1 files changed, 158 insertions, 0 deletions
diff --git a/cdbmake.c b/cdbmake.c
new file mode 100644
index 0000000..28e170c
--- /dev/null
+++ b/cdbmake.c
@@ -0,0 +1,158 @@
+#include <unistd.h>
+#include "seek.h"
+#include "error.h"
+#include "alloc.h"
+#include "cdbread.h"
+#include "cdbmake.h"
+
+/**
+	@file	cdbmake.c
+	@author djb
+	@source ucspi-tcp
+	@brief constant data base (cdb) generation
+*/
+
+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 = ENOMEM; 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 = ENOMEM; return -1; }
+  if (datalen > 0xffffffff) { errno = ENOMEM; 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 < 256; ++i)
+    c->count[i] = 0;
+
+  for (x = c->head; x; x = x->next) {
+    i = x->num;
+    while (i--)
+      ++c->count[255 & x->hp[i].h];
+  }
+
+  memsize = 1;
+  for (i = 0; i < 256; ++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 = ENOMEM; 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 < 256; ++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[255 & x->hp[i].h]] = x->hp[i];
+  }
+
+  for (i = 0; i < 256; ++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 >> 8) % 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));
+}