IDZEBRA  2.1.2
su_codec.c
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1 /* This file is part of the Zebra server.
2  Copyright (C) Index Data
3 
4 Zebra is free software; you can redistribute it and/or modify it under
5 the terms of the GNU General Public License as published by the Free
6 Software Foundation; either version 2, or (at your option) any later
7 version.
8 
9 Zebra is distributed in the hope that it will be useful, but WITHOUT ANY
10 WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 for more details.
13 
14 You should have received a copy of the GNU General Public License
15 along with this program; if not, write to the Free Software
16 Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
17 
18 */
19 
20 #if HAVE_CONFIG_H
21 #include <config.h>
22 #endif
23 #include <stdlib.h>
24 #include <string.h>
25 #include <stdio.h>
26 #include <assert.h>
27 
28 #include <yaz/xmalloc.h>
29 #include <su_codec.h>
30 
31 int key_SU_encode (int ch, char *out)
32 {
33  int i;
34 
35  if (ch == -1)
36  {
37  /* unique value .. which is different from ch >= 0 case */
38  /* is used to generate queries with "null" hits, bug #1142 */
39  out[0] = 129;
40  return 1;
41  }
42  for (i = 0; ch; i++)
43  {
44  if (ch >= 64)
45  out[i] = 65 + (ch & 63);
46  else
47  out[i] = 1 + ch;
48  ch = ch >> 6;
49  }
50  return i;
51  /* in out
52  0 1
53  1 2
54  63 64
55  64 65, 2
56  65 66, 2
57  127 128, 2
58  128 65, 3
59  191 128, 3
60  192 65, 4
61  */
62 }
63 
64 int key_SU_decode (int *ch, const unsigned char *out)
65 {
66  int len = 1;
67  int fact = 1;
68  *ch = 0;
69  for (len = 1; *out >= 65; len++, out++)
70  {
71  *ch += (*out - 65) * fact;
72  fact <<= 6;
73  }
74  *ch += (*out - 1) * fact;
75  return len;
76 }
77 
78 /*
79  * Local variables:
80  * c-basic-offset: 4
81  * c-file-style: "Stroustrup"
82  * indent-tabs-mode: nil
83  * End:
84  * vim: shiftwidth=4 tabstop=8 expandtab
85  */
86 
int key_SU_decode(int *ch, const unsigned char *out)
Definition: su_codec.c:64
int key_SU_encode(int ch, char *out)
Definition: su_codec.c:31