Hello Alexey, On 03/10/2017 10:56 AM, Alexey Botchkov wrote: > Ok, i see. > > Last question then. > - item->cast_to_int_type() == cast_to_int_type() && > + item->cast_to_int_type_handler() == > cast_to_int_type_handler() && > Are you sure we should compare typehandlers here, not their ->cmp_type()?
Item_hex_constant can be: 1. Either Item_hex_hybrid, which can act as a string or as a number, depending on context: SELECT 0x30, 0x30+1; +------+--------+ | 0x30 | 0x30+1 | +------+--------+ | 0 | 49 | +------+--------+ (the first 0x30 is a string '0', the second 0x30 is an integer 0x30, which is decimal 48) 2. Or Item_hex_string, which is always a string: SELECT X'30', X'30'+1; +-------+---------+ | X'30' | X'30'+1 | +-------+---------+ | 0 | 1 | +-------+---------+ (both X'30's are strings '0') The method Item_hex_constant::eq() needs to make sure that X'30' and 0x30 are considered as different items, and thus don't replace each other, e.g. in equal field propagation. Item_hex_hybrid::cast_to_int_type_handler() returns &type_handler_longlong. Item_hex_string::cast_to_int_type_handler() returns &type_handler_varchar. Comparing type handlers should be enough here. Comparing cmp_type() would be also correct, but would involve one extra virtual call, which is nice to avoid. > > Also i don't like that we have the 'val_int_signed_typecast' as a > virtual functions. Code would > be much nicer without that and all it was done just for Item_dyncol_get. > Not that simple to fix it though and I agree that it shouldn't be > touched as a part of this patch. > Probably sometime later... Maybe. Perhaps some related code will also migrate to Type_handler. Probably this would do: virtual longlong Type_handler::val_int_signed_typecast(Item *item); But I'm not 100% sure. Let's return to this later. Thanks! > > Best regards. > HF > > > > On Fri, Mar 10, 2017 at 1:10 AM, Alexander Barkov <b...@mariadb.org > <mailto:b...@mariadb.org>> wrote: > > Hello Alexey, > > > On 03/09/2017 11:38 PM, Alexey Botchkov wrote: > > Hi, Alexander. > > > > Some questions about the patch. > > > > I don't get why we have two sets of functions > > Type_handler_**::+bool > > Type_handler_int_result::Item_func_abs_fix_length_and_dec > > and > > Type_handler_**::+bool > > Type_handler_int_result::Item_func_neg_fix_length_and_dec > > > > As far as i can see these are equal and we just can have one > > Type_handler_**::+bool > > Type_handler_int_result::Item_func_abs_neg_fix_length_and_dec > > Did I miss something? > > > They might look similar: > > > bool Type_handler_int_result:: > Item_func_abs_fix_length_and_dec(Item_func_abs *item) const > { > item->fix_length_and_dec_int(); > return false; > } > > bool Type_handler_int_result:: > Item_func_neg_fix_length_and_dec(Item_func_neg *item) const > { > item->fix_length_and_dec_int(); > return false; > } > > > But they have arguments of different pointer types! > > > The former calls Item_func_abs::fix_length_and_dec_int(), and > the latter calls Item_func_neg::fix_length_and_dec_int(), > > and those are different. > > > > > Secondly, since Item_func::fix_length_and_dec() was historically 'void' > > and i don't see you're > > changing it, why do all these typehandler's 'xxx_fix_length_and_dec' > > return something? > > Nobody checks their return anyway. > > > Currently fix_fields() does this: > > fix_length_and_dec(); > if (thd->is_error()) // An error inside fix_length_and_dec occurred > return TRUE; > > I'm thinking of eventually changing this to: > > if (fix_length_and_dec()) > return true; > > > So I decided to make all Type_handler::xxxx_fix_length_and_dec() > return bool right now, so we have to do less changes in the future. > > > Thanks! > > > > > Best regards. > > HF > > > > > > On Tue, Mar 7, 2017 at 6:15 PM, Alexander Barkov <b...@mariadb.org > <mailto:b...@mariadb.org> > > <mailto:b...@mariadb.org <mailto:b...@mariadb.org>>> wrote: > > > > Hello Alexey, > > > > Please review a patch for MDEV-12199. > > > > Thanks! > > > > > > _______________________________________________ Mailing list: https://launchpad.net/~maria-developers Post to : maria-developers@lists.launchpad.net Unsubscribe : https://launchpad.net/~maria-developers More help : https://help.launchpad.net/ListHelp
