summaryrefslogtreecommitdiff
path: root/mysys/my_bitmap.c
diff options
context:
space:
mode:
authorSergei Golubchik <sergii@pisem.net>2013-07-21 16:39:19 +0200
committerSergei Golubchik <sergii@pisem.net>2013-07-21 16:39:19 +0200
commitb7b5f6f1ab49948b0e15b762266d4640b3d6b7fb (patch)
tree7c302c2025184dbd053aa6135f0ff28c8ce6f359 /mysys/my_bitmap.c
parent5f6380adde2dac3f32b40339b9b702c0135eb7d6 (diff)
parentc1d6a2d7e194225ccc19a68ea5d0f368632620d0 (diff)
downloadmariadb-git-b7b5f6f1ab49948b0e15b762266d4640b3d6b7fb.tar.gz
10.0-monty merge
includes: * remove some remnants of "Bug#14521864: MYSQL 5.1 TO 5.5 BUGS PARTITIONING" * introduce LOCK_share, now LOCK_ha_data is strictly for engines * rea_create_table() always creates .par file (even in "frm-only" mode) * fix a 5.6 bug, temp file leak on dummy ALTER TABLE
Diffstat (limited to 'mysys/my_bitmap.c')
-rw-r--r--mysys/my_bitmap.c111
1 files changed, 84 insertions, 27 deletions
diff --git a/mysys/my_bitmap.c b/mysys/my_bitmap.c
index 851fe2b1026..3105f4b1daf 100644
--- a/mysys/my_bitmap.c
+++ b/mysys/my_bitmap.c
@@ -147,6 +147,26 @@ static inline void bitmap_unlock(MY_BITMAP *map __attribute__((unused)))
}
+static inline uint get_first_set(my_bitmap_map value, uint word_pos)
+{
+ uchar *byte_ptr= (uchar*)&value;
+ uchar byte_value;
+ uint byte_pos, bit_pos;
+
+ DBUG_ASSERT(value);
+ for (byte_pos=0; ; byte_pos++, byte_ptr++)
+ {
+ if ((byte_value= *byte_ptr))
+ {
+ for (bit_pos=0; ; bit_pos++)
+ if (byte_value & (1 << bit_pos))
+ return (word_pos*32) + (byte_pos*8) + bit_pos;
+ }
+ }
+ return MY_BIT_NONE; /* Impossible */
+}
+
+
my_bool bitmap_init(MY_BITMAP *map, my_bitmap_map *buf, uint n_bits,
my_bool thread_safe __attribute__((unused)))
{
@@ -405,7 +425,7 @@ void bitmap_intersect(MY_BITMAP *map, const MY_BITMAP *map2)
DBUG_ASSERT(map->bitmap && map2->bitmap);
- end= to+min(len,len2);
+ end= to+MY_MIN(len,len2);
while (to < end)
*to++ &= *from++;
@@ -597,12 +617,10 @@ void bitmap_copy(MY_BITMAP *map, const MY_BITMAP *map2)
uint bitmap_get_first_set(const MY_BITMAP *map)
{
- uchar *byte_ptr;
- uint i,j,k;
- my_bitmap_map *data_ptr, *end= map->last_word_ptr;
+ uint i;
+ my_bitmap_map *data_ptr= map->bitmap, *end= map->last_word_ptr;
DBUG_ASSERT(map->bitmap);
- data_ptr= map->bitmap;
for (i=0; data_ptr < end; data_ptr++, i++)
if (*data_ptr)
@@ -611,25 +629,66 @@ uint bitmap_get_first_set(const MY_BITMAP *map)
return MY_BIT_NONE;
found:
+ return get_first_set(*data_ptr, i);
+}
+
+
+/**
+ Get the next set bit.
+
+ @param map Bitmap
+ @param bitmap_bit Bit to start search from
+
+ @return Index to first bit set after bitmap_bit
+*/
+
+uint bitmap_get_next_set(const MY_BITMAP *map, uint bitmap_bit)
+{
+ uint word_pos, byte_to_mask, i;
+ union { my_bitmap_map bitmap ; uchar bitmap_buff[sizeof(my_bitmap_map)]; }
+ first_word;
+ uchar *ptr= &first_word.bitmap_buff[0];
+ my_bitmap_map *data_ptr, *end= map->last_word_ptr;
+
+ DBUG_ASSERT(map->bitmap);
+
+ /* Look for the next bit */
+ bitmap_bit++;
+ if (bitmap_bit >= map->n_bits)
+ return MY_BIT_NONE;
+ word_pos= bitmap_bit / 32;
+ data_ptr= map->bitmap + word_pos;
+ first_word.bitmap= *data_ptr;
+
+ /* Mask out previous bits from first_word */
+ byte_to_mask= (bitmap_bit % 32) / 8;
+ for (i= 0; i < byte_to_mask; i++)
+ ptr[i]= 0;
+ ptr[byte_to_mask]&= 0xFFU << (bitmap_bit & 7);
+
+ if (data_ptr == end)
{
- byte_ptr= (uchar*)data_ptr;
- for (j=0; ; j++, byte_ptr++)
- {
- if (*byte_ptr)
- {
- for (k=0; ; k++)
- {
- if (*byte_ptr & (1 << k))
- return (i*32) + (j*8) + k;
- }
- }
- }
+ if (first_word.bitmap & ~map->last_word_mask)
+ return get_first_set(first_word.bitmap, word_pos);
+ else
+ return MY_BIT_NONE;
}
- DBUG_ASSERT(0);
- return MY_BIT_NONE; /* Impossible */
+
+ if (first_word.bitmap)
+ return get_first_set(first_word.bitmap, word_pos);
+
+ for (data_ptr++, word_pos++; data_ptr < end; data_ptr++, word_pos++)
+ if (*data_ptr)
+ return get_first_set(*data_ptr, word_pos);
+
+ if (!(*end & ~map->last_word_mask))
+ return MY_BIT_NONE;
+ return get_first_set(*end, word_pos);
}
+/* Get first free bit */
+
uint bitmap_get_first(const MY_BITMAP *map)
{
uchar *byte_ptr;
@@ -647,17 +706,15 @@ uint bitmap_get_first(const MY_BITMAP *map)
return MY_BIT_NONE;
found:
+ byte_ptr= (uchar*)data_ptr;
+ for (j=0; ; j++, byte_ptr++)
{
- byte_ptr= (uchar*)data_ptr;
- for (j=0; ; j++, byte_ptr++)
+ if (*byte_ptr != 0xFF)
{
- if (*byte_ptr != 0xFF)
+ for (k=0; ; k++)
{
- for (k=0; ; k++)
- {
- if (!(*byte_ptr & (1 << k)))
- return (i*32) + (j*8) + k;
- }
+ if (!(*byte_ptr & (1 << k)))
+ return (i*32) + (j*8) + k;
}
}
}