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#if !defined(lint) && !defined(SABER)
static char rcsid[] = "$Id: db_dict.c,v 8.1 1997/09/26 17:55:40 halley Exp $";
#endif /* not lint */
/*
* Portions Copyright (c) 1997 by Internet Software Consortium.
*
* 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 INTERNET SOFTWARE CONSORTIUM DISCLAIMS
* ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
* CONSORTIUM 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.
*/
#include "port_before.h"
#include <sys/types.h>
#include <sys/uio.h>
#include <sys/param.h>
#include <sys/stat.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <arpa/nameser.h>
#include <assert.h>
#include <errno.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <isc/eventlib.h>
#include <isc/logging.h>
#include <isc/memcluster.h>
#include "port_after.h"
#include "named.h"
#define DICT_BLOCKBITS 8
#define DICT_BLOCKSHIFT 16
#define DICT_BLOCKMAX (1 << DICT_BLOCKBITS)
#define DICT_OFFSETBITS 16
#define DICT_OFFSETSHIFT 0
#define DICT_OFFSETMAX (1 << DICT_OFFSETBITS)
#define DICT_CONSUMED(Length) ((Length) + 1)
#define DICT_INDEX(Block,Offset) (((Block) << DICT_BLOCKSHIFT) | \
((Offset) << DICT_OFFSETSHIFT))
static int dict_new(const char *, int);
static char * blocks[DICT_BLOCKMAX];
static int offsets[DICT_BLOCKMAX];
static int cur_block = 0;
static int cur_offset = -1;
int
dict_lookup(const char *text, int length, int flags) {
int block, offset, ret;
/* XXX this is a proof of concept, some kind of hash is needed. */
for (block = 0; block <= cur_block; block++) {
const char *cur = &blocks[block][0];
const char *end = &blocks[block][offsets[block]];
while (cur < end) {
int xlength = *cur;
if (xlength == length &&
memcmp(cur+1, text, length) == 0)
return (DICT_INDEX(block, offset));
cur += DICT_CONSUMED(length);
}
}
if ((flags & DICT_INSERT_P) != 0)
return (dict_new(text, length));
return (-ENOENT);
}
static int
dict_new(const char *text, int length) {
int ret;
if (length < 0 || length > DICT_MAXLENGTH)
return (-E2BIG);
if (cur_offset + DICT_CONSUMED(length) >= DICT_OFFSETMAX) {
if (cur_block + 1 == DICT_BLOCKMAX)
return (-ENOSPC);
cur_block++;
blocks[cur_block] = memget(DICT_OFFSETMAX);
if (blocks[cur_block] == NULL)
return (-ENOMEM);
cur_offset = 0;
}
assert(cur_offset >= 0);
assert(cur_offset + DICT_CONSUMED(length) < DICT_OFFSETMAX);
ret = DICT_INDEX(cur_block, cur_offset);
blocks[cur_block][cur_offset] = length;
memcpy(&blocks[cur_block][cur_offset+1], text, length);
cur_offset += DICT_CONSUMED(length);
offsets[cur_block] = cur_offset;
return (ret);
}
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