| /* $Id$ */ |
| /* |
| * Copyright (C) 2008-2011 Teluu Inc. (http://www.teluu.com) |
| * Copyright (C) 2003-2008 Benny Prijono <benny@prijono.org> |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License as published by |
| * the Free Software Foundation; either version 2 of the License, or |
| * (at your option) any later version. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public License |
| * along with this program; if not, write to the Free Software |
| * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
| */ |
| #include <pj/hash.h> |
| #include <pj/log.h> |
| #include <pj/string.h> |
| #include <pj/pool.h> |
| #include <pj/os.h> |
| #include <pj/ctype.h> |
| #include <pj/assert.h> |
| |
| /** |
| * The hash multiplier used to calculate hash value. |
| */ |
| #define PJ_HASH_MULTIPLIER 33 |
| |
| |
| struct pj_hash_entry |
| { |
| struct pj_hash_entry *next; |
| 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 pj_uint8_t *p = (const pj_uint8_t*)key; |
| for ( ; *p; ++p ) { |
| hash = (hash * PJ_HASH_MULTIPLIER) + *p; |
| } |
| } else { |
| const pj_uint8_t *p = (const pj_uint8_t*)key, |
| *end = p + keylen; |
| for ( ; p!=end; ++p) { |
| hash = (hash * PJ_HASH_MULTIPLIER) + *p; |
| } |
| } |
| return hash; |
| } |
| |
| PJ_DEF(pj_uint32_t) pj_hash_calc_tolower( pj_uint32_t hval, |
| char *result, |
| const pj_str_t *key) |
| { |
| long i; |
| |
| #if defined(PJ_HASH_USE_OWN_TOLOWER) && PJ_HASH_USE_OWN_TOLOWER != 0 |
| for (i=0; i<key->slen; ++i) { |
| pj_uint8_t c = key->ptr[i]; |
| char lower; |
| if (c & 64) |
| lower = (char)(c | 32); |
| else |
| lower = (char)c; |
| if (result) |
| result[i] = lower; |
| hval = hval * PJ_HASH_MULTIPLIER + lower; |
| } |
| #else |
| for (i=0; i<key->slen; ++i) { |
| char lower = (char)pj_tolower(key->ptr[i]); |
| if (result) |
| result[i] = lower; |
| hval = hval * PJ_HASH_MULTIPLIER + lower; |
| } |
| #endif |
| |
| return hval; |
| } |
| |
| |
| PJ_DEF(pj_hash_table_t*) pj_hash_create(pj_pool_t *pool, unsigned size) |
| { |
| pj_hash_table_t *h; |
| unsigned table_size; |
| |
| /* Check that PJ_HASH_ENTRY_BUF_SIZE is correct. */ |
| PJ_ASSERT_RETURN(sizeof(pj_hash_entry)<=PJ_HASH_ENTRY_BUF_SIZE, NULL); |
| |
| h = PJ_POOL_ALLOC_T(pool, pj_hash_table_t); |
| h->count = 0; |
| |
| PJ_LOG( 6, ("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_hash_entry**) |
| 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 *hval, |
| void *entry_buf, pj_bool_t lower) |
| { |
| pj_uint32_t hash; |
| pj_hash_entry **p_entry, *entry; |
| |
| if (hval && *hval != 0) { |
| hash = *hval; |
| if (keylen==PJ_HASH_KEY_STRING) { |
| keylen = (unsigned)pj_ansi_strlen((const char*)key); |
| } |
| } else { |
| /* This slightly differs with pj_hash_calc() because we need |
| * to get the keylen when keylen is PJ_HASH_KEY_STRING. |
| */ |
| hash=0; |
| if (keylen==PJ_HASH_KEY_STRING) { |
| const pj_uint8_t *p = (const pj_uint8_t*)key; |
| for ( ; *p; ++p ) { |
| if (lower) |
| hash = hash * PJ_HASH_MULTIPLIER + pj_tolower(*p); |
| else |
| hash = hash * PJ_HASH_MULTIPLIER + *p; |
| } |
| keylen = (unsigned)(p - (const unsigned char*)key); |
| } else { |
| const pj_uint8_t *p = (const pj_uint8_t*)key, |
| *end = p + keylen; |
| for ( ; p!=end; ++p) { |
| if (lower) |
| hash = hash * PJ_HASH_MULTIPLIER + pj_tolower(*p); |
| else |
| hash = hash * PJ_HASH_MULTIPLIER + *p; |
| } |
| } |
| |
| /* Report back the computed hash. */ |
| if (hval) |
| *hval = hash; |
| } |
| |
| /* 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 && |
| ((lower && pj_ansi_strnicmp((const char*)entry->key, |
| (const char*)key, keylen)==0) || |
| (!lower && pj_memcmp(entry->key, key, keylen)==0))) |
| { |
| break; |
| } |
| } |
| |
| if (entry || val==NULL) |
| return p_entry; |
| |
| /* Entry not found, create a new one. |
| * If entry_buf is specified, use it. Otherwise allocate from pool. |
| */ |
| if (entry_buf) { |
| entry = (pj_hash_entry*)entry_buf; |
| } else { |
| /* Pool must be specified! */ |
| PJ_ASSERT_RETURN(pool != NULL, NULL); |
| |
| entry = PJ_POOL_ALLOC_T(pool, pj_hash_entry); |
| PJ_LOG(6, ("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; |
| if (pool) { |
| entry->key = pj_pool_alloc(pool, keylen); |
| pj_memcpy(entry->key, key, keylen); |
| } else { |
| entry->key = (void*)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_uint32_t *hval) |
| { |
| pj_hash_entry *entry; |
| entry = *find_entry( NULL, ht, key, keylen, NULL, hval, NULL, PJ_FALSE); |
| return entry ? entry->value : NULL; |
| } |
| |
| PJ_DEF(void *) pj_hash_get_lower( pj_hash_table_t *ht, |
| const void *key, unsigned keylen, |
| pj_uint32_t *hval) |
| { |
| pj_hash_entry *entry; |
| entry = *find_entry( NULL, ht, key, keylen, NULL, hval, NULL, PJ_TRUE); |
| return entry ? entry->value : NULL; |
| } |
| |
| static void hash_set( pj_pool_t *pool, pj_hash_table_t *ht, |
| const void *key, unsigned keylen, pj_uint32_t hval, |
| void *value, void *entry_buf, pj_bool_t lower ) |
| { |
| pj_hash_entry **p_entry; |
| |
| p_entry = find_entry( pool, ht, key, keylen, value, &hval, entry_buf, |
| lower); |
| if (*p_entry) { |
| if (value == NULL) { |
| /* delete entry */ |
| PJ_LOG(6, ("hashtbl", "%p: p_entry %p deleted", ht, *p_entry)); |
| *p_entry = (*p_entry)->next; |
| --ht->count; |
| |
| } else { |
| /* overwrite */ |
| (*p_entry)->value = value; |
| PJ_LOG(6, ("hashtbl", "%p: p_entry %p value set to %p", ht, |
| *p_entry, value)); |
| } |
| } |
| } |
| |
| PJ_DEF(void) pj_hash_set( pj_pool_t *pool, pj_hash_table_t *ht, |
| const void *key, unsigned keylen, pj_uint32_t hval, |
| void *value ) |
| { |
| hash_set(pool, ht, key, keylen, hval, value, NULL, PJ_FALSE); |
| } |
| |
| PJ_DEF(void) pj_hash_set_lower( pj_pool_t *pool, pj_hash_table_t *ht, |
| const void *key, unsigned keylen, |
| pj_uint32_t hval, void *value ) |
| { |
| hash_set(pool, ht, key, keylen, hval, value, NULL, PJ_TRUE); |
| } |
| |
| PJ_DEF(void) pj_hash_set_np( pj_hash_table_t *ht, |
| const void *key, unsigned keylen, |
| pj_uint32_t hval, pj_hash_entry_buf entry_buf, |
| void *value) |
| { |
| hash_set(NULL, ht, key, keylen, hval, value, (void *)entry_buf, PJ_FALSE); |
| } |
| |
| PJ_DEF(void) pj_hash_set_np_lower( pj_hash_table_t *ht, |
| const void *key, unsigned keylen, |
| pj_uint32_t hval, |
| pj_hash_entry_buf entry_buf, |
| void *value) |
| { |
| hash_set(NULL, ht, key, keylen, hval, value, (void *)entry_buf, PJ_TRUE); |
| } |
| |
| 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 |
| |
| |