From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Wed, 21 Mar 2018 12:14:55 +0300 From: Vladimir Davydov Subject: Re: [PATCH 2/5] lua: port console yaml formatting to C Message-ID: <20180321091455.3td6h42oe3l2omlg@esperanza> References: <881a3705ddfd6c3885171fe3a748b0e2baaded92.1521466428.git.v.shpilevoy@tarantool.org> <20180320175113.bnocgitvdf5eh2dn@esperanza> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: To: "v.shpilevoy@tarantool.org" Cc: tarantool-patches@freelists.org List-ID: On Tue, Mar 20, 2018 at 09:04:09PM +0300, v.shpilevoy@tarantool.org wrote: > > > > 20 марта 2018 г., в 20:51, Vladimir Davydov 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 > >> --- > >> 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 , that seems to be too > complicated for a single propose - format push message. But if you > insist, I can do full port. I'm not sure... Obviously, I don't want you to rewrite the yaml encode. I just want to understand if there are alternatives to exporting the yaml encoder to the Lua console module, just to use it in C. Please take a look at how src/lua/msgpack.c is implemented - may be, we could borrow some ideas from it.