← Back to branch summary

~drizzle-trunk/drizzle/development

« back to all changes in this revision

Viewing changes to plugin/myisam/mi_checksum.cc

  • Committer: Monty Taylor
  • Date: 2009-04-25 20:45:19 UTC
  • mto: (997.2.5 mordred)
  • mto: This revision was merged to the branch mainline in revision 1003.
  • Revision ID: mordred@inaugust.com-20090425204519-lgrl7mz2r66v0jby
Blackhole.

Show diffs side-by-side

added added

removed removed

Lines of Context:
plugin/myisam/mi_checksum.cc
1
 
/* Copyright (C) 2000-2001, 2003-2004 MySQL AB
2
 
 
3
 
   This program is free software; you can redistribute it and/or modify
4
 
   it under the terms of the GNU General Public License as published by
5
 
   the Free Software Foundation; version 2 of the License.
6
 
 
7
 
   This program is distributed in the hope that it will be useful,
8
 
   but WITHOUT ANY WARRANTY; without even the implied warranty of
9
 
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
10
 
   GNU General Public License for more details.
11
 
 
12
 
   You should have received a copy of the GNU General Public License
13
 
   along with this program; if not, write to the Free Software
14
 
   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */
15
 
 
16
 
/* Calculate a checksum for a row */
17
 
 
18
 
#include "myisam_priv.h"
19
 
 
20
 
using namespace drizzled;
21
 
 
22
 
internal::ha_checksum mi_checksum(MI_INFO *info, const unsigned char *buf)
23
 
{
24
 
  uint32_t i;
25
 
  internal::ha_checksum crc=0;
26
 
  MI_COLUMNDEF *rec=info->s->rec;
27
 
 
28
 
  for (i=info->s->base.fields ; i-- ; buf+=(rec++)->length)
29
 
  {
30
 
    const unsigned char *pos;
31
 
    ulong length;
32
 
    switch (rec->type) {
33
 
    case FIELD_BLOB:
34
 
    {
35
 
      length=_mi_calc_blob_length(rec->length-
36
 
                                        portable_sizeof_char_ptr,
37
 
                                        buf);
38
 
      memcpy(&pos, buf+rec->length - portable_sizeof_char_ptr, sizeof(char*));
39
 
      break;
40
 
    }
41
 
    case FIELD_VARCHAR:
42
 
    {
43
 
      uint32_t pack_length= HA_VARCHAR_PACKLENGTH(rec->length-1);
44
 
      if (pack_length == 1)
45
 
        length= (ulong) *(unsigned char*) buf;
46
 
      else
47
 
        length= uint2korr(buf);
48
 
      pos= buf+pack_length;
49
 
      break;
50
 
    }
51
 
    default:
52
 
      length=rec->length;
53
 
      pos=buf;
54
 
      break;
55
 
    }
56
 
    crc=internal::my_checksum(crc, pos ? pos : (unsigned char*) "", length);
57
 
  }
58
 
  return crc;
59
 
}
60
 
 
61
 
 
62
 
internal::ha_checksum mi_static_checksum(MI_INFO *info, const unsigned char *pos)
63
 
{
64
 
  return internal::my_checksum(0, pos, info->s->base.reclength);
65
 
}