a simple hash table implementation More...

#include "hashtable.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

Functions
hash_table_element_t *	hash_table_element_new ()

void	hash_table_element_delete (hash_table_t table, hash_table_element_t element)

hash_table_t *	hash_table_new (hash_table_mode_t mode)

void	hash_table_delete (hash_table_t *table)

int	hash_table_add (hash_table_t table, void key, size_t key_len, void *value, size_t value_len)

int	hash_table_remove (hash_table_t table, void key, size_t key_len)

void *	hash_table_lookup (hash_table_t table, void key, size_t key_len)

int	hash_table_has_key (hash_table_t table, void key, size_t key_len)

size_t	hash_table_get_keys (hash_table_t table, void **keys_ptr)

size_t	hash_table_get_elements (hash_table_t table, hash_table_element_t **elements)

uint16_t	hash_table_do_hash (void *key, size_t key_len, uint16_t max_key)

int	hash_table_resize (hash_table_t *table, size_t len)

int	hash_table_iterate (hash_table_t table, int(fct)(void user, void value, void key, size_t key_len), void user)

Detailed Description

a simple hash table implementation

License GPLv3+

Author: Ankur Shrivastava

Function Documentation

int hash_table_add	(	hash_table_t *	table,
		void *	key,
		size_t	key_len,
		void *	value,
		size_t	value_len
	)

Function to add a key - value pair to the hash table, use HT_ADD macro

Parameters

table	hash table to add element to
key	pointer to the key for the hash table
key_len	length of the key in bytes
value	pointer to the value to be added against the key
value_len	length of the value in bytes

Returns: 0 on sucess; -1 when no memory

void hash_table_delete ( hash_table_t * table )

Function to delete the hash table

Parameters

table hash table to be deleted

uint16_t hash_table_do_hash	(	void *	key,
		size_t	key_len,
		uint16_t	max_key
	)

Function that returns a hash value for a given key and key_len

Parameters

key	pointer to the key
key_len	length of the key
max_key	max value of the hash to be returned by the function

Returns: hash value belonging to [0, max_key)

void hash_table_element_delete	(	hash_table_t *	table,
		hash_table_element_t *	element
	)

Function to delete an hash table element

Parameters

table	table from which element has to be deleted
element	hash table element to be deleted

hash_table_element_t* hash_table_element_new ( )

Function to create a now hash_table element

Returns: hash_table_element_t object when success; NULL when no memory

size_t hash_table_get_elements	(	hash_table_t *	table,
		hash_table_element_t ***	elements
	)

Function to get all elements (key - value pairs) from the given hash table

Parameters

table	hash table from which elements have to be retrieved
elements	a pointer to an array of hash_table_element_t pointer (malloced by function)

Returns: 1 when no memory; count of elements

size_t hash_table_get_keys	(	hash_table_t *	table,
		void ***	keys_ptr
	)

Function to return all the keys in a given hash table

Parameters

table	hash table from which key are to be reterived
keys	a void** pointer where keys are filled in (memory allocated internally and must be freed)

Returns: total number of keys filled in keys

int hash_table_has_key	(	hash_table_t *	table,
		void *	key,
		size_t	key_len
	)

Function to look if the exists in the hash table

Parameters

key	pointer to key to be looked for
key_len	size of the key to be searched

Returns: 0 when key is not found; 1 when key is found

int hash_table_iterate	(	hash_table_t *	table,
		int()(void user, void value, void key, size_t key_len)	fct,
		void *	user
	)

Function to iterate through all elements of the hashtable

Parameters

table	hash table to be iterated
fct	pointer to a function returning 1 if the element has to be removed
user	arbitrary user pointer passed to the fct callback

Returns: 0 when success

void* hash_table_lookup	(	hash_table_t *	table,
		void *	key,
		size_t	key_len
	)

Function to lookup a key in a particular table

Parameters

table	table to look key in
key	pointer to key to be looked for
key_len	size of the key to be searched

Returns: NULL when key is not found in the hash table; void* pointer to the value in the table

hash_table_t* hash_table_new ( hash_table_mode_t mode )

Fuction to create a new hash table

Parameters

mode	hash_table_mode which the hash table should follow

Returns: hash_table_t object which references the hash table; NULL when no memory

int hash_table_remove	(	hash_table_t *	table,
		void *	key,
		size_t	key_len
	)

Function to remove an hash table element (for a given key) from a given hash table

Parameters

table	hash table from which element has to be removed
key	pointer to the key which has to be removed
key_len	size of the key in bytes

Returns: 0 on sucess; -1 when key is not found

int hash_table_resize	(	hash_table_t *	table,
		size_t	len
	)

Function to resize the hash table store house

Parameters

table	hash table to be resized
len	new length of the hash table

Returns: -1 when no elements in hash table; -2 when no emmory for new store house; 0 when sucess

Functions

Detailed Description

Function Documentation