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mariadb/sql/sql_string.cc
Alexey Kopytov 12f364ece7 Backport of WL #2934: Make/find library for doing float/double 
to string conversions and vice versa" 
Initial import of the dtoa.c code and custom wrappers around it 
to allow its usage from the server code. 
 
Conversion of FLOAT/DOUBLE values to DECIMAL ones or strings 
and vice versa has been significantly reworked. As the new 
algoritms are more precise than the older ones, results of such 
conversions may not always match those obtained from older 
server versions. This in turn may break compatibility for some 
applications. 
 
This patch also fixes the following bugs: 
- bug #12860 "Difference in zero padding of exponent between 
Unix and Windows" 
- bug #21497 "DOUBLE truncated to unusable value" 
- bug #26788 "mysqld (debug) aborts when inserting specific 
numbers into char fields" 
- bug #24541 "Data truncated..." on decimal type columns 
without any good reason"
2009-12-22 19:23:13 +03:00

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/* 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 */
/* This file is originally from the mysql distribution. Coded by monty */
#ifdef USE_PRAGMA_IMPLEMENTATION
#pragma implementation // gcc: Class implementation
#endif
#include <my_global.h>
#include <my_sys.h>
#include <m_string.h>
#include <m_ctype.h>
#include <mysql_com.h>
/*
The following extern declarations are ok as these are interface functions
required by the string function
*/
extern uchar* sql_alloc(unsigned size);
extern void sql_element_free(void *ptr);
#include "sql_string.h"
/*****************************************************************************
** String functions
*****************************************************************************/
bool String::real_alloc(uint32 arg_length)
{
arg_length=ALIGN_SIZE(arg_length+1);
str_length=0;
if (Alloced_length < arg_length)
{
free();
if (!(Ptr=(char*) my_malloc(arg_length,MYF(MY_WME))))
return TRUE;
Alloced_length=arg_length;
alloced=1;
}
Ptr[0]=0;
return FALSE;
}
/*
** Check that string is big enough. Set string[alloc_length] to 0
** (for C functions)
*/
bool String::realloc(uint32 alloc_length)
{
uint32 len=ALIGN_SIZE(alloc_length+1);
if (Alloced_length < len)
{
char *new_ptr;
if (alloced)
{
if (!(new_ptr= (char*) my_realloc(Ptr,len,MYF(MY_WME))))
return TRUE; // Signal error
}
else if ((new_ptr= (char*) my_malloc(len,MYF(MY_WME))))
{
if (str_length > len - 1)
str_length= 0;
if (str_length) // Avoid bugs in memcpy on AIX
memcpy(new_ptr,Ptr,str_length);
new_ptr[str_length]=0;
alloced=1;
}
else
return TRUE; // Signal error
Ptr= new_ptr;
Alloced_length= len;
}
Ptr[alloc_length]=0; // This make other funcs shorter
return FALSE;
}
bool String::set_int(longlong num, bool unsigned_flag, CHARSET_INFO *cs)
{
uint l=20*cs->mbmaxlen+1;
int base= unsigned_flag ? 10 : -10;
if (alloc(l))
return TRUE;
str_length=(uint32) (cs->cset->longlong10_to_str)(cs,Ptr,l,base,num);
str_charset=cs;
return FALSE;
}
bool String::set_real(double num,uint decimals, CHARSET_INFO *cs)
{
char buff[FLOATING_POINT_BUFFER];
uint dummy_errors;
size_t len;
str_charset=cs;
if (decimals >= NOT_FIXED_DEC)
{
len= my_gcvt(num, MY_GCVT_ARG_DOUBLE, sizeof(buff) - 1, buff, NULL);
return copy(buff, len, &my_charset_latin1, cs, &dummy_errors);
}
len= my_fcvt(num, decimals, buff, NULL);
return copy(buff, (uint32) len, &my_charset_latin1, cs,
&dummy_errors);
}
bool String::copy()
{
if (!alloced)
{
Alloced_length=0; // Force realloc
return realloc(str_length);
}
return FALSE;
}
bool String::copy(const String &str)
{
if (alloc(str.str_length))
return TRUE;
str_length=str.str_length;
bmove(Ptr,str.Ptr,str_length); // May be overlapping
Ptr[str_length]=0;
str_charset=str.str_charset;
return FALSE;
}
bool String::copy(const char *str,uint32 arg_length, CHARSET_INFO *cs)
{
if (alloc(arg_length))
return TRUE;
if ((str_length=arg_length))
memcpy(Ptr,str,arg_length);
Ptr[arg_length]=0;
str_charset=cs;
return FALSE;
}
/*
Checks that the source string can be just copied to the destination string
without conversion.
SYNPOSIS
needs_conversion()
arg_length Length of string to copy.
from_cs Character set to copy from
to_cs Character set to copy to
uint32 *offset Returns number of unaligned characters.
RETURN
0 No conversion needed
1 Either character set conversion or adding leading zeros
(e.g. for UCS-2) must be done
NOTE
to_cs may be NULL for "no conversion" if the system variable
character_set_results is NULL.
*/
bool String::needs_conversion(uint32 arg_length,
CHARSET_INFO *from_cs,
CHARSET_INFO *to_cs,
uint32 *offset)
{
*offset= 0;
if (!to_cs ||
(to_cs == &my_charset_bin) ||
(to_cs == from_cs) ||
my_charset_same(from_cs, to_cs) ||
((from_cs == &my_charset_bin) &&
(!(*offset=(arg_length % to_cs->mbminlen)))))
return FALSE;
return TRUE;
}
/*
Copy a multi-byte character sets with adding leading zeros.
SYNOPSIS
copy_aligned()
str String to copy
arg_length Length of string. This should NOT be dividable with
cs->mbminlen.
offset arg_length % cs->mb_minlength
cs Character set for 'str'
NOTES
For real multi-byte, ascii incompatible charactser sets,
like UCS-2, add leading zeros if we have an incomplete character.
Thus,
SELECT _ucs2 0xAA
will automatically be converted into
SELECT _ucs2 0x00AA
RETURN
0 ok
1 error
*/
bool String::copy_aligned(const char *str,uint32 arg_length, uint32 offset,
CHARSET_INFO *cs)
{
/* How many bytes are in incomplete character */
offset= cs->mbmaxlen - offset; /* How many zeros we should prepend */
DBUG_ASSERT(offset && offset != cs->mbmaxlen);
uint32 aligned_length= arg_length + offset;
if (alloc(aligned_length))
return TRUE;
/*
Note, this is only safe for big-endian UCS-2.
If we add little-endian UCS-2 sometimes, this code
will be more complicated. But it's OK for now.
*/
bzero((char*) Ptr, offset);
memcpy(Ptr + offset, str, arg_length);
Ptr[aligned_length]=0;
/* str_length is always >= 0 as arg_length is != 0 */
str_length= aligned_length;
str_charset= cs;
return FALSE;
}
bool String::set_or_copy_aligned(const char *str,uint32 arg_length,
CHARSET_INFO *cs)
{
/* How many bytes are in incomplete character */
uint32 offset= (arg_length % cs->mbminlen);
if (!offset) /* All characters are complete, just copy */
{
set(str, arg_length, cs);
return FALSE;
}
return copy_aligned(str, arg_length, offset, cs);
}
/**
Copies the character data into this String, with optional character set
conversion.
@return
FALSE ok
TRUE Could not allocate result buffer
*/
bool String::copy(const char *str, uint32 arg_length,
CHARSET_INFO *from_cs, CHARSET_INFO *to_cs, uint *errors)
{
uint32 offset;
DBUG_ASSERT(!str || str != Ptr);
if (!needs_conversion(arg_length, from_cs, to_cs, &offset))
{
*errors= 0;
return copy(str, arg_length, to_cs);
}
if ((from_cs == &my_charset_bin) && offset)
{
*errors= 0;
return copy_aligned(str, arg_length, offset, to_cs);
}
uint32 new_length= to_cs->mbmaxlen*arg_length;
if (alloc(new_length))
return TRUE;
str_length=copy_and_convert((char*) Ptr, new_length, to_cs,
str, arg_length, from_cs, errors);
str_charset=to_cs;
return FALSE;
}
/*
Set a string to the value of a latin1-string, keeping the original charset
SYNOPSIS
copy_or_set()
str String of a simple charset (latin1)
arg_length Length of string
IMPLEMENTATION
If string object is of a simple character set, set it to point to the
given string.
If not, make a copy and convert it to the new character set.
RETURN
0 ok
1 Could not allocate result buffer
*/
bool String::set_ascii(const char *str, uint32 arg_length)
{
if (str_charset->mbminlen == 1)
{
set(str, arg_length, str_charset);
return 0;
}
uint dummy_errors;
return copy(str, arg_length, &my_charset_latin1, str_charset, &dummy_errors);
}
/* This is used by mysql.cc */
bool String::fill(uint32 max_length,char fill_char)
{
if (str_length > max_length)
Ptr[str_length=max_length]=0;
else
{
if (realloc(max_length))
return TRUE;
bfill(Ptr+str_length,max_length-str_length,fill_char);
str_length=max_length;
}
return FALSE;
}
void String::strip_sp()
{
while (str_length && my_isspace(str_charset,Ptr[str_length-1]))
str_length--;
}
bool String::append(const String &s)
{
if (s.length())
{
if (realloc(str_length+s.length()))
return TRUE;
memcpy(Ptr+str_length,s.ptr(),s.length());
str_length+=s.length();
}
return FALSE;
}
/*
Append an ASCII string to the a string of the current character set
*/
bool String::append(const char *s,uint32 arg_length)
{
if (!arg_length)
return FALSE;
/*
For an ASCII incompatible string, e.g. UCS-2, we need to convert
*/
if (str_charset->mbminlen > 1)
{
uint32 add_length=arg_length * str_charset->mbmaxlen;
uint dummy_errors;
if (realloc(str_length+ add_length))
return TRUE;
str_length+= copy_and_convert(Ptr+str_length, add_length, str_charset,
s, arg_length, &my_charset_latin1,
&dummy_errors);
return FALSE;
}
/*
For an ASCII compatinble string we can just append.
*/
if (realloc(str_length+arg_length))
return TRUE;
memcpy(Ptr+str_length,s,arg_length);
str_length+=arg_length;
return FALSE;
}
/*
Append a 0-terminated ASCII string
*/
bool String::append(const char *s)
{
return append(s, (uint) strlen(s));
}
/*
Append a string in the given charset to the string
with character set recoding
*/
bool String::append(const char *s,uint32 arg_length, CHARSET_INFO *cs)
{
uint32 dummy_offset;
if (needs_conversion(arg_length, cs, str_charset, &dummy_offset))
{
uint32 add_length= arg_length / cs->mbminlen * str_charset->mbmaxlen;
uint dummy_errors;
if (realloc(str_length + add_length))
return TRUE;
str_length+= copy_and_convert(Ptr+str_length, add_length, str_charset,
s, arg_length, cs, &dummy_errors);
}
else
{
if (realloc(str_length + arg_length))
return TRUE;
memcpy(Ptr + str_length, s, arg_length);
str_length+= arg_length;
}
return FALSE;
}
bool String::append(IO_CACHE* file, uint32 arg_length)
{
if (realloc(str_length+arg_length))
return TRUE;
if (my_b_read(file, (uchar*) Ptr + str_length, arg_length))
{
shrink(str_length);
return TRUE;
}
str_length+=arg_length;
return FALSE;
}
bool String::append_with_prefill(const char *s,uint32 arg_length,
uint32 full_length, char fill_char)
{
int t_length= arg_length > full_length ? arg_length : full_length;
if (realloc(str_length + t_length))
return TRUE;
t_length= full_length - arg_length;
if (t_length > 0)
{
bfill(Ptr+str_length, t_length, fill_char);
str_length=str_length + t_length;
}
append(s, arg_length);
return FALSE;
}
uint32 String::numchars()
{
return str_charset->cset->numchars(str_charset, Ptr, Ptr+str_length);
}
int String::charpos(int i,uint32 offset)
{
if (i <= 0)
return i;
return str_charset->cset->charpos(str_charset,Ptr+offset,Ptr+str_length,i);
}
int String::strstr(const String &s,uint32 offset)
{
if (s.length()+offset <= str_length)
{
if (!s.length())
return ((int) offset); // Empty string is always found
register const char *str = Ptr+offset;
register const char *search=s.ptr();
const char *end=Ptr+str_length-s.length()+1;
const char *search_end=s.ptr()+s.length();
skip:
while (str != end)
{
if (*str++ == *search)
{
register char *i,*j;
i=(char*) str; j=(char*) search+1;
while (j != search_end)
if (*i++ != *j++) goto skip;
return (int) (str-Ptr) -1;
}
}
}
return -1;
}
/*
** Search string from end. Offset is offset to the end of string
*/
int String::strrstr(const String &s,uint32 offset)
{
if (s.length() <= offset && offset <= str_length)
{
if (!s.length())
return offset; // Empty string is always found
register const char *str = Ptr+offset-1;
register const char *search=s.ptr()+s.length()-1;
const char *end=Ptr+s.length()-2;
const char *search_end=s.ptr()-1;
skip:
while (str != end)
{
if (*str-- == *search)
{
register char *i,*j;
i=(char*) str; j=(char*) search-1;
while (j != search_end)
if (*i-- != *j--) goto skip;
return (int) (i-Ptr) +1;
}
}
}
return -1;
}
/*
Replace substring with string
If wrong parameter or not enough memory, do nothing
*/
bool String::replace(uint32 offset,uint32 arg_length,const String &to)
{
return replace(offset,arg_length,to.ptr(),to.length());
}
bool String::replace(uint32 offset,uint32 arg_length,
const char *to, uint32 to_length)
{
long diff = (long) to_length-(long) arg_length;
if (offset+arg_length <= str_length)
{
if (diff < 0)
{
if (to_length)
memcpy(Ptr+offset,to,to_length);
bmove(Ptr+offset+to_length,Ptr+offset+arg_length,
str_length-offset-arg_length);
}
else
{
if (diff)
{
if (realloc(str_length+(uint32) diff))
return TRUE;
bmove_upp((uchar*) Ptr+str_length+diff, (uchar*) Ptr+str_length,
str_length-offset-arg_length);
}
if (to_length)
memcpy(Ptr+offset,to,to_length);
}
str_length+=(uint32) diff;
}
return FALSE;
}
// added by Holyfoot for "geometry" needs
int String::reserve(uint32 space_needed, uint32 grow_by)
{
if (Alloced_length < str_length + space_needed)
{
if (realloc(Alloced_length + max(space_needed, grow_by) - 1))
return TRUE;
}
return FALSE;
}
void String::qs_append(const char *str, uint32 len)
{
memcpy(Ptr + str_length, str, len + 1);
str_length += len;
}
void String::qs_append(double d)
{
char *buff = Ptr + str_length;
str_length+= my_gcvt(d, MY_GCVT_ARG_DOUBLE, FLOATING_POINT_BUFFER - 1, buff,
NULL);
}
void String::qs_append(double *d)
{
double ld;
float8get(ld, (char*) d);
qs_append(ld);
}
void String::qs_append(int i)
{
char *buff= Ptr + str_length;
char *end= int10_to_str(i, buff, -10);
str_length+= (int) (end-buff);
}
void String::qs_append(uint i)
{
char *buff= Ptr + str_length;
char *end= int10_to_str(i, buff, 10);
str_length+= (int) (end-buff);
}
/*
Compare strings according to collation, without end space.
SYNOPSIS
sortcmp()
s First string
t Second string
cs Collation
NOTE:
Normally this is case sensitive comparison
RETURN
< 0 s < t
0 s == t
> 0 s > t
*/
int sortcmp(const String *s,const String *t, CHARSET_INFO *cs)
{
return cs->coll->strnncollsp(cs,
(uchar *) s->ptr(),s->length(),
(uchar *) t->ptr(),t->length(), 0);
}
/*
Compare strings byte by byte. End spaces are also compared.
SYNOPSIS
stringcmp()
s First string
t Second string
NOTE:
Strings are compared as a stream of uchars
RETURN
< 0 s < t
0 s == t
> 0 s > t
*/
int stringcmp(const String *s,const String *t)
{
uint32 s_len=s->length(),t_len=t->length(),len=min(s_len,t_len);
int cmp= memcmp(s->ptr(), t->ptr(), len);
return (cmp) ? cmp : (int) (s_len - t_len);
}
String *copy_if_not_alloced(String *to,String *from,uint32 from_length)
{
if (from->Alloced_length >= from_length)
return from;
if (from->alloced || !to || from == to)
{
(void) from->realloc(from_length);
return from;
}
if (to->realloc(from_length))
return from; // Actually an error
if ((to->str_length=min(from->str_length,from_length)))
memcpy(to->Ptr,from->Ptr,to->str_length);
to->str_charset=from->str_charset;
return to;
}
/****************************************************************************
Help functions
****************************************************************************/
/*
copy a string from one character set to another
SYNOPSIS
copy_and_convert()
to Store result here
to_cs Character set of result string
from Copy from here
from_length Length of from string
from_cs From character set
NOTES
'to' must be big enough as form_length * to_cs->mbmaxlen
RETURN
length of bytes copied to 'to'
*/
static uint32
copy_and_convert_extended(char *to, uint32 to_length, CHARSET_INFO *to_cs,
const char *from, uint32 from_length,
CHARSET_INFO *from_cs,
uint *errors)
{
int cnvres;
my_wc_t wc;
const uchar *from_end= (const uchar*) from+from_length;
char *to_start= to;
uchar *to_end= (uchar*) to+to_length;
my_charset_conv_mb_wc mb_wc= from_cs->cset->mb_wc;
my_charset_conv_wc_mb wc_mb= to_cs->cset->wc_mb;
uint error_count= 0;
while (1)
{
if ((cnvres= (*mb_wc)(from_cs, &wc, (uchar*) from,
from_end)) > 0)
from+= cnvres;
else if (cnvres == MY_CS_ILSEQ)
{
error_count++;
from++;
wc= '?';
}
else if (cnvres > MY_CS_TOOSMALL)
{
/*
A correct multibyte sequence detected
But it doesn't have Unicode mapping.
*/
error_count++;
from+= (-cnvres);
wc= '?';
}
else
break; // Not enough characters
outp:
if ((cnvres= (*wc_mb)(to_cs, wc, (uchar*) to, to_end)) > 0)
to+= cnvres;
else if (cnvres == MY_CS_ILUNI && wc != '?')
{
error_count++;
wc= '?';
goto outp;
}
else
break;
}
*errors= error_count;
return (uint32) (to - to_start);
}
/*
Optimized for quick copying of ASCII characters in the range 0x00..0x7F.
*/
uint32
copy_and_convert(char *to, uint32 to_length, CHARSET_INFO *to_cs,
const char *from, uint32 from_length, CHARSET_INFO *from_cs,
uint *errors)
{
/*
If any of the character sets is not ASCII compatible,
immediately switch to slow mb_wc->wc_mb method.
*/
if ((to_cs->state | from_cs->state) & MY_CS_NONASCII)
return copy_and_convert_extended(to, to_length, to_cs,
from, from_length, from_cs, errors);
uint32 length= min(to_length, from_length), length2= length;
#if defined(__i386__)
/*
Special loop for i386, it allows to refer to a
non-aligned memory block as UINT32, which makes
it possible to copy four bytes at once. This
gives about 10% performance improvement comparing
to byte-by-byte loop.
*/
for ( ; length >= 4; length-= 4, from+= 4, to+= 4)
{
if ((*(uint32*)from) & 0x80808080)
break;
*((uint32*) to)= *((const uint32*) from);
}
#endif
for (; ; *to++= *from++, length--)
{
if (!length)
{
*errors= 0;
return length2;
}
if (*((unsigned char*) from) > 0x7F) /* A non-ASCII character */
{
uint32 copied_length= length2 - length;
to_length-= copied_length;
from_length-= copied_length;
return copied_length + copy_and_convert_extended(to, to_length,
to_cs,
from, from_length,
from_cs,
errors);
}
}
DBUG_ASSERT(FALSE); // Should never get to here
return 0; // Make compiler happy
}
/**
Copy string with HEX-encoding of "bad" characters.
@details This functions copies the string pointed by "src"
to the string pointed by "dst". Not more than "srclen" bytes
are read from "src". Any sequences of bytes representing
a not-well-formed substring (according to cs) are hex-encoded,
and all well-formed substrings (according to cs) are copied as is.
Not more than "dstlen" bytes are written to "dst". The number
of bytes written to "dst" is returned.
@param cs character set pointer of the destination string
@param[out] dst destination string
@param dstlen size of dst
@param src source string
@param srclen length of src
@retval result length
*/
size_t
my_copy_with_hex_escaping(CHARSET_INFO *cs,
char *dst, size_t dstlen,
const char *src, size_t srclen)
{
const char *srcend= src + srclen;
char *dst0= dst;
for ( ; src < srcend ; )
{
size_t chlen;
if ((chlen= my_ismbchar(cs, src, srcend)))
{
if (dstlen < chlen)
break; /* purecov: inspected */
memcpy(dst, src, chlen);
src+= chlen;
dst+= chlen;
dstlen-= chlen;
}
else if (*src & 0x80)
{
if (dstlen < 4)
break; /* purecov: inspected */
*dst++= '\\';
*dst++= 'x';
*dst++= _dig_vec_upper[((unsigned char) *src) >> 4];
*dst++= _dig_vec_upper[((unsigned char) *src) & 15];
src++;
dstlen-= 4;
}
else
{
if (dstlen < 1)
break; /* purecov: inspected */
*dst++= *src++;
dstlen--;
}
}
return dst - dst0;
}
/*
copy a string,
with optional character set conversion,
with optional left padding (for binary -> UCS2 conversion)
SYNOPSIS
well_formed_copy_nchars()
to Store result here
to_length Maxinum length of "to" string
to_cs Character set of "to" string
from Copy from here
from_length Length of from string
from_cs From character set
nchars Copy not more that nchars characters
well_formed_error_pos Return position when "from" is not well formed
or NULL otherwise.
cannot_convert_error_pos Return position where a not convertable
character met, or NULL otherwise.
from_end_pos Return position where scanning of "from"
string stopped.
NOTES
RETURN
length of bytes copied to 'to'
*/
uint32
well_formed_copy_nchars(CHARSET_INFO *to_cs,
char *to, uint to_length,
CHARSET_INFO *from_cs,
const char *from, uint from_length,
uint nchars,
const char **well_formed_error_pos,
const char **cannot_convert_error_pos,
const char **from_end_pos)
{
uint res;
if ((to_cs == &my_charset_bin) ||
(from_cs == &my_charset_bin) ||
(to_cs == from_cs) ||
my_charset_same(from_cs, to_cs))
{
if (to_length < to_cs->mbminlen || !nchars)
{
*from_end_pos= from;
*cannot_convert_error_pos= NULL;
*well_formed_error_pos= NULL;
return 0;
}
if (to_cs == &my_charset_bin)
{
res= min(min(nchars, to_length), from_length);
memmove(to, from, res);
*from_end_pos= from + res;
*well_formed_error_pos= NULL;
*cannot_convert_error_pos= NULL;
}
else
{
int well_formed_error;
uint from_offset;
if ((from_offset= (from_length % to_cs->mbminlen)) &&
(from_cs == &my_charset_bin))
{
/*
Copying from BINARY to UCS2 needs to prepend zeros sometimes:
INSERT INTO t1 (ucs2_column) VALUES (0x01);
0x01 -> 0x0001
*/
uint pad_length= to_cs->mbminlen - from_offset;
bzero(to, pad_length);
memmove(to + pad_length, from, from_offset);
nchars--;
from+= from_offset;
from_length-= from_offset;
to+= to_cs->mbminlen;
to_length-= to_cs->mbminlen;
}
set_if_smaller(from_length, to_length);
res= to_cs->cset->well_formed_len(to_cs, from, from + from_length,
nchars, &well_formed_error);
memmove(to, from, res);
*from_end_pos= from + res;
*well_formed_error_pos= well_formed_error ? from + res : NULL;
*cannot_convert_error_pos= NULL;
if (from_offset)
res+= to_cs->mbminlen;
}
}
else
{
int cnvres;
my_wc_t wc;
my_charset_conv_mb_wc mb_wc= from_cs->cset->mb_wc;
my_charset_conv_wc_mb wc_mb= to_cs->cset->wc_mb;
const uchar *from_end= (const uchar*) from + from_length;
uchar *to_end= (uchar*) to + to_length;
char *to_start= to;
*well_formed_error_pos= NULL;
*cannot_convert_error_pos= NULL;
for ( ; nchars; nchars--)
{
const char *from_prev= from;
if ((cnvres= (*mb_wc)(from_cs, &wc, (uchar*) from, from_end)) > 0)
from+= cnvres;
else if (cnvres == MY_CS_ILSEQ)
{
if (!*well_formed_error_pos)
*well_formed_error_pos= from;
from++;
wc= '?';
}
else if (cnvres > MY_CS_TOOSMALL)
{
/*
A correct multibyte sequence detected
But it doesn't have Unicode mapping.
*/
if (!*cannot_convert_error_pos)
*cannot_convert_error_pos= from;
from+= (-cnvres);
wc= '?';
}
else
break; // Not enough characters
outp:
if ((cnvres= (*wc_mb)(to_cs, wc, (uchar*) to, to_end)) > 0)
to+= cnvres;
else if (cnvres == MY_CS_ILUNI && wc != '?')
{
if (!*cannot_convert_error_pos)
*cannot_convert_error_pos= from_prev;
wc= '?';
goto outp;
}
else
{
from= from_prev;
break;
}
}
*from_end_pos= from;
res= (uint) (to - to_start);
}
return (uint32) res;
}
void String::print(String *str)
{
char *st= (char*)Ptr, *end= st+str_length;
for (; st < end; st++)
{
uchar c= *st;
switch (c)
{
case '\\':
str->append(STRING_WITH_LEN("\\\\"));
break;
case '\0':
str->append(STRING_WITH_LEN("\\0"));
break;
case '\'':
str->append(STRING_WITH_LEN("\\'"));
break;
case '\n':
str->append(STRING_WITH_LEN("\\n"));
break;
case '\r':
str->append(STRING_WITH_LEN("\\r"));
break;
case '\032': // Ctrl-Z
str->append(STRING_WITH_LEN("\\Z"));
break;
default:
str->append(c);
}
}
}
/*
Exchange state of this object and argument.
SYNOPSIS
String::swap()
RETURN
Target string will contain state of this object and vice versa.
*/
void String::swap(String &s)
{
swap_variables(char *, Ptr, s.Ptr);
swap_variables(uint32, str_length, s.str_length);
swap_variables(uint32, Alloced_length, s.Alloced_length);
swap_variables(bool, alloced, s.alloced);
swap_variables(CHARSET_INFO*, str_charset, s.str_charset);
}
/**
Convert string to printable ASCII string
@details This function converts input string "from" replacing non-ASCII bytes
with hexadecimal sequences ("\xXX") optionally appending "..." to the end of
the resulting string.
This function used in the ER_TRUNCATED_WRONG_VALUE_FOR_FIELD error messages,
e.g. when a string cannot be converted to a result charset.
@param to output buffer
@param to_len size of the output buffer (8 bytes or greater)
@param from input string
@param from_len size of the input string
@param from_cs input charset
@param nbytes maximal number of bytes to convert (from_len if 0)
@return number of bytes in the output string
*/
uint convert_to_printable(char *to, size_t to_len,
const char *from, size_t from_len,
CHARSET_INFO *from_cs, size_t nbytes /*= 0*/)
{
/* needs at least 8 bytes for '\xXX...' and zero byte */
DBUG_ASSERT(to_len >= 8);
char *t= to;
char *t_end= to + to_len - 1; // '- 1' is for the '\0' at the end
const char *f= from;
const char *f_end= from + (nbytes ? min(from_len, nbytes) : from_len);
char *dots= to; // last safe place to append '...'
if (!f || t == t_end)
return 0;
for (; t < t_end && f < f_end; f++)
{
/*
If the source string is ASCII compatible (mbminlen==1)
and the source character is in ASCII printable range (0x20..0x7F),
then display the character as is.
Otherwise, if the source string is not ASCII compatible (e.g. UCS2),
or the source character is not in the printable range,
then print the character using HEX notation.
*/
if (((unsigned char) *f) >= 0x20 &&
((unsigned char) *f) <= 0x7F &&
from_cs->mbminlen == 1)
{
*t++= *f;
}
else
{
if (t_end - t < 4) // \xXX
break;
*t++= '\\';
*t++= 'x';
*t++= _dig_vec_upper[((unsigned char) *f) >> 4];
*t++= _dig_vec_upper[((unsigned char) *f) & 0x0F];
}
if (t_end - t >= 3) // '...'
dots= t;
}
if (f < from + from_len)
memcpy(dots, STRING_WITH_LEN("...\0"));
else
*t= '\0';
return t - to;
}
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