mirror of
https://github.com/ArduPilot/ardupilot.git
synced 2026-02-05 14:56:25 -06:00
a550087eee
The `luaL_testudata` and `luaL_checkudata` functions correctly treat the absence of a metatable for the type to check as the type not matching, so there is no need to have the type's metatable in memory until an object using it exists. Therefore we can defer the metatable's creation until the first time an object of that type is created. Saves some 4500 bytes of Lua heap RAM, at least if no such objects are created. The created metatables are shared between all scripts, so there is no increase in the total RAM usage if all objects are used. However, there is some increased risk of heap fragmentation and unexpected out-of-memory errors on rarely used code paths. It would be nice to construct the object in the new utility function, but it's not possible in C++ to take the address of a constructor. Instead passing in a lambda is ugly, hardly any more efficient, and screws up constructors which take parameters. Also optimizes by using the generated userdata creators where possible, and convincing the compiler to omit unnecessary checks.
87 lines
2.9 KiB
C
87 lines
2.9 KiB
C
#pragma once
|
|
|
|
// for inclusion at the end of the generated .cpp
|
|
|
|
void * new_ap_object(lua_State *L, size_t size, const char * name) {
|
|
void * ud = lua_newuserdata(L, size);
|
|
if (luaL_newmetatable(L, name)) { // metatable just created, set it up
|
|
for (uint32_t i = 0; i < ARRAY_SIZE(ap_object_fun); i++) {
|
|
if (strcmp(name, ap_object_fun[i].name) == 0) {
|
|
lua_pushcfunction(L, ap_object_fun[i].func);
|
|
lua_setfield(L, -2, "__index");
|
|
break;
|
|
}
|
|
}
|
|
// if no name matched, the metatable will be pointless but otherwise
|
|
// valid, so it's safe to continue. since this function isn't
|
|
// accessible to user code, it's probably not worth raising an error.
|
|
}
|
|
// correct metatable is on stack regardless of if we just set it up
|
|
lua_setmetatable(L, -2);
|
|
return ud;
|
|
}
|
|
|
|
void set_userdata_metatable(lua_State *L, const char * name) {
|
|
if (luaL_newmetatable(L, name)) { // metatable just created, set it up
|
|
for (uint32_t i = 0; i < ARRAY_SIZE(userdata_fun); i++) {
|
|
if (strcmp(name, userdata_fun[i].name) == 0) {
|
|
lua_pushcfunction(L, userdata_fun[i].func);
|
|
lua_setfield(L, -2, "__index");
|
|
if (userdata_fun[i].operators != nullptr) {
|
|
luaL_setfuncs(L, userdata_fun[i].operators, 0);
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
// if no name matched, the metatable will be pointless but otherwise
|
|
// valid, so it's safe to continue. since this function isn't
|
|
// accessible to user code, it's probably not worth raising an error.
|
|
}
|
|
// correct metatable is on stack regardless of if we just set it up
|
|
lua_setmetatable(L, -2);
|
|
}
|
|
|
|
static int binding_index(lua_State *L) {
|
|
const char * name = luaL_checkstring(L, 2);
|
|
|
|
bool found = false;
|
|
for (uint32_t i = 0; i < ARRAY_SIZE(singleton_fun); i++) {
|
|
if (strcmp(name, singleton_fun[i].name) == 0) {
|
|
lua_newuserdata(L, 0);
|
|
if (luaL_newmetatable(L, name)) { // need to create metatable
|
|
lua_pushcfunction(L, singleton_fun[i].func);
|
|
lua_setfield(L, -2, "__index");
|
|
}
|
|
lua_setmetatable(L, -2);
|
|
found = true;
|
|
break;
|
|
}
|
|
}
|
|
if (!found) {
|
|
for (uint32_t i = 0; i < ARRAY_SIZE(new_userdata); i++) {
|
|
if (strcmp(name, new_userdata[i].name) == 0) {
|
|
lua_pushcfunction(L, new_userdata[i].fun);
|
|
found = true;
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
if (!found) {
|
|
return 0;
|
|
}
|
|
|
|
// store found value to avoid a re-index
|
|
lua_pushvalue(L, -2);
|
|
lua_pushvalue(L, -2);
|
|
lua_settable(L, -5);
|
|
|
|
return 1;
|
|
}
|
|
|
|
void load_generated_sandbox(lua_State *L) {
|
|
lua_createtable(L, 0, 1);
|
|
lua_pushcfunction(L, binding_index);
|
|
lua_setfield(L, -2, "__index");
|
|
lua_setmetatable(L, -2);
|
|
}
|