hashmap.h File Reference

C hashmap implementation. More...

#include <stdlib.h>
#include <stdbool.h>

Go to the source code of this file.

Classes
struct	hashmap_elem_t
struct	hashmap_t

Macros
#define	HASHMAP_LOOP(MAP, VALUE_TYPE, CODE)

Enumerations
enum	hashmap_ret_t {   MAP_SUCCESS = 0, MAP_FULL = -1, MAP_OMEM = -2, MAP_KEY_EXISTS = -3,   MAP_KEY_NOT_EXISTS = -4 }

Functions
hashmap_t *	hashmap_new (size_t init_size)
hashmap_ret_t	hashmap_put (hashmap_t *map, const char *key, void *val, void(*free_fn)(void *))
void *	hashmap_get (hashmap_t *map, const char *key)
hashmap_ret_t	hashmap_remove (hashmap_t *map, const char *key)
void	hashmap_destroy (hashmap_t *map)

Detailed Description

C hashmap implementation.

Macro Definition Documentation

HASHMAP_LOOP

#define HASHMAP_LOOP	(		MAP,
			VALUE_TYPE,
			CODE
	)

Value:

    for(int i = 0; i < MAP->max_size; i++) { \
        if(MAP->elems[i].in_use) { \
            VALUE_TYPE* value = MAP->elems[i].value; \
            const char* key = MAP->elems[i].key; \
            CODE \
        } \
    }

Helper macro for looping over all of the elements in the hashmap.

For the given code block (i.e. the CODE parameter), there is a value and key variable made available with the const char* for the key and the value casted to the given VALUE_TYPE.

Note

This is not necessarily super efficient, because it must loop over all of the allocated/in-use elements. So it will be O(N) where N is the current max_size of the hashmap.

Parameters

MAP	- The hashmap to loop over
VALUE_TYPE	- Type to cast the void* value to to make available
CODE	- Code block to be executed on each (key, value) pair

Enumeration Type Documentation

hashmap_ret_t

enum hashmap_ret_t

Hashmap return values

Function Documentation

hashmap_destroy()

void hashmap_destroy

(

hashmap_t *

map

)

Destroy the given hashmap.

Parameters

map	- Hashmap to destroy

hashmap_get()

void* hashmap_get	(	hashmap_t *	map,
		const char *	key
	)

Get the value associated with the given key if it exists.

Parameters

map	- Hashmap to retrieve a value from.
key	- Key for the value

Returns

void*, or NULL if the key does not exist

hashmap_new()

hashmap_t* hashmap_new

(

size_t

init_size

)

Create a new hashmap.

Note

init_size will be the initial size of the hashmap. When it grows past that it will allocated init_size amount of additional memory.

Parameters

init_size

- Initial size of the hashmap

Returns

hashmap_t*

hashmap_put()

hashmap_ret_t hashmap_put	(	hashmap_t *	map,
		const char *	key,
		void *	val,
		void(*)(void *)	free_fn
	)

Put a (key, value) pair into the hashmap.

Parameters

map	- Hashmap to put the pair into
key	- Key for the value
val	- Value associated with the key
free_fn	- Free function for the value

Returns

hashmap_ret_t

hashmap_remove()

hashmap_ret_t hashmap_remove	(	hashmap_t *	map,
		const char *	key
	)

Remove item from the hashmap.

Parameters

map	- Hashmap to remove value from
key	- Key for the value

Returns

hashmap_ret_t