1 files changed, 67 insertions, 0 deletions
diff --git a/myisam/mi_checksum.c b/myisam/mi_checksum.c
new file mode 100644
index 00000000000..9dabe55e239
--- /dev/null
+++ b/myisam/mi_checksum.c
@@ -0,0 +1,67 @@
+/* Copyright (C) 2000 MySQL AB & MySQL Finland AB & TCX DataKonsult AB
+   
+   This program 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 of the License, or
+   (at your option) any later version.
+   
+   This program 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */
+
+/* Calculate a checksum for a row */
+
+#include "myisamdef.h"
+
+ha_checksum mi_checksum(MI_INFO *info, const byte *buf)
+{
+  uint i;
+  ha_checksum crc=0;
+  MI_COLUMNDEF *rec=info->s->rec;
+
+  for (i=info->s->base.fields ; i-- ; buf+=(rec++)->length)
+  {
+    const byte *pos;
+    const byte *end;
+    switch (rec->type) {
+    case FIELD_BLOB:
+    {
+      ulong length=_mi_calc_blob_length(rec->length-
+					mi_portable_sizeof_char_ptr,
+					buf);
+      memcpy((char*) &pos, buf+rec->length- mi_portable_sizeof_char_ptr,
+	     sizeof(char*));
+      end=pos+length;
+      break;
+    }
+    case FIELD_VARCHAR:
+    {
+      uint length;
+      length=uint2korr(buf);
+      pos=buf+2; end=pos+length;
+      break;
+    }
+    default:
+      pos=buf; end=buf+rec->length;
+      break;
+    }
+    for ( ; pos != end ; pos++)
+      crc=((crc << 8) + *((uchar*) pos)) + (crc >> (8*sizeof(ha_checksum)-8));
+  }
+  return crc;
+}
+
+
+ha_checksum mi_static_checksum(MI_INFO *info, const byte *pos)
+{
+  ha_checksum crc;
+  const byte *end=pos+info->s->base.reclength;
+  for (crc=0; pos != end; pos++)
+      crc=((crc << 8) + *((uchar*) pos)) + (crc >> (8*sizeof(ha_checksum)-8));
+  return crc;
+}