hashmap.c File Reference

Implementation of the hashmap. More...

#include "hashmap.h"
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <assert.h>

Include dependency graph for hashmap.c:

Go to the source code of this file.

Functions
static void	rehash (hashmap *map)
	Doubles the size of the hashmap and re-inserts all old elements.
static int	insert (hashmap *map, void *data, char *key)
	Ensures that a given element is present in the hashmap without copying the key.
static hashmapEntry *	find (const hashmap *map, const char *key)
	Searches for the hashmap entry using the key and returns the first free index if the entry could not be found.
static int	compare (const hashmapEntry *lhs, const hashmapEntry *rhs)
	Compares two hashmap entries lexicographically according to their keys, if they exist.
static unsigned long	hash1 (const char *rawKey)
	Computes the SDBM 32-Bit hashcode. (Sleepycats Berkeley DataBase).
static unsigned long	hash2 (const char *rawKey)
	Computes the FNV 32-Bit hashcode. (Fowler/Noll/Vo).
hashmap *	newHashmap (unsigned int hint)
	Creates a new hashmap.
void	deleteHashmap (hashmap *map)
	Destroys the hashmap without touching saved data.
int	hashmapSet (hashmap *map, void *data, const char *key)
	Inserts a new element into the map or updates an existing one.
void *	hashmapGet (const hashmap *map, const char *key)
	Returns the element associated with a given key.
void *	hashmapRemove (hashmap *map, const char *key)
	Removes the element associated with a given key from the map and returns it.
void	hashmapProcess (const hashmap *map, fHashmapProc proc)
	Processes all elements of the map in lexicographical order of their keys.

---

Detailed Description

Implementation of the hashmap.

Author:

Dorian Weber

Definition in file hashmap.c.

---

Function Documentation

static int compare	(	const hashmapEntry *	lhs,
		const hashmapEntry *	rhs
	)			[static]

Compares two hashmap entries lexicographically according to their keys, if they exist.

Definition at line 198 of file hashmap.c.

void deleteHashmap

(

hashmap *

map

)

Destroys the hashmap without touching saved data.

Parameters:

[in]

map

target hashmap

Definition at line 234 of file hashmap.c.

static hashmapEntry * find	(	const hashmap *	map,
		const char *	key
	)			[static]

Searches for the hashmap entry using the key and returns the first free index if the entry could not be found.

Definition at line 115 of file hashmap.c.

static unsigned long hash1

(

const char *

rawKey

)

[static]

Computes the SDBM 32-Bit hashcode. (Sleepycats Berkeley DataBase).

Definition at line 59 of file hashmap.c.

static unsigned long hash2

(

const char *

rawKey

)

[static]

Computes the FNV 32-Bit hashcode. (Fowler/Noll/Vo).

Definition at line 75 of file hashmap.c.

void* hashmapGet	(	const hashmap *	map,
		const char *	key
	)

Returns the element associated with a given key.

Parameters:

[in]	map	target hashmap
[in]	key	the key

Returns:

the element associated with a key, if existing,
NULL otherwise

Definition at line 257 of file hashmap.c.

void hashmapProcess	(	const hashmap *	map,
		fHashmapProc	proc
	)

Processes all elements of the map in lexicographical order of their keys.

Precondition:

proc is not NULL

Parameters:

[in]	map	target hashmap
[in]	proc	function that processes an item

Definition at line 294 of file hashmap.c.

void* hashmapRemove	(	hashmap *	map,
		const char *	key
	)

Removes the element associated with a given key from the map and returns it.

Parameters:

[in]	map	target hashmap
[in]	key	the key

Returns:

the element associated with a key, if existing,
NULL otherwise

Definition at line 270 of file hashmap.c.

int hashmapSet	(	hashmap *	map,
		void *	data,
		const char *	key
	)

Inserts a new element into the map or updates an existing one.

Precondition:

key is not NULL or empty.

Parameters:

[in]	map	target hashmap
[in]	data	pointer to the data
[in]	key	the key

Returns:

HASHMAP_ILLEGAL, if the key is invalid (NULL or empty)
HASHMAP_INSERT, if the element was inserted
HASHMAP_UPDATE, if the element got updated (overwritten)

Definition at line 251 of file hashmap.c.

static int insert	(	hashmap *	map,
		void *	data,
		char *	key
	)			[static]

Ensures that a given element is present in the hashmap without copying the key.

Returns:

HASHMAP_INSERT, if the hashmaps count changed
HASHMAP_UPDATE, if the element got updated

Definition at line 163 of file hashmap.c.

hashmap* newHashmap

(

unsigned int

hint

)

Creates a new hashmap.

Note:

The hashmap resizes itself automatically.

Parameters:

[in]

hint

indicates the estimated number of entries

Returns:

pointer to a hashmap

Definition at line 206 of file hashmap.c.

static void rehash

(

hashmap *

map

)

[static]

Doubles the size of the hashmap and re-inserts all old elements.

Definition at line 90 of file hashmap.c.