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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.
42 lines
1.2 KiB
C++
42 lines
1.2 KiB
C++
/* -*- c-basic-offset: 2 -*- */
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/*
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Copyright(C) 2017 Kouhei Sutou <kou@clear-code.com>
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This library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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This library 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 GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with this library; 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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*/
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#include "mrn_smart_bitmap.hpp"
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namespace mrn {
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SmartBitmap::SmartBitmap(MY_BITMAP *bitmap)
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: bitmap_(bitmap) {
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}
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SmartBitmap::~SmartBitmap() {
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if (bitmap_) {
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my_bitmap_free(bitmap_);
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}
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}
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MY_BITMAP *SmartBitmap::get() {
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return bitmap_;
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}
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MY_BITMAP *SmartBitmap::release() {
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MY_BITMAP *bitmap = bitmap_;
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bitmap_ = NULL;
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return bitmap;
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}
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}
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