Skip to content
This repository
branch: master
Fetching contributors…

Octocat-spinner-32-eaf2f5

Cannot retrieve contributors at this time

file 154 lines (129 sloc) 3.785 kb
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153
/* Public domain. */

#include "readwrite.h"
#include "seek.h"
#include "error.h"
#include "alloc.h"
#include "cdb.h"
#include "cdb_make.h"

int cdb_make_start(struct cdb_make *c,int fd)
{
  c->head = 0;
  c->split = 0;
  c->hash = 0;
  c->numentries = 0;
  c->fd = fd;
  c->pos = sizeof c->final;
  buffer_init(&c->b,write,fd,c->bspace,sizeof c->bspace);
  return seek_set(fd,c->pos);
}

static int posplus(struct cdb_make *c,uint32 len)
{
  uint32 newpos = c->pos + len;
  if (newpos < len) { errno = error_nomem; return -1; }
  c->pos = newpos;
  return 0;
}

int cdb_make_addend(struct cdb_make *c,unsigned int keylen,unsigned int datalen,uint32 h)
{
  struct cdb_hplist *head;

  head = c->head;
  if (!head || (head->num >= CDB_HPLIST)) {
head = (struct cdb_hplist *) alloc(sizeof(struct cdb_hplist));
if (!head) return -1;
head->num = 0;
head->next = c->head;
c->head = head;
  }
  head->hp[head->num].h = h;
  head->hp[head->num].p = c->pos;
  ++head->num;
  ++c->numentries;
  if (posplus(c,8) == -1) return -1;
  if (posplus(c,keylen) == -1) return -1;
  if (posplus(c,datalen) == -1) return -1;
  return 0;
}

int cdb_make_addbegin(struct cdb_make *c,unsigned int keylen,unsigned int datalen)
{
  char buf[8];

  if (keylen > 0xffffffff) { errno = error_nomem; return -1; }
  if (datalen > 0xffffffff) { errno = error_nomem; return -1; }

  uint32_pack(buf,keylen);
  uint32_pack(buf + 4,datalen);
  if (buffer_putalign(&c->b,buf,8) == -1) return -1;
  return 0;
}

int cdb_make_add(struct cdb_make *c,char *key,unsigned int keylen,char *data,unsigned int datalen)
{
  if (cdb_make_addbegin(c,keylen,datalen) == -1) return -1;
  if (buffer_putalign(&c->b,key,keylen) == -1) return -1;
  if (buffer_putalign(&c->b,data,datalen) == -1) return -1;
  return cdb_make_addend(c,keylen,datalen,cdb_hash(key,keylen));
}

int cdb_make_finish(struct cdb_make *c)
{
  char buf[8];
  int i;
  uint32 len;
  uint32 u;
  uint32 memsize;
  uint32 count;
  uint32 where;
  struct cdb_hplist *x;
  struct cdb_hp *hp;

  for (i = 0;i < CDB_NUM_HASH_TABLE_POINTER;++i)
c->count[i] = 0;

  for (x = c->head;x;x = x->next) {
i = x->num;
while (i--)
++c->count[(CDB_NUM_HASH_TABLE_POINTER-1) & x->hp[i].h];
  }

  memsize = 1;
  for (i = 0;i < CDB_NUM_HASH_TABLE_POINTER;++i) {
u = c->count[i] * 2;
if (u > memsize)
memsize = u;
  }

  memsize += c->numentries; /* no overflow possible up to now */
  u = (uint32) 0 - (uint32) 1;
  u /= sizeof(struct cdb_hp);
  if (memsize > u) { errno = error_nomem; return -1; }

  c->split = (struct cdb_hp *) alloc(memsize * sizeof(struct cdb_hp));
  if (!c->split) return -1;

  c->hash = c->split + c->numentries;

  u = 0;
  for (i = 0;i < CDB_NUM_HASH_TABLE_POINTER;++i) {
u += c->count[i]; /* bounded by numentries, so no overflow */
c->start[i] = u;
  }

  for (x = c->head;x;x = x->next) {
i = x->num;
while (i--)
c->split[--c->start[(CDB_NUM_HASH_TABLE_POINTER-1) & x->hp[i].h]] = x->hp[i];
  }

  for (i = 0;i < CDB_NUM_HASH_TABLE_POINTER;++i) {
count = c->count[i];

len = count + count; /* no overflow possible */
uint32_pack(c->final + 8 * i,c->pos);
uint32_pack(c->final + 8 * i + 4,len);

for (u = 0;u < len;++u)
c->hash[u].h = c->hash[u].p = 0;

hp = c->split + c->start[i];
for (u = 0;u < count;++u) {
where = (hp->h / CDB_NUM_HASH_TABLE_POINTER) % len;
while (c->hash[where].p)
if (++where == len)
where = 0;
c->hash[where] = *hp++;
}

for (u = 0;u < len;++u) {
uint32_pack(buf,c->hash[u].h);
uint32_pack(buf + 4,c->hash[u].p);
if (buffer_putalign(&c->b,buf,8) == -1) return -1;
if (posplus(c,8) == -1) return -1;
}
  }

  if (buffer_flush(&c->b) == -1) return -1;
  if (seek_begin(c->fd) == -1) return -1;
  return buffer_putflush(&c->b,c->final,sizeof c->final);
}
Something went wrong with that request. Please try again.