253 lines
5.4 KiB
C
253 lines
5.4 KiB
C
/* $Header: /pjproject-0.3/pjlib/src/pj/hash.c 8 10/14/05 12:26a Bennylp $ */
|
|
/* $Log: /pjproject-0.3/pjlib/src/pj/hash.c $
|
|
*
|
|
* 8 10/14/05 12:26a Bennylp
|
|
* Finished error code framework, some fixes in ioqueue, etc. Pretty
|
|
* major.
|
|
*
|
|
* 7 9/17/05 10:37a Bennylp
|
|
* Major reorganization towards version 0.3.
|
|
*
|
|
*/
|
|
#include <pj/hash.h>
|
|
#include <pj/log.h>
|
|
#include <pj/string.h>
|
|
#include <pj/pool.h>
|
|
#include <pj/os.h>
|
|
|
|
/**
|
|
* The hash multiplier used to calculate hash value.
|
|
*/
|
|
#define PJ_HASH_MULTIPLIER 33
|
|
|
|
|
|
struct pj_hash_entry
|
|
{
|
|
struct pj_hash_entry *next;
|
|
const void *key;
|
|
pj_uint32_t hash;
|
|
pj_uint32_t keylen;
|
|
void *value;
|
|
};
|
|
|
|
|
|
struct pj_hash_table_t
|
|
{
|
|
pj_hash_entry **table;
|
|
unsigned count, rows;
|
|
pj_hash_iterator_t iterator;
|
|
};
|
|
|
|
|
|
|
|
PJ_DEF(pj_uint32_t) pj_hash_calc(pj_uint32_t hash, const void *key, unsigned keylen)
|
|
{
|
|
PJ_CHECK_STACK();
|
|
|
|
if (keylen==PJ_HASH_KEY_STRING) {
|
|
const unsigned char *p = key;
|
|
for ( ; *p; ++p ) {
|
|
hash = hash * PJ_HASH_MULTIPLIER + *p;
|
|
}
|
|
keylen = p - (const unsigned char*)key;
|
|
} else {
|
|
const unsigned char *p = key,
|
|
*end = p + keylen;
|
|
for ( ; p!=end; ++p) {
|
|
hash = hash * PJ_HASH_MULTIPLIER + *p;
|
|
}
|
|
}
|
|
return hash;
|
|
}
|
|
|
|
|
|
PJ_DEF(pj_hash_table_t*) pj_hash_create(pj_pool_t *pool, unsigned size)
|
|
{
|
|
pj_hash_table_t *h;
|
|
unsigned table_size;
|
|
|
|
h = pj_pool_alloc(pool, sizeof(pj_hash_table_t));
|
|
h->count = 0;
|
|
|
|
PJ_LOG( 5, ("hashtbl", "hash table %p created from pool %s", h, pj_pool_getobjname(pool)));
|
|
|
|
/* size must be 2^n - 1.
|
|
round-up the size to this rule, except when size is 2^n, then size
|
|
will be round-down to 2^n-1.
|
|
*/
|
|
table_size = 8;
|
|
do {
|
|
table_size <<= 1;
|
|
} while (table_size <= size);
|
|
table_size -= 1;
|
|
|
|
h->rows = table_size;
|
|
h->table = pj_pool_calloc(pool, table_size+1, sizeof(pj_hash_entry*));
|
|
return h;
|
|
}
|
|
|
|
static pj_hash_entry **find_entry( pj_pool_t *pool, pj_hash_table_t *ht,
|
|
const void *key, unsigned keylen,
|
|
void *val)
|
|
{
|
|
pj_uint32_t hash;
|
|
pj_hash_entry **p_entry, *entry;
|
|
|
|
hash=0;
|
|
if (keylen==PJ_HASH_KEY_STRING) {
|
|
const unsigned char *p = key;
|
|
for ( ; *p; ++p ) {
|
|
hash = hash * PJ_HASH_MULTIPLIER + *p;
|
|
}
|
|
keylen = p - (const unsigned char*)key;
|
|
} else {
|
|
const unsigned char *p = key,
|
|
*end = p + keylen;
|
|
for ( ; p!=end; ++p) {
|
|
hash = hash * PJ_HASH_MULTIPLIER + *p;
|
|
}
|
|
}
|
|
|
|
/* scan the linked list */
|
|
for (p_entry = &ht->table[hash & ht->rows], entry=*p_entry;
|
|
entry;
|
|
p_entry = &entry->next, entry = *p_entry)
|
|
{
|
|
if (entry->hash==hash && entry->keylen==keylen &&
|
|
memcmp(entry->key, key, keylen)==0)
|
|
{
|
|
break;
|
|
}
|
|
}
|
|
|
|
if (entry || val==NULL)
|
|
return p_entry;
|
|
|
|
/* create a new entry */
|
|
entry = pj_pool_alloc(pool, sizeof(pj_hash_entry));
|
|
PJ_LOG(5, ("hashtbl", "%p: New p_entry %p created, pool used=%u, cap=%u", ht, entry,
|
|
pj_pool_get_used_size(pool), pj_pool_get_capacity(pool)));
|
|
entry->next = NULL;
|
|
entry->hash = hash;
|
|
entry->key = key;
|
|
entry->keylen = keylen;
|
|
entry->value = val;
|
|
*p_entry = entry;
|
|
|
|
++ht->count;
|
|
|
|
return p_entry;
|
|
}
|
|
|
|
PJ_DEF(void *) pj_hash_get( pj_hash_table_t *ht,
|
|
const void *key, unsigned keylen )
|
|
{
|
|
pj_hash_entry *entry;
|
|
entry = *find_entry( NULL, ht, key, keylen, NULL);
|
|
return entry ? entry->value : NULL;
|
|
}
|
|
|
|
PJ_DEF(void) pj_hash_set( pj_pool_t *pool, pj_hash_table_t *ht,
|
|
const void *key, unsigned keylen,
|
|
void *value )
|
|
{
|
|
pj_hash_entry **p_entry;
|
|
|
|
p_entry = find_entry( pool, ht, key, keylen, value );
|
|
if (*p_entry) {
|
|
if (value == NULL) {
|
|
/* delete entry */
|
|
PJ_LOG(5, ("hashtbl", "%p: p_entry %p deleted", ht, *p_entry));
|
|
*p_entry = (*p_entry)->next;
|
|
--ht->count;
|
|
|
|
} else {
|
|
/* overwrite */
|
|
(*p_entry)->value = value;
|
|
PJ_LOG(5, ("hashtbl", "%p: p_entry %p value set to %p", ht, *p_entry, value));
|
|
}
|
|
}
|
|
}
|
|
|
|
PJ_DEF(unsigned) pj_hash_count( pj_hash_table_t *ht )
|
|
{
|
|
return ht->count;
|
|
}
|
|
|
|
PJ_DEF(pj_hash_iterator_t*) pj_hash_first( pj_hash_table_t *ht,
|
|
pj_hash_iterator_t *it )
|
|
{
|
|
it->index = 0;
|
|
it->entry = NULL;
|
|
|
|
for (; it->index < ht->rows; ++it->index) {
|
|
it->entry = ht->table[it->index];
|
|
if (it->entry) {
|
|
break;
|
|
}
|
|
}
|
|
|
|
return it->entry ? it : NULL;
|
|
}
|
|
|
|
PJ_DEF(pj_hash_iterator_t*) pj_hash_next( pj_hash_table_t *ht,
|
|
pj_hash_iterator_t *it )
|
|
{
|
|
it->entry = it->entry->next;
|
|
if (it->entry) {
|
|
return it;
|
|
}
|
|
|
|
for (++it->index; it->index < ht->rows; ++it->index) {
|
|
it->entry = ht->table[it->index];
|
|
if (it->entry) {
|
|
break;
|
|
}
|
|
}
|
|
|
|
return it->entry ? it : NULL;
|
|
}
|
|
|
|
PJ_DEF(void*) pj_hash_this( pj_hash_table_t *ht, pj_hash_iterator_t *it )
|
|
{
|
|
PJ_CHECK_STACK();
|
|
PJ_UNUSED_ARG(ht);
|
|
return it->entry->value;
|
|
}
|
|
|
|
#if 0
|
|
void pj_hash_dump_collision( pj_hash_table_t *ht )
|
|
{
|
|
unsigned min=0xFFFFFFFF, max=0;
|
|
unsigned i;
|
|
char line[120];
|
|
int len, totlen = 0;
|
|
|
|
for (i=0; i<ht->rows; ++i) {
|
|
unsigned count = 0;
|
|
pj_hash_entry *entry = ht->table[i];
|
|
while (entry) {
|
|
++count;
|
|
entry = entry->next;
|
|
}
|
|
if (count < min)
|
|
min = count;
|
|
if (count > max)
|
|
max = count;
|
|
len = pj_snprintf( line+totlen, sizeof(line)-totlen, "%3d:%3d ", i, count);
|
|
if (len < 1)
|
|
break;
|
|
totlen += len;
|
|
|
|
if ((i+1) % 10 == 0) {
|
|
line[totlen] = '\0';
|
|
PJ_LOG(4,(__FILE__, line));
|
|
}
|
|
}
|
|
|
|
PJ_LOG(4,(__FILE__,"Count: %d, min: %d, max: %d\n", ht->count, min, max));
|
|
}
|
|
#endif
|
|
|
|
|