path: root/mysys/my_bitmap.c

/* Copyright (C) 2000 MySQL AB, 2008-2009 Sun Microsystems, Inc

   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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */

/*
  Handling of uchar arrays as large bitmaps.

  API limitations (or, rather asserted safety assumptions,
  to encourage correct programming)

    * the internal size is a set of 32 bit words
    * the number of bits specified in creation can be any number > 0
    * there are THREAD safe versions of most calls called bitmap_lock_*

  TODO:
  Make assembler THREAD safe versions of these using test-and-set instructions

  Original version created by Sergei Golubchik 2001 - 2004.
  New version written and test program added and some changes to the interface
  was made by Mikael Ronström 2005, with assistance of Tomas Ulin and Mats
  Kindahl.
*/

#include "mysys_priv.h"
#include <my_bitmap.h>
#include <m_string.h>
#include <my_bit.h>

void create_last_word_mask(MY_BITMAP *map)
{
  /* Get the number of used bits (1..8) in the last byte */
  unsigned int const used= 1U + ((map->n_bits-1U) & 0x7U);

  /*
    Create a mask with the upper 'unused' bits set and the lower 'used'
    bits clear. The bits within each byte is stored in big-endian order.
   */
  unsigned char const mask= (~((1 << used) - 1)) & 255;

  /*
    The first bytes are to be set to zero since they represent real  bits
    in the bitvector. The last bytes are set to 0xFF since they  represent
    bytes not used by the bitvector. Finally the last byte contains  bits
    as set by the mask above.
  */
  unsigned char *ptr= (unsigned char*)&map->last_word_mask;

  map->last_word_ptr= map->bitmap + no_words_in_map(map)-1;
  switch (no_bytes_in_map(map) & 3) {
  case 1:
    map->last_word_mask= ~0U;
    ptr[0]= mask;
    return;
  case 2:
    map->last_word_mask= ~0U;
    ptr[0]= 0;
    ptr[1]= mask;
    return;
  case 3:
    map->last_word_mask= 0U;
    ptr[2]= mask;
    ptr[3]= 0xFFU;
    return;
  case 0:
    map->last_word_mask= 0U;
    ptr[3]= mask;
    return;
  }
}


static inline void bitmap_lock(MY_BITMAP *map __attribute__((unused)))
{
  if (map->mutex)
    mysql_mutex_lock(map->mutex);
}

static inline void bitmap_unlock(MY_BITMAP *map __attribute__((unused)))
{
  if (map->mutex)
    mysql_mutex_unlock(map->mutex);
}


my_bool bitmap_init(MY_BITMAP *map, my_bitmap_map *buf, uint n_bits,
		    my_bool thread_safe __attribute__((unused)))
{
  DBUG_ENTER("bitmap_init");
  if (!buf)
  {
    uint size_in_bytes= bitmap_buffer_size(n_bits);
    uint extra= 0;

    if (thread_safe)
    {
      size_in_bytes= ALIGN_SIZE(size_in_bytes);
      extra= sizeof(mysql_mutex_t);
    }
    map->mutex= 0;

    if (!(buf= (my_bitmap_map*) my_malloc(size_in_bytes+extra, MYF(MY_WME))))
      DBUG_RETURN(1);

    if (thread_safe)
    {
      map->mutex= (mysql_mutex_t *) ((char*) buf + size_in_bytes);
      mysql_mutex_init(key_BITMAP_mutex, map->mutex, MY_MUTEX_INIT_FAST);
    }

  }

  else
  {
    DBUG_ASSERT(thread_safe == 0);
  }


  map->bitmap= buf;
  map->n_bits= n_bits;
  create_last_word_mask(map);
  bitmap_clear_all(map);
  DBUG_RETURN(0);
}


void bitmap_free(MY_BITMAP *map)
{
  DBUG_ENTER("bitmap_free");
  if (map->bitmap)
  {
    if (map->mutex)
      mysql_mutex_destroy(map->mutex);

    my_free(map->bitmap);
    map->bitmap=0;
  }
  DBUG_VOID_RETURN;
}


/*
  test if bit already set and set it if it was not (thread unsafe method)

  SYNOPSIS
    bitmap_fast_test_and_set()
    MAP   bit map struct
    BIT   bit number

  RETURN
    0    bit was not set
    !=0  bit was set
*/

my_bool bitmap_fast_test_and_set(MY_BITMAP *map, uint bitmap_bit)
{
  uchar *value= ((uchar*) map->bitmap) + (bitmap_bit / 8);
  uchar bit= 1 << ((bitmap_bit) & 7);
  uchar res= (*value) & bit;
  *value|= bit;
  return res;
}


/*
  test if bit already set and set it if it was not (thread safe method)

  SYNOPSIS
    bitmap_fast_test_and_set()
    map          bit map struct
    bitmap_bit   bit number

  RETURN
    0    bit was not set
    !=0  bit was set
*/

my_bool bitmap_test_and_set(MY_BITMAP *map, uint bitmap_bit)
{
  my_bool res;
  DBUG_ASSERT(map->bitmap && bitmap_bit < map->n_bits);
  bitmap_lock(map);
  res= bitmap_fast_test_and_set(map, bitmap_bit);
  bitmap_unlock(map);
  return res;
}

/*
  test if bit already set and clear it if it was set(thread unsafe method)

  SYNOPSIS
    bitmap_fast_test_and_set()
    MAP   bit map struct
    BIT   bit number

  RETURN
    0    bit was not set
    !=0  bit was set
*/

my_bool bitmap_fast_test_and_clear(MY_BITMAP *map, uint bitmap_bit)
{
  uchar *byte= (uchar*) map->bitmap + (bitmap_bit / 8);
  uchar bit= 1 << ((bitmap_bit) & 7);
  uchar res= (*byte) & bit;
  *byte&= ~bit;
  return res;
}


my_bool bitmap_test_and_clear(MY_BITMAP *map, uint bitmap_bit)
{
  my_bool res;
  DBUG_ASSERT(map->bitmap && bitmap_bit < map->n_bits);
  bitmap_lock(map);
  res= bitmap_fast_test_and_clear(map, bitmap_bit);
  bitmap_unlock(map);
  return res;
}


uint bitmap_set_next(MY_BITMAP *map)
{
  uint bit_found;
  DBUG_ASSERT(map->bitmap);
  if ((bit_found= bitmap_get_first(map)) != MY_BIT_NONE)
    bitmap_set_bit(map, bit_found);
  return bit_found;
}


void bitmap_set_prefix(MY_BITMAP *map, uint prefix_size)
{
  uint prefix_bytes, prefix_bits, d;
  uchar *m= (uchar *)map->bitmap;

  DBUG_ASSERT(map->bitmap &&
	      (prefix_size <= map->n_bits || prefix_size == (uint) ~0));
  set_if_smaller(prefix_size, map->n_bits);
  if ((prefix_bytes= prefix_size / 8))
    memset(m, 0xff, prefix_bytes);
  m+= prefix_bytes;
  if ((prefix_bits= prefix_size & 7))
    *m++= (1 << prefix_bits)-1;
  if ((d= no_bytes_in_map(map)-prefix_bytes))
    bzero(m, d);
}


my_bool bitmap_is_prefix(const MY_BITMAP *map, uint prefix_size)
{
  uint prefix_bits= prefix_size & 0x7, res;
  uchar *m= (uchar*)map->bitmap;
  uchar *end_prefix= m+prefix_size/8;
  uchar *end;
  DBUG_ASSERT(m && prefix_size <= map->n_bits);
  end= m+no_bytes_in_map(map);

  while (m < end_prefix)
    if (*m++ != 0xff)
      return 0;

  *map->last_word_ptr&= ~map->last_word_mask; /*Clear bits*/
  res= 0;
  if (prefix_bits && *m++ != (1 << prefix_bits)-1)
    goto ret;

  while (m < end)
    if (*m++ != 0)
      goto ret;
  res= 1;
ret:
  return res; 
}


my_bool bitmap_is_set_all(const MY_BITMAP *map)
{
  my_bitmap_map *data_ptr= map->bitmap;
  my_bitmap_map *end= map->last_word_ptr;
  *map->last_word_ptr |= map->last_word_mask;
  for (; data_ptr <= end; data_ptr++)
    if (*data_ptr != 0xFFFFFFFF)
      return FALSE;
  return TRUE;
}


my_bool bitmap_is_clear_all(const MY_BITMAP *map)
{
  my_bitmap_map *data_ptr= map->bitmap;
  my_bitmap_map *end;
  if (*map->last_word_ptr & ~map->last_word_mask)
    return FALSE;
  end= map->last_word_ptr;
  for (; data_ptr < end; data_ptr++)
    if (*data_ptr)
      return FALSE;
  return TRUE;
}

/* Return TRUE if map1 is a subset of map2 */

my_bool bitmap_is_subset(const MY_BITMAP *map1, const MY_BITMAP *map2)
{
  my_bitmap_map *m1= map1->bitmap, *m2= map2->bitmap, *end;

  DBUG_ASSERT(map1->bitmap && map2->bitmap &&
              map1->n_bits==map2->n_bits);

  end= map1->last_word_ptr;
  *map1->last_word_ptr &= ~map1->last_word_mask;
  *map2->last_word_ptr &= ~map2->last_word_mask;
  while (m1 <= end)
  {
    if ((*m1++) & ~(*m2++))
      return 0;
  }
  return 1;
}

/* True if bitmaps has any common bits */

my_bool bitmap_is_overlapping(const MY_BITMAP *map1, const MY_BITMAP *map2)
{
  my_bitmap_map *m1= map1->bitmap, *m2= map2->bitmap, *end;

  DBUG_ASSERT(map1->bitmap && map2->bitmap &&
              map1->n_bits==map2->n_bits);

  end= map1->last_word_ptr;
  *map1->last_word_ptr &= ~map1->last_word_mask;
  *map2->last_word_ptr &= ~map2->last_word_mask;
  while (m1 <= end)
  {
    if ((*m1++) & (*m2++))
      return 1;
  }
  return 0;
}


void bitmap_intersect(MY_BITMAP *map, const MY_BITMAP *map2)
{
  my_bitmap_map *to= map->bitmap, *from= map2->bitmap, *end;
  uint len= no_words_in_map(map), len2 = no_words_in_map(map2);

  DBUG_ASSERT(map->bitmap && map2->bitmap);

  end= to+min(len,len2);
  *map2->last_word_ptr&= ~map2->last_word_mask; /*Clear last bits in map2*/
  while (to < end)
    *to++ &= *from++;

  if (len2 < len)
  {
    end+=len-len2;
    while (to < end)
      *to++=0;
  }
}


/*
  Set/clear all bits above a bit.

  SYNOPSIS
    bitmap_set_above()
    map                  RETURN The bitmap to change.
    from_byte                   The bitmap buffer byte offset to start with.
    use_bit                     The bit value (1/0) to use for all upper bits.

  NOTE
    You can only set/clear full bytes.
    The function is meant for the situation that you copy a smaller bitmap
    to a bigger bitmap. Bitmap lengths are always multiple of eigth (the
    size of a byte). Using 'from_byte' saves multiplication and division
    by eight during parameter passing.

  RETURN
    void
*/

void bitmap_set_above(MY_BITMAP *map, uint from_byte, uint use_bit)
{
  uchar use_byte= use_bit ? 0xff : 0;
  uchar *to= (uchar *)map->bitmap + from_byte;
  uchar *end= (uchar *)map->bitmap + (map->n_bits+7)/8;

  while (to < end)
    *to++= use_byte;
}


void bitmap_subtract(MY_BITMAP *map, const MY_BITMAP *map2)
{
  my_bitmap_map *to= map->bitmap, *from= map2->bitmap, *end;
  DBUG_ASSERT(map->bitmap && map2->bitmap &&
              map->n_bits==map2->n_bits);

  end= map->last_word_ptr;

  while (to <= end)
    *to++ &= ~(*from++);
}


void bitmap_union(MY_BITMAP *map, const MY_BITMAP *map2)
{
  my_bitmap_map *to= map->bitmap, *from= map2->bitmap, *end;

  DBUG_ASSERT(map->bitmap && map2->bitmap &&
              map->n_bits==map2->n_bits);
  end= map->last_word_ptr;

  while (to <= end)
    *to++ |= *from++;
}


void bitmap_xor(MY_BITMAP *map, const MY_BITMAP *map2)
{
  my_bitmap_map *to= map->bitmap, *from= map2->bitmap, *end= map->last_word_ptr;
  DBUG_ASSERT(map->bitmap && map2->bitmap &&
              map->n_bits==map2->n_bits);
  while (to <= end)
    *to++ ^= *from++;
}


void bitmap_invert(MY_BITMAP *map)
{
  my_bitmap_map *to= map->bitmap, *end;

  DBUG_ASSERT(map->bitmap);
  end= map->last_word_ptr;

  while (to <= end)
    *to++ ^= 0xFFFFFFFF;
}


uint bitmap_bits_set(const MY_BITMAP *map)
{  
  uchar *m= (uchar*)map->bitmap;
  uchar *end= m + no_bytes_in_map(map);
  uint res= 0;

  DBUG_ASSERT(map->bitmap);
  *map->last_word_ptr&= ~map->last_word_mask; /*Reset last bits to zero*/
  while (m < end)
    res+= my_count_bits_ushort(*m++);
  return res;
}


void bitmap_copy(MY_BITMAP *map, const MY_BITMAP *map2)
{
  my_bitmap_map *to= map->bitmap, *from= map2->bitmap, *end;

  DBUG_ASSERT(map->bitmap && map2->bitmap &&
              map->n_bits==map2->n_bits);
  end= map->last_word_ptr;
  while (to <= end)
    *to++ = *from++;
}


uint bitmap_get_first_set(const MY_BITMAP *map)
{
  uchar *byte_ptr;
  uint i,j,k;
  my_bitmap_map *data_ptr, *end= map->last_word_ptr;

  DBUG_ASSERT(map->bitmap);
  data_ptr= map->bitmap;
  *map->last_word_ptr &= ~map->last_word_mask;

  for (i=0; data_ptr <= end; data_ptr++, i++)
  {
    if (*data_ptr)
    {
      byte_ptr= (uchar*)data_ptr;
      for (j=0; ; j++, byte_ptr++)
      {
        if (*byte_ptr)
        {
          for (k=0; ; k++)
          {
            if (*byte_ptr & (1 << k))
              return (i*32) + (j*8) + k;
          }
        }
      }
    }
  }
  return MY_BIT_NONE;
}


uint bitmap_get_first(const MY_BITMAP *map)
{
  uchar *byte_ptr;
  uint i,j,k;
  my_bitmap_map *data_ptr, *end= map->last_word_ptr;

  DBUG_ASSERT(map->bitmap);
  data_ptr= map->bitmap;
  *map->last_word_ptr|= map->last_word_mask;

  for (i=0; data_ptr <= end; data_ptr++, i++)
  {
    if (*data_ptr != 0xFFFFFFFF)
    {
      byte_ptr= (uchar*)data_ptr;
      for (j=0; ; j++, byte_ptr++)
      {
        if (*byte_ptr != 0xFF)
        {
          for (k=0; ; k++)
          {
            if (!(*byte_ptr & (1 << k)))
              return (i*32) + (j*8) + k;
          }
        }
      }
    }
  }
  return MY_BIT_NONE;
}


uint bitmap_lock_set_next(MY_BITMAP *map)
{
  uint bit_found;
  bitmap_lock(map);
  bit_found= bitmap_set_next(map);
  bitmap_unlock(map);
  return bit_found;
}


void bitmap_lock_clear_bit(MY_BITMAP *map, uint bitmap_bit)
{
  bitmap_lock(map);
  DBUG_ASSERT(map->bitmap && bitmap_bit < map->n_bits);
  bitmap_clear_bit(map, bitmap_bit);
  bitmap_unlock(map);
}

#ifdef MAIN

uint get_rand_bit(uint bitsize)
{
  return (rand() % bitsize);
}

bool test_set_get_clear_bit(MY_BITMAP *map, uint bitsize)
{
  uint i, test_bit;
  uint no_loops= bitsize > 128 ? 128 : bitsize;
  for (i=0; i < no_loops; i++)
  {
    test_bit= get_rand_bit(bitsize);
    bitmap_set_bit(map, test_bit);
    if (!bitmap_is_set(map, test_bit))
      goto error1;
    bitmap_clear_bit(map, test_bit);
    if (bitmap_is_set(map, test_bit))
      goto error2;
  }
  return FALSE;
error1:
  printf("Error in set bit, bit %u, bitsize = %u", test_bit, bitsize);
  return TRUE;
error2:
  printf("Error in clear bit, bit %u, bitsize = %u", test_bit, bitsize);
  return TRUE;
}

bool test_flip_bit(MY_BITMAP *map, uint bitsize)
{
  uint i, test_bit;
  uint no_loops= bitsize > 128 ? 128 : bitsize;
  for (i=0; i < no_loops; i++)
  {
    test_bit= get_rand_bit(bitsize);
    bitmap_flip_bit(map, test_bit);
    if (!bitmap_is_set(map, test_bit))
      goto error1;
    bitmap_flip_bit(map, test_bit);
    if (bitmap_is_set(map, test_bit))
      goto error2;
  }
  return FALSE;
error1:
  printf("Error in flip bit 1, bit %u, bitsize = %u", test_bit, bitsize);
  return TRUE;
error2:
  printf("Error in flip bit 2, bit %u, bitsize = %u", test_bit, bitsize);
  return TRUE;
}

bool test_operators(MY_BITMAP *map __attribute__((unused)),
                    uint bitsize __attribute__((unused)))
{
  return FALSE;
}

bool test_get_all_bits(MY_BITMAP *map, uint bitsize)
{
  uint i;
  bitmap_set_all(map);
  if (!bitmap_is_set_all(map))
    goto error1;
  if (!bitmap_is_prefix(map, bitsize))
    goto error5;
  bitmap_clear_all(map);
  if (!bitmap_is_clear_all(map))
    goto error2;
  if (!bitmap_is_prefix(map, 0))
    goto error6;
  for (i=0; i<bitsize;i++)
    bitmap_set_bit(map, i);
  if (!bitmap_is_set_all(map))
    goto error3;
  for (i=0; i<bitsize;i++)
    bitmap_clear_bit(map, i);
  if (!bitmap_is_clear_all(map))
    goto error4;
  return FALSE;
error1:
  printf("Error in set_all, bitsize = %u", bitsize);
  return TRUE;
error2:
  printf("Error in clear_all, bitsize = %u", bitsize);
  return TRUE;
error3:
  printf("Error in bitmap_is_set_all, bitsize = %u", bitsize);
  return TRUE;
error4:
  printf("Error in bitmap_is_clear_all, bitsize = %u", bitsize);
  return TRUE;
error5:
  printf("Error in set_all through set_prefix, bitsize = %u", bitsize);
  return TRUE;
error6:
  printf("Error in clear_all through set_prefix, bitsize = %u", bitsize);
  return TRUE;
}

bool test_compare_operators(MY_BITMAP *map, uint bitsize)
{
  uint i, j, test_bit1, test_bit2, test_bit3,test_bit4;
  uint no_loops= bitsize > 128 ? 128 : bitsize;
  MY_BITMAP map2_obj, map3_obj;
  MY_BITMAP *map2= &map2_obj, *map3= &map3_obj;
  my_bitmap_map map2buf[1024];
  my_bitmap_map map3buf[1024];
  bitmap_init(&map2_obj, map2buf, bitsize, FALSE);
  bitmap_init(&map3_obj, map3buf, bitsize, FALSE);
  bitmap_clear_all(map2);
  bitmap_clear_all(map3);
  for (i=0; i < no_loops; i++)
  {
    test_bit1=get_rand_bit(bitsize);
    bitmap_set_prefix(map, test_bit1);
    test_bit2=get_rand_bit(bitsize);
    bitmap_set_prefix(map2, test_bit2);
    bitmap_intersect(map, map2);
    test_bit3= test_bit2 < test_bit1 ? test_bit2 : test_bit1;
    bitmap_set_prefix(map3, test_bit3);
    if (!bitmap_cmp(map, map3))
      goto error1;
    bitmap_clear_all(map);
    bitmap_clear_all(map2);
    bitmap_clear_all(map3);
    test_bit1=get_rand_bit(bitsize);
    test_bit2=get_rand_bit(bitsize);
    test_bit3=get_rand_bit(bitsize);
    bitmap_set_prefix(map, test_bit1);
    bitmap_set_prefix(map2, test_bit2);
    test_bit3= test_bit2 > test_bit1 ? test_bit2 : test_bit1;
    bitmap_set_prefix(map3, test_bit3);
    bitmap_union(map, map2);
    if (!bitmap_cmp(map, map3))
      goto error2;
    bitmap_clear_all(map);
    bitmap_clear_all(map2);
    bitmap_clear_all(map3);
    test_bit1=get_rand_bit(bitsize);
    test_bit2=get_rand_bit(bitsize);
    test_bit3=get_rand_bit(bitsize);
    bitmap_set_prefix(map, test_bit1);
    bitmap_set_prefix(map2, test_bit2);
    bitmap_xor(map, map2);
    test_bit3= test_bit2 > test_bit1 ? test_bit2 : test_bit1;
    test_bit4= test_bit2 < test_bit1 ? test_bit2 : test_bit1;
    bitmap_set_prefix(map3, test_bit3);
    for (j=0; j < test_bit4; j++)
      bitmap_clear_bit(map3, j);
    if (!bitmap_cmp(map, map3))
      goto error3;
    bitmap_clear_all(map);
    bitmap_clear_all(map2);
    bitmap_clear_all(map3);
    test_bit1=get_rand_bit(bitsize);
    test_bit2=get_rand_bit(bitsize);
    test_bit3=get_rand_bit(bitsize);
    bitmap_set_prefix(map, test_bit1);
    bitmap_set_prefix(map2, test_bit2);
    bitmap_subtract(map, map2);
    if (test_bit2 < test_bit1)
    {
      bitmap_set_prefix(map3, test_bit1);
      for (j=0; j < test_bit2; j++)
        bitmap_clear_bit(map3, j);
    }
    if (!bitmap_cmp(map, map3))
      goto error4;
    bitmap_clear_all(map);
    bitmap_clear_all(map2);
    bitmap_clear_all(map3);
    test_bit1=get_rand_bit(bitsize);
    bitmap_set_prefix(map, test_bit1);
    bitmap_invert(map);
    bitmap_set_all(map3);
    for (j=0; j < test_bit1; j++)
      bitmap_clear_bit(map3, j);
    if (!bitmap_cmp(map, map3))
      goto error5;
    bitmap_clear_all(map);
    bitmap_clear_all(map3);
  }
  return FALSE;
error1:
  printf("intersect error  bitsize=%u,size1=%u,size2=%u", bitsize,
  test_bit1,test_bit2);
  return TRUE;
error2:
  printf("union error  bitsize=%u,size1=%u,size2=%u", bitsize,
  test_bit1,test_bit2);
  return TRUE;
error3:
  printf("xor error  bitsize=%u,size1=%u,size2=%u", bitsize,
  test_bit1,test_bit2);
  return TRUE;
error4:
  printf("subtract error  bitsize=%u,size1=%u,size2=%u", bitsize,
  test_bit1,test_bit2);
  return TRUE;
error5:
  printf("invert error  bitsize=%u,size=%u", bitsize,
  test_bit1);
  return TRUE;
}

bool test_count_bits_set(MY_BITMAP *map, uint bitsize)
{
  uint i, bit_count=0, test_bit;
  uint no_loops= bitsize > 128 ? 128 : bitsize;
  for (i=0; i < no_loops; i++)
  {
    test_bit=get_rand_bit(bitsize);
    if (!bitmap_is_set(map, test_bit))
    {
      bitmap_set_bit(map, test_bit);
      bit_count++;
    }
  }
  if (bit_count==0 && bitsize > 0)
    goto error1;
  if (bitmap_bits_set(map) != bit_count)
    goto error2;
  return FALSE;
error1:
  printf("No bits set  bitsize = %u", bitsize);
  return TRUE;
error2:
  printf("Wrong count of bits set, bitsize = %u", bitsize);
  return TRUE;
}

bool test_get_first_bit(MY_BITMAP *map, uint bitsize)
{
  uint i, test_bit;
  uint no_loops= bitsize > 128 ? 128 : bitsize;
  for (i=0; i < no_loops; i++)
  {
    test_bit=get_rand_bit(bitsize);
    bitmap_set_bit(map, test_bit);
    if (bitmap_get_first_set(map) != test_bit)
      goto error1;
    bitmap_set_all(map);
    bitmap_clear_bit(map, test_bit);
    if (bitmap_get_first(map) != test_bit)
      goto error2;
    bitmap_clear_all(map);
  }
  return FALSE;
error1:
  printf("get_first_set error bitsize=%u,prefix_size=%u",bitsize,test_bit);
  return TRUE;
error2:
  printf("get_first error bitsize= %u, prefix_size= %u",bitsize,test_bit);
  return TRUE;
}

bool test_get_next_bit(MY_BITMAP *map, uint bitsize)
{
  uint i, j, test_bit;
  uint no_loops= bitsize > 128 ? 128 : bitsize;
  for (i=0; i < no_loops; i++)
  {
    test_bit=get_rand_bit(bitsize);
    for (j=0; j < test_bit; j++)
      bitmap_set_next(map);
    if (!bitmap_is_prefix(map, test_bit))
      goto error1;
    bitmap_clear_all(map);
  }
  return FALSE;
error1:
  printf("get_next error  bitsize= %u, prefix_size= %u", bitsize,test_bit);
  return TRUE;
}

bool test_prefix(MY_BITMAP *map, uint bitsize)
{
  uint i, j, test_bit;
  uint no_loops= bitsize > 128 ? 128 : bitsize;
  for (i=0; i < no_loops; i++)
  {
    test_bit=get_rand_bit(bitsize);
    bitmap_set_prefix(map, test_bit);
    if (!bitmap_is_prefix(map, test_bit))
      goto error1;
    bitmap_clear_all(map);
    for (j=0; j < test_bit; j++)
      bitmap_set_bit(map, j);
    if (!bitmap_is_prefix(map, test_bit))
      goto error2;
    bitmap_set_all(map);
    for (j=bitsize - 1; ~(j-test_bit); j--)
      bitmap_clear_bit(map, j);
    if (!bitmap_is_prefix(map, test_bit))
      goto error3;
    bitmap_clear_all(map);
  }
  return FALSE;
error1:
  printf("prefix1 error  bitsize = %u, prefix_size = %u", bitsize,test_bit);
  return TRUE;
error2:
  printf("prefix2 error  bitsize = %u, prefix_size = %u", bitsize,test_bit);
  return TRUE;
error3:
  printf("prefix3 error  bitsize = %u, prefix_size = %u", bitsize,test_bit);
  return TRUE;
}


bool do_test(uint bitsize)
{
  MY_BITMAP map;
  my_bitmap_map buf[1024];
  if (bitmap_init(&map, buf, bitsize, FALSE))
  {
    printf("init error for bitsize %d", bitsize);
    goto error;
  }
  if (test_set_get_clear_bit(&map,bitsize))
    goto error;
  bitmap_clear_all(&map);
  if (test_flip_bit(&map,bitsize))
    goto error;
  bitmap_clear_all(&map);
  if (test_operators(&map,bitsize))
    goto error;
  bitmap_clear_all(&map);
  if (test_get_all_bits(&map, bitsize))
    goto error;
  bitmap_clear_all(&map);
  if (test_compare_operators(&map,bitsize))
    goto error;
  bitmap_clear_all(&map);
  if (test_count_bits_set(&map,bitsize))
    goto error;
  bitmap_clear_all(&map);
  if (test_get_first_bit(&map,bitsize))
    goto error;
  bitmap_clear_all(&map);
  if (test_get_next_bit(&map,bitsize))
    goto error;
  if (test_prefix(&map,bitsize))
    goto error;
  return FALSE;
error:
  printf("\n");
  return TRUE;
}

int main()
{
  int i;
  for (i= 1; i < 4096; i++)
  {
    printf("Start test for bitsize=%u\n",i);
    if (do_test(i))
      return -1;
  }
  printf("OK\n");
  return 0;
}

/*
  In directory mysys:
  make test_bitmap
  will build the bitmap tests and ./test_bitmap will execute it
*/

#endif