Hash Table Iterator

Collaboration diagram for Hash Table Iterator:

Data Structures
struct	_amxc_htable_it
	The hash table iterator structure. More...

Macros
#define	amxc_htable_it_get_data(it, type, member)    ((type*) (((char*) it) - offsetof(type, member)))
	Gets the data pointer from an hash table iterator. More...

Functions
int	amxc_htable_it_init (amxc_htable_it_t *const it)
	Initializes a hash table.iterator. More...
void	amxc_htable_it_clean (amxc_htable_it_t *const it, amxc_htable_it_delete_t func)
	Removes the iterator from the htable and frees allocated memory. More...
amxc_htable_it_t *	amxc_htable_it_get_next (const amxc_htable_it_t *const reference)
	Gets the next iterator in the hash table. More...
amxc_htable_it_t *	amxc_htable_it_get_previous (const amxc_htable_it_t *const reference)
	Gets the previous iterator in the hash table. More...
amxc_htable_it_t *	amxc_htable_it_get_next_key (const amxc_htable_it_t *const reference)
	Gets the next iterator in the hash table with the same key. More...
amxc_htable_it_t *	amxc_htable_it_get_previous_key (const amxc_htable_it_t *const reference)
	Gets the previous iterator in the hash table with the same key. More...
void	amxc_htable_it_take (amxc_htable_it_t *const it)
	Removes the iterator from the hash table. More...
AMXC_INLINE const char *	amxc_htable_it_get_key (const amxc_htable_it_t *const it)
	Gets the key from the iterator. More...

Detailed Description

Macro Definition Documentation

amxc_htable_it_get_data

#define amxc_htable_it_get_data	(		it,
			type,
			member
	)		((type*) (((char*) it) - offsetof(type, member)))

Gets the data pointer from an hash table iterator.

Definition at line 87 of file amxc_htable.h.

Function Documentation

amxc_htable_it_clean()

void amxc_htable_it_clean	(	amxc_htable_it_t *const	it,
		amxc_htable_it_delete_t	func
	)

Removes the iterator from the htable and frees allocated memory.

If the iterator is in a hash table, it is removed from the table, when a delete function is provided, it is called to free up the memory.

Note

This function is not freeing the memory taken by the iterator, it uses a callback function for this.

Parameters

it	a pointer to the hash table iterator structure
func	pointer to a function that is called to free the hash table item

Definition at line 82 of file amxc_htable_it.c.

                                                                                    {
    char* key = NULL;
    when_null(it, exit);
 
    // remove from htable if it is in one
    amxc_htable_it_take(it);
    key = it->key;
    it->key = NULL;
    if(func != NULL) {
        func(key, it);
    }
 
    free(key);
 
exit:
    return;
}

amxc_htable_it_get_key()

AMXC_INLINE const char* amxc_htable_it_get_key

(

const amxc_htable_it_t *const

it

)

Gets the key from the iterator.

When an iterator is in a hash table, it has a key set. An iterator that is not in a list can have a key set.

Parameters

it	a pointer to the hash table iterator structure

Returns

the key of the iterator or NULL if the iterator has no key

Definition at line 672 of file amxc_htable.h.

                                                                     {
    return it != NULL ? it->key : NULL;
}

amxc_htable_it_get_next()

amxc_htable_it_t* amxc_htable_it_get_next

(

const amxc_htable_it_t *const

reference

)

Gets the next iterator in the hash table.

Searches the next hash table iterator in the hash table, using the provided iterator as a reference. The iterator returned can have another key as the reference provided. If it must have the same key, you should use amxc_htable_it_get_next_key

Parameters

reference

a pointer to the hash table iterator structure

Returns

The next iterator in the hash table, starting from the reference or NULL if the reference was the last in the table.

Definition at line 100 of file amxc_htable_it.c.

                                                                                   {
    amxc_htable_it_t* it = NULL;
    when_null(reference, exit);
    when_null(reference->ait, exit);
 
    if(reference->next != NULL) {
        it = reference->next;
    } else {
        amxc_array_it_t* ait = amxc_array_it_get_next(reference->ait);
        when_null(ait, exit);
        it = (amxc_htable_it_t*) ait->data;
    }
 
exit:
    return it;
}

amxc_htable_it_get_next_key()

amxc_htable_it_t* amxc_htable_it_get_next_key

(

const amxc_htable_it_t *const

reference

)

Gets the next iterator in the hash table with the same key.

Searches the next hash table iterator in the hash table, using the provided iterator as a reference. The iterator returned has the same key as the reference provided.

Parameters

reference

a pointer to the hash table iterator structure

Returns

The next iterator in the hash table with the same key, starting from the reference or NULL if the reference was the last in the table with that key.

Definition at line 134 of file amxc_htable_it.c.

                                                                                       {
    amxc_htable_it_t* it = NULL;
    when_null(reference, exit);
    when_null(reference->ait, exit);
 
    it = reference->next;
    while(it != NULL && strcmp(it->key, reference->key) != 0) {
        it = it->next;
    }
 
exit:
    return it;
}

amxc_htable_it_get_previous()

amxc_htable_it_t* amxc_htable_it_get_previous

(

const amxc_htable_it_t *const

reference

)

Gets the previous iterator in the hash table.

Searches the previous hash table iterator in the hash table, using the provided iterator as a reference. The iterator returned can have another key as the reference provided. If it must have the same key, you should use amxc_htable_it_get_previous_key

Parameters

reference

a pointer to the hash table iterator structure

Returns

The previous iterator in the hash table, starting from the reference or NULL if the reference was the first in the table.

Definition at line 117 of file amxc_htable_it.c.

                                                                                       {
    amxc_htable_it_t* it = NULL;
    when_null(reference, exit);
    when_null(reference->ait, exit);
 
    if(reference->next != NULL) {
        it = reference->next;
    } else {
        amxc_array_it_t* ait = amxc_array_it_get_previous(reference->ait);
        when_null(ait, exit);
        it = (amxc_htable_it_t*) ait->data;
    }
 
exit:
    return it;
}

amxc_htable_it_get_previous_key()

amxc_htable_it_t* amxc_htable_it_get_previous_key

(

const amxc_htable_it_t *const

reference

)

Gets the previous iterator in the hash table with the same key.

Searches the previous hash table iterator in the hash table, using the provided iterator as a reference. The iterator returned has the same key as the reference provided.

Parameters

reference

a pointer to the hash table iterator structure

Returns

The previous iterator in the hash table with the same key, starting from the reference or NULL if the reference was the first in the table with that key.

Definition at line 148 of file amxc_htable_it.c.

                                                                                           {
    return amxc_htable_it_get_next_key(reference);
}

amxc_htable_it_init()

int amxc_htable_it_init

(

amxc_htable_it_t *const

it

)

Initializes a hash table.iterator.

Initializes the hash table iterator structure. All pointers are reset to NULL.

Note

When calling this function on an already initialized hash table iterator, the hash table iterator is reset and data can be lost. Use amxc_htable_it_clean to remove the iterator from the table and to clean up the iterator.

Parameters

it	a pointer to the hash table iterator structure.

Returns

0 on success. -1 if a NULL pointer is given.

Definition at line 68 of file amxc_htable_it.c.

                                                    {
    int retval = -1;
    when_null(it, exit);
 
    it->ait = NULL;
    it->key = NULL;
    it->next = NULL;
 
    retval = 0;
 
exit:
    return retval;
}

amxc_htable_it_take()

void amxc_htable_it_take

(

amxc_htable_it_t *const

it

)

Removes the iterator from the hash table.

This function only removes the iterator from the hash table, it does not clean any memory allocated for the iterator.

Parameters

it	a pointer to the hash table iterator structure

Definition at line 152 of file amxc_htable_it.c.

                                                     {
    amxc_htable_t* htable = NULL;
    when_null(it, exit);
    when_null(it->ait, exit);
 
    htable = (amxc_htable_t*) it->ait->array;
    if(it->ait->data != it) {
        amxc_htable_it_t* prev = (amxc_htable_it_t*) it->ait->data;
        while(prev->next != it) {
            prev = prev->next;
        }
        prev->next = it->next;
    } else {
        if(it->next != NULL) {
            amxc_array_it_set_data(it->ait, it->next);
            it->next = NULL;
        } else {
            amxc_array_it_take_data(it->ait);
        }
    }
    it->ait = NULL;
    it->next = NULL;
    htable->items--;
 
exit:
    return;
}