mirror/mariadb
1
0
Fork 0
mirror of https://github.com/MariaDB/server.git synced 2026-04-22 08:15:31 +02:00
Code Issues Projects Releases Packages Wiki Activity

Merge DS-MRR/CPK improvements into 5.3-main

Browse source
This commit is contained in:
Sergey Petrunya 2010-12-13 13:42:40 +03:00
commit 58b646001a
41 changed files with 3224 additions and 508 deletions
Download patch file Download diff file Expand all files Collapse all files

51
sql/key.cc
View file

@ -567,3 +567,54 @@ next_loop:
} while (key_info); /* no more keys to test */
DBUG_RETURN(0);
}
/*
Compare two key tuples.
@brief
Compare two key tuples, i.e. two key values in KeyTupleFormat.
@param part KEY_PART_INFO with key description
@param key1 First key to compare
@param key2 Second key to compare
@param tuple_length Length of key1 (and key2, they are the same) in bytes.
@return
@retval 0 key1 == key2
@retval -1 key1 < key2
@retval +1 key1 > key2
*/
int key_tuple_cmp(KEY_PART_INFO *part, uchar *key1, uchar *key2,
uint tuple_length)
{
uchar *key1_end= key1 + tuple_length;
int len;
int res;
LINT_INIT(len);
for (;key1 < key1_end; key1 += len, key2 += len, part++)
{
len= part->store_length;
if (part->null_bit)
{
if (*key1) // key1 == NULL
{
if (!*key2) // key1(NULL) < key2(notNULL)
return -1;
continue;
}
else if (*key2) // key1(notNULL) > key2 (NULL)
return 1;
/* Step over the NULL bytes for key_cmp() call */
key1++;
key2++;
len--;
}
if ((res= part->field->key_cmp(key1, key2)))
return res;
}
return 0;
}