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Diffstat (limited to 'sql/sql_bitmap.h')
| -rw-r--r-- | sql/sql_bitmap.h | 122 |
1 files changed, 122 insertions, 0 deletions
diff --git a/sql/sql_bitmap.h b/sql/sql_bitmap.h new file mode 100644 index 00000000000..0274cd700da --- /dev/null +++ b/sql/sql_bitmap.h @@ -0,0 +1,122 @@ +/* Copyright (C) 2003 MySQL AB + + 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; either version 2 of the License, or + (at your option) any later version. + + 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ + +/* + Implementation of a bitmap type. + The idea with this is to be able to handle any constant number of bits but + also be able to use 32 or 64 bits bitmaps very efficiently +*/ + +#include <my_bitmap.h> + +template <uint default_width> class Bitmap +{ + MY_BITMAP map; + uchar buffer[(default_width+7)/8]; +public: + Bitmap() { init(); } + Bitmap(Bitmap& from) { *this=from; } + explicit Bitmap(uint prefix_to_set) { init(prefix_to_set); } + void init() { bitmap_init(&map, buffer, default_width, 0); } + void init(uint prefix_to_set) { init(); set_prefix(prefix_to_set); } + uint length() const { return default_width; } + Bitmap& operator=(const Bitmap& map2) + { + init(); + memcpy(buffer, map2.buffer, sizeof(buffer)); + return *this; + } + void set_bit(uint n) { bitmap_set_bit(&map, n); } + void clear_bit(uint n) { bitmap_clear_bit(&map, n); } + void set_prefix(uint n) { bitmap_set_prefix(&map, n); } + void set_all() { bitmap_set_all(&map); } + void clear_all() { bitmap_clear_all(&map); } + void intersect(Bitmap& map2) { bitmap_intersect(&map, &map2.map); } + void intersect(ulonglong map2buff) + { + MY_BITMAP map2; + bitmap_init(&map2, (uchar *)&map2buff, sizeof(ulonglong)*8, 0); + bitmap_intersect(&map, &map2); + } + void subtract(Bitmap& map2) { bitmap_subtract(&map, &map2.map); } + void merge(Bitmap& map2) { bitmap_union(&map, &map2.map); } + my_bool is_set(uint n) const { return bitmap_is_set(&map, n); } + my_bool is_prefix(uint n) const { return bitmap_is_prefix(&map, n); } + my_bool is_clear_all() const { return bitmap_is_clear_all(&map); } + my_bool is_set_all() const { return bitmap_is_set_all(&map); } + my_bool is_subset(const Bitmap& map2) const { return bitmap_is_subset(&map, &map2.map); } + my_bool operator==(const Bitmap& map2) const { return bitmap_cmp(&map, &map2.map); } + char *print(char *buf) const + { + char *s=buf; int i; + for (i=sizeof(buffer)-1; i>=0 ; i--) + { + if ((*s=_dig_vec[buffer[i] >> 4]) != '0') + break; + if ((*s=_dig_vec[buffer[i] & 15]) != '0') + break; + } + for (s++, i-- ; i>=0 ; i--) + { + *s++=_dig_vec[buffer[i] >> 4]; + *s++=_dig_vec[buffer[i] & 15]; + } + *s=0; + return buf; + } + ulonglong to_ulonglong() const + { + if (sizeof(buffer) >= 8) + return uint8korr(buffer); + DBUG_ASSERT(sizeof(buffer) >= 4); + uint4korr(buffer); + } +}; + +template <> class Bitmap<64> +{ + ulonglong map; +public: + Bitmap<64>() { } + explicit Bitmap<64>(uint prefix_to_set) { set_prefix(prefix_to_set); } + void init() { } + void init(uint prefix_to_set) { set_prefix(prefix_to_set); } + uint length() const { return 64; } + void set_bit(uint n) { map|= ((ulonglong)1) << n; } + void clear_bit(uint n) { map&= ~(((ulonglong)1) << n); } + void set_prefix(uint n) + { + if (n >= length()) + set_all(); + else + map= (((ulonglong)1) << n)-1; + } + void set_all() { map=~(ulonglong)0; } + void clear_all() { map=(ulonglong)0; } + void intersect(Bitmap<64>& map2) { map&= map2.map; } + void intersect(ulonglong map2) { map&= map2; } + void subtract(Bitmap<64>& map2) { map&= ~map2.map; } + void merge(Bitmap<64>& map2) { map|= map2.map; } + my_bool is_set(uint n) const { return test(map & (((ulonglong)1) << n)); } + my_bool is_prefix(uint n) const { return map == (((ulonglong)1) << n)-1; } + my_bool is_clear_all() const { return map == (ulonglong)0; } + my_bool is_set_all() const { return map == ~(ulonglong)0; } + my_bool is_subset(const Bitmap<64>& map2) const { return !(map & ~map2.map); } + my_bool operator==(const Bitmap<64>& map2) const { return map == map2.map; } + char *print(char *buf) const { longlong2str(map,buf,16); return buf; } + ulonglong to_ulonglong() const { return map; } +}; + |