# HG changeset patch
# User jbe
# Date 1449692184 -3600
# Node ID 762ab1e877028348f9150e57fe5230f3139a6b0f
# Parent  ae1a66bb6b7dbdb6618f912ea1082aac74fa0ee3
Use uservalues rather than ephemeron tables in mondelefant

diff -r ae1a66bb6b7d -r 762ab1e87702 libraries/mondelefant/mondelefant_native.c
--- a/libraries/mondelefant/mondelefant_native.c	Wed Dec 09 05:23:42 2015 +0100
+++ b/libraries/mondelefant/mondelefant_native.c	Wed Dec 09 21:16:24 2015 +0100
@@ -15,8 +15,6 @@
 #define MONDELEFANT_MODULE_REGKEY (MONDELEFANT_REGKEY "module")
 // registry key of meta-table for database connections:
 #define MONDELEFANT_CONN_MT_REGKEY (MONDELEFANT_REGKEY "connection")
-// registry key of table storing connection specific data:
-#define MONDELEFANT_CONN_DATA_REGKEY (MONDELEFANT_REGKEY "connection_data")
 // registry key of meta-table for database result lists and objects:
 #define MONDELEFANT_RESULT_MT_REGKEY (MONDELEFANT_REGKEY "result")
 // registry key of meta-table for database error objects:
@@ -306,15 +304,12 @@
   // set meta-table of userdata:
   luaL_getmetatable(L, MONDELEFANT_CONN_MT_REGKEY);  // 2
   lua_setmetatable(L, 1);
-  // create entry in table storing connection specific data and associate
-  // created userdata with it:
-  lua_getfield(L, LUA_REGISTRYINDEX, MONDELEFANT_CONN_DATA_REGKEY);  // 2
-  lua_pushvalue(L, 1);  // 3
-  lua_newtable(L);  // 4
-  lua_pushinteger(L, PQsocket(pgconn));  // determine file descriptor
-  lua_setfield(L, 4, "fd");  // set "fd" attribute
-  lua_settable(L, 2);
-  lua_settop(L, 1);
+  // create and associate userdata table:
+  lua_newtable(L);
+  lua_setuservalue(L, 1);
+  // store key "fd" with file descriptor of connection:
+  lua_pushinteger(L, PQsocket(pgconn));
+  lua_setfield(L, 1, "fd");
   // store key "engine" with value "postgresql" as connection specific data:
   lua_pushliteral(L, "postgresql");
   lua_setfield(L, 1, "engine");
@@ -338,10 +333,7 @@
 static int mondelefant_conn_index(lua_State *L) {
   // try table for connection specific data:
   lua_settop(L, 2);
-  lua_getfield(L, LUA_REGISTRYINDEX, MONDELEFANT_CONN_DATA_REGKEY);  // 3
-  lua_pushvalue(L, 1);  // 4
-  lua_gettable(L, 3);  // 4
-  lua_remove(L, 3);  // connection specific data-table at stack position 3
+  lua_getuservalue(L, 1);  // 3
   lua_pushvalue(L, 2);  // 4
   lua_gettable(L, 3);  // 4
   if (!lua_isnil(L, 4)) return 1;
@@ -378,10 +370,7 @@
 static int mondelefant_conn_newindex(lua_State *L) {
   // store key-value pair in table for connection specific data:
   lua_settop(L, 3);
-  lua_getfield(L, LUA_REGISTRYINDEX, MONDELEFANT_CONN_DATA_REGKEY);  // 4
-  lua_pushvalue(L, 1);  // 5
-  lua_gettable(L, 4);  // 5
-  lua_remove(L, 4);  // connection specific data-table at stack position 4
+  lua_getuservalue(L, 1);  // 4
   lua_pushvalue(L, 2);
   lua_pushvalue(L, 3);
   lua_settable(L, 4);
@@ -405,11 +394,8 @@
   conn = mondelefant_get_conn(L, 1);
   PQfinish(conn->pgconn);
   conn->pgconn = NULL;
-  lua_getfield(L, LUA_REGISTRYINDEX, MONDELEFANT_CONN_DATA_REGKEY);  // 2
-  lua_pushvalue(L, 1);  // 3
-  lua_gettable(L, 2);  // 3
-  lua_pushnil(L);  // 4
-  lua_setfield(L, 3, "fd");  // set "fd" attribute to nil
+  lua_pushnil(L);  // 2
+  lua_setfield(L, 1, "fd");  // set "fd" attribute to nil
   return 0;
 }
 
@@ -1990,15 +1976,6 @@
   lua_setfield(L, LUA_REGISTRYINDEX, MONDELEFANT_CLASS_PROTO_REGKEY);
   lua_setfield(L, 1, "class_prototype");
 
-  lua_newtable(L);  // 2
-  lua_pushliteral(L, "k");  // 3
-  lua_setfield(L, 2, "__mode");
-  lua_newtable(L);  // 3
-  lua_pushvalue(L, 2);  // 4
-  lua_setmetatable(L, 3);
-  lua_setfield(L, LUA_REGISTRYINDEX, MONDELEFANT_CONN_DATA_REGKEY);
-  lua_settop(L, 1);
-
   luaL_newmetatable(L, MONDELEFANT_ERROROBJECT_MT_REGKEY);  // 2
 #if LUA_VERSION_NUM >= 502
   luaL_setfuncs(L, mondelefant_errorobject_mt_functions, 0);