diff options
Diffstat (limited to 'sql/sql_string.cc')
| -rw-r--r-- | sql/sql_string.cc | 131 |
1 files changed, 74 insertions, 57 deletions
diff --git a/sql/sql_string.cc b/sql/sql_string.cc index debe42046f0..e76c7902210 100644 --- a/sql/sql_string.cc +++ b/sql/sql_string.cc @@ -24,6 +24,7 @@ #include <my_sys.h> #include <m_string.h> #include <m_ctype.h> +#include <assert.h> #ifdef HAVE_FCONVERT #include <floatingpoint.h> #endif @@ -230,68 +231,86 @@ bool String::copy(const char *str,uint32 arg_length, CHARSET_INFO *cs) /* - Checks that the source string can be just copied - to the destination string without conversion. - If either character set conversion or adding leading - zeros (e.g. for UCS-2) must be done then return - value is TRUE else 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 */ -bool String::needs_conversion(const char *str, uint32 arg_length, - CHARSET_INFO *from_cs, - CHARSET_INFO *to_cs) + +bool String::needs_conversion(uint32 arg_length, + CHARSET_INFO *from_cs, + CHARSET_INFO *to_cs, + uint32 *offset) { + *offset= 0; if ((to_cs == &my_charset_bin) || (to_cs == from_cs) || my_charset_same(from_cs, to_cs) || - ((from_cs == &my_charset_bin) && (!(arg_length % to_cs->mbminlen)))) + ((from_cs == &my_charset_bin) && + (!(*offset=(arg_length % to_cs->mbminlen))))) return FALSE; - return TRUE; } + /* -** 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 + 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, +bool String::copy_aligned(const char *str,uint32 arg_length, uint32 offset, CHARSET_INFO *cs) { /* How many bytes are in incomplete character */ - uint32 offs= (arg_length % cs->mbminlen); + offset= cs->mbmaxlen - offset; /* How many zeros we should prepend */ + DBUG_ASSERT(offset && offset != cs->mbmaxlen); - if (!offs) /* All characters are complete, just copy */ - { - copy(str, arg_length, cs); - return FALSE; - } - - offs= cs->mbmaxlen - offs; /* How many zeros we should prepend */ - uint32 aligned_length= arg_length + offs; + uint32 aligned_length= arg_length + offset; if (alloc(aligned_length)) return TRUE; /* - Probably this condition is not really necessary - because if aligned_length is 0 then offs is 0 too - and we'll return after calling set(). + Note, this is only safe for little-endian UCS-2. + If we add big-endian UCS-2 sometimes, this code + will be more complicated. But it's OK for now. */ - if ((str_length= aligned_length)) - { - /* - Note, this is only safe for little-endian UCS-2. - If we add big-endian UCS-2 sometimes, this code - will be more complicated. But it's OK for now. - */ - bzero((char*)Ptr, offs); - memcpy(Ptr + offs, str, arg_length); - } + bzero((char*) Ptr, offset); + memcpy(Ptr + offset, str, arg_length); Ptr[aligned_length]=0; - str_charset=cs; + /* str_length is always >= 0 as arg_length is != 0 */ + str_length= aligned_length; + str_charset= cs; return FALSE; } @@ -300,14 +319,14 @@ bool String::set_or_copy_aligned(const char *str,uint32 arg_length, CHARSET_INFO *cs) { /* How many bytes are in incomplete character */ - uint32 offs= (arg_length % cs->mbminlen); + uint32 offset= (arg_length % cs->mbminlen); - if (!offs) /* All characters are complete, just copy */ + if (!offset) /* All characters are complete, just copy */ { set(str, arg_length, cs); return FALSE; } - return copy_aligned(str, arg_length, cs); + return copy_aligned(str, arg_length, offset, cs); } /* Copy with charset convertion */ @@ -315,14 +334,11 @@ bool String::set_or_copy_aligned(const char *str,uint32 arg_length, bool String::copy(const char *str, uint32 arg_length, CHARSET_INFO *from_cs, CHARSET_INFO *to_cs) { - if (!needs_conversion(str, arg_length, from_cs, to_cs)) - { + uint32 offset; + if (!needs_conversion(arg_length, from_cs, to_cs, &offset)) return copy(str, arg_length, to_cs); - } - if ((from_cs == &my_charset_bin) && (arg_length % to_cs->mbminlen)) - { - return copy_aligned(str, arg_length, to_cs); - } + if ((from_cs == &my_charset_bin) && offset) + return copy_aligned(str, arg_length, offset, to_cs); uint32 new_length= to_cs->mbmaxlen*arg_length; if (alloc(new_length)) @@ -521,7 +537,7 @@ int String::strstr(const String &s,uint32 offset) register const char *search=s.ptr(); const char *end=Ptr+str_length-s.length()+1; const char *search_end=s.ptr()+s.length(); -skipp: +skip: while (str != end) { if (*str++ == *search) @@ -529,7 +545,7 @@ skipp: register char *i,*j; i=(char*) str; j=(char*) search+1; while (j != search_end) - if (*i++ != *j++) goto skipp; + if (*i++ != *j++) goto skip; return (int) (str-Ptr) -1; } } @@ -553,7 +569,7 @@ int String::strstr_case(const String &s,uint32 offset) register const char *search=s.ptr(); const char *end=Ptr+str_length-s.length()+1; const char *search_end=s.ptr()+s.length(); -skipp: +skip: while (str != end) { if (str_charset->sort_order[*str++] == str_charset->sort_order[*search]) @@ -563,7 +579,7 @@ skipp: while (j != search_end) if (str_charset->sort_order[*i++] != str_charset->sort_order[*j++]) - goto skipp; + goto skip; return (int) (str-Ptr) -1; } } @@ -586,7 +602,7 @@ int String::strrstr(const String &s,uint32 offset) const char *end=Ptr+s.length()-2; const char *search_end=s.ptr()-1; -skipp: +skip: while (str != end) { if (*str-- == *search) @@ -594,7 +610,7 @@ skipp: register char *i,*j; i=(char*) str; j=(char*) search-1; while (j != search_end) - if (*i-- != *j--) goto skipp; + if (*i-- != *j--) goto skip; return (int) (i-Ptr) +1; } } @@ -744,7 +760,8 @@ copy_and_convert(char *to, uint32 to_length, CHARSET_INFO *to_cs, while (1) { - if ((cnvres=from_cs->cset->mb_wc(from_cs, &wc, (uchar*) from, from_end)) > 0) + if ((cnvres= from_cs->cset->mb_wc(from_cs, &wc, (uchar*) from, + from_end)) > 0) from+= cnvres; else if (cnvres == MY_CS_ILSEQ) { |