Re: [Tarantool-patches] [PATCH v2 06/15] WIP: module api/lua: add luaT_tuple_encode()

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

> >  /**
> >   * Encode a Lua values on a Lua stack as an MsgPack array.
> >   *
> >   * Raise a Lua error when encoding fails.
> > + *
> > + * Helper for <lbox_tuple_new>().
> 
> 1. Should be a part of the previous patch?

Sure. Sorry for the mess.

> 
> >   */
> >  static int
> >  luaT_tuple_encode_values(struct lua_State *L)
> > @@ -122,6 +143,22 @@ luaT_tuple_encode_values(struct lua_State *L)
> >  	return 0;
> >  }
> >  
> > +typedef void luaT_mpstream_init_f(struct mpstream *stream, struct lua_State *L);
> > +
> > +static void
> > +luaT_mpstream_init_lua_ibuf(struct mpstream *stream, struct lua_State *L)
> > +{
> > +	mpstream_init(stream, tarantool_lua_ibuf, ibuf_reserve_cb,
> > +		      ibuf_alloc_cb, luamp_error, L);
> > +}
> > +
> > +static void
> > +luaT_mpstream_init_box_region(struct mpstream *stream, struct lua_State *L)
> > +{
> > +	mpstream_init(stream, &fiber()->gc, region_reserve_cb, region_alloc_cb,
> > +		      luamp_error, L);
> 
> 2. If you throw after some allocations are done, will the region leak? I don't
> see a truncate in case luaT_tuple_encode_helper fails.

Good point. Added truncate in luaT_tuple_encode().

> > +/**
> > + * Encode a Lua table / tuple to given mpstream.
> > + */
> > +static int
> > +luaT_tuple_encode_helper(struct lua_State *L, int idx,
> > +			 luaT_mpstream_init_f *luaT_mpstream_init_f)
> 
> 3. Function name is usually a verb. Here I can propose
> luaT_tuple_encode_on_mpstream.

Nice proposal! I'll apply.

> > @@ -163,18 +201,53 @@ luaT_tuple_encode_on_lua_ibuf(struct lua_State *L, int idx,
> >  	lua_rawgeti(L, LUA_REGISTRYINDEX, luaT_tuple_encode_table_ref);
> >  	assert(lua_isfunction(L, -1));
> >  
> > +	lua_pushlightuserdata(L, luaT_mpstream_init_f);
> >  	lua_pushvalue(L, idx);
> >  
> > -	int rc = luaT_call(L, 1, 0);
> > +	int rc = luaT_call(L, 2, 0);
> >  	lua_settop(L, top);
> > -	if (rc != 0)
> > +	return rc == 0 ? 0 : -1;
> 
> 4. Why not simply 'return rc;'?

Some mess occurs. Thanks for the catch!