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mariadb/mysys/my_handler.c
monty@mysql.com 67ce247965 Add support for up to VARCHAR (size up to 65535) 
Renamed HA_VAR_LENGTH to HA_VAR_LENGTH_PART
Renamed in all files FIELD_TYPE_STRING and FIELD_TYPE_VAR_STRING to MYSQL_TYPE_STRING and MYSQL_TYPE_VAR_STRING to make it easy to catch all possible errors
Added support for VARCHAR KEYS to heap
Removed support for ISAM
Now only long VARCHAR columns are changed to TEXT on demand (not CHAR)
Internal temporary files can now use fixed length tables if the used VARCHAR columns are short
2004-12-06 02:00:37 +02:00

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/* Copyright (C) 2000 MySQL AB & MySQL Finland AB & TCX DataKonsult AB
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public
License as published by the Free Software Foundation; either
version 2 of the License, or (at your option) any later version.
This library 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
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with this library; if not, write to the Free
Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
MA 02111-1307, USA */
#include "my_handler.h"
int mi_compare_text(CHARSET_INFO *charset_info, uchar *a, uint a_length,
uchar *b, uint b_length, my_bool part_key,
my_bool skip_end_space)
{
if (!part_key)
return charset_info->coll->strnncollsp(charset_info, a, a_length,
b, b_length, !skip_end_space);
return charset_info->coll->strnncoll(charset_info, a, a_length,
b, b_length, part_key);
}
static int compare_bin(uchar *a, uint a_length, uchar *b, uint b_length,
my_bool part_key, my_bool skip_end_space)
{
uint length= min(a_length,b_length);
uchar *end= a+ length;
int flag;
while (a < end)
if ((flag= (int) *a++ - (int) *b++))
return flag;
if (part_key && b_length < a_length)
return 0;
if (skip_end_space && a_length != b_length)
{
int swap= 0;
/*
We are using space compression. We have to check if longer key
has next character < ' ', in which case it's less than the shorter
key that has an implicite space afterwards.
This code is identical to the one in
strings/ctype-simple.c:my_strnncollsp_simple
*/
if (a_length < b_length)
{
/* put shorter key in a */
a_length= b_length;
a= b;
swap= -1; /* swap sign of result */
}
for (end= a + a_length-length; a < end ; a++)
{
if (*a != ' ')
return ((int) *a - (int) ' ') ^ swap;
}
return 0;
}
return (int) (a_length-b_length);
}
/*
Compare two keys
SYNOPSIS
ha_key_cmp()
keyseg Key segments of key to compare
a First key to compare, in format from _mi_pack_key()
This is normally key specified by user
b Second key to compare. This is always from a row
key_length Length of key to compare. This can be shorter than
a to just compare sub keys
next_flag How keys should be compared
If bit SEARCH_FIND is not set the keys includes the row
position and this should also be compared
NOTES
Number-keys can't be splited
RETURN VALUES
<0 If a < b
0 If a == b
>0 If a > b
*/
#define FCMP(A,B) ((int) (A) - (int) (B))
int ha_key_cmp(register HA_KEYSEG *keyseg, register uchar *a,
register uchar *b, uint key_length, uint nextflag,
uint *diff_pos)
{
int flag;
int16 s_1,s_2;
int32 l_1,l_2;
uint32 u_1,u_2;
float f_1,f_2;
double d_1,d_2;
uint next_key_length;
*diff_pos=0;
for ( ; (int) key_length >0 ; key_length=next_key_length, keyseg++)
{
uchar *end;
uint piks=! (keyseg->flag & HA_NO_SORT);
(*diff_pos)++;
/* Handle NULL part */
if (keyseg->null_bit)
{
key_length--;
if (*a != *b && piks)
{
flag = (int) *a - (int) *b;
return ((keyseg->flag & HA_REVERSE_SORT) ? -flag : flag);
}
b++;
if (!*a++) /* If key was NULL */
{
if (nextflag == (SEARCH_FIND | SEARCH_UPDATE))
nextflag=SEARCH_SAME; /* Allow duplicate keys */
else if (nextflag & SEARCH_NULL_ARE_NOT_EQUAL)
{
/*
This is only used from mi_check() to calculate cardinality.
It can't be used when searching for a key as this would cause
compare of (a,b) and (b,a) to return the same value.
*/
return -1;
}
next_key_length=key_length;
continue; /* To next key part */
}
}
end= a+ min(keyseg->length,key_length);
next_key_length=key_length-keyseg->length;
switch ((enum ha_base_keytype) keyseg->type) {
case HA_KEYTYPE_TEXT: /* Ascii; Key is converted */
if (keyseg->flag & HA_SPACE_PACK)
{
int a_length,b_length,pack_length;
get_key_length(a_length,a);
get_key_pack_length(b_length,pack_length,b);
next_key_length=key_length-b_length-pack_length;
if (piks &&
(flag=mi_compare_text(keyseg->charset,a,a_length,b,b_length,
(my_bool) ((nextflag & SEARCH_PREFIX) &&
next_key_length <= 0),
(my_bool)!(nextflag & SEARCH_PREFIX))))
return ((keyseg->flag & HA_REVERSE_SORT) ? -flag : flag);
a+=a_length;
b+=b_length;
break;
}
else
{
uint length=(uint) (end-a), a_length=length, b_length=length;
if (piks &&
(flag= mi_compare_text(keyseg->charset, a, a_length, b, b_length,
(my_bool) ((nextflag & SEARCH_PREFIX) &&
next_key_length <= 0),
(my_bool)!(nextflag & SEARCH_PREFIX))))
return ((keyseg->flag & HA_REVERSE_SORT) ? -flag : flag);
a=end;
b+=length;
}
break;
case HA_KEYTYPE_BINARY:
if (keyseg->flag & HA_SPACE_PACK)
{
int a_length,b_length,pack_length;
get_key_length(a_length,a);
get_key_pack_length(b_length,pack_length,b);
next_key_length=key_length-b_length-pack_length;
if (piks &&
(flag=compare_bin(a,a_length,b,b_length,
(my_bool) ((nextflag & SEARCH_PREFIX) &&
next_key_length <= 0),1)))
return ((keyseg->flag & HA_REVERSE_SORT) ? -flag : flag);
a+=a_length;
b+=b_length;
break;
}
else
{
uint length=keyseg->length;
if (piks &&
(flag=compare_bin(a,length,b,length,
(my_bool) ((nextflag & SEARCH_PREFIX) &&
next_key_length <= 0),0)))
return ((keyseg->flag & HA_REVERSE_SORT) ? -flag : flag);
a+=length;
b+=length;
}
break;
case HA_KEYTYPE_VARTEXT:
{
int a_length,b_length,pack_length;
get_key_length(a_length,a);
get_key_pack_length(b_length,pack_length,b);
next_key_length=key_length-b_length-pack_length;
if (piks &&
(flag= mi_compare_text(keyseg->charset,a,a_length,b,b_length,
(my_bool) ((nextflag & SEARCH_PREFIX) &&
next_key_length <= 0),
(my_bool) ((nextflag & (SEARCH_FIND |
SEARCH_UPDATE)) ==
SEARCH_FIND &&
! (keyseg->flag &
HA_END_SPACE_ARE_EQUAL)))))
return ((keyseg->flag & HA_REVERSE_SORT) ? -flag : flag);
a+= a_length;
b+= b_length;
break;
}
break;
case HA_KEYTYPE_VARBINARY:
{
int a_length,b_length,pack_length;
get_key_length(a_length,a);
get_key_pack_length(b_length,pack_length,b);
next_key_length=key_length-b_length-pack_length;
if (piks &&
(flag=compare_bin(a,a_length,b,b_length,
(my_bool) ((nextflag & SEARCH_PREFIX) &&
next_key_length <= 0), 0)))
return ((keyseg->flag & HA_REVERSE_SORT) ? -flag : flag);
a+=a_length;
b+=b_length;
break;
}
break;
case HA_KEYTYPE_INT8:
{
int i_1= (int) *((signed char*) a);
int i_2= (int) *((signed char*) b);
if (piks && (flag = CMP_NUM(i_1,i_2)))
return ((keyseg->flag & HA_REVERSE_SORT) ? -flag : flag);
a= end;
b++;
break;
}
case HA_KEYTYPE_SHORT_INT:
s_1= mi_sint2korr(a);
s_2= mi_sint2korr(b);
if (piks && (flag = CMP_NUM(s_1,s_2)))
return ((keyseg->flag & HA_REVERSE_SORT) ? -flag : flag);
a= end;
b+= 2; /* sizeof(short int); */
break;
case HA_KEYTYPE_USHORT_INT:
{
uint16 us_1,us_2;
us_1= mi_sint2korr(a);
us_2= mi_sint2korr(b);
if (piks && (flag = CMP_NUM(us_1,us_2)))
return ((keyseg->flag & HA_REVERSE_SORT) ? -flag : flag);
a= end;
b+=2; /* sizeof(short int); */
break;
}
case HA_KEYTYPE_LONG_INT:
l_1= mi_sint4korr(a);
l_2= mi_sint4korr(b);
if (piks && (flag = CMP_NUM(l_1,l_2)))
return ((keyseg->flag & HA_REVERSE_SORT) ? -flag : flag);
a= end;
b+= 4; /* sizeof(long int); */
break;
case HA_KEYTYPE_ULONG_INT:
u_1= mi_sint4korr(a);
u_2= mi_sint4korr(b);
if (piks && (flag = CMP_NUM(u_1,u_2)))
return ((keyseg->flag & HA_REVERSE_SORT) ? -flag : flag);
a= end;
b+= 4; /* sizeof(long int); */
break;
case HA_KEYTYPE_INT24:
l_1=mi_sint3korr(a);
l_2=mi_sint3korr(b);
if (piks && (flag = CMP_NUM(l_1,l_2)))
return ((keyseg->flag & HA_REVERSE_SORT) ? -flag : flag);
a= end;
b+= 3;
break;
case HA_KEYTYPE_UINT24:
l_1=mi_uint3korr(a);
l_2=mi_uint3korr(b);
if (piks && (flag = CMP_NUM(l_1,l_2)))
return ((keyseg->flag & HA_REVERSE_SORT) ? -flag : flag);
a= end;
b+= 3;
break;
case HA_KEYTYPE_FLOAT:
mi_float4get(f_1,a);
mi_float4get(f_2,b);
/*
The following may give a compiler warning about floating point
comparison not being safe, but this is ok in this context as
we are bascily doing sorting
*/
if (piks && (flag = CMP_NUM(f_1,f_2)))
return ((keyseg->flag & HA_REVERSE_SORT) ? -flag : flag);
a= end;
b+= 4; /* sizeof(float); */
break;
case HA_KEYTYPE_DOUBLE:
mi_float8get(d_1,a);
mi_float8get(d_2,b);
/*
The following may give a compiler warning about floating point
comparison not being safe, but this is ok in this context as
we are bascily doing sorting
*/
if (piks && (flag = CMP_NUM(d_1,d_2)))
return ((keyseg->flag & HA_REVERSE_SORT) ? -flag : flag);
a= end;
b+= 8; /* sizeof(double); */
break;
case HA_KEYTYPE_NUM: /* Numeric key */
{
int swap_flag= 0;
int alength,blength;
if (keyseg->flag & HA_REVERSE_SORT)
{
swap_variables(uchar*, a, b);
swap_flag=1; /* Remember swap of a & b */
end= a+ (int) (end-b);
}
if (keyseg->flag & HA_SPACE_PACK)
{
alength= *a++; blength= *b++;
end=a+alength;
next_key_length=key_length-blength-1;
}
else
{
alength= (int) (end-a);
blength=keyseg->length;
/* remove pre space from keys */
for ( ; alength && *a == ' ' ; a++, alength--) ;
for ( ; blength && *b == ' ' ; b++, blength--) ;
}
if (piks)
{
if (*a == '-')
{
if (*b != '-')
return -1;
a++; b++;
swap_variables(uchar*, a, b);
swap_variables(int, alength, blength);
swap_flag=1-swap_flag;
alength--; blength--;
end=a+alength;
}
else if (*b == '-')
return 1;
while (alength && (*a == '+' || *a == '0'))
{
a++; alength--;
}
while (blength && (*b == '+' || *b == '0'))
{
b++; blength--;
}
if (alength != blength)
return (alength < blength) ? -1 : 1;
while (a < end)
if (*a++ != *b++)
return ((int) a[-1] - (int) b[-1]);
}
else
{
b+=(end-a);
a=end;
}
if (swap_flag) /* Restore pointers */
swap_variables(uchar*, a, b);
break;
}
#ifdef HAVE_LONG_LONG
case HA_KEYTYPE_LONGLONG:
{
longlong ll_a,ll_b;
ll_a= mi_sint8korr(a);
ll_b= mi_sint8korr(b);
if (piks && (flag = CMP_NUM(ll_a,ll_b)))
return ((keyseg->flag & HA_REVERSE_SORT) ? -flag : flag);
a= end;
b+= 8;
break;
}
case HA_KEYTYPE_ULONGLONG:
{
ulonglong ll_a,ll_b;
ll_a= mi_uint8korr(a);
ll_b= mi_uint8korr(b);
if (piks && (flag = CMP_NUM(ll_a,ll_b)))
return ((keyseg->flag & HA_REVERSE_SORT) ? -flag : flag);
a= end;
b+= 8;
break;
}
#endif
case HA_KEYTYPE_END: /* Ready */
goto end; /* diff_pos is incremented */
}
}
(*diff_pos)++;
end:
if (!(nextflag & SEARCH_FIND))
{
uint i;
if (nextflag & (SEARCH_NO_FIND | SEARCH_LAST)) /* Find record after key */
return (nextflag & (SEARCH_BIGGER | SEARCH_LAST)) ? -1 : 1;
flag=0;
for (i=keyseg->length ; i-- > 0 ; )
{
if (*a++ != *b++)
{
flag= FCMP(a[-1],b[-1]);
break;
}
}
if (nextflag & SEARCH_SAME)
return (flag); /* read same */
if (nextflag & SEARCH_BIGGER)
return (flag <= 0 ? -1 : 1); /* read next */
return (flag < 0 ? -1 : 1); /* read previous */
}
return 0;
} /* ha_key_cmp */
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