[tarantool-patches] Re: [PATCH v1 1/1] Tarantoolctl "enter" with set language

[Vladislav Shpilevoy <v.shpilevoy@tarantool.org>]

On 25/07/2018 10:51, imeevma@tarantool.org wrote:
> This patch allow to use option "--language" with
> "tarantoolctl enter" command. Also default value
> for language were added in default configuration
> file. Language is either SQL or Lua.
> 
> Closes #2385.
> ---
> Branch: https://github.com/tarantool/tarantool/tree/imeevma/gh-2385-select-input-language-tarantoolctl
> Issue: https://github.com/tarantool/tarantool/issues/2385
> 
> diff --git a/extra/dist/tarantoolctl.in b/extra/dist/tarantoolctl.in
> index 2dd5d74..55711b8 100755
> --- a/extra/dist/tarantoolctl.in
> +++ b/extra/dist/tarantoolctl.in
> @@ -155,6 +155,11 @@ local function load_default_file(default_file)
>       d.vinyl_dir = fio.pathjoin(d.vinyl_dir, instance_name)
>       d.log       = fio.pathjoin(d.log,       instance_name .. '.log')
>   
> +    d.language  = (d.language or "lua"):lower()
> +    if d.language ~= "lua" and d.language ~= "sql" then
> +        d.language = "lua"

1. Please, do not ignore unknown language. Log this error like others
in the same function already do.

2. Why do you need language in default_cfg? It is box.cfg as I
understand and box.cfg has no language option. It is not? If you
need to parse a language from the file, then you can store it in
another table or even in a separate variable like others on lines
30-49.

> +    end
> +
>       default_cfg = d
>   
>       if not usermode the> @@ -629,6 +635,17 @@ local function logrotate()
>   end
>   
>   local function enter()
> +    local options = keyword_arguments
> +    local language = options.language
> +    if language ~= nil then
> +        language = language:lower()
> +        if language ~= "lua" and language ~= "sql" then
> +            log.warn("Language \"%s\" is not recognized. Default language" ..
> +                     " \"%s\" is set.", language, default_cfg.language)
> +            language = nil

3. For enter() function it is ok to fail on unknown language.
You should not ignore the error because a caller could use
something like this:

     cat my_script.sql | tarantoolctl enter --language sqlll

And if you ignore invalid language, this command will feed the
entire script on SQL into Lua console. It will produce huge
number of syntax errors if no worse.

> +        end
> +    end
> +    language = language or default_cfg.language
>       local console_sock_path = uri.parse(console_sock).service
>       if fio.stat(console_sock_path) == nil then
>           log.error("Can't connect to %s (%s)", console_sock_path, errno.strerror())
> @@ -644,7 +661,9 @@ local function enter()
>           console_sock, TIMEOUT_INFINITY
>       )
>   
> -    console.on_start(function(self) self:eval(cmd) end)
> +    local cmd_language = string.format("\\set language %s", language)

4. Why not to merge cmd_language into cmd? It is created a line above.

> +
> +    console.on_start(function(self) self:eval(cmd) self:eval(cmd_language) end)
>       console.on_client_disconnect(function(self) self.running = false end)
>       console.start()
>       return 0
> @@ -1284,6 +1303,7 @@ do
>           { 'chdir',       'string'  },
>           { 'only-server', 'string'  },
>           { 'server',      'string'  },
> +        { 'language',    'string'  },
>       })
>   
>       local cmd_name
> 

5. Lets add the same option to 'eval', 'connect' to make the commands
symmetric.

6. Please, update the comments. For example, on line 1028 I
still see the comment about 'enter': "Enter an instance's interactive Lua console",
but actually it is not complete now - you can choose SQL.