hashtable.h File Reference

This file Defines the HashTable functions and macros The HashTable uses locate3.c 's hashing functions. More...

Go to the source code of this file.

Data Structures
struct	SNF_ht_item_t
	Defines the structure of each element of the HashTable. More...
struct	SNF_ht_t
	Defines the structure of the hashTable. More...

Typedefs
typedef struct SNF_ht_item_t	SNF_ht_item
	Shortened definiton of struct SNF_ht_item_t .
typedef struct SNF_ht_t	SNF_ht
	Shortened definiton of struct SNF_ht_t .

Functions
SNF_ht *	snf_hashtable_inis (int MaxItems)
	Initializes the HashTime and allocates the needed amount.
int	snf_hashtable_insert (SNF_ht *HashTable, const char *Key, void *Content)
	Inserts a new Item into a HashTable.
SNF_ht_item *	snf_hashtable_lookup (SNF_ht *HashTable, const char *key)
	Fetches (looks up) an Item from a HashTable.
SNF_ht_item *	snf_hashtable_delete (SNF_ht *HashTable, const char *key)
	Removed an Item from a HashTable.

Detailed Description

This file Defines the HashTable functions and macros The HashTable uses locate3.c 's hashing functions.

Typedef Documentation

SNF_ht_item

typedef struct SNF_ht_item_t SNF_ht_item

Shortened definiton of struct SNF_ht_item_t .

SNF_ht

typedef struct SNF_ht_t SNF_ht

Shortened definiton of struct SNF_ht_t .

Function Documentation

snf_hashtable_inis()

SNF_ht * snf_hashtable_inis ( int MaxItems )

extern

Initializes the HashTime and allocates the needed amount.

Parameters

MaxItems

The amount used to calculate the length (See note)

Returns

The results:

• NULL Upon failure
• SNF_ht* (The HashTable's pointer)

Note

MaxItems is used to count the smallest power of 2 that could fit MaxItems, the latter would be used as the actual size of the HashTable

Example : if MaxItems == 5 , then the smallest power of 2 is 3, and the actual size of the has table is 8 (2 to the power of 3)

• this is due to the HashTable where it is recommended the HashTable's lenghth is a power of two for best performance.

snf_hashtable_insert()

int snf_hashtable_insert ( SNF_ht * HashTable, const char * Key, void * Content )

extern

Inserts a new Item into a HashTable.

Parameters

HashTable	The Hash tbale to be inserted to.
Key	Item's key
Content	Item's Content

Returns

The results:

• -1 Upon failure
• 0 Upon Success

snf_hashtable_lookup()

SNF_ht_item * snf_hashtable_lookup ( SNF_ht * HashTable, const char * key )

extern

Fetches (looks up) an Item from a HashTable.

Parameters

HashTable	The HashTable to search on.
key	The Item's Key

Returns

The result of the search:

• NULL if item was not found or given paramters are invalid
• SNF_ht_item (HashTable Item's pointer)

Warning

Do not Free the resulting pointer! if you want the item and be able to free it afterwards, use snf_hashtable_delete instead

snf_hashtable_delete()

SNF_ht_item * snf_hashtable_delete ( SNF_ht * HashTable, const char * key )

extern

Removed an Item from a HashTable.

Parameters

HashTable	The HashTable to search on.
key	The Item's Key

Returns

The result of the deletion:

• NULL if item was not found or given paramters are invalid
• SNF_ht_item (Deleted HashTable Item's pointer)

Note

make sure to free the returned item or else you'd get a memory leak.