#include "switch.h"
#include "private/switch_hashtable_private.h"

Include dependency graph for switch_hashtable.c:

Functions
switch_status_t	switch_create_hashtable (switch_hashtable_t *hp, unsigned int minsize, unsigned int(hashf)(void ), int(eqf)(void , void ))

static int	hashtable_expand (switch_hashtable_t *h)

unsigned int	switch_hashtable_count (switch_hashtable_t *h)

static void *	_switch_hashtable_remove (switch_hashtable_t h, void k, unsigned int hashvalue, unsigned int index)

int	switch_hashtable_insert_destructor (switch_hashtable_t h, void k, void *v, hashtable_flag_t flags, hashtable_destructor_t destructor)

void *	switch_hashtable_search (switch_hashtable_t h, void k)

void *	switch_hashtable_remove (switch_hashtable_t h, void k)

void	switch_hashtable_destroy (switch_hashtable_t **h)

switch_hashtable_iterator_t *	switch_hashtable_next (switch_hashtable_iterator_t **iP)

switch_hashtable_iterator_t *	switch_hashtable_first_iter (switch_hashtable_t h, switch_hashtable_iterator_t it)

void	switch_hashtable_this_val (switch_hashtable_iterator_t i, void val)

void	switch_hashtable_this (switch_hashtable_iterator_t i, const void key, switch_ssize_t klen, void **val)

Variables
static const unsigned int	primes []

const unsigned int	prime_table_length = sizeof(primes)/sizeof(primes[0])

const float	max_load_factor = 0.65f

Function Documentation

static void* _switch_hashtable_remove	(	switch_hashtable_t *	h,
		void *	k,
		unsigned int	hashvalue,
		unsigned int	index
	)

static

Definition at line 156 of file switch_hashtable.c.

References entry::destructor, switch_hashtable::entrycount, switch_hashtable::eqfn, entry::flags, freekey, entry::h, HASHTABLE_FLAG_FREE_KEY, HASHTABLE_FLAG_FREE_VALUE, entry::k, entry::next, switch_safe_free, switch_hashtable::table, and entry::v.

Referenced by switch_hashtable_insert_destructor(), and switch_hashtable_remove().

                                                                                                                    {
         /* TODO: consider compacting the table when the load factor drops enough,
          *       or provide a 'compact' method. */
 
         struct entry *e;
         struct entry **pE;
         void *v;
 
 
         pE = &(h->table[index]);
         e = *pE;
         while (NULL != e) {
                 /* Check hash value to short circuit heavier comparison */
                 if ((hashvalue == e->h) && (h->eqfn(k, e->k))) {
                         *pE = e->next;
                         h->entrycount--;
                         v = e->v;
                         if (e->flags & HASHTABLE_FLAG_FREE_KEY) {
                                 freekey(e->k);
                         }
                         if (e->flags & HASHTABLE_FLAG_FREE_VALUE) {
                                 switch_safe_free(e->v); 
                                 v = NULL;
                         } else if (e->destructor) {
                                 e->destructor(e->v);
                                 v = e->v = NULL;
                         }
                         switch_safe_free(e);
                         return v;
                 }
                 pE = &(e->next);
                 e = e->next;
         }
         return NULL;
 }

static int hashtable_expand ( switch_hashtable_t * h )

static

Definition at line 94 of file switch_hashtable.c.

References entry::h, indexFor(), switch_hashtable::loadlimit, memset(), entry::next, prime_table_length, switch_hashtable::primeindex, primes, switch_safe_free, switch_hashtable::table, and switch_hashtable::tablelength.

Referenced by switch_hashtable_insert_destructor().

 {
         /* Double the size of the table to accomodate more entries */
         struct entry **newtable;
         struct entry *e;
         struct entry **pE;
         unsigned int newsize, i, index;
         /* Check we're not hitting max capacity */
         if (h->primeindex == (prime_table_length - 1)) return 0;
         newsize = primes[++(h->primeindex)];
 
         newtable = (struct entry **)malloc(sizeof(struct entry*) * newsize);
         if (NULL != newtable)
                 {
                         memset(newtable, 0, newsize * sizeof(struct entry *));
                         /* This algorithm is not 'stable'. ie. it reverses the list
                          * when it transfers entries between the tables */
                         for (i = 0; i < h->tablelength; i++) {
                                 while (NULL != (e = h->table[i])) {
                                         h->table[i] = e->next;
                                         index = indexFor(newsize,e->h);
                                         e->next = newtable[index];
                                         newtable[index] = e;
                                 }
                         }
                         switch_safe_free(h->table);
                         h->table = newtable;
                 }
         /* Plan B: realloc instead */
         else 
                 {
                         newtable = (struct entry **)
                                 realloc(h->table, newsize * sizeof(struct entry *));
                         if (NULL == newtable) { (h->primeindex)--; return 0; }
                         h->table = newtable;
                         memset(newtable[h->tablelength], 0, newsize - h->tablelength);
                         for (i = 0; i < h->tablelength; i++) {
                                 for (pE = &(newtable[i]), e = *pE; e != NULL; e = *pE) {
                                         index = indexFor(newsize,e->h);
 
                                         if (index == i) {
                                                 pE = &(e->next);
                                         } else {
                                                 *pE = e->next;
                                                 e->next = newtable[index];
                                                 newtable[index] = e;
                                         }
                                 }
                         }
                 }
         h->tablelength = newsize;
         h->loadlimit   = (unsigned int) ceil(newsize * max_load_factor);
         return -1;
 }

switch_status_t switch_create_hashtable	(	switch_hashtable_t **	hp,
		unsigned int	minsize,
		unsigned int()(void )	hashf,
		int()(void , void *)	eqf
	)

Definition at line 56 of file switch_hashtable.c.

References switch_hashtable::entrycount, switch_hashtable::eqfn, entry::h, switch_hashtable::hashfn, switch_hashtable::loadlimit, memset(), prime_table_length, switch_hashtable::primeindex, primes, SWITCH_STATUS_FALSE, SWITCH_STATUS_SUCCESS, switch_hashtable::table, and switch_hashtable::tablelength.

Referenced by switch_core_hash_init_case(), and switch_core_inthash_init().

 {
         switch_hashtable_t *h;
         unsigned int pindex, size = primes[0];
 
         /* Check requested hashtable isn't too large */
         if (minsize > (1u << 30)) {*hp = NULL; return SWITCH_STATUS_FALSE;}
         /* Enforce size as prime */
         for (pindex=0; pindex < prime_table_length; pindex++) {
                 if (primes[pindex] > minsize) { 
                         size = primes[pindex]; 
                         break; 
                 }
         }
         h = (switch_hashtable_t *) malloc(sizeof(switch_hashtable_t));
 
         if (NULL == h) abort(); /*oom*/
 
         h->table = (struct entry **)malloc(sizeof(struct entry*) * size);
 
         if (NULL == h->table) abort(); /*oom*/
 
         memset(h->table, 0, size * sizeof(struct entry *));
         h->tablelength  = size;
         h->primeindex   = pindex;
         h->entrycount   = 0;
         h->hashfn       = hashf;
         h->eqfn         = eqf;
         h->loadlimit    = (unsigned int) ceil(size * max_load_factor);
 
         *hp = h;
         return SWITCH_STATUS_SUCCESS;
 }

unsigned int switch_hashtable_count ( switch_hashtable_t * h )

Definition at line 151 of file switch_hashtable.c.

 {
         return h->entrycount;
 }

void switch_hashtable_destroy ( switch_hashtable_t ** h )

Definition at line 253 of file switch_hashtable.c.

References entry::destructor, entry::flags, freekey, HASHTABLE_FLAG_FREE_KEY, HASHTABLE_FLAG_FREE_VALUE, entry::k, entry::next, switch_safe_free, and entry::v.

Referenced by switch_core_hash_destroy(), and switch_core_inthash_destroy().

 {
         unsigned int i;
         struct entry *e, *f;
         struct entry **table = (*h)->table;
 
         for (i = 0; i < (*h)->tablelength; i++) {
                 e = table[i];
                 while (NULL != e) {
                         f = e; e = e->next; 
 
                         if (f->flags & HASHTABLE_FLAG_FREE_KEY) {
                                 freekey(f->k); 
                         }
                         
                         if (f->flags & HASHTABLE_FLAG_FREE_VALUE) {
                                 switch_safe_free(f->v); 
                         } else if (f->destructor) {
                                 f->destructor(f->v);
                                 f->v = NULL;
                         }
                         switch_safe_free(f); 
                 }
         }
 
         switch_safe_free((*h)->table);
         free(*h);
         *h = NULL;
 }

switch_hashtable_iterator_t* switch_hashtable_first_iter	(	switch_hashtable_t *	h,
		switch_hashtable_iterator_t *	it
	)

Definition at line 316 of file switch_hashtable.c.

References switch_hashtable_iterator::e, entry::h, switch_hashtable_iterator::h, switch_hashtable_iterator::pos, switch_assert, switch_hashtable_next(), and switch_zmalloc.

Referenced by switch_core_hash_first_iter().

 {
         switch_hashtable_iterator_t *iterator;
 
         if (it) {
                 iterator = it;
         } else {
                 switch_zmalloc(iterator, sizeof(*iterator));
         }
 
         switch_assert(iterator);
 
         iterator->pos = 0;
         iterator->e = NULL;
         iterator->h = h;
 
         return switch_hashtable_next(&iterator);
 }

int switch_hashtable_insert_destructor	(	switch_hashtable_t *	h,
		void *	k,
		void *	v,
		hashtable_flag_t	flags,
		hashtable_destructor_t	destructor
	)

Definition at line 194 of file switch_hashtable.c.

References _switch_hashtable_remove(), entry::destructor, entry::flags, entry::h, hash, HASHTABLE_DUP_CHECK, hashtable_expand(), indexFor(), entry::k, entry::next, and entry::v.

Referenced by switch_core_hash_insert_destructor(), and switch_core_inthash_insert().

 {
         struct entry *e;
         unsigned int hashvalue = hash(h, k);
         unsigned index = indexFor(h->tablelength, hashvalue);
 
         if (flags & HASHTABLE_DUP_CHECK) {
                 _switch_hashtable_remove(h, k, hashvalue, index);
         }
 
         if (++(h->entrycount) > h->loadlimit)
                 {
                         /* Ignore the return value. If expand fails, we should
                          * still try cramming just this value into the existing table
                          * -- we may not have memory for a larger table, but one more
                          * element may be ok. Next time we insert, we'll try expanding again.*/
                         hashtable_expand(h);
                         index = indexFor(h->tablelength, hashvalue);
                 }
         e = (struct entry *)malloc(sizeof(struct entry));
         if (NULL == e) { --(h->entrycount); return 0; } /*oom*/
         e->h = hashvalue;
         e->k = k;
         e->v = v;
         e->flags = flags;
         e->destructor = destructor;
         e->next = h->table[index];
         h->table[index] = e;
         return -1;
 }

switch_hashtable_iterator_t* switch_hashtable_next ( switch_hashtable_iterator_t ** iP )

Definition at line 283 of file switch_hashtable.c.

References switch_hashtable_iterator::e, switch_hashtable_iterator::h, entry::next, switch_hashtable_iterator::pos, switch_hashtable::table, and switch_hashtable::tablelength.

Referenced by switch_core_hash_next(), and switch_hashtable_first_iter().

 {
 
         switch_hashtable_iterator_t *i = *iP;
         
         if (i->e) {
                 if ((i->e = i->e->next) != 0) { 
                         return i;
                 } else {
                         i->pos++;
                 }
         }
 
         while(i->pos < i->h->tablelength && !i->h->table[i->pos]) {
                 i->pos++;
         }
         
         if (i->pos >= i->h->tablelength) {
                 goto end;
         }
         
         if ((i->e = i->h->table[i->pos]) != 0) { 
                 return i;
         }
 
  end:
 
         free(i);
         *iP = NULL;
 
         return NULL;
 }

void* switch_hashtable_remove	(	switch_hashtable_t *	h,
		void *	k
	)

Definition at line 244 of file switch_hashtable.c.

References _switch_hashtable_remove(), hash, and indexFor().

Referenced by switch_core_hash_delete(), and switch_core_inthash_delete().

 {
         unsigned int hashvalue = hash(h,k);
         return _switch_hashtable_remove(h, k, hashvalue, indexFor(h->tablelength,hashvalue));
 }

void* switch_hashtable_search	(	switch_hashtable_t *	h,
		void *	k
	)

Definition at line 227 of file switch_hashtable.c.

References entry::h, hash, indexFor(), entry::k, entry::next, and entry::v.

Referenced by switch_core_hash_find(), and switch_core_inthash_find().

 {
         struct entry *e;
         unsigned int hashvalue, index;
         hashvalue = hash(h,k);
         index = indexFor(h->tablelength,hashvalue);
         e = h->table[index];
         while (NULL != e) {
                 /* Check hash value to short circuit heavier comparison */
                 if ((hashvalue == e->h) && (h->eqfn(k, e->k))) return e->v;
                 e = e->next;
         }
         return NULL;
 }

void switch_hashtable_this	(	switch_hashtable_iterator_t *	i,
		const void **	key,
		switch_ssize_t *	klen,
		void **	val
	)

Definition at line 342 of file switch_hashtable.c.

Referenced by switch_core_hash_this().

 {
         if (i->e) {
                 if (key) {
                         *key = i->e->k;
                 }
                 if (klen) {
                         *klen = (int)strlen(i->e->k);
                 }
                 if (val) {
                         *val = i->e->v;
                 }
         } else {
                 if (key) {
                         *key = NULL;
                 }
                 if (klen) {
                         *klen = 0;
                 }
                 if (val) {
                         *val = NULL;
                 }
         }
 }

void switch_hashtable_this_val	(	switch_hashtable_iterator_t *	i,
		void *	val
	)

Definition at line 335 of file switch_hashtable.c.

Referenced by switch_core_hash_this_val().

 {
         if (i->e) {
                 i->e->v = val;
         }
 }

Variable Documentation

const float max_load_factor = 0.65f

Definition at line 52 of file switch_hashtable.c.

const unsigned int prime_table_length = sizeof(primes)/sizeof(primes[0])

Definition at line 51 of file switch_hashtable.c.

Referenced by hashtable_expand(), and switch_create_hashtable().

const unsigned int primes[]

static

Initial value:

= {
        53, 97, 193, 389,
        769, 1543, 3079, 6151,
        12289, 24593, 49157, 98317,
        196613, 393241, 786433, 1572869,
        3145739, 6291469, 12582917, 25165843,
        50331653, 100663319, 201326611, 402653189,
        805306457, 1610612741
}

Definition at line 42 of file switch_hashtable.c.

Referenced by hashtable_expand(), and switch_create_hashtable().

Functions

Variables

Function Documentation

Variable Documentation