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authorunknown <joerg@mysql.com>2005-03-07 10:28:56 +0100
committerunknown <joerg@mysql.com>2005-03-07 10:28:56 +0100
commitc8399bb6b5ae367298bc1b7cfaf415b95c2eb59a (patch)
tree560985c65fc3dd69633467ccf592994ddddad991 /mysys/my_bitmap.c
parent25ca5723412ffe912e8c1f82aceb601ef0b1c608 (diff)
downloadmariadb-git-c8399bb6b5ae367298bc1b7cfaf415b95c2eb59a.tar.gz
Merge 4.0.24 compile changes into the 4.1 tree.
mysys/my_bitmap.c: Resolved merge conflict (identical change in 4.0 and 4.1).
Diffstat (limited to 'mysys/my_bitmap.c')
-rw-r--r--mysys/my_bitmap.c259
1 files changed, 222 insertions, 37 deletions
diff --git a/mysys/my_bitmap.c b/mysys/my_bitmap.c
index 9662f219418..f0d3339535d 100644
--- a/mysys/my_bitmap.c
+++ b/mysys/my_bitmap.c
@@ -16,7 +16,18 @@
/*
Handling of uchar arrays as large bitmaps.
- We assume that the size of the used bitmap is less than ~(uint) 0
+
+ API limitations (or, rather asserted safety assumptions,
+ to encourage correct programming)
+
+ * the size of the used bitmap is less than ~(uint) 0
+ * it's a multiple of 8 (for efficiency reasons)
+ * when arguments are a bitmap and a bit number, the number
+ must be within bitmap size
+ * bitmap_set_prefix() is an exception - one can use ~0 to set all bits
+ * when both arguments are bitmaps, they must be of the same size
+ * bitmap_intersect() is an exception :)
+ (for for Bitmap::intersect(ulonglong map2buff))
TODO:
Make assembler THREAD safe versions of these using test-and-set instructions
@@ -24,60 +35,74 @@
#include "mysys_priv.h"
#include <my_bitmap.h>
-#include <assert.h>
#include <m_string.h>
static inline void bitmap_lock(MY_BITMAP* map)
{
#ifdef THREAD
- if (map->thread_safe)
- pthread_mutex_lock(&map->mutex);
+ if (map->mutex)
+ pthread_mutex_lock(map->mutex);
#endif
}
static inline void bitmap_unlock(MY_BITMAP* map)
{
#ifdef THREAD
- if (map->thread_safe)
- pthread_mutex_unlock(&map->mutex);
+ if (map->mutex)
+ pthread_mutex_unlock(map->mutex);
#endif
}
-my_bool bitmap_init(MY_BITMAP *map, uint bitmap_size, my_bool thread_safe)
+
+my_bool bitmap_init(MY_BITMAP *map, uchar *buf, uint bitmap_size,
+ my_bool thread_safe)
{
- if (!(map->bitmap=(uchar*) my_malloc((bitmap_size+7)/8,
- MYF(MY_WME | MY_ZEROFILL))))
+ DBUG_ENTER("bitmap_init");
+
+ DBUG_ASSERT((bitmap_size & 7) == 0);
+ bitmap_size/=8;
+ if (!(map->bitmap=buf) &&
+ !(map->bitmap= (uchar*) my_malloc(bitmap_size +
+ (thread_safe ?
+ sizeof(pthread_mutex_t) : 0),
+ MYF(MY_WME | MY_ZEROFILL))))
return 1;
- DBUG_ASSERT(bitmap_size != ~(uint) 0);
+ map->bitmap_size=bitmap_size;
#ifdef THREAD
- if ((map->thread_safe = thread_safe))
- pthread_mutex_init(&map->mutex, MY_MUTEX_INIT_FAST);
+ if (thread_safe)
+ {
+ map->mutex=(pthread_mutex_t *)(map->bitmap+bitmap_size);
+ pthread_mutex_init(map->mutex, MY_MUTEX_INIT_FAST);
+ }
+ else
+ map->mutex=0;
#endif
- map->bitmap_size=bitmap_size;
- return 0;
+ DBUG_RETURN(0);
}
+
void bitmap_free(MY_BITMAP *map)
{
+ DBUG_ENTER("bitmap_free");
if (map->bitmap)
{
- my_free((char*) map->bitmap, MYF(0));
- map->bitmap=0;
#ifdef THREAD
- if (map->thread_safe)
- pthread_mutex_destroy(&map->mutex);
+ if (map->mutex)
+ pthread_mutex_destroy(map->mutex);
#endif
+ my_free((char*) map->bitmap, MYF(0));
+ map->bitmap=0;
}
+ DBUG_VOID_RETURN;
}
+
void bitmap_set_bit(MY_BITMAP *map, uint bitmap_bit)
{
- if (bitmap_bit < map->bitmap_size)
- {
- bitmap_lock(map);
- map->bitmap[bitmap_bit / 8] |= (1 << (bitmap_bit & 7));
- bitmap_unlock(map);
- }
+ DBUG_ASSERT(map->bitmap && bitmap_bit < map->bitmap_size*8);
+ bitmap_lock(map);
+ bitmap_fast_set_bit(map, bitmap_bit);
+ bitmap_unlock(map);
}
@@ -85,9 +110,10 @@ uint bitmap_set_next(MY_BITMAP *map)
{
uchar *bitmap=map->bitmap;
uint bit_found = MY_BIT_NONE;
- uint bitmap_size=map->bitmap_size;
+ uint bitmap_size=map->bitmap_size*8;
uint i;
+ DBUG_ASSERT(map->bitmap);
bitmap_lock(map);
for (i=0; i < bitmap_size ; i++, bitmap++)
{
@@ -113,32 +139,191 @@ uint bitmap_set_next(MY_BITMAP *map)
void bitmap_clear_bit(MY_BITMAP *map, uint bitmap_bit)
{
- if (bitmap_bit < map->bitmap_size)
+ DBUG_ASSERT(map->bitmap && bitmap_bit < map->bitmap_size*8);
+ bitmap_lock(map);
+ bitmap_fast_clear_bit(map, bitmap_bit);
+ bitmap_unlock(map);
+}
+
+
+void bitmap_set_prefix(MY_BITMAP *map, uint prefix_size)
+{
+ uint prefix_bytes, prefix_bits;
+
+ DBUG_ASSERT(map->bitmap &&
+ (prefix_size <= map->bitmap_size*8 || prefix_size == (uint) ~0));
+ bitmap_lock(map);
+ set_if_smaller(prefix_size, map->bitmap_size*8);
+ if ((prefix_bytes= prefix_size / 8))
+ memset(map->bitmap, 0xff, prefix_bytes);
+ if ((prefix_bits= prefix_size & 7))
+ map->bitmap[prefix_bytes++]= (1 << prefix_bits)-1;
+ if (prefix_bytes < map->bitmap_size)
+ bzero(map->bitmap+prefix_bytes, map->bitmap_size-prefix_bytes);
+ bitmap_unlock(map);
+}
+
+
+void bitmap_clear_all(MY_BITMAP *map)
+{
+ bitmap_set_prefix(map, 0);
+}
+
+
+void bitmap_set_all(MY_BITMAP *map)
+{
+ bitmap_set_prefix(map, ~0);
+}
+
+
+my_bool bitmap_is_prefix(const MY_BITMAP *map, uint prefix_size)
+{
+ uint prefix_bits= prefix_size & 7, res= 0;
+ uchar *m= map->bitmap, *end_prefix= map->bitmap+prefix_size/8,
+ *end= map->bitmap+map->bitmap_size;
+
+ DBUG_ASSERT(map->bitmap && prefix_size <= map->bitmap_size*8);
+
+ bitmap_lock((MY_BITMAP *)map);
+ while (m < end_prefix)
+ if (*m++ != 0xff)
+ goto ret;
+
+ if (prefix_bits && *m++ != (1 << prefix_bits)-1)
+ goto ret;
+
+ while (m < end)
+ if (*m++ != 0)
+ goto ret;
+
+ res=1;
+ret:
+ bitmap_unlock((MY_BITMAP *)map);
+ return res;
+}
+
+
+my_bool bitmap_is_clear_all(const MY_BITMAP *map)
+{
+ return bitmap_is_prefix(map, 0);
+}
+
+my_bool bitmap_is_set_all(const MY_BITMAP *map)
+{
+ return bitmap_is_prefix(map, map->bitmap_size*8);
+}
+
+
+my_bool bitmap_is_set(const MY_BITMAP *map, uint bitmap_bit)
+{
+ DBUG_ASSERT(map->bitmap && bitmap_bit < map->bitmap_size*8);
+ return bitmap_fast_is_set(map, bitmap_bit);
+}
+
+
+my_bool bitmap_is_subset(const MY_BITMAP *map1, const MY_BITMAP *map2)
+{
+ uint res=0;
+ uchar *m1=map1->bitmap, *m2=map2->bitmap, *end;
+
+ DBUG_ASSERT(map1->bitmap && map2->bitmap &&
+ map1->bitmap_size==map2->bitmap_size);
+ bitmap_lock((MY_BITMAP *)map1);
+ bitmap_lock((MY_BITMAP *)map2);
+
+ end= m1+map1->bitmap_size;
+
+ while (m1 < end)
{
- bitmap_lock(map);
- map->bitmap[bitmap_bit / 8] &= ~ (1 << (bitmap_bit & 7));
- bitmap_unlock(map);
+ if ((*m1++) & ~(*m2++))
+ goto ret;
}
+
+ res=1;
+ret:
+ bitmap_unlock((MY_BITMAP *)map2);
+ bitmap_unlock((MY_BITMAP *)map1);
+ return res;
}
-void bitmap_set_all(MY_BITMAP* map)
+my_bool bitmap_cmp(const MY_BITMAP *map1, const MY_BITMAP *map2)
{
+ uint res;
+
+ DBUG_ASSERT(map1->bitmap && map2->bitmap &&
+ map1->bitmap_size==map2->bitmap_size);
+ bitmap_lock((MY_BITMAP *)map1);
+ bitmap_lock((MY_BITMAP *)map2);
+
+ res= memcmp(map1->bitmap, map2->bitmap, map1->bitmap_size)==0;
+
+ bitmap_unlock((MY_BITMAP *)map2);
+ bitmap_unlock((MY_BITMAP *)map1);
+ return res;
+}
+
+
+void bitmap_intersect(MY_BITMAP *map, const MY_BITMAP *map2)
+{
+ uchar *to=map->bitmap, *from=map2->bitmap, *end;
+ uint len=map->bitmap_size, len2=map2->bitmap_size;
+
+ DBUG_ASSERT(map->bitmap && map2->bitmap);
bitmap_lock(map);
- memset(map->bitmap, 0xff, (map->bitmap_size+7)/8);
+ bitmap_lock((MY_BITMAP *)map2);
+
+ end= to+min(len,len2);
+
+ while (to < end)
+ *to++ &= *from++;
+
+ if (len2 < len)
+ {
+ end+=len-len2;
+ while (to < end)
+ *to++=0;
+ }
+
+ bitmap_unlock((MY_BITMAP *)map2);
bitmap_unlock(map);
}
-my_bool bitmap_is_set(MY_BITMAP* map, uint bitmap_bit)
+
+void bitmap_subtract(MY_BITMAP *map, const MY_BITMAP *map2)
{
- return (bitmap_bit < map->bitmap_size) ?
- (map->bitmap[bitmap_bit / 8] & (1 << (bitmap_bit & 7))) :
- 0;
+ uchar *to=map->bitmap, *from=map2->bitmap, *end;
+
+ DBUG_ASSERT(map->bitmap && map2->bitmap &&
+ map->bitmap_size==map2->bitmap_size);
+ bitmap_lock(map);
+ bitmap_lock((MY_BITMAP *)map2);
+
+ end= to+map->bitmap_size;
+
+ while (to < end)
+ *to++ &= ~(*from++);
+
+ bitmap_unlock((MY_BITMAP *)map2);
+ bitmap_unlock(map);
}
-void bitmap_clear_all(MY_BITMAP* map)
+
+void bitmap_union(MY_BITMAP *map, const MY_BITMAP *map2)
{
+ uchar *to=map->bitmap, *from=map2->bitmap, *end;
+
+ DBUG_ASSERT(map->bitmap && map2->bitmap &&
+ map->bitmap_size==map2->bitmap_size);
bitmap_lock(map);
- bzero(map->bitmap,(map->bitmap_size+7)/8);
+ bitmap_lock((MY_BITMAP *)map2);
+
+ end= to+map->bitmap_size;
+
+ while (to < end)
+ *to++ |= *from++;
+
+ bitmap_unlock((MY_BITMAP *)map2);
bitmap_unlock(map);
}
+