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sysadm |
1.1 |
/* routines to search in in-progress cdb file
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*
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* This file is a part of tinycdb package by Michael Tokarev, mjt@corpit.ru.
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* Public domain.
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*/
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#include "common/setup_before.h"
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#include <stdio.h>
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#include "cdb_int.h"
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#include "common/setup_after.h"
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static int
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match(FILE *fd, unsigned pos, const char *key, unsigned klen)
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{
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unsigned char buf[64]; /*XXX cdb_buf may be used here instead */
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if (fseek(fd, pos, SEEK_SET) || fread(buf, 1, 8, fd) != 8)
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return -1;
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if (cdb_unpack(buf) != klen)
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return 0;
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while(klen > sizeof(buf)) {
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if (fread(buf, 1, sizeof(buf), fd) != sizeof(buf))
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return -1;
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if (memcmp(buf, key, sizeof(buf)) != 0)
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return 0;
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key += sizeof(buf);
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klen -= sizeof(buf);
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}
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if (klen) {
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if (fread(buf, 1, klen, fd) != klen)
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return -1;
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if (memcmp(buf, key, klen) != 0)
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return 0;
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}
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return 1;
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}
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int
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_cdb_make_find(struct cdb_make *cdbmp,
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const void *key, unsigned klen, unsigned hval,
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struct cdb_rl **rlp)
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{
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struct cdb_rl *rl = cdbmp->cdb_rec[hval&255];
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int r, i;
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int seeked = 0;
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while(rl) {
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for(i = rl->cnt - 1; i >= 0; --i) { /* search backward */
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if (rl->rec[i].hval != hval)
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continue;
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/*XXX this explicit flush may be unnecessary having
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* smarter match() that looks to cdb_buf too, but
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* most of a time here spent in finding hash values
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* (above), not keys */
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if (cdbmp->cdb_bpos != cdbmp->cdb_buf) {
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if (fwrite(cdbmp->cdb_buf, 1,
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cdbmp->cdb_bpos - cdbmp->cdb_buf, cdbmp->cdb_fd) < 0)
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return -1;
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cdbmp->cdb_bpos = cdbmp->cdb_buf;
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}
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seeked = 1;
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r = match(cdbmp->cdb_fd, rl->rec[i].rpos, key, klen);
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if (!r)
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continue;
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if (r < 0)
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return -1;
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if (fseek(cdbmp->cdb_fd, cdbmp->cdb_dpos, SEEK_SET))
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return -1;
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if (rlp)
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*rlp = rl;
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return i + 1;
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}
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rl = rl->next;
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}
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if (seeked && fseek(cdbmp->cdb_fd, cdbmp->cdb_dpos, SEEK_SET))
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return -1;
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return 0;
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}
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int
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cdb_make_exists(struct cdb_make *cdbmp,
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const void *key, unsigned klen)
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{
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return _cdb_make_find(cdbmp, key, klen, cdb_hash(key, klen), NULL);
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}
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