degesch: Lua: add a "buffer" property to servers

1 files changed, 46 insertions, 11 deletions

diff --git a/degesch.c b/degesch.c
index 2ef07db..90f441c 100644
--- a/degesch.c
+++ b/degesch.c
@@ -7447,6 +7447,19 @@ lua_server_gc (lua_State *L)
 }
 
 static int
+lua_server_get_buffer (lua_State *L)
+{
+	struct lua_server *wrapper = luaL_checkudata (L, 1, XLUA_SERVER_METATABLE);
+	luaL_argcheck (L, wrapper->server, 1, "dead reference used");
+
+	if (wrapper->server->buffer)
+		lua_plugin_push_buffer (wrapper->plugin, wrapper->server->buffer);
+	else
+		lua_pushnil (L);
+	return 1;
+}
+
+static int
 lua_server_send (lua_State *L)
 {
 	struct lua_server *wrapper = luaL_checkudata (L, 1, XLUA_SERVER_METATABLE);
@@ -7460,9 +7473,10 @@ lua_server_send (lua_State *L)
 static luaL_Reg lua_server_table[] =
 {
 	// TODO: some useful methods or values
-	{ "__gc", lua_server_gc   },
-	{ "send", lua_server_send },
-	{ NULL,   NULL            }
+	{ "__gc",       lua_server_gc         },
+	{ "get_buffer", lua_server_get_buffer },
+	{ "send",       lua_server_send       },
+	{ NULL,         NULL                  }
 };
 
 static void
@@ -7820,20 +7834,41 @@ lua_plugin_panic (lua_State *L)
 	return 0;
 }
 
+static int
+lua_plugin_property_get (lua_State *L)
+{
+	luaL_checktype (L, 1, LUA_TUSERDATA);
+	const char *property_name = luaL_checkstring (L, 2);
+
+	// Either it's directly present in the metatable
+	if (luaL_getmetafield (L, 1, property_name))
+		return 1;
+
+	// Or we try to find and eventually call a getter method
+	char *getter_name = xstrdup_printf ("get_%s", property_name);
+	bool found = luaL_getmetafield (L, 1, getter_name);
+	free (getter_name);
+
+	if (found)
+	{
+		lua_pushvalue (L, 1);
+		lua_call (L, 1, 1);
+		return 1;
+	}
+
+	return luaL_error (L, "%s: %s",
+		"no such method or property", property_name);
+}
+
 static void
 lua_plugin_create_meta (lua_State *L, const char *name, luaL_Reg *fns)
 {
 	luaL_newmetatable (L, name);
 	luaL_setfuncs (L, fns, 0);
 
-	// Otherwise any non-meta functions would be inaccessible
-	bool has_own_index = (lua_getfield (L, -1, "__index") != LUA_TNIL);
-	lua_pop (L, 1);
-	if (!has_own_index)
-	{
-		lua_pushvalue (L, -1);
-		lua_setfield (L, -2, "__index");
-	}
+	// Emulate properties for convenience
+	lua_pushcfunction (L, lua_plugin_property_get);
+	lua_setfield (L, -2, "__index");
 	lua_pop (L, 1);
 }