You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
70 lines
1.5 KiB
70 lines
1.5 KiB
2 years ago
|
/*
|
||
|
|
* This Source Code Form is subject to the terms of the Mozilla Public
|
||
|
|
* License, v. 2.0. If a copy of the MPL was not distributed with this
|
||
|
|
* file, You can obtain one at http://mozilla.org/MPL/2.0/.
|
||
|
|
*
|
||
|
|
* Copyright 1997 - July 2008 CWI, August 2008 - 2022 MonetDB B.V.
|
||
|
|
*/
|
||
|
|
|
||
|
|
#ifndef SQL_HASH_H
|
||
|
|
#define SQL_HASH_H
|
||
|
|
|
||
|
|
/* sql_hash implementation
|
||
|
|
* used to optimize search in expression and statement lists
|
||
|
|
*/
|
||
|
|
|
||
|
|
#include "sql_mem.h"
|
||
|
|
|
||
|
|
#define HASH_MIN_SIZE 4
|
||
|
|
|
||
|
|
typedef int (*fkeyvalue) (void *data);
|
||
|
|
|
||
|
|
typedef struct sql_hash_e {
|
||
|
|
int key;
|
||
|
|
void *value;
|
||
|
|
struct sql_hash_e *chain;
|
||
|
|
} sql_hash_e;
|
||
|
|
|
||
|
|
typedef struct sql_hash {
|
||
|
|
sql_allocator *sa;
|
||
|
|
int size; /* power of 2 */
|
||
|
|
sql_hash_e **buckets;
|
||
|
|
fkeyvalue key;
|
||
|
|
int entries;
|
||
|
|
} sql_hash;
|
||
|
|
|
||
|
|
extern sql_hash *hash_new(sql_allocator *sa, int size, fkeyvalue key);
|
||
|
|
extern int hash_entries(sql_hash *h);
|
||
|
|
extern int hash_empty(sql_hash *h);
|
||
|
|
extern void hash_del(sql_hash *ht, int key, void *value);
|
||
|
|
extern void hash_clear(sql_hash *h);
|
||
|
|
extern void hash_destroy(sql_hash *h);
|
||
|
|
|
||
|
|
static inline sql_hash_e*
|
||
|
|
hash_add(sql_hash *h, int key, void *value)
|
||
|
|
{
|
||
|
|
sql_hash_e *e = (h->sa)?SA_NEW(h->sa, sql_hash_e):MNEW(sql_hash_e);
|
||
|
|
|
||
|
|
if (e == NULL)
|
||
|
|
return NULL;
|
||
|
|
e->chain = h->buckets[key&(h->size-1)];
|
||
|
|
h->buckets[key&(h->size-1)] = e;
|
||
|
|
e->key = key;
|
||
|
|
e->value = value;
|
||
|
|
h->entries++;
|
||
|
|
return e;
|
||
|
|
}
|
||
|
|
|
||
|
|
static inline unsigned int
|
||
|
|
hash_key(const char *restrict k)
|
||
|
|
{
|
||
|
|
unsigned int h = 37; /* prime number */
|
||
|
|
while (*k) {
|
||
|
|
h = (h * 54059) ^ (k[0] * 76963); /* prime numbers */
|
||
|
|
k++;
|
||
|
|
}
|
||
|
|
return h;
|
||
|
|
}
|
||
|
|
|
||
|
|
#endif /* SQL_HASH_H */
|