112 lines
3.1 KiB
C
112 lines
3.1 KiB
C
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#if !defined(lint) && !defined(SABER)
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static char rcsid[] = "$Id: db_dict.c,v 8.1 1997/09/26 17:55:40 halley Exp $";
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#endif /* not lint */
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/*
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* Portions Copyright (c) 1997 by Internet Software Consortium.
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*
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* Permission to use, copy, modify, and distribute this software for any
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* purpose with or without fee is hereby granted, provided that the above
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* copyright notice and this permission notice appear in all copies.
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*
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* THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
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* ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
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* OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
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* CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
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* DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
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* PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
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* ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
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* SOFTWARE.
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*/
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#include "port_before.h"
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#include <sys/types.h>
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#include <sys/uio.h>
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#include <sys/param.h>
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#include <sys/stat.h>
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#include <netinet/in.h>
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#include <arpa/inet.h>
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#include <arpa/nameser.h>
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#include <assert.h>
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#include <errno.h>
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#include <stdlib.h>
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#include <string.h>
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#include <time.h>
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#include <isc/eventlib.h>
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#include <isc/logging.h>
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#include <isc/memcluster.h>
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#include "port_after.h"
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#include "named.h"
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#define DICT_BLOCKBITS 8
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#define DICT_BLOCKSHIFT 16
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#define DICT_BLOCKMAX (1 << DICT_BLOCKBITS)
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#define DICT_OFFSETBITS 16
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#define DICT_OFFSETSHIFT 0
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#define DICT_OFFSETMAX (1 << DICT_OFFSETBITS)
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#define DICT_CONSUMED(Length) ((Length) + 1)
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#define DICT_INDEX(Block,Offset) (((Block) << DICT_BLOCKSHIFT) | \
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((Offset) << DICT_OFFSETSHIFT))
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static int dict_new(const char *, int);
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static char * blocks[DICT_BLOCKMAX];
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static int offsets[DICT_BLOCKMAX];
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static int cur_block = 0;
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static int cur_offset = -1;
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int
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dict_lookup(const char *text, int length, int flags) {
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int block, offset, ret;
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/* XXX this is a proof of concept, some kind of hash is needed. */
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for (block = 0; block <= cur_block; block++) {
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const char *cur = &blocks[block][0];
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const char *end = &blocks[block][offsets[block]];
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while (cur < end) {
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int xlength = *cur;
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if (xlength == length &&
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memcmp(cur+1, text, length) == 0)
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return (DICT_INDEX(block, offset));
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cur += DICT_CONSUMED(length);
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}
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}
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if ((flags & DICT_INSERT_P) != 0)
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return (dict_new(text, length));
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return (-ENOENT);
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}
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static int
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dict_new(const char *text, int length) {
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int ret;
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if (length < 0 || length > DICT_MAXLENGTH)
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return (-E2BIG);
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if (cur_offset + DICT_CONSUMED(length) >= DICT_OFFSETMAX) {
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if (cur_block + 1 == DICT_BLOCKMAX)
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return (-ENOSPC);
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cur_block++;
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blocks[cur_block] = memget(DICT_OFFSETMAX);
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if (blocks[cur_block] == NULL)
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return (-ENOMEM);
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cur_offset = 0;
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}
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assert(cur_offset >= 0);
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assert(cur_offset + DICT_CONSUMED(length) < DICT_OFFSETMAX);
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ret = DICT_INDEX(cur_block, cur_offset);
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blocks[cur_block][cur_offset] = length;
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memcpy(&blocks[cur_block][cur_offset+1], text, length);
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cur_offset += DICT_CONSUMED(length);
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offsets[cur_block] = cur_offset;
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return (ret);
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}
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