Split it_key stuff into it_key.c. For indexing, sort key chunks in a separate

[idzebra-moved-to-github.git] / util / su_codec.c

diff --git a/util/su_codec.c b/util/su_codec.c
new file mode 100644 (file)
index 0000000..745d938
--- /dev/null
+++ b/util/su_codec.c
@@ -0,0 +1,77 @@
+/* $Id: su_codec.c,v 1.1 2006-11-21 14:32:38 adam Exp $
+   Copyright (C) 1995-2006
+   Index Data ApS
+
+This file is part of the Zebra server.
+
+Zebra is free software; you can redistribute it and/or modify it under
+the terms of the GNU General Public License as published by the Free
+Software Foundation; either version 2, or (at your option) any later
+version.
+
+Zebra is distributed in the hope that it will be useful, but WITHOUT ANY
+WARRANTY; without even the implied warranty of MERCHANTABILITY or
+FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program; if not, write to the Free Software
+Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+
+*/
+
+#include <stdlib.h>
+#include <string.h>
+#include <stdio.h>
+#include <assert.h>
+
+#include <yaz/xmalloc.h>
+#include <su_codec.h>
+
+int key_SU_encode (int ch, char *out)
+{
+    int i;
+    for (i = 0; ch; i++)
+    {
+       if (ch >= 64)
+           out[i] = 65 + (ch & 63);
+       else
+           out[i] = 1 + ch;
+       ch = ch >> 6;
+    }
+    return i;
+    /* in   out
+       0     1
+       1     2
+       63    64
+       64    65, 2
+       65    66, 2
+       127   128, 2
+       128   65, 3
+       191   128, 3
+       192   65, 4
+    */
+}
+
+int key_SU_decode (int *ch, const unsigned char *out)
+{
+    int len = 1;
+    int fact = 1;
+    *ch = 0;
+    for (len = 1; *out >= 65; len++, out++)
+    {
+       *ch += (*out - 65) * fact;
+       fact <<= 6;
+    }
+    *ch += (*out - 1) * fact;
+    return len;
+}
+
+/*
+ * Local variables:
+ * c-basic-offset: 4
+ * indent-tabs-mode: nil
+ * End:
+ * vim: shiftwidth=4 tabstop=8 expandtab
+ */
+