1 files changed, 145 insertions, 0 deletions
diff --git a/src/libstddjb/cdb_make.c b/src/libstddjb/cdb_make.c
new file mode 100644
index 0000000..0ec3423
--- /dev/null
+++ b/src/libstddjb/cdb_make.c
@@ -0,0 +1,145 @@
+/* ISC license. */
+
+#include <unistd.h>
+#include <errno.h>
+#include <skalibs/uint32.h>
+#include <skalibs/diuint32.h>
+#include <skalibs/genalloc.h>
+#include <skalibs/buffer.h>
+#include <skalibs/djbunix.h>
+#include <skalibs/cdb.h>
+#include <skalibs/cdb_make.h>
+
+static void cdb_make_free (struct cdb_make *c)
+{
+  struct cdb_make zero = CDB_MAKE_ZERO ;
+  genalloc_free(diuint32, &c->hplist) ;
+  *c = zero ;
+}
+
+int cdb_make_start (struct cdb_make *c, int fd)
+{
+  c->hplist = genalloc_zero ;
+  c->fd = fd ;
+  c->pos = 2048 ;
+  buffer_init(&c->b, &buffer_write, fd, c->buf, BUFFER_OUTSIZE) ;
+  return seek_set(fd, c->pos) ;
+}
+
+static int posplus (struct cdb_make *c, uint32 len)
+{
+  register uint32 newpos = c->pos + len ;
+  if (newpos < len) return (errno = ENOMEM, 0) ;
+  c->pos = newpos ;
+  return 1 ;
+}
+
+static int cdb_make_addend (struct cdb_make *c, unsigned int keylen, unsigned int datalen, uint32 h)
+{
+  diuint32 blah = { h, c->pos } ;
+  if (!genalloc_append(diuint32, &c->hplist, &blah) || !posplus(c, 8) || !posplus(c, keylen) || !posplus(c, datalen))
+  {
+    cdb_make_free(c) ;
+    return -1 ;
+  }
+  return 0 ;
+}
+
+static int cdb_make_addbegin (struct cdb_make *c, unsigned int keylen, unsigned int datalen)
+{
+  char buf[8] ;
+  if ((keylen > 0xffffffff) || (datalen > 0xffffffff))
+  {
+    errno = ENOMEM ;
+    goto err ;
+  }
+  uint32_pack(buf, keylen) ;
+  uint32_pack(buf + 4, datalen) ;
+  if (buffer_put(&c->b, buf, 8) < 0) goto err ;
+  return 0 ;
+err:
+  cdb_make_free(c) ;
+  return -1 ;
+}
+
+int cdb_make_add (struct cdb_make *c, char const *key, unsigned int keylen, char const *data, unsigned int datalen)
+{
+  if ((cdb_make_addbegin(c, keylen, datalen) < 0)
+   || (buffer_put(&c->b, key, keylen) < 0)
+   || (buffer_put(&c->b, data, datalen) < 0)
+   || (cdb_make_addend(c, keylen, datalen, cdb_hash(key, keylen)) < 0))
+    return -1 ;
+  return 0 ;
+}
+
+int cdb_make_finish (struct cdb_make *c)
+{
+  uint32 count[256] ;
+  uint32 start[256] ;
+  char final[2048] ;
+  unsigned int size = 1 ;
+  unsigned int n = genalloc_len(diuint32, &c->hplist) ;
+  register unsigned int i = 0 ;
+  register diuint32 *hp = genalloc_s(diuint32, &c->hplist) ;
+
+  for ( ; i < 256 ; i++) count[i] = 0 ;
+  for (i = 0 ; i < n ; i++) ++count[hp[i].left & 255] ;
+
+  {
+    register uint32 u = 0 ;
+    for (i = 0 ; i < 256 ; i++) start[i] = u += count[i] ; /* bounded by n */
+    for (i = 0 ; i < 256 ; i++)
+    {
+      u = count[i] << 1 ;
+      if (u > size) size = u ;
+    }
+    size += n ; /* no overflow possible up to now */
+    u = 0xffffffffUL ; u /= sizeof(diuint32) ;
+    if (size > u) return (errno = ENOMEM, -1) ;
+  }
+  i = n ;
+  {
+    diuint32 split[size] ;
+    while (i--) split[--start[hp[i].left & 255]] = hp[i] ;
+    genalloc_free(diuint32, &c->hplist) ;
+    hp = split + n ;
+
+    for (i = 0 ; i < 256 ; ++i)
+    {
+      char buf[8] ;
+      register uint32 k = count[i] ;
+      register uint32 len = k << 1 ; /* no overflow possible */
+      register diuint32 *p = split + start[i] ;
+      register unsigned int j = 0 ;
+
+      uint32_pack(final + (i << 3), c->pos) ;
+      uint32_pack(final + (i << 3) + 4, len) ;
+
+      for ( ; j < len ; j++) hp[j].left = hp[j].right = 0 ;
+      for (j = 0 ; j < k ; j++)
+      {
+        register uint32 where = (p->left >> 8) % len ;
+        while (hp[where].right) if (++where == len) where = 0 ;
+        hp[where] = *p++ ;
+      }
+
+      for (j = 0 ; j < len ; j++)
+      {
+        uint32_pack(buf, hp[j].left) ;
+        uint32_pack(buf + 4, hp[j].right) ;
+        if (buffer_put(&c->b, buf, 8) < 0) goto err0 ;
+        if (!posplus(c, 8)) goto err0 ;
+      }
+    }
+  }
+
+  if (!buffer_flush(&c->b)) goto err0 ;
+  if (seek_begin(c->fd) == -1) goto err0 ;
+  if (buffer_putflush(&c->b, final, 2048) < 0) goto err0 ;
+  cdb_make_free(c) ;
+  return 0 ;
+
+err0:
+  cdb_make_free(c) ;
+  return -1 ;
+}