg_hashtable_insert	(	arg_hashtable_t *	h,
		void *	k,
		void *	v
	)

This function will cause the table to expand if the insertion would take the ratio of entries to table size over the maximum load factor.

This function does not check for repeated insertions with a duplicate key. The value returned when using a duplicate key is undefined – when the hash table changes size, the order of retrieval of duplicate key entries is reversed. If in doubt, remove before insert.

Parameters

h	the hash table to insert into
k	the key - hash table claims ownership and will free on removal
v	the value - does not claim ownership

Returns

non-zero for successful insertion

arg_hashtable_search()

void * arg_hashtable_search	(	arg_hashtable_t *	h,
		const void *	k
	)

Search the specified key in the hash table.

Parameters

h	the hash table to search
k	the key to search for - does not claim ownership

Returns

the value associated with the key, or NULL if none found

arg_hashtable_remove()

void arg_hashtable_remove	(	arg_hashtable_t *	h,
		const void *	k
	)

Remove the specified key from the hash table.

Parameters

h	the hash table to remove the item from
k	the key to search for - does not claim ownership

arg_hashtable_destroy()

void arg_hashtable_destroy	(	arg_hashtable_t *	h,
		int	free_values
	)

Free the hash table and the memory allocated for each key-value pair.

Parameters

h	the hash table
free_values	whether to call 'free' on the remaining values

arg_hashtable_itr_create()

arg_hashtable_itr_t * arg_hashtable_itr_create

(

arg_hashtable_t *

h

)

arg_hashtable_itr_destroy()

void arg_hashtable_itr_destroy

(

arg_hashtable_itr_t *

itr

)

arg_hashtable_itr_key()

void * arg_hashtable_itr_key

(

arg_hashtable_itr_t *

i

)

Return the value of the (key,value) pair at the current position.

arg_hashtable_itr_value()

void * arg_hashtable_itr_value

(

arg_hashtable_itr_t *

i

)

Return the value of the (key,value) pair at the current position.

arg_hashtable_itr_advance()

int arg_hashtable_itr_advance

(

arg_hashtable_itr_t *

itr

)

Advance the iterator to the next element. Returns zero if advanced to end of table.

arg_hashtable_itr_remove()

int arg_hashtable_itr_remove

(

arg_hashtable_itr_t *

itr

)

Remove current element and advance the iterator to the next element.

arg_hashtable_itr_search()

int arg_hashtable_itr_search	(	arg_hashtable_itr_t *	itr,
		arg_hashtable_t *	h,
		void *	k
	)

Search and overwrite the supplied iterator, to point to the entry matching the supplied key.

Returns

Zero if not found.

arg_hashtable_change()

int arg_hashtable_change	(	arg_hashtable_t *	h,
		void *	k,
		void *	v
	)

Variable Documentation

prime_table_length

const unsigned int prime_table_length = sizeof(primes) / sizeof(primes[0])

max_load_factor

const float max_load_factor = (float)0.65