~drizzle-trunk/drizzle/development

/* Copyright (C) 2000 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; 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 unsigned char 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

  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 <mysys/my_bitmap.h>

#include <mystrings/m_string.h>

#include <mysys/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= UINT32_MAX;

    ptr[0]= mask;

    return;

  case 2:

    map->last_word_mask= UINT32_MAX;

    ptr[0]= 0;

    ptr[1]= mask;

    return;

  case 3:

    map->last_word_mask= 0;

    ptr[2]= mask;

    ptr[3]= 0xFFU;

    return;

  case 0:

    map->last_word_mask= 0U;

    ptr[3]= mask;

    return;

  }

}

bool bitmap_init(MY_BITMAP *map, my_bitmap_map *buf, uint32_t n_bits)

{

  if (!buf)

  {

    uint32_t size_in_bytes= bitmap_buffer_size(n_bits);

    size_in_bytes= ALIGN_SIZE(size_in_bytes);

    if (!(buf= (my_bitmap_map*) malloc(size_in_bytes)))

      return(1);

  }

  map->bitmap= buf;

  map->n_bits= n_bits;

  create_last_word_mask(map);

  bitmap_clear_all(map);

  return(0);

}

void bitmap_free(MY_BITMAP *map)

{

  if (map->bitmap)

  {

    free((char*) map->bitmap);

    map->bitmap=0;

  }

  return;

}

/*

  test if bit already set and set it if it was not

  SYNOPSIS

    bitmap_test_and_set()

    MAP   bit map struct

    BIT   bit number

  RETURN

    0    bit was not set

    !=0  bit was set

*/

bool bitmap_test_and_set(MY_BITMAP *map, uint32_t bitmap_bit)

{

  unsigned char *value= ((unsigned char*) map->bitmap) + (bitmap_bit / 8);

  unsigned char bit= 1 << ((bitmap_bit) & 7);

  unsigned char res= (*value) & bit;

  *value|= bit;

  return res;

}

/*

  test if bit already set and clear it if it was set

  SYNOPSIS

    bitmap_test_and_set()

    MAP   bit map struct

    BIT   bit number

  RETURN

    0    bit was not set

    !=0  bit was set

*/

bool bitmap_test_and_clear(MY_BITMAP *map, uint32_t bitmap_bit)

{

  unsigned char *byte= (unsigned char*) map->bitmap + (bitmap_bit / 8);

  unsigned char bit= 1 << ((bitmap_bit) & 7);

  unsigned char res= (*byte) & bit;

  *byte&= ~bit;

  return res;

}

uint32_t bitmap_set_next(MY_BITMAP *map)

{

  uint32_t bit_found;

  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, uint32_t prefix_size)

{

  uint32_t prefix_bytes, prefix_bits, d;

  unsigned char *m= (unsigned char *)map->bitmap;

  assert(map->bitmap &&

	      (prefix_size <= map->n_bits || prefix_size == UINT32_MAX));

  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))

    memset(m, 0, d);

}

bool bitmap_is_prefix(const MY_BITMAP *map, uint32_t prefix_size)

{

  uint32_t prefix_bits= prefix_size & 0x7, res;

  unsigned char *m= (unsigned char*)map->bitmap;

  unsigned char *end_prefix= m+prefix_size/8;

  unsigned char *end;

  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;

}

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;

}

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 */

bool bitmap_is_subset(const MY_BITMAP *map1, const MY_BITMAP *map2)

{

  my_bitmap_map *m1= map1->bitmap, *m2= map2->bitmap, *end;

  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 */

bool bitmap_is_overlapping(const MY_BITMAP *map1, const MY_BITMAP *map2)

{

  my_bitmap_map *m1= map1->bitmap, *m2= map2->bitmap, *end;

  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;

  uint32_t len= no_words_in_map(map), len2 = no_words_in_map(map2);

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

  end= to+cmin(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, uint32_t from_byte, uint32_t use_bit)

{

  unsigned char use_byte= use_bit ? 0xff : 0;

  unsigned char *to= (unsigned char *)map->bitmap + from_byte;

  unsigned char *end= (unsigned char *)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;

  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;

  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;

  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;

  assert(map->bitmap);

  end= map->last_word_ptr;

  while (to <= end)

    *to++ ^= 0xFFFFFFFF;

}

uint32_t bitmap_bits_set(const MY_BITMAP *map)

{

  unsigned char *m= (unsigned char*)map->bitmap;

  unsigned char *end= m + no_bytes_in_map(map);

  uint32_t res= 0;

  assert(map->bitmap);

  *map->last_word_ptr&= ~map->last_word_mask; /*Reset last bits to zero*/

  while (m < end)

    res+= my_count_bits_uint16(*m++);

  return res;

}

void bitmap_copy(MY_BITMAP *map, const MY_BITMAP *map2)

{

  my_bitmap_map *to= map->bitmap, *from= map2->bitmap, *end;

  assert(map->bitmap && map2->bitmap &&

              map->n_bits==map2->n_bits);

  end= map->last_word_ptr;

  while (to <= end)

    *to++ = *from++;

}

uint32_t bitmap_get_first_set(const MY_BITMAP *map)

{

  unsigned char *byte_ptr;

  uint32_t i,j,k;

  my_bitmap_map *data_ptr, *end= map->last_word_ptr;

  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= (unsigned char*)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;

}

uint32_t bitmap_get_first(const MY_BITMAP *map)

{

  unsigned char *byte_ptr;

  uint32_t i,j,k;

  my_bitmap_map *data_ptr, *end= map->last_word_ptr;

  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= (unsigned char*)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;

}

#ifdef MAIN

uint32_t get_rand_bit(uint32_t bitsize)

{

  return (rand() % bitsize);

}

bool test_set_get_clear_bit(MY_BITMAP *map, uint32_t bitsize)

{

  uint32_t i, test_bit;

  uint32_t 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, uint32_t bitsize)

{

  uint32_t i, test_bit;

  uint32_t 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 *, uint32_t)

{

  return false;

}

bool test_get_all_bits(MY_BITMAP *map, uint32_t bitsize)

{

  uint32_t 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, uint32_t bitsize)

{

  uint32_t i, j, test_bit1, test_bit2, test_bit3,test_bit4;

  uint32_t 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);

  bitmap_init(&map3_obj, map3buf, bitsize);

  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, uint32_t bitsize)

{

  uint32_t i, bit_count=0, test_bit;

  uint32_t 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, uint32_t bitsize)

{

  uint32_t i, test_bit;

  uint32_t 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, uint32_t bitsize)

{

  uint32_t i, j, test_bit;

  uint32_t 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, uint32_t bitsize)

{

  uint32_t i, j, test_bit;