#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#ifdef HAVE_OHASH
int dummy;
#else
/* $OpenBSD: ohash_int.h,v 1.3 2006/01/16 15:52:25 espie Exp $ */
#include <stddef.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include "compat_ohash.h"
struct _ohash_record {
u_int32_t hv;
const char *p;
};
#define DELETED ((const char *)h)
#define NONE (h->size)
/* Don't bother changing the hash table if the change is small enough. */
#define MINSIZE (1UL << 4)
#define MINDELETED 4
/* $OpenBSD: ohash_create_entry.c,v 1.2 2004/06/22 20:00:16 espie Exp $ */
/* ex:ts=8 sw=4:
*/
/* Copyright (c) 1999, 2004 Marc Espie <espie@openbsd.org>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
/* This handles the common case of variable length keys, where the
* key is stored at the end of the record.
*/
void *
ohash_create_entry(struct ohash_info *i, const char *start, const char **end)
{
char *p;
if (!*end)
*end = start + strlen(start);
p = (i->alloc)(i->key_offset + (*end - start) + 1, i->data);
if (p) {
memcpy(p+i->key_offset, start, *end-start);
p[i->key_offset + (*end - start)] = '\0';
}
return (void *)p;
}
/* hash_delete only frees the hash structure. Use hash_first/hash_next
* to free entries as well. */
void
ohash_delete(struct ohash *h)
{
(h->info.hfree)(h->t, sizeof(struct _ohash_record) * h->size,
h->info.data);
#ifndef NDEBUG
h->t = NULL;
#endif
}
static void ohash_resize(struct ohash *);
static void
ohash_resize(struct ohash *h)
{
struct _ohash_record *n;
unsigned int ns, j;
unsigned int i, incr;
if (4 * h->deleted < h->total)
ns = h->size << 1;
else if (3 * h->deleted > 2 * h->total)
ns = h->size >> 1;
else
ns = h->size;
if (ns < MINSIZE)
ns = MINSIZE;
#ifdef STATS_HASH
STAT_HASH_EXPAND++;
STAT_HASH_SIZE += ns - h->size;
#endif
n = (h->info.halloc)(sizeof(struct _ohash_record) * ns, h->info.data);
if (!n)
return;
for (j = 0; j < h->size; j++) {
if (h->t[j].p != NULL && h->t[j].p != DELETED) {
i = h->t[j].hv % ns;
incr = ((h->t[j].hv % (ns - 2)) & ~1) + 1;
while (n[i].p != NULL) {
i += incr;
if (i >= ns)
i -= ns;
}
n[i].hv = h->t[j].hv;
n[i].p = h->t[j].p;
}
}
(h->info.hfree)(h->t, sizeof(struct _ohash_record) * h->size,
h->info.data);
h->t = n;
h->size = ns;
h->total -= h->deleted;
h->deleted = 0;
}
void *
ohash_remove(struct ohash *h, unsigned int i)
{
void *result = (void *)h->t[i].p;
if (result == NULL || result == DELETED)
return NULL;
#ifdef STATS_HASH
STAT_HASH_ENTRIES--;
#endif
h->t[i].p = DELETED;
h->deleted++;
if (h->deleted >= MINDELETED && 4 * h->deleted > h->total)
ohash_resize(h);
return result;
}
void *
ohash_find(struct ohash *h, unsigned int i)
{
if (h->t[i].p == DELETED)
return NULL;
else
return (void *)h->t[i].p;
}
void *
ohash_insert(struct ohash *h, unsigned int i, void *p)
{
#ifdef STATS_HASH
STAT_HASH_ENTRIES++;
#endif
if (h->t[i].p == DELETED) {
h->deleted--;
h->t[i].p = p;
} else {
h->t[i].p = p;
/* Arbitrary resize boundary. Tweak if not efficient enough. */
if (++h->total * 4 > h->size * 3)
ohash_resize(h);
}
return p;
}
unsigned int
ohash_entries(struct ohash *h)
{
return h->total - h->deleted;
}
void *
ohash_first(struct ohash *h, unsigned int *pos)
{
*pos = 0;
return ohash_next(h, pos);
}
void *
ohash_next(struct ohash *h, unsigned int *pos)
{
for (; *pos < h->size; (*pos)++)
if (h->t[*pos].p != DELETED && h->t[*pos].p != NULL)
return (void *)h->t[(*pos)++].p;
return NULL;
}
void
ohash_init(struct ohash *h, unsigned int size, struct ohash_info *info)
{
h->size = 1UL << size;
if (h->size < MINSIZE)
h->size = MINSIZE;
#ifdef STATS_HASH
STAT_HASH_CREATION++;
STAT_HASH_SIZE += h->size;
#endif
/* Copy info so that caller may free it. */
h->info.key_offset = info->key_offset;
h->info.halloc = info->halloc;
h->info.hfree = info->hfree;
h->info.alloc = info->alloc;
h->info.data = info->data;
h->t = (h->info.halloc)(sizeof(struct _ohash_record) * h->size,
h->info.data);
h->total = h->deleted = 0;
}
uint32_t
ohash_interval(const char *s, const char **e)
{
uint32_t k;
if (!*e)
*e = s + strlen(s);
if (s == *e)
k = 0;
else
k = *s++;
while (s != *e)
k = ((k << 2) | (k >> 30)) ^ *s++;
return k;
}
unsigned int
ohash_lookup_interval(struct ohash *h, const char *start, const char *end,
uint32_t hv)
{
unsigned int i, incr;
unsigned int empty;
#ifdef STATS_HASH
STAT_HASH_LOOKUP++;
#endif
empty = NONE;
i = hv % h->size;
incr = ((hv % (h->size-2)) & ~1) + 1;
while (h->t[i].p != NULL) {
#ifdef STATS_HASH
STAT_HASH_LENGTH++;
#endif
if (h->t[i].p == DELETED) {
if (empty == NONE)
empty = i;
} else if (h->t[i].hv == hv &&
strncmp(h->t[i].p+h->info.key_offset, start,
end - start) == 0 &&
(h->t[i].p+h->info.key_offset)[end-start] == '\0') {
if (empty != NONE) {
h->t[empty].hv = hv;
h->t[empty].p = h->t[i].p;
h->t[i].p = DELETED;
return empty;
} else {
#ifdef STATS_HASH
STAT_HASH_POSITIVE++;
#endif
return i;
}
}
i += incr;
if (i >= h->size)
i -= h->size;
}
/* Found an empty position. */
if (empty != NONE)
i = empty;
h->t[i].hv = hv;
return i;
}
unsigned int
ohash_lookup_memory(struct ohash *h, const char *k, size_t size, uint32_t hv)
{
unsigned int i, incr;
unsigned int empty;
#ifdef STATS_HASH
STAT_HASH_LOOKUP++;
#endif
empty = NONE;
i = hv % h->size;
incr = ((hv % (h->size-2)) & ~1) + 1;
while (h->t[i].p != NULL) {
#ifdef STATS_HASH
STAT_HASH_LENGTH++;
#endif
if (h->t[i].p == DELETED) {
if (empty == NONE)
empty = i;
} else if (h->t[i].hv == hv &&
memcmp(h->t[i].p+h->info.key_offset, k, size) == 0) {
if (empty != NONE) {
h->t[empty].hv = hv;
h->t[empty].p = h->t[i].p;
h->t[i].p = DELETED;
return empty;
} else {
#ifdef STATS_HASH
STAT_HASH_POSITIVE++;
#endif
} return i;
}
i += incr;
if (i >= h->size)
i -= h->size;
}
/* Found an empty position. */
if (empty != NONE)
i = empty;
h->t[i].hv = hv;
return i;
}
unsigned int
ohash_qlookup(struct ohash *h, const char *s)
{
const char *e = NULL;
return ohash_qlookupi(h, s, &e);
}
unsigned int
ohash_qlookupi(struct ohash *h, const char *s, const char **e)
{
u_int32_t hv;
hv = ohash_interval(s, e);
return ohash_lookup_interval(h, s, *e, hv);
}
#endif /*!HAVE_OHASH*/
