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efl/legacy/eina/src/lib/eina_hash.c

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#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
#include <stdint.h>
#include "eina_hash.h"
#include "eina_inlist.h"
#include "eina_error.h"
#include "eina_private.h"
/*============================================================================*
* Local *
*============================================================================*/
typedef struct _Eina_Hash_El Eina_Hash_El;
struct _Eina_Hash
{
Eina_Key_Length key_length_cb;
Eina_Key_Cmp key_cmp_cb;
Eina_Key_Hash key_hash_cb;
Eina_Inlist *buckets[256];
int population;
};
struct _Eina_Hash_El
{
Eina_Inlist _list_data;
void *data;
const void *key;
unsigned int length;
};
static int _eina_hash_init_count = 0;
static int EINA_HASH_ERROR_OUT_OF_MEMORY = 0;
static inline Eina_Hash_El *
_eina_hash_find_by_hash(const Eina_Hash *hash, const char *key, int key_length, int key_hash)
{
Eina_Hash_El *el;
key_hash &= 0xFF;
EINA_INLIST_ITER_NEXT(hash->buckets[key_hash], el)
if (!hash->key_cmp_cb(el->key, el->length, key, key_length)) return el;
return NULL;
}
static inline Eina_Hash_El *
_eina_hash_find_by_data(const Eina_Hash *hash, const void *data, int *key_hash)
{
Eina_Hash_El *el;
int hash_num;
/* FIXME: Use an iterator for this stuff */
for (hash_num = 0; hash_num < 256; hash_num++)
EINA_INLIST_ITER_NEXT(hash->buckets[hash_num], el)
if (el->data == data)
{
*key_hash = hash_num;
return el;
}
return NULL;
}
static inline void
_eina_hash_reorder(Eina_Hash *hash, Eina_Hash_El *el, int key_hash)
{
key_hash &= 0xFF;
if ((void*) el != (void*) hash->buckets[key_hash])
{
hash->buckets[key_hash] = eina_inlist_remove(hash->buckets[key_hash], el);
hash->buckets[key_hash] = eina_inlist_prepend(hash->buckets[key_hash], el);
}
}
static unsigned int
_eina_string_key_length(const char *key)
{
if (!key) return 0;
return strlen(key) + 1;
}
static int
_eina_string_key_cmp(const char *key1, __UNUSED__ int key1_length,
const char *key2, __UNUSED__ int key2_length)
{
return strcmp(key1, key2);
}
/*============================================================================*
* Global *
*============================================================================*/
/*============================================================================*
* API *
*============================================================================*/
/**
* Initialize the eina hash internal structure.
* @return Zero on failure, non-zero on successful initialization.
*/
EAPI int
eina_hash_init(void)
{
_eina_hash_init_count++;
if (_eina_hash_init_count == 1)
{
eina_error_init();
EINA_HASH_ERROR_OUT_OF_MEMORY = eina_error_register("Eina_Hash out of memory");
}
return _eina_hash_init_count;
}
/**
* Shutdown the eina hash internal structures
*/
EAPI int
eina_hash_shutdown(void)
{
_eina_hash_init_count--;
if (_eina_hash_init_count == 0) eina_error_shutdown();
return _eina_hash_init_count;
}
EAPI Eina_Hash *
eina_hash_new(Eina_Key_Length key_length_cb,
Eina_Key_Cmp key_cmp_cb,
Eina_Key_Hash key_hash_cb)
{
/* FIXME: Use mempool. */
Eina_Hash *new;
eina_error_set(0);
if (!key_length_cb || !key_cmp_cb) return NULL;
new = calloc(1, sizeof (Eina_Hash));
if (!new) goto on_error;
new->key_length_cb = key_length_cb;
new->key_cmp_cb = key_cmp_cb;
new->key_hash_cb = key_hash_cb;
return new;
on_error:
eina_error_set(EINA_HASH_ERROR_OUT_OF_MEMORY);
return NULL;
}
EAPI Eina_Hash *
eina_hash_string_djb2_new(void)
{
return eina_hash_new(EINA_KEY_LENGTH(_eina_string_key_length),
EINA_KEY_CMP(_eina_string_key_cmp),
EINA_KEY_HASH(eina_hash_djb2));
}
EAPI Eina_Hash *
eina_hash_string_superfast_new(void)
{
return eina_hash_new(EINA_KEY_LENGTH(_eina_string_key_length),
EINA_KEY_CMP(_eina_string_key_cmp),
EINA_KEY_HASH(eina_hash_superfast));
}
/**
* Adds an entry to the given hash table.
*
* @p key is expected to be a unique string within the hash table.
* Otherwise, you cannot be sure which inserted data pointer will be
* accessed with @ref eina_hash_find , and removed with
* @ref eina_hash_del .
*
* @p key_hash is expected to always match @p key. Otherwise, you
* cannot be sure to find it again with @ref eina_hash_find_by_hash.
*
* Key strings are case sensitive.
*
* @ref eina_error_get should be used to determine if an
* allocation error occurred during this function.
*
* @param hash The given hash table. Can be @c NULL.
* @param key A unique key. Can be @c NULL.
* @param key_length Should be the length of @p key (don't forget to count '\0' for string).
* @param key_hash The hash that will always match key.
* @param data Data to associate with the string given by @p key.
* @return Will return EINA_FALSE if an error occured, and EINA_TRUE if every
* thing goes fine.
* @ingroup Eina_Hash_Data
*/
EAPI Eina_Bool
eina_hash_add_by_hash(Eina_Hash *hash,
const void *key, int key_length, int key_hash,
const void *data)
{
Eina_Hash_El *el;
eina_error_set(0);
if ((!hash) || (!key) || (!data)) return EINA_FALSE;
/* Alloc every needed thing.*/
el = malloc(sizeof (Eina_Hash_El) + key_length);
if (!el) goto on_error;
/* Setup the element */
el->length = key_length;
el->data = (void *) data;
el->key = (char *) (el + 1);
memcpy((char *) el->key, key, key_length);
/* eina hash have 256 buckets. */
key_hash &= 0xFF;
/* add the new element to the hash. */
hash->buckets[key_hash] = eina_inlist_prepend(hash->buckets[key_hash], el);
hash->population++;
return EINA_TRUE;
on_error:
eina_error_set(EINA_HASH_ERROR_OUT_OF_MEMORY);
return EINA_FALSE;
}
/**
* Adds an entry to the given hash table and does not duplicate the string key.
*
* @p key is expected to be a unique string within the hash table.
* Otherwise, you cannot be sure which inserted data pointer will be
* accessed with @ref eina_hash_find , and removed with
* @ref eina_hash_del . This call does not make a copy of the key so it must
* be a string constant or stored elsewhere (in the object being added) etc.
*
* @p key_hash is expected to always match @p key. Otherwise, you
* cannot be sure to find it again with @ref eina_hash_find_by_hash.
*
* Key strings are case sensitive.
*
* @ref eina_error_get should be used to determine if an
* allocation error occurred during this function.
*
* @param hash The given hash table. Can be @c NULL.
* @param key A unique key. Can be @c NULL.
* @param key_length Should be the length of @p key (don't forget to count '\0' for string).
* @param key_hash The hash that will always match key.
* @param data Data to associate with the string given by @p key.
* @return Will return EINA_FALSE if an error occured, and EINA_TRUE if every
* thing goes fine.
* @ingroup Eina_Hash_Data
*/
EAPI Eina_Bool
eina_hash_direct_add_by_hash(Eina_Hash *hash,
const void *key, int key_length, int key_hash,
const void *data)
{
Eina_Hash_El *el;
eina_error_set(0);
if ((!hash) || (!key) || (!data)) return EINA_FALSE;
/* Alloc every needed thing.*/
el = malloc(sizeof (Eina_Hash_El));
if (!el) goto on_error;
/* Setup the element */
el->length = key_length;
el->data = (void *) data;
el->key = key;
/* eina hash have 256 buckets. */
key_hash &= 0xFF;
/* add the new element to the hash. */
hash->buckets[key_hash] = eina_inlist_prepend(hash->buckets[key_hash], el);
hash->population++;
return EINA_TRUE;
on_error:
eina_error_set(EINA_HASH_ERROR_OUT_OF_MEMORY);
return EINA_FALSE;
}
/**
* Adds an entry to the given hash table.
*
* @p key is expected to be a unique string within the hash table.
* Otherwise, you cannot be sure which inserted data pointer will be
* accessed with @ref eina_hash_find , and removed with
* @ref eina_hash_del .
*
* Key strings are case sensitive.
*
* @ref eina_hash_alloc_error should be used to determine if an
* allocation error occurred during this function.
*
* @param hash The given hash table. Can be @c NULL.
* @param key A unique key. Can be @c NULL.
* @param data Data to associate with the string given by @p key.
* @return Will return EINA_FALSE if an error occured, and EINA_TRUE if every
* thing goes fine.
* @ingroup Eina_Hash_Data
*/
EAPI Eina_Bool
eina_hash_add(Eina_Hash *hash, const void *key, const void *data)
{
unsigned int key_length;
int key_hash;
if ((!hash) || (!key) || (!data)) return EINA_FALSE;
key_length = hash->key_length_cb(key);
key_hash = hash->key_hash_cb(key, key_length);
return eina_hash_add_by_hash(hash, key, key_length, key_hash, data);
}
/**
* Adds an entry to the given hash table and does not duplicate the string key.
*
* @p key is expected to be a unique string within the hash table.
* Otherwise, you cannot be sure which inserted data pointer will be
* accessed with @ref eina_hash_find , and removed with
* @ref eina_hash_del . This call does not make a copy of the key so it must
* be a string constant or stored elsewhere (in the object being added) etc.
*
* Key strings are case sensitive.
*
* @ref eina_hash_alloc_error should be used to determine if an
* allocation error occurred during this function.
*
* @param hash The given hash table. Can be @c NULL.
* @param key A unique key. Can be @c NULL.
* @param data Data to associate with the string given by @p key.
* @return Will return EINA_FALSE if an error occured, and EINA_TRUE if every
* thing goes fine.
* @ingroup Eina_Hash_Data
*/
EAPI Eina_Bool
eina_hash_direct_add(Eina_Hash *hash, const void *key, const void *data)
{
int key_length;
int key_hash;
if ((!hash) || (!key) || (!data)) return EINA_FALSE;
key_length = hash->key_length_cb(key);
key_hash = hash->key_hash_cb(key, key_length);
return eina_hash_direct_add_by_hash(hash, key, key_length, key_hash, data);
}
/**
* Removes the entry identified by @p key and @p key_hash or @p data from the given
* hash table.
*
* If @p key is @c NULL, then @p data is used to find a match to
* remove.
*
* @param hash The given hash table.
* @param key The key. Can be @c NULL.
* @param key_hash The hash that always match the key. Ignored if @p key is @c NULL.
* @param data The data pointer to remove if @p key is @c NULL.
* Otherwise, not required and can be @c NULL.
* @return Will return EINA_FALSE if an error occured, and EINA_TRUE if every
* thing goes fine.
* @ingroup Eina_Hash_Data
*/
EAPI Eina_Bool
eina_hash_del_by_hash(Eina_Hash *hash, const void *key, int key_length, int key_hash, const void *data)
{
Eina_Hash_El *el = NULL;
if (!hash) return EINA_FALSE;
if (!key) el = _eina_hash_find_by_data(hash, data, &key_hash);
else el = _eina_hash_find_by_hash(hash, key, key_length, key_hash);
if (!el) return EINA_FALSE;
key_hash &= 0xFF;
hash->buckets[key_hash] = eina_inlist_remove(hash->buckets[key_hash], el);
free(el);
hash->population--;
return EINA_TRUE;
}
/**
* Removes the entry identified by @p key or @p data from the given
* hash table.
*
* If @p key is @c NULL, then @p data is used to find a match to
* remove.
*
* @param hash The given hash table.
* @param key The key. Can be @c NULL.
* @param data The data pointer to remove if @p key is @c NULL.
* Otherwise, not required and can be @c NULL.
* @return Will return EINA_FALSE if an error occured, and EINA_TRUE if every
* thing goes fine.
* @ingroup Eina_Hash_Data
*/
EAPI Eina_Bool
eina_hash_del(Eina_Hash *hash, const void *key, const void *data)
{
int key_length = 0;
int hash_num;
if (!hash) return EINA_FALSE;
if (key)
{
key_length = hash->key_length_cb(key);
hash_num = hash->key_hash_cb(key, key_length);
}
return eina_hash_del_by_hash(hash, key, key_length, hash_num, data);
}
/**
* Retrieves a specific entry in the given hash table.
* @param hash The given hash table.
* @param key The key of the entry to find.
* @param key_hash The hash that always match the key. Ignored if @p key is @c NULL.
* @return The data pointer for the stored entry, or @c NULL if not
* found.
* @ingroup Eina_Hash_Data
*/
EAPI void *
eina_hash_find_by_hash(const Eina_Hash *hash, const void *key, int key_length, int key_hash)
{
Eina_Hash_El *el;
if ((!hash) || (!key)) return NULL;
el = _eina_hash_find_by_hash(hash, key, key_length, key_hash);
if (el)
{
_eina_hash_reorder((Eina_Hash *) hash, el, key_hash);
return el->data;
}
return NULL;
}
/**
* Retrieves a specific entry in the given hash table.
* @param hash The given hash table.
* @param key The key of the entry to find.
* @return The data pointer for the stored entry, or @c NULL if not
* found.
* @ingroup Eina_Hash_Data
*/
EAPI void *
eina_hash_find(const Eina_Hash *hash, const void *key)
{
int key_length;
int hash_num;
if ((!hash) || (!key)) return NULL;
key_length = hash->key_length_cb(key);
hash_num = hash->key_hash_cb(key, key_length);
return eina_hash_find_by_hash(hash, key, key_length, hash_num);
}
/**
* Modifies the entry pointer at the specified key and returns the old entry
* @param hash The given hash table.
* @param key The key of the entry to modify.
* @param key_hash The hash that always match the key. Ignored if @p key is @c NULL.
* @param data The data to replace the old entry, if it exists.
* @return The data pointer for the old stored entry, or @c NULL if not
* found. If an existing entry is not found, nothing is added to the
* hash.
* @ingroup Eina_Hash_Data
*/
EAPI void *
eina_hash_modify_by_hash(Eina_Hash *hash, const void *key, int key_length, int key_hash, const void *data)
{
Eina_Hash_El *el;
void *old_data = NULL;
if (!hash) return NULL;
el = _eina_hash_find_by_hash(hash, key, key_length, key_hash);
if (el)
{
_eina_hash_reorder((Eina_Hash *) hash, el, key_hash);
old_data = el->data;
el->data = (void *) data;
}
return old_data;
}
/**
* Modifies the entry pointer at the specified key and returns the old entry
* @param hash The given hash table.
* @param key The key of the entry to modify.
* @param data The data to replace the old entry, if it exists.
* @return The data pointer for the old stored entry, or @c NULL if not
* found. If an existing entry is not found, nothing is added to the
* hash.
* @ingroup Eina_Hash_Data
*/
EAPI void *
eina_hash_modify(Eina_Hash *hash, const void *key, const void *data)
{
int key_length;
int hash_num;
if (!hash) return NULL;
key_length = hash->key_length_cb(key);
hash_num = hash->key_hash_cb(key, key_length);
return eina_hash_modify_by_hash(hash, key, key_length, hash_num, data);
}
/**
* @defgroup Eina_Hash_General_Group Hash General Functions
*
* Miscellaneous functions that operate on hash objects.
*/
/**
* Retrieves the number of buckets available in the given hash table.
* @param hash The given hash table.
* @return @c 256 if @p hash is not @c NULL. @c 0 otherwise.
* @ingroup Eina_Hash_General_Group
*/
EAPI int
eina_hash_population(const Eina_Hash *hash)
{
if (!hash) return 0;
return hash->population;
}
/**
* @todo Complete polishing documentation for eina_hash.c. The
* functions' docs may be grouped, but they need some simplification.
*/
/**
* Free an entire hash table
* @param hash The hash table to be freed
*
* This function frees up all the memory allocated to storing the specified
* hash tale pointed to by @p hash. Any entries in the table that the program
* has no more pointers for elsewhere may now be lost, so this should only be
* called if the program has lready freed any allocated data in the hash table
* or has the pointers for data in teh table stored elswehere as well.
*
* Example:
* @code
* extern Eina_Hash *hash;
*
* eina_hash_free(hash);
* hash = NULL;
* @endcode
* @ingroup Eina_Hash_General_Group
*/
EAPI void
eina_hash_free(Eina_Hash *hash)
{
int i;
if (!hash) return;
/* FIXME: Should have used an iterator. */
for (i = 0; i < 256; i++)
{
while (hash->buckets[i])
{
Eina_Hash_El *el;
el = (Eina_Hash_El *)hash->buckets[i];
hash->buckets[i] = eina_inlist_remove(hash->buckets[i], el);
free(el);
}
}
free(hash);
}
/* FIXME: Create a generic foreach function in the iterator implementation. */
/**
* Call a function on every member stored in the hash table
* @param hash The hash table whose members will be walked
* @param func The function to call on each parameter
* @param fdata The data pointer to pass to the function being called
*
* This function goes through every entry in the hash table @p hash and calls
* the function @p func on each member. The function should NOT modify the
* hash table contents if it returns 1. IF the hash table contents are
* modified by this function or the function wishes to stop processing it must
* return 0, otherwise return 1 to keep processing.
*
* Example:
* @code
* extern Eina_Hash *hash;
*
* Eina_Bool hash_fn(Eina_Hash *hash, const char *key, void *data, void *fdata)
* {
* printf("Func data: %s, Hash entry: %s / %p\n", fdata, key, data);
* return 1;
* }
*
* int main(int argc, char **argv)
* {
* char *hash_fn_data;
*
* hash_fn_data = strdup("Hello World");
* eina_hash_foreach(hash, hash_fn, hash_fn_data);
* free(hash_fn_data);
* }
* @endcode
* @ingroup Eina_Hash_General_Group
*/
EAPI void eina_hash_foreach(
const Eina_Hash *hash,
Eina_Foreach func,
const void *fdata)
{
int i;
if (!hash) return;
for (i = 0; i < 256; i++)
{
Eina_Inlist *l, *next_l;
for (l = hash->buckets[i]; l;)
{
Eina_Hash_El *el;
next_l = l->next;
el = (Eina_Hash_El *)l;
if (!func(hash, el->key, el->data, (void *)fdata))
return;
l = next_l;
}
}
}
/* Common hash functions */
/* Paul Hsieh (http://www.azillionmonkeys.com/qed/hash.html)
used by WebCore (http://webkit.org/blog/8/hashtables-part-2/) */
#undef get16bits
#if (defined(__GNUC__) && defined(__i386__)) || defined(__WATCOMC__) \
|| defined(_MSC_VER) || defined (__BORLANDC__) || defined (__TURBOC__)
#define get16bits(d) (*((const uint16_t *) (d)))
#endif
#if !defined (get16bits)
#define get16bits(d) ((((uint32_t)(((const uint8_t *)(d))[1])) << 8)\
+(uint32_t)(((const uint8_t *)(d))[0]) )
#endif
int
eina_hash_superfast(const char *key, int len)
{
int hash = len, tmp;
int rem;
rem = len & 3;
len >>= 2;
/* Main loop */
for ( ;len > 0; len--)
{
hash += get16bits(key);
tmp = (get16bits(key + 2) << 11) ^ hash;
hash = (hash << 16) ^ tmp;
key += 2 * sizeof (uint16_t);
hash += hash >> 11;
}
/* Handle end cases */
switch (rem)
{
case 3:
hash += get16bits(key);
hash ^= hash << 16;
hash ^= key[sizeof (uint16_t)] << 18;
hash += hash >> 11;
break;
case 2:
hash += get16bits(key);
hash ^= hash << 11;
hash += hash >> 17;
break;
case 1:
hash += *key;
hash ^= hash << 10;
hash += hash >> 1;
}
/* Force "avalanching" of final 127 bits */
hash ^= hash << 3;
hash += hash >> 5;
hash ^= hash << 4;
hash += hash >> 17;
hash ^= hash << 25;
hash += hash >> 6;
return hash;
}
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