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b5d65fc105
MDEV-33502 Slowdown when running nested statement with many partitions This change was triggered to help some MariaDB users with close to 10000 bits in their bitmaps. - Change underlaying storage to be 64 bit instead of 32bit. - This reduses number of loops to scan bitmaps. - This can cause some bitmaps to be 4 byte large. - Ensure that all not used top-bits are always 0 (simplifes code as the last 64 bit storage is not a special case anymore). - Use my_find_first_bit() to find the first set bit which is much faster than scanning trough things byte by byte and then bit by bit. Other things: - Added a bool to remember if my_bitmap_init() did allocate the bitmap array. my_bitmap_free() will only free arrays it did allocate. This allowed me to remove setting 'bitmap=0' before calling my_bitmap_free() for cases where the bitmap's where allocated externally. - my_bitmap_init() sets bitmap to 0 in case of failure. - Added 'universal' asserts to most bitmap functions. - Change all remaining calls to bitmap_init() to my_bitmap_init(). - To finish the change from 2014. - Changed all usage of uint32 in my_bitmap.h to my_bitmap_map. - Updated bitmap_copy() to handle bitmaps of different size. - Removed const from bitmap_exists_intersection() as this caused casts on all usage. - Removed not used function bitmap_set_above(). - Renamed create_last_word_mask() to create_last_bit_mask() (to match name changes in my_bitmap.cc) - Extended bitmap-t with test for more bitmap functions.
150 lines
5.4 KiB
C
150 lines
5.4 KiB
C
/* Copyright (c) 2001, 2011, Oracle and/or its affiliates.
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Copyright (c) 2009, 2020, MariaDB Corporation.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; version 2 of the License.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1335 USA */
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#ifndef _my_bitmap_h_
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#define _my_bitmap_h_
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#define MY_BIT_NONE (~(uint) 0)
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#include <m_string.h>
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#include <my_pthread.h>
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typedef ulonglong my_bitmap_map;
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typedef struct st_bitmap
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{
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my_bitmap_map *bitmap;
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my_bitmap_map *last_word_ptr;
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/*
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mutex will be acquired for the duration of each bitmap operation if
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thread_safe flag in bitmap_init was set. Otherwise, we optimize by not
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acquiring the mutex
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*/
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mysql_mutex_t *mutex;
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my_bitmap_map last_bit_mask;
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uint32 n_bits; /* number of bits occupied by the above */
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my_bool bitmap_allocated;
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} MY_BITMAP;
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#ifdef __cplusplus
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extern "C" {
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#endif
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/* Reset memory. Faster then doing a full bzero */
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#define my_bitmap_clear(A) ((A)->bitmap= 0)
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extern void create_last_bit_mask(MY_BITMAP *map);
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extern my_bool my_bitmap_init(MY_BITMAP *map, my_bitmap_map *buf, uint n_bits,
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my_bool thread_safe);
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extern my_bool bitmap_is_clear_all(const MY_BITMAP *map);
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extern my_bool bitmap_is_prefix(const MY_BITMAP *map, uint prefix_size);
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extern my_bool bitmap_is_set_all(const MY_BITMAP *map);
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extern my_bool bitmap_is_subset(const MY_BITMAP *map1, const MY_BITMAP *map2);
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extern my_bool bitmap_is_overlapping(const MY_BITMAP *map1,
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const MY_BITMAP *map2);
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extern my_bool bitmap_test_and_set(MY_BITMAP *map, uint bitmap_bit);
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extern my_bool bitmap_test_and_clear(MY_BITMAP *map, uint bitmap_bit);
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extern my_bool bitmap_fast_test_and_set(MY_BITMAP *map, uint bitmap_bit);
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extern my_bool bitmap_fast_test_and_clear(MY_BITMAP *map, uint bitmap_bit);
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extern my_bool bitmap_union_is_set_all(const MY_BITMAP *map1,
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const MY_BITMAP *map2);
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extern my_bool bitmap_exists_intersection(MY_BITMAP **bitmap_array,
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uint bitmap_count,
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uint start_bit, uint end_bit);
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extern uint bitmap_set_next(MY_BITMAP *map);
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extern uint bitmap_get_first_clear(const MY_BITMAP *map);
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extern uint bitmap_get_first_set(const MY_BITMAP *map);
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extern uint bitmap_bits_set(const MY_BITMAP *map);
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extern uint bitmap_get_next_set(const MY_BITMAP *map, uint bitmap_bit);
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extern void my_bitmap_free(MY_BITMAP *map);
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extern void bitmap_set_above(MY_BITMAP *map, uint from_byte, uint use_bit);
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extern void bitmap_set_prefix(MY_BITMAP *map, uint prefix_size);
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extern void bitmap_intersect(MY_BITMAP *map, const MY_BITMAP *map2);
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extern void bitmap_subtract(MY_BITMAP *map, const MY_BITMAP *map2);
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extern void bitmap_union(MY_BITMAP *map, const MY_BITMAP *map2);
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extern void bitmap_xor(MY_BITMAP *map, const MY_BITMAP *map2);
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extern void bitmap_invert(MY_BITMAP *map);
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extern void bitmap_copy(MY_BITMAP *map, const MY_BITMAP *map2);
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extern uint bitmap_lock_set_next(MY_BITMAP *map);
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extern void bitmap_lock_clear_bit(MY_BITMAP *map, uint bitmap_bit);
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#define my_bitmap_map_bytes sizeof(my_bitmap_map)
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#define my_bitmap_map_bits (my_bitmap_map_bytes*8)
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#define bitmap_buffer_size(bits) (MY_ALIGN(bits, my_bitmap_map_bits)*my_bitmap_map_bytes)
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#define no_bytes_in_map(map) (((map)->n_bits + 7)/8)
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#define no_words_in_map(map) (((map)->n_bits + (my_bitmap_map_bits-1))/my_bitmap_map_bits)
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#define bytes_word_aligned(bytes) (8*((bytes + 7)/8))
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/* Fast, not thread safe, bitmap functions */
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/* The following functions must be compatible with create_last_bit_mask()! */
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static inline void
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bitmap_set_bit(MY_BITMAP *map,uint bit)
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{
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uchar *b= (uchar*) map->bitmap + bit / 8;
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DBUG_ASSERT(bit < map->n_bits);
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*b= (uchar) (*b | 1U << (bit & 7));
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}
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static inline void
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bitmap_flip_bit(MY_BITMAP *map,uint bit)
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{
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uchar *b= (uchar*) map->bitmap + bit / 8;
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DBUG_ASSERT(bit < map->n_bits);
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*b= (uchar) (*b ^ 1U << (bit & 7));
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}
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static inline void
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bitmap_clear_bit(MY_BITMAP *map,uint bit)
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{
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uchar *b= (uchar*) map->bitmap + bit / 8;
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DBUG_ASSERT(bit < map->n_bits);
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*b= (uchar) (*b & ~(1U << (bit & 7)));
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}
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static inline uint
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bitmap_is_set(const MY_BITMAP *map,uint bit)
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{
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const uchar *b= (const uchar*) map->bitmap + bit / 8;
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DBUG_ASSERT(bit < map->n_bits);
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return !!(*b & (1U << (bit & 7)));
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}
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/* Return true if bitmaps are equal */
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static inline my_bool bitmap_cmp(const MY_BITMAP *map1, const MY_BITMAP *map2)
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{
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DBUG_ASSERT(map1->n_bits == map2->n_bits);
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return (memcmp(map1->bitmap, map2->bitmap, 8*(no_words_in_map(map1))) == 0);
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}
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#define bitmap_clear_all(MAP) \
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{ memset((MAP)->bitmap, 0, 8*no_words_in_map((MAP))); }
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static inline void
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bitmap_set_all(const MY_BITMAP *map)
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{
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if (map->n_bits)
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{
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memset(map->bitmap, 0xFF, 8*(no_words_in_map(map)-1));
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DBUG_ASSERT(map->bitmap + no_words_in_map(map)-1 == map->last_word_ptr);
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*map->last_word_ptr= ~map->last_bit_mask;
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}
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}
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#ifdef __cplusplus
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}
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#endif
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#endif /* _my_bitmap_h_ */
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