> 20 марта 2018 г., в 20:51, Vladimir Davydov <vdavydov.dev@gmail.com> написал(а):
> 
> On Mon, Mar 19, 2018 at 04:34:49PM +0300, Vladislav Shpilevoy wrote:
>> Box.session.push() will be implemented in C lbox_session_push()
>> function, which will use port to encapsulate different session
>> types (binary, text) push() logic. And push() must be able to
>> either encode an argument into message pack, or format it as a
>> string using yaml. This formatting can not be done in Lua before
>> push() call, since it breaks push() virtualization.
>> 
>> Needed for #2677
>> 
>> Signed-off-by: Vladislav Shpilevoy <v.shpilevoy@tarantool.org>
>> ---
>> src/box/lua/console.c         | 42 ++++++++++++++++++++++++++++++++++++++++++
>> src/box/lua/console.lua       | 34 ++++++++--------------------------
>> third_party/lua-yaml/lyaml.cc |  9 +++------
>> third_party/lua-yaml/lyaml.h  |  3 +++
>> 4 files changed, 56 insertions(+), 32 deletions(-)
>> 
>> diff --git a/src/box/lua/console.c b/src/box/lua/console.c
> 
>> @@ -328,6 +329,32 @@ lbox_console_add_history(struct lua_State *L)
>> 	return 0;
>> }
>> 
>> +static int
>> +lbox_console_format(struct lua_State *L)
>> +{
>> +	int arg_count = lua_gettop(L);
>> +	if (arg_count == 0) {
>> +		lua_pushstring(L, "---\n...\n");
>> +		return 1;
>> +	}
>> +	lua_getfield(L, LUA_REGISTRYINDEX, "_LOADED");
>> +	lua_getfield(L, -1, "console");
>> +	lua_getfield(L, -1, "formatter");
>> +	lua_getfield(L, -1, "encode");
>> +	lua_createtable(L, arg_count, 0);
>> +	for (int i = 0; i < arg_count; ++i) {
>> +		if (lua_isnil(L, i + 1))
>> +			lua_getfield(L, -3, "NULL");
>> +		else
>> +			lua_pushvalue(L, i + 1);
>> +		lua_rawseti(L, -2, i + 1);
>> +	}
>> +	lua_call(L, 1, 1);
>> +	lua_insert(L, -4);
>> +	lua_pop(L, 3);
>> +	return 1;
>> +}
>> +
>> void
>> tarantool_lua_console_init(struct lua_State *L)
>> {
> 
>> @@ -344,6 +372,20 @@ tarantool_lua_console_init(struct lua_State *L)
>> 	lua_getfield(L, -1, "completion_handler");
>> 	lua_pushcclosure(L, lbox_console_readline, 1);
>> 	lua_setfield(L, -2, "readline");
>> +
>> +	lua_yaml_new_formatter(L);
>> +	lua_getfield(L, -1, "cfg");
>> +	lua_createtable(L, 0, 4);
>> +	lua_pushboolean(L, true);
>> +	lua_setfield(L, -2, "encode_invalid_numbers");
>> +	lua_pushboolean(L, true);
>> +	lua_setfield(L, -2, "encode_load_metatables");
>> +	lua_pushboolean(L, true);
>> +	lua_setfield(L, -2, "encode_use_tostring");
>> +	lua_pushboolean(L, true);
>> +	lua_setfield(L, -2, "encode_invalid_as_nil");
>> +	lua_call(L, 1, 0);
>> +	lua_setfield(L, -2, "formatter");
> 
>> diff --git a/src/box/lua/console.lua b/src/box/lua/console.lua
>> @@ -395,4 +375,6 @@ package.loaded['console'] = {
>>     on_start = on_start;
>>     on_client_disconnect = on_client_disconnect;
>>     completion_handler = internal.completion_handler;
>> +    formatter = internal.formatter;
> 
> I don't like that we export the serializer to Lua, but never use it in
> Lua code, only in C. Can't we create a serializer in C and pass it to
> the encoder function explicitly?

The problem of Lua formatter is that it is Lua table, not cdata. And to fully port it on C it is necessary to rewrite luaL_serializer and l_dump in lyaml.cc <http://lyaml.cc/>, that seems to be too complicated for a single propose - format push message. But if you insist, I can do full port.