my_bitmap.h

/* Copyright (c) 2001, 2011, Oracle and/or its affiliates.
   Copyright (c) 2009, 2020, MariaDB Corporation.

   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; version 2 of the License.

   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., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1335  USA */

#ifndef _my_bitmap_h_
#define _my_bitmap_h_

#define MY_BIT_NONE (~(uint) 0)

#include <m_string.h>
#include <my_pthread.h>

typedef ulonglong my_bitmap_map;

typedef struct st_bitmap
{
  my_bitmap_map *bitmap;
  my_bitmap_map *last_word_ptr;
  my_bitmap_map last_bit_mask;
  uint32	n_bits; /* number of bits occupied by the above */
  my_bool       bitmap_allocated;
} MY_BITMAP;

#ifdef	__cplusplus
extern "C" {
#endif

/* Reset memory. Faster then doing a full bzero */
#define my_bitmap_clear(A) ((A)->bitmap= 0)

extern void create_last_bit_mask(MY_BITMAP *map);
extern my_bool my_bitmap_init(MY_BITMAP *map, my_bitmap_map *buf, uint n_bits);
extern my_bool bitmap_is_clear_all(const MY_BITMAP *map);
extern my_bool bitmap_is_prefix(const MY_BITMAP *map, uint prefix_size);
extern my_bool bitmap_is_set_all(const MY_BITMAP *map);
extern my_bool bitmap_is_subset(const MY_BITMAP *map1, const MY_BITMAP *map2);
extern my_bool bitmap_is_overlapping(const MY_BITMAP *map1,
                                     const MY_BITMAP *map2);
extern my_bool bitmap_test_and_set(MY_BITMAP *map, uint bitmap_bit);
extern my_bool bitmap_test_and_clear(MY_BITMAP *map, uint bitmap_bit);
extern my_bool bitmap_fast_test_and_set(MY_BITMAP *map, uint bitmap_bit);
extern my_bool bitmap_fast_test_and_clear(MY_BITMAP *map, uint bitmap_bit);
extern my_bool bitmap_union_is_set_all(const MY_BITMAP *map1,
                                       const MY_BITMAP *map2);
extern my_bool bitmap_exists_intersection(MY_BITMAP **bitmap_array,
                                          uint bitmap_count,
                                          uint start_bit, uint end_bit);

extern uint bitmap_set_next(MY_BITMAP *map);
extern uint bitmap_get_first_clear(const MY_BITMAP *map);
extern uint bitmap_get_first_set(const MY_BITMAP *map);
extern uint bitmap_bits_set(const MY_BITMAP *map);
extern uint bitmap_get_next_set(const MY_BITMAP *map, uint bitmap_bit);
extern void my_bitmap_free(MY_BITMAP *map);
extern void bitmap_set_above(MY_BITMAP *map, uint from_byte, uint use_bit);
extern void bitmap_set_prefix(MY_BITMAP *map, uint prefix_size);
extern void bitmap_intersect(MY_BITMAP *map, const MY_BITMAP *map2);
extern void bitmap_subtract(MY_BITMAP *map, const MY_BITMAP *map2);
extern void bitmap_union(MY_BITMAP *map, const MY_BITMAP *map2);
extern void bitmap_xor(MY_BITMAP *map, const MY_BITMAP *map2);
extern void bitmap_invert(MY_BITMAP *map);
extern void bitmap_copy(MY_BITMAP *map, const MY_BITMAP *map2);
/* Functions to export/import bitmaps to an architecture independent format */
extern void bitmap_export(uchar *to, MY_BITMAP *map);
extern void bitmap_import(MY_BITMAP *map, uchar *from);

#define my_bitmap_map_bytes sizeof(my_bitmap_map)
#define my_bitmap_map_bits  (my_bitmap_map_bytes*8)
/* Size in bytes to store 'bits' number of bits */
#define bitmap_buffer_size(bits) (MY_ALIGN((bits), my_bitmap_map_bits)/8)
#define my_bitmap_buffer_size(map) bitmap_buffer_size((map)->n_bits)
#define no_bytes_in_export_map(map) (((map)->n_bits + 7)/8)
#define no_words_in_map(map) (((map)->n_bits + (my_bitmap_map_bits-1))/my_bitmap_map_bits)

/* Fast, not thread safe, bitmap functions */
/* The following functions must be compatible with create_last_bit_mask()! */
static inline void
bitmap_set_bit(MY_BITMAP *map,uint bit)
{
  DBUG_ASSERT(bit < map->n_bits);
  map->bitmap[bit/my_bitmap_map_bits]|=
    (1ULL << (bit & (my_bitmap_map_bits-1)));
}
static inline void
bitmap_flip_bit(MY_BITMAP *map,uint bit)
{
  DBUG_ASSERT(bit < map->n_bits);
  map->bitmap[bit/my_bitmap_map_bits]^=
    (1ULL << (bit & (my_bitmap_map_bits-1)));
}
static inline void
bitmap_clear_bit(MY_BITMAP *map,uint bit)
{
  DBUG_ASSERT(bit < map->n_bits);
  map->bitmap[bit/my_bitmap_map_bits]&=
    ~(1ULL << (bit & (my_bitmap_map_bits-1)));
}
static inline uint
bitmap_is_set(const MY_BITMAP *map,uint bit)
{
  DBUG_ASSERT(bit < map->n_bits);
  return (!!(map->bitmap[bit/my_bitmap_map_bits] &
             (1ULL << (bit & (my_bitmap_map_bits-1)))));
}

/* Return true if bitmaps are equal */
static inline my_bool bitmap_cmp(const MY_BITMAP *map1, const MY_BITMAP *map2)
{
  DBUG_ASSERT(map1->n_bits == map2->n_bits);
  return (memcmp(map1->bitmap, map2->bitmap,
                 my_bitmap_buffer_size(map1)) == 0);
}

#define bitmap_clear_all(MAP) \
  { memset((MAP)->bitmap, 0, my_bitmap_buffer_size(MAP)); }

static inline void
bitmap_set_all(const MY_BITMAP *map)
{
  if (map->n_bits)
  {
    memset(map->bitmap, 0xFF, my_bitmap_map_bytes * (no_words_in_map(map)-1));
    DBUG_ASSERT(map->bitmap + no_words_in_map(map)-1 == map->last_word_ptr);
    *map->last_word_ptr= ~map->last_bit_mask;
  }
}

#ifdef	__cplusplus
}
#endif

#endif /* _my_bitmap_h_ */