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/* basic cdb creation routines
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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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#ifdef STDC_HEADERS
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# include <stdlib.h>
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#else
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# ifdef HAVE_MALLOC_H
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# include <malloc.h>
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# endif
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#endif
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#ifdef HAVE_STRING_H
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# include <string.h>
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#else
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# ifdef HAVE_STRINGS_H
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# include <strings.h>
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# endif
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# ifdef HAVE_MEMORY_H
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# include <memory.h>
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# endif
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#endif
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#include "common/xalloc.h"
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#include "cdb_int.h"
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#include "common/setup_after.h"
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void
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cdb_pack(unsigned num, unsigned char buf[4])
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{
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buf[0] = num & 255; num >>= 8;
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buf[1] = num & 255; num >>= 8;
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buf[2] = num & 255;
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buf[3] = num >> 8;
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}
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int
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cdb_make_start(struct cdb_make *cdbmp, FILE *fd)
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{
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memset(cdbmp, 0, sizeof(*cdbmp));
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cdbmp->cdb_fd = fd;
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cdbmp->cdb_dpos = 2048;
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cdbmp->cdb_bpos = cdbmp->cdb_buf + 2048;
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return 0;
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}
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static int
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ewrite(FILE *fd, const char *buf, int len)
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{
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while(len) {
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int l = fwrite(buf, 1, len, fd);
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if (l < 0 && errno != EINTR)
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return -1;
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len -= l;
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buf += l;
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}
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return 0;
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}
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int
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_cdb_make_write(struct cdb_make *cdbmp, const char *ptr, unsigned len)
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{
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unsigned l = sizeof(cdbmp->cdb_buf) - (cdbmp->cdb_bpos - cdbmp->cdb_buf);
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cdbmp->cdb_dpos += len;
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if (len > l) {
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memcpy(cdbmp->cdb_bpos, ptr, l);
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if (ewrite(cdbmp->cdb_fd, cdbmp->cdb_buf, sizeof(cdbmp->cdb_buf)) < 0)
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return -1;
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ptr += l; len -= l;
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l = len / sizeof(cdbmp->cdb_buf);
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if (l) {
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l *= sizeof(cdbmp->cdb_buf);
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if (ewrite(cdbmp->cdb_fd, ptr, l) < 0)
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return -1;
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ptr += l; len -= l;
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}
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cdbmp->cdb_bpos = cdbmp->cdb_buf;
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}
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if (len) {
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memcpy(cdbmp->cdb_bpos, ptr, len);
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cdbmp->cdb_bpos += len;
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}
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return 0;
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}
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static int
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cdb_make_finish_internal(struct cdb_make *cdbmp)
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{
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unsigned hcnt[256]; /* hash table counts */
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unsigned hpos[256]; /* hash table positions */
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struct cdb_rec *htab;
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unsigned char *p;
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struct cdb_rl *rl;
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unsigned hsize;
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unsigned t, i;
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if (((0xffffffff - cdbmp->cdb_dpos) >> 3) < cdbmp->cdb_rcnt)
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return errno = ENOMEM, -1;
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/* count htab sizes and reorder reclists */
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hsize = 0;
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for (t = 0; t < 256; ++t) {
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struct cdb_rl *rlt = NULL;
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i = 0;
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rl = cdbmp->cdb_rec[t];
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while(rl) {
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struct cdb_rl *rln = rl->next;
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rl->next = rlt;
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rlt = rl;
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i += rl->cnt;
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rl = rln;
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}
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cdbmp->cdb_rec[t] = rlt;
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if (hsize < (hcnt[t] = i << 1))
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hsize = hcnt[t];
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}
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/* allocate memory to hold max htable */
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htab = (struct cdb_rec*)xmalloc((hsize + 2) * sizeof(struct cdb_rec));
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if (!htab)
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return errno = ENOENT, -1;
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p = (unsigned char *)htab;
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htab += 2;
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/* build hash tables */
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for (t = 0; t < 256; ++t) {
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unsigned len, hi;
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hpos[t] = cdbmp->cdb_dpos;
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if ((len = hcnt[t]) == 0)
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continue;
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for (i = 0; i < len; ++i)
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htab[i].hval = htab[i].rpos = 0;
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for (rl = cdbmp->cdb_rec[t]; rl; rl = rl->next)
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for (i = 0; i < rl->cnt; ++i) {
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hi = (rl->rec[i].hval >> 8) % len;
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while(htab[hi].rpos)
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if (++hi == len)
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hi = 0;
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htab[hi] = rl->rec[i];
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}
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for (i = 0; i < len; ++i) {
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cdb_pack(htab[i].hval, p + (i << 3));
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cdb_pack(htab[i].rpos, p + (i << 3) + 4);
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}
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if (_cdb_make_write(cdbmp, p, len << 3) < 0) {
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xfree(p);
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return -1;
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}
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}
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xfree(p);
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if (cdbmp->cdb_bpos != cdbmp->cdb_buf &&
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ewrite(cdbmp->cdb_fd, cdbmp->cdb_buf,
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cdbmp->cdb_bpos - cdbmp->cdb_buf) != 0)
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return -1;
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p = cdbmp->cdb_buf;
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for (t = 0; t < 256; ++t) {
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cdb_pack(hpos[t], p + (t << 3));
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cdb_pack(hcnt[t], p + (t << 3) + 4);
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}
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rewind(cdbmp->cdb_fd);
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if (ewrite(cdbmp->cdb_fd, p, 2048) != 0)
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return -1;
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return 0;
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}
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static void
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cdb_make_free(struct cdb_make *cdbmp)
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{
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unsigned t;
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for(t = 0; t < 256; ++t) {
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struct cdb_rl *rl = cdbmp->cdb_rec[t];
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while(rl) {
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struct cdb_rl *tm = rl;
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rl = rl->next;
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xfree(tm);
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}
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}
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}
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int
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cdb_make_finish(struct cdb_make *cdbmp)
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{
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int r = cdb_make_finish_internal(cdbmp);
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cdb_make_free(cdbmp);
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return r;
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}
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