Dictionary

Simple hash table API (string keys) More...

Typedefs
typedef void(*	ec_dict_elt_free_t) (void *)

Functions
struct ec_dict *	ec_dict (void)
void *	ec_dict_get (const struct ec_dict *dict, const char *key)
bool	ec_dict_has_key (const struct ec_dict *dict, const char *key)
int	ec_dict_del (struct ec_dict *dict, const char *key)
int	ec_dict_set (struct ec_dict *dict, const char *key, void *val, ec_dict_elt_free_t free_cb)
void	ec_dict_free (struct ec_dict *dict)
size_t	ec_dict_len (const struct ec_dict *dict)
struct ec_dict *	ec_dict_dup (const struct ec_dict *dict)
void	ec_dict_dump (FILE *out, const struct ec_dict *dict)
struct ec_dict_elt_ref *	ec_dict_iter (const struct ec_dict *dict)
struct ec_dict_elt_ref *	ec_dict_iter_next (struct ec_dict_elt_ref *iter)
const char *	ec_dict_iter_get_key (const struct ec_dict_elt_ref *iter)
void *	ec_dict_iter_get_val (const struct ec_dict_elt_ref *iter)

Detailed Description

Simple hash table API (string keys)

This file provides functions to store objects in hash tables, using strings as keys.

Typedef Documentation

ec_dict_elt_free_t

typedef void(* ec_dict_elt_free_t) (void *)

Callback function for freeing dictionary elements.

Definition at line 21 of file dict.h.

Function Documentation

ec_dict()

struct ec_dict * ec_dict

(

void

)

Create a hash table.

Returns

The hash table, or NULL on error (errno is set).

ec_dict_get()

void * ec_dict_get	(	const struct ec_dict *	dict,
		const char *	key )

Get a value from the hash table.

Parameters

dict	The hash table.
key	The key string. Must not be NULL.

Returns

The element if it is found, or NULL on error (errno is set). In case of success but the element is NULL, errno is set to 0. If key is NULL, errno is set to EINVAL.

Examples

readline/main.c.

ec_dict_has_key()

bool ec_dict_has_key	(	const struct ec_dict *	dict,
		const char *	key )

Check if the hash table contains this key.

Parameters

dict	The hash table.
key	The key string. Must not be NULL.

Returns

true if it contains the key, false otherwise. If key is NULL, false is returned and errno is set to EINVAL.

ec_dict_del()

int ec_dict_del	(	struct ec_dict *	dict,
		const char *	key )

Delete an object from the hash table.

Parameters

dict	The hash table.
key	The key string. Must not be NULL.

Returns

0 on success, or -1 on error (errno is set).

ec_dict_set()

int ec_dict_set	(	struct ec_dict *	dict,
		const char *	key,
		void *	val,
		ec_dict_elt_free_t	free_cb )

Add/replace an object in the hash table.

Parameters

dict	The hash table.
key	The key string. Must not be NULL.
val	The pointer to be saved in the hash table.
free_cb	An optional pointer to a destructor function called when an object is destroyed (ec_dict_del() or ec_dict_free()).

Returns

0 on success, or -1 on error (errno is set). On error, the passed value is freed (free_cb(val) is called).

Examples

readline/main.c.

ec_dict_free()

void ec_dict_free

(

struct ec_dict *

dict

)

Free a hash table and all its objects.

Parameters

dict	The hash table.

ec_dict_len()

size_t ec_dict_len

(

const struct ec_dict *

dict

)

Get the length of a hash table.

Parameters

dict	The hash table.

Returns

The length of the hash table.

ec_dict_dup()

struct ec_dict * ec_dict_dup

(

const struct ec_dict *

dict

)

Duplicate a hash table.

A reference counter is shared between the clones of hash tables so that the objects are freed only when the last reference is destroyed.

Parameters

dict	The hash table.

Returns

The duplicated hash table, or NULL on error (errno is set).

ec_dict_dump()

void ec_dict_dump	(	FILE *	out,
		const struct ec_dict *	dict )

Dump a hash table.

Parameters

out	The stream where the dump is sent.
dict	The hash table.

ec_dict_iter()

struct ec_dict_elt_ref * ec_dict_iter

(

const struct ec_dict *

dict

)

Iterate the elements in the hash table.

The typical usage is as below:

for (iter = ec_dict_iter(dict);
     iter != NULL;
     iter = ec_dict_iter_next(iter)) {
   printf("  %s: %p\n",
       ec_dict_iter_get_key(iter),
       ec_dict_iter_get_val(iter));
}

Parameters

dict	The hash table.

Returns

An iterator element, or NULL if the dict is empty.

ec_dict_iter_next()

struct ec_dict_elt_ref * ec_dict_iter_next

(

struct ec_dict_elt_ref *

iter

)

Make the iterator point to the next element in the hash table.

Parameters

iter	The hash table iterator.

Returns

An iterator element, or NULL if there is no more element.

ec_dict_iter_get_key()

const char * ec_dict_iter_get_key

(

const struct ec_dict_elt_ref *

iter

)

Get a pointer to the key of the current element.

Parameters

iter	The hash table iterator.

Returns

The current element key, or NULL if the iterator points to an invalid element.

ec_dict_iter_get_val()

void * ec_dict_iter_get_val

(

const struct ec_dict_elt_ref *

iter

)

Get the value of the current element.

Parameters

iter	The hash table iterator.

Returns

The current element value, or NULL if the iterator points to an invalid element.