[Tarantool-patches] [server-dev] Re: [tarantool-patches] Re: [PATCH v2 1/2] lua: return getaddrinfo() errors

[Alexander Turenko]

> commit 9810ccd869183de068939cdce5a157ad35916d36
> Author: Roman Khabibov <roman.habibov at tarantool.org>
> Date:   Tue Jul 30 15:49:13 2019 +0300
> 
>     lua: return getaddrinfo() errors
>     
>     Add getaddrinfo() errors into the several fuctions of socket. Now
>     getaddrinfo() can return a pair of values (nil and error message)
>     in case of error.
>     
>     Closes #4138
>     
>     @TarantoolBot document
>     Title: socket_object:connect

`socket_object:connect` is not valid Lua syntax. It is better to write
it as socket_object:connect() or socket_object.connect.

net.box API also was changed.

>     
>     Connect to a remote host using tcp_connect() within. If it is no
>     error, return a socket object.

It is hard to understood w/o a context. Please, either describe API
changes formally or give an example that will show the API change.

> diff --git a/src/lua/socket.lua b/src/lua/socket.lua
> index a334ad45b..e4815adbb 100644
> --- a/src/lua/socket.lua
> +++ b/src/lua/socket.lua
> @@ -1041,9 +1041,12 @@ local function tcp_connect(host, port, timeout)
>      end
>      local timeout = timeout or TIMEOUT_INFINITY
>      local stop = fiber.clock() + timeout
> -    local dns = getaddrinfo(host, port, timeout, { type = 'SOCK_STREAM',
> +    local dns, err = getaddrinfo(host, port, timeout, { type = 'SOCK_STREAM',
>          protocol = 'tcp' })
> -    if dns == nil or #dns == 0 then
> +    if dns == nil then
> +        return nil, err
> +    end
> +    if #dns == 0 then
>          boxerrno(boxerrno.EINVAL)
>          return nil
>      end

Cited to link from below.

> @@ -1360,9 +1363,16 @@ local function lsocket_tcp_connect(self, host, port)
>      -- This function is broken by design
>      local ga_opts = { family = 'AF_INET', type = 'SOCK_STREAM' }
>      local timeout = deadline - fiber.clock()
> -    local dns = getaddrinfo(host, port, timeout, ga_opts)
> +    local dns, err = getaddrinfo(host, port, timeout, ga_opts)
>      if dns == nil or #dns == 0 then
> -        self._errno = boxerrno.EINVAL
> +        return nil, err
> +    end
> +    if dns == nil then
> +        boxerrno(self._errno)
> +        return nil, err
> +    end
> +    if #dns == 0 then
> +        boxerrno(self._errno)
>          return nil, socket_error(self)
>      end

We'll never reach the last two if's bodies. However the similar fragment
above in tcp_connect() was changed in the right way.