1 files changed, 71 insertions, 0 deletions
diff --git a/storage/myisam/mi_checksum.c b/storage/myisam/mi_checksum.c
new file mode 100644
index 00000000..ff84fa67
--- /dev/null
+++ b/storage/myisam/mi_checksum.c
@@ -0,0 +1,71 @@
+/* Copyright (c) 2000, 2013, Oracle and/or its affiliates. All rights reserved.
+
+   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; version 2 of the License.
+
+   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., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1335  USA */
+
+/* Calculate a checksum for a row */
+
+#include "myisamdef.h"
+
+ha_checksum mi_checksum(MI_INFO *info, const uchar *buf)
+{
+  ha_checksum crc=0;
+  const uchar *record= buf;
+  MI_COLUMNDEF *column= info->s->rec;
+  MI_COLUMNDEF *column_end= column+ info->s->base.fields;
+  my_bool skip_null_bits= MY_TEST(info->s->options & HA_OPTION_NULL_FIELDS);
+
+  for ( ; column != column_end ; buf+= column++->length)
+  {
+    const uchar *pos;
+    ulong length;
+
+    if ((record[column->null_pos] & column->null_bit) &&
+        skip_null_bits)
+      continue;                                 /* Null field */
+
+    switch (column->type) {
+    case FIELD_BLOB:
+    {
+      length=_mi_calc_blob_length(column->length-
+                                  portable_sizeof_char_ptr,
+                                  buf);
+      memcpy((void*) &pos, buf+column->length - portable_sizeof_char_ptr,
+	     sizeof(char*));
+      break;
+    }
+    case FIELD_VARCHAR:
+    {
+      uint pack_length= HA_VARCHAR_PACKLENGTH(column->length-1);
+      if (pack_length == 1)
+        length= (ulong) *(uchar*) buf;
+      else
+        length= uint2korr(buf);
+      pos= buf+pack_length;
+      break;
+    }
+    default:
+      length=column->length;
+      pos=buf;
+      break;
+    }
+    crc=my_checksum(crc, pos ? pos : (uchar*) "", length);
+  }
+  return crc;
+}
+
+
+ha_checksum mi_static_checksum(MI_INFO *info, const uchar *pos)
+{
+  return my_checksum(0, pos, info->s->base.reclength);
+}