mirror of
https://github.com/MariaDB/server.git
synced 2025-01-18 21:12:26 +01:00
343644dd5d
Added support for key_block_size to MyISAM. Simplify interface to 'new Key' to make it easier to add new key options. mysqld option --new is used to define where key options are printed. (In 5.3 we should move all key options to after key part definition to avoid problem with reserved names) Fixed some compiler warnings and a memory leak in ssl
108 lines
3.4 KiB
C
108 lines
3.4 KiB
C
/* 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; either version 2 of the License, or
|
|
(at your option) any later version.
|
|
|
|
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 */
|
|
|
|
/* Some useful bit functions */
|
|
|
|
#include "mysys_priv.h"
|
|
|
|
/*
|
|
Find smallest X in 2^X >= value
|
|
This can be used to divide a number with value by doing a shift instead
|
|
*/
|
|
|
|
uint my_bit_log2(ulong value)
|
|
{
|
|
uint bit;
|
|
for (bit=0 ; value > 1 ; value>>=1, bit++) ;
|
|
return bit;
|
|
}
|
|
|
|
static char nbits[256] = {
|
|
0, 1, 1, 2, 1, 2, 2, 3, 1, 2, 2, 3, 2, 3, 3, 4,
|
|
1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5,
|
|
1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5,
|
|
2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6,
|
|
1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5,
|
|
2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6,
|
|
2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6,
|
|
3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7,
|
|
1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5,
|
|
2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6,
|
|
2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6,
|
|
3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7,
|
|
2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6,
|
|
3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7,
|
|
3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7,
|
|
4, 5, 5, 6, 5, 6, 6, 7, 5, 6, 6, 7, 6, 7, 7, 8,
|
|
};
|
|
|
|
uint my_count_bits(ulonglong v)
|
|
{
|
|
#if SIZEOF_LONG_LONG > 4
|
|
/* The following code is a bit faster on 16 bit machines than if we would
|
|
only shift v */
|
|
ulong v2=(ulong) (v >> 32);
|
|
return (uint) (uchar) (nbits[(uchar) v] +
|
|
nbits[(uchar) (v >> 8)] +
|
|
nbits[(uchar) (v >> 16)] +
|
|
nbits[(uchar) (v >> 24)] +
|
|
nbits[(uchar) (v2)] +
|
|
nbits[(uchar) (v2 >> 8)] +
|
|
nbits[(uchar) (v2 >> 16)] +
|
|
nbits[(uchar) (v2 >> 24)]);
|
|
#else
|
|
return (uint) (uchar) (nbits[(uchar) v] +
|
|
nbits[(uchar) (v >> 8)] +
|
|
nbits[(uchar) (v >> 16)] +
|
|
nbits[(uchar) (v >> 24)]);
|
|
#endif
|
|
}
|
|
|
|
uint my_count_bits_ushort(ushort v)
|
|
{
|
|
return nbits[v];
|
|
}
|
|
|
|
|
|
/*
|
|
Next highest power of two
|
|
|
|
SYNOPSIS
|
|
my_round_up_to_next_power()
|
|
v Value to check
|
|
|
|
RETURN
|
|
Next or equal power of 2
|
|
Note: 0 will return 0
|
|
|
|
NOTES
|
|
Algorithm by Sean Anderson, according to:
|
|
http://graphics.stanford.edu/~seander/bithacks.html
|
|
(Orignal code public domain)
|
|
|
|
Comments shows how this works with 01100000000000000000000000001011
|
|
*/
|
|
|
|
uint32 my_round_up_to_next_power(uint32 v)
|
|
{
|
|
v--; /* 01100000000000000000000000001010 */
|
|
v|= v >> 1; /* 01110000000000000000000000001111 */
|
|
v|= v >> 2; /* 01111100000000000000000000001111 */
|
|
v|= v >> 4; /* 01111111110000000000000000001111 */
|
|
v|= v >> 8; /* 01111111111111111100000000001111 */
|
|
v|= v >> 16; /* 01111111111111111111111111111111 */
|
|
return v+1; /* 10000000000000000000000000000000 */
|
|
}
|