From 0e5b2871ca6456b01d4bf037a6e68badf1ff1a41 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Henryk=20Pl=C3=B6tz?= <henryk@ploetzli.ch>
Date: Fri, 3 Oct 2014 19:58:52 +0200
Subject: Initial commit of djbdns-1.05.tar.gz Source was
 http://cr.yp.to/djbdns/djbdns-1.05.tar.gz, SHA1
 2efdb3a039d0c548f40936aa9cb30829e0ce8c3d

---
 cdb_make.c | 152 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 152 insertions(+)
 create mode 100644 cdb_make.c

(limited to 'cdb_make.c')

diff --git a/cdb_make.c b/cdb_make.c
new file mode 100644
index 0000000..278420f
--- /dev/null
+++ b/cdb_make.c
@@ -0,0 +1,152 @@
+/* Public domain. */
+
+#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,buffer_unixwrite,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,const char *key,unsigned int keylen,const 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 = 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 < 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);
+}
-- 
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