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authorsergefp@mysql.com <>2004-05-29 02:04:01 +0400
committersergefp@mysql.com <>2004-05-29 02:04:01 +0400
commitdff98a8ef7b3c18b056497ac62a82231ed542037 (patch)
tree4df748977d76ebdb15b772574de0ba3d74ff2a78 /mysys/my_bitmap.c
parent8b4ea8337f2aba2aad1ffb154ef0d2f2acb908ab (diff)
downloadmariadb-git-dff98a8ef7b3c18b056497ac62a82231ed542037.tar.gz
* New index_merge EXPLAIN output format
* Fixed a problem with wrong query results for partially covering keys in ROR-index_merge * ROR-intersection retrieval plan choice algorithm now uses less disk IO - and properly processes clustered PK range scans * Fixed several minor range optimizer problems * Added more comments * Code cleanup
Diffstat (limited to 'mysys/my_bitmap.c')
-rw-r--r--mysys/my_bitmap.c22
1 files changed, 16 insertions, 6 deletions
diff --git a/mysys/my_bitmap.c b/mysys/my_bitmap.c
index 3c4caa413a9..a6a37fd5441 100644
--- a/mysys/my_bitmap.c
+++ b/mysys/my_bitmap.c
@@ -28,6 +28,9 @@
* when both arguments are bitmaps, they must be of the same size
* bitmap_intersect() is an exception :)
(for for Bitmap::intersect(ulonglong map2buff))
+
+ If THREAD is defined all bitmap operations except bitmap_init/bitmap_free
+ are thread-safe.
TODO:
Make assembler THREAD safe versions of these using test-and-set instructions
@@ -332,29 +335,36 @@ void bitmap_union(MY_BITMAP *map, const MY_BITMAP *map2)
/*
- Get number of set bits in the bitmap
+ SYNOPSIS
+ bitmap_bits_set()
+ map
+ RETURN
+ Number of set bits in the bitmap.
*/
+
uint bitmap_bits_set(const MY_BITMAP *map)
{
- uchar *m= map->bitmap,
- *end= map->bitmap+map->bitmap_size;
+ uchar *m= map->bitmap;
+ uchar *end= m + map->bitmap_size;
uint res= 0;
DBUG_ASSERT(map->bitmap);
-
bitmap_lock((MY_BITMAP *)map);
while (m < end)
{
res+= my_count_bits_ushort(*m++);
}
-
bitmap_unlock((MY_BITMAP *)map);
return res;
}
/*
- Return number of first zero bit or MY_BIT_NONE if all bits are set.
+ SYNOPSIS
+ bitmap_get_first()
+ map
+ RETURN
+ Number of first unset bit in the bitmap or MY_BIT_NONE if all bits are set.
*/
uint bitmap_get_first(const MY_BITMAP *map)