Re: [Tarantool-patches] [PATCH] Msgpackffi considers msgpack.cfg options now

[Alexander Turenko <alexander.turenko@tarantool.org>]

Sorry again for the late reply.

> > I think we also should implement encode_sparse_* options to
> > be compatible with msgpack module.
>
> Could you please explain how do you propose to implement them? It
> seems to me the purpose of those configs is to handle excessively
> sparse arrays as maps (as stated in src/lua/utils.h). Which does not
> seem relevant to lua module where the only container type is table.
> What do I miss here? 

It is about encoding, not decoding: encode a Lua table with numeric keys
as MP_ARRAY, MP_MAP or give an error. It seems that nothing prevent us
from implementing this logic on Lua.

> Subject: [PATCH 1/2] Msgpackffi considers msgpack.cfg options now
> Msgpack.cfg options changes did not affect msgpackffi serializer state.
> This patch fixes it for options encode_load_metatables, decode_ and
> encode_invalid_numbers, encode_use_tostring and encode_invalid_as_nil.
> Closes #4499
> ---
> Issue:
> https://github.com/tarantool/tarantool/issues/4499
> Branch:
> https://github.com/tarantool/tarantool/compare/eljashm/gh-4499-msgpackffi-ignores-msgpack.cfg-options

> @@ -261,6 +263,19 @@ local function encode_r(buf, obj, level)
>          else
>              error("Invalid __serialize value")
>          end
> +    elseif type(obj) == math.huge or type(obj) == -math.huge or 
> +        type(obj) == math.nan then
> +        if msgpack.cfg.encode_invalid_numbers then
> +            if obj == math.huge then
> +                obj = 1/0
> +            elseif obj == -math.huge then
> +                obj = -1/0
> +            else
> +                obj = 0/0
> +            end
> +        else
> +            encode_nil(buf)
> +        end

I would save 1/0, -1/0, 0/0 as module local variables for readability,
like as it is done in test_double().

I also found that math.huge is 1/0 (inf) and there is no math.nan (it
just nil).

> @@ -562,6 +589,15 @@ decode_r = function(data)
>      elseif c >= 0xe0 then
>          return tonumber(ffi.cast('signed char',c)) -- negfixint
>      elseif c == 0xc0 then
> +        if msgpack.cfg.decode_invalid_numbers then
> +            if c == 0/0 then
> +                return math.nan
> +            elseif c == 1/0 then
> +                return math.huge
> +            elseif c == -1/0 then
> +                return -math.huge
> +            end
> +        end

Same as above.

> @@ -628,6 +664,8 @@ return {
>      on_encode = on_encode;
>      decode_unchecked = decode_unchecked;
>      decode = decode_unchecked; -- just for tests
> +    cfg = msgpack.cfg;
> +    new = msgpack.new; -- for serializer tests to work properly

So they'll test msgpack, not msgpackffi.