[tarantool-patches] Re: [PATCH v2 7/8] sql: get rid of FuncDef function hash

[Kirill Shcherbatov]

>> +	REG_FUNC("ABS", ARGC_MASK(1), FIELD_TYPE_NUMBER, 0,
>> +		 absFunc, NULL, true),
> 
> 
> This looks like huge overengineering.
> 
> A bunch of macros, a binary search, can you just open-code
> inserting all of these functions into the hash? It would be
> perhaps a bit more copy-paste, but it will be easy to maintain.
> 
> Am I missing something?

This constructor is called automatically during function recovery
by prototype defined in snapshot. Thus all functions are
initialized in a one place: in on_replace_dd_func trigger.

I like this concept because it is uniform and all implementation-dependent
details (like the completion of the function definition initialization) are hidden
in the corresponding module (sql/func.c).


Technically we may skip a function cache entry creation for SQL_BUILTIN 
tuple type in on_replace_dd_func trigger, to perform the whole preparements
during Tarantool initialization. This require to distinguish SQL_BUILTIN entries
and other types in trigger and this is not cool, I believe.

Finally, a current approach enforces keeping snapshot will all built in definitions
in actual state.