diff options
Diffstat (limited to 'sql/strfunc.cc')
-rw-r--r-- | sql/strfunc.cc | 202 |
1 files changed, 202 insertions, 0 deletions
diff --git a/sql/strfunc.cc b/sql/strfunc.cc index d6f9784e4ad..5ff2efe2020 100644 --- a/sql/strfunc.cc +++ b/sql/strfunc.cc @@ -89,6 +89,208 @@ ulonglong find_set(TYPELIB *lib, const char *str, uint length, } +static const char *on_off_default_names[]= +{ + "off","on","default", NullS +}; + +static const unsigned int on_off_default_names_len[]= +{ + sizeof("off") - 1, + sizeof("on") - 1, + sizeof("default") - 1 +}; + +static TYPELIB on_off_default_typelib= {array_elements(on_off_default_names)-1, + "", on_off_default_names, + (unsigned int *)on_off_default_names_len}; + + +/* + Parse a TYPELIB name from the buffer + + SYNOPSIS + parse_name() + lib Set of names to scan for. + strpos INOUT Start of the buffer (updated to point to the next + character after the name) + end End of the buffer + cs Charset used in the buffer + + DESCRIPTION + Parse a TYPELIB name from the buffer. The buffer is assumed to contain + one of the names specified in the TYPELIB, followed by comma, '=', or + end of the buffer. + + RETURN + 0 No matching name + >0 Offset+1 in typelib for matched name +*/ + +static uint parse_name(TYPELIB *lib, const char **strpos, const char *end, + CHARSET_INFO *cs) +{ + const char *pos= *strpos; + const char *start= pos; + + /* Find the length */ + if (cs && cs->mbminlen > 1) + { + int mblen= 0; + for ( ; pos < end; pos+= mblen) + { + my_wc_t wc; + if ((mblen= cs->cset->mb_wc(cs, &wc, (const uchar *) pos, + (const uchar *) end)) < 1) + mblen= 1; // Not to hang on a wrong multibyte sequence + if (wc == (my_wc_t) '=' || wc == (my_wc_t) ',') + break; + } + } + else + for (; pos != end && *pos != '=' && *pos !=',' ; pos++); + + uint var_len= (uint) (pos - start); + /* Determine which flag it is */ + uint find= cs ? find_type2(lib, start, var_len, cs) : + find_type(lib, start, var_len, (bool) 0); + *strpos= pos; + return find; +} + + +/* Read next character from the buffer in a charset-aware way */ + +static my_wc_t get_next_char(const char **pos, const char *end, CHARSET_INFO *cs) +{ + my_wc_t wc; + if (*pos == end) + return (my_wc_t)-1; + + if (cs && cs->mbminlen > 1) + { + int mblen; + if ((mblen= cs->cset->mb_wc(cs, &wc, (const uchar *) *pos, + (const uchar *) end)) < 1) + mblen= 1; // Not to hang on a wrong multibyte sequence + *pos += mblen; + return wc; + } + else + return *((*pos)++); +} + + +/* + Parse and apply a set of flag assingments + + SYNOPSIS + find_set_from_flags() + lib Flag names + default_name Number of "default" in the typelib + cur_set Current set of flags (start from this state) + default_set Default set of flags (use this for assign-default + keyword and flag=default assignments) + str String to be parsed + length Length of the string + cs String charset + err_pos OUT If error, set to point to start of wrong set string + NULL on success + err_len OUT If error, set to the length of wrong set string + set_warning OUT TRUE <=> Some string in set couldn't be used + + DESCRIPTION + Parse a set of flag assignments, that is, parse a string in form: + + param_name1=value1,param_name2=value2,... + + where the names are specified in the TYPELIB, and each value can be + either 'on','off', or 'default'. Setting the same name twice is not + allowed. + + Besides param=val assignments, we support the "default" keyword (keyword + #default_name in the typelib). It can be used one time, if specified it + causes us to build the new set over the default_set rather than cur_set + value. + + RETURN + Parsed set value if (*errpos == NULL) + Otherwise undefined +*/ + +ulonglong find_set_from_flags(TYPELIB *lib, uint default_name, + ulonglong cur_set, ulonglong default_set, + const char *str, uint length, CHARSET_INFO *cs, + char **err_pos, uint *err_len, bool *set_warning) +{ + CHARSET_INFO *strip= cs ? cs : &my_charset_latin1; + const char *end= str + strip->cset->lengthsp(strip, str, length); + ulonglong flags_to_set= 0, flags_to_clear= 0; + bool set_defaults= 0; + *err_pos= 0; // No error yet + if (str != end) + { + const char *start= str; + for (;;) + { + const char *pos= start; + uint flag_no, value; + + if (!(flag_no= parse_name(lib, &pos, end, cs))) + goto err; + + if (flag_no == default_name) + { + /* Using 'default' twice isn't allowed. */ + if (set_defaults) + goto err; + set_defaults= TRUE; + } + else + { + ulonglong bit= ((longlong) 1 << (flag_no - 1)); + /* parse the '=on|off|default' */ + if ((flags_to_clear | flags_to_set) & bit || + get_next_char(&pos, end, cs) != '=' || + !(value= parse_name(&on_off_default_typelib, &pos, end, cs))) + { + goto err; + } + + if (value == 1) // this is '=off' + flags_to_clear|= bit; + else if (value == 2) // this is '=on' + flags_to_set|= bit; + else // this is '=default' + { + if (default_set & bit) + flags_to_set|= bit; + else + flags_to_clear|= bit; + } + } + if (pos >= end) + break; + + if (get_next_char(&pos, end, cs) != ',') + goto err; + + start=pos; + continue; + err: + *err_pos= (char*)start; + *err_len= end - start; + *set_warning= TRUE; + break; + } + } + ulonglong res= set_defaults? default_set : cur_set; + res|= flags_to_set; + res&= ~flags_to_clear; + return res; +} + + /* Function to find a string in a TYPELIB (Same format as mysys/typelib.c) |