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mlua/src/lua.rs
Alex Orlenko eed7b1f3af
More ffi module refactoring
2022-03-20 20:30:20 +00:00

3758 lines
134 KiB
Rust
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use std::any::{Any, TypeId};
use std::cell::{Ref, RefCell, RefMut, UnsafeCell};
use std::collections::HashMap;
use std::ffi::CString;
use std::fmt;
use std::marker::PhantomData;
use std::os::raw::{c_char, c_int, c_void};
use std::panic::{catch_unwind, resume_unwind, AssertUnwindSafe, Location};
use std::sync::{Arc, Mutex, RwLock};
use std::{mem, ptr, str};
use rustc_hash::FxHashMap;
use crate::error::{Error, Result};
use crate::ffi;
use crate::function::Function;
#[cfg(not(feature = "luau"))]
use crate::hook::{Debug, HookTriggers};
use crate::scope::Scope;
use crate::stdlib::StdLib;
use crate::string::String;
use crate::table::Table;
use crate::thread::Thread;
use crate::types::{
Callback, CallbackUpvalue, DestructedUserdataMT, /*HookCallback,*/ Integer, LightUserData,
LuaRef, MaybeSend, Number, RegistryKey,
};
use crate::userdata::{
AnyUserData, MetaMethod, UserData, UserDataCell, UserDataFields, UserDataMethods,
};
use crate::util::{
self, assert_stack, callback_error, check_stack, get_destructed_userdata_metatable,
get_gc_metatable, get_gc_userdata, get_main_state, get_userdata, init_error_registry,
init_gc_metatable, init_userdata_metatable, pop_error, push_gc_userdata, push_string,
push_table, rawset_field, safe_pcall, safe_xpcall, StackGuard, WrappedFailure,
};
use crate::value::{FromLua, FromLuaMulti, MultiValue, Nil, ToLua, ToLuaMulti, Value};
#[cfg(not(feature = "luau"))]
use crate::types::HookCallback;
#[cfg(not(feature = "lua54"))]
use crate::util::push_userdata;
#[cfg(feature = "lua54")]
use {
crate::{types::WarnCallback, userdata::USER_VALUE_MAXSLOT, util::push_userdata_uv},
std::ffi::CStr,
};
#[cfg(not(feature = "send"))]
use std::rc::Rc;
#[cfg(feature = "async")]
use {
crate::types::{AsyncCallback, AsyncCallbackUpvalue, AsyncPollUpvalue},
futures_core::{
future::{Future, LocalBoxFuture},
task::{Context, Poll, Waker},
},
futures_task::noop_waker,
futures_util::future::{self, TryFutureExt},
};
#[cfg(feature = "serialize")]
use serde::Serialize;
/// Top level Lua struct which holds the Lua state itself.
pub struct Lua {
pub(crate) state: *mut ffi::lua_State,
main_state: Option<*mut ffi::lua_State>,
extra: Arc<UnsafeCell<ExtraData>>,
ephemeral: bool,
safe: bool,
// Lua has lots of interior mutability, should not be RefUnwindSafe
_no_ref_unwind_safe: PhantomData<UnsafeCell<()>>,
}
// Data associated with the Lua.
struct ExtraData {
registered_userdata: FxHashMap<TypeId, c_int>,
registered_userdata_mt: FxHashMap<*const c_void, Option<TypeId>>,
registry_unref_list: Arc<Mutex<Option<Vec<c_int>>>>,
#[cfg(not(feature = "send"))]
app_data: RefCell<HashMap<TypeId, Box<dyn Any>>>,
#[cfg(feature = "send")]
app_data: RefCell<HashMap<TypeId, Box<dyn Any + Send>>>,
libs: StdLib,
mem_info: Option<ptr::NonNull<MemoryInfo>>,
safe: bool, // Same as in the Lua struct
ref_thread: *mut ffi::lua_State,
ref_stack_size: c_int,
ref_stack_top: c_int,
ref_free: Vec<c_int>,
// Cache of `WrappedFailure` enums on the ref thread (as userdata)
wrapped_failures_cache: Vec<c_int>,
// Cache of recycled `MultiValue` containers
multivalue_cache: Vec<MultiValue<'static>>,
// Cache of recycled `Thread`s (coroutines)
#[cfg(feature = "async")]
recycled_thread_cache: Vec<c_int>,
// Index of `Option<Waker>` userdata on the ref thread
#[cfg(feature = "async")]
ref_waker_idx: c_int,
#[cfg(not(feature = "luau"))]
hook_callback: Option<HookCallback>,
#[cfg(feature = "lua54")]
warn_callback: Option<WarnCallback>,
}
#[cfg_attr(any(feature = "lua51", feature = "luajit"), allow(dead_code))]
struct MemoryInfo {
used_memory: isize,
memory_limit: isize,
}
/// Mode of the Lua garbage collector (GC).
///
/// In Lua 5.4 GC can work in two modes: incremental and generational.
/// Previous Lua versions support only incremental GC.
///
/// More information can be found in the Lua [documentation].
///
/// [documentation]: https://www.lua.org/manual/5.4/manual.html#2.5
#[derive(Clone, Copy, Debug, PartialEq, Eq)]
pub enum GCMode {
Incremental,
/// Requires `feature = "lua54"`
#[cfg(any(feature = "lua54"))]
Generational,
}
/// Controls Lua interpreter behavior such as Rust panics handling.
#[derive(Clone, Debug)]
#[non_exhaustive]
pub struct LuaOptions {
/// Catch Rust panics when using [`pcall`]/[`xpcall`].
///
/// If disabled, wraps these functions and automatically resumes panic if found.
/// Also in Lua 5.1 adds ability to provide arguments to [`xpcall`] similar to Lua >= 5.2.
///
/// If enabled, keeps [`pcall`]/[`xpcall`] unmodified.
/// Panics are still automatically resumed if returned to the Rust side.
///
/// Default: **true**
///
/// [`pcall`]: https://www.lua.org/manual/5.4/manual.html#pdf-pcall
/// [`xpcall`]: https://www.lua.org/manual/5.4/manual.html#pdf-xpcall
pub catch_rust_panics: bool,
/// Max size of thread (coroutine) object cache used to execute asynchronous functions.
///
/// It works only on Lua 5.4 or LuaJIT (vendored) with [`lua_resetthread`] function,
/// and allows to reuse old coroutines with reset state.
///
/// Default: **0** (disabled)
///
/// [`lua_resetthread`]: https://www.lua.org/manual/5.4/manual.html#lua_resetthread
#[cfg(feature = "async")]
#[cfg_attr(docsrs, doc(cfg(feature = "async")))]
pub thread_cache_size: usize,
}
impl Default for LuaOptions {
fn default() -> Self {
LuaOptions::new()
}
}
impl LuaOptions {
/// Returns a new instance of `LuaOptions` with default parameters.
pub const fn new() -> Self {
LuaOptions {
catch_rust_panics: true,
#[cfg(feature = "async")]
thread_cache_size: 0,
}
}
/// Sets [`catch_rust_panics`] option.
///
/// [`catch_rust_panics`]: #structfield.catch_rust_panics
#[must_use]
pub const fn catch_rust_panics(mut self, enabled: bool) -> Self {
self.catch_rust_panics = enabled;
self
}
/// Sets [`thread_cache_size`] option.
///
/// [`thread_cache_size`]: #structfield.thread_cache_size
#[cfg(feature = "async")]
#[cfg_attr(docsrs, doc(cfg(feature = "async")))]
#[must_use]
pub const fn thread_cache_size(mut self, size: usize) -> Self {
self.thread_cache_size = size;
self
}
}
#[cfg(feature = "async")]
pub(crate) static ASYNC_POLL_PENDING: u8 = 0;
pub(crate) static EXTRA_REGISTRY_KEY: u8 = 0;
const WRAPPED_FAILURES_CACHE_SIZE: usize = 16;
const MULTIVALUE_CACHE_SIZE: usize = 16;
/// Requires `feature = "send"`
#[cfg(feature = "send")]
#[cfg_attr(docsrs, doc(cfg(feature = "send")))]
unsafe impl Send for Lua {}
impl Drop for Lua {
fn drop(&mut self) {
unsafe {
if !self.ephemeral {
let extra = &mut *self.extra.get();
let drain_iter = extra.wrapped_failures_cache.drain(..);
#[cfg(feature = "async")]
let drain_iter = drain_iter.chain(extra.recycled_thread_cache.drain(..));
for index in drain_iter {
ffi::lua_pushnil(extra.ref_thread);
ffi::lua_replace(extra.ref_thread, index);
extra.ref_free.push(index);
}
#[cfg(feature = "async")]
{
// Destroy Waker slot
ffi::lua_pushnil(extra.ref_thread);
ffi::lua_replace(extra.ref_thread, extra.ref_waker_idx);
extra.ref_free.push(extra.ref_waker_idx);
}
mlua_debug_assert!(
ffi::lua_gettop(extra.ref_thread) == extra.ref_stack_top
&& extra.ref_stack_top as usize == extra.ref_free.len(),
"reference leak detected"
);
ffi::lua_close(mlua_expect!(self.main_state, "main_state is null"));
}
}
}
}
impl Drop for ExtraData {
fn drop(&mut self) {
*mlua_expect!(self.registry_unref_list.lock(), "unref list poisoned") = None;
if let Some(mem_info) = self.mem_info {
drop(unsafe { Box::from_raw(mem_info.as_ptr()) });
}
}
}
impl fmt::Debug for Lua {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
write!(f, "Lua({:p})", self.state)
}
}
impl Lua {
/// Creates a new Lua state and loads the **safe** subset of the standard libraries.
///
/// # Safety
/// The created Lua state would have _some_ safety guarantees and would not allow to load unsafe
/// standard libraries or C modules.
///
/// See [`StdLib`] documentation for a list of unsafe modules that cannot be loaded.
///
/// [`StdLib`]: crate::StdLib
#[allow(clippy::new_without_default)]
pub fn new() -> Lua {
mlua_expect!(
Self::new_with(StdLib::ALL_SAFE, LuaOptions::default()),
"can't create new safe Lua state"
)
}
/// Creates a new Lua state and loads all the standard libraries.
///
/// # Safety
/// The created Lua state would not have safety guarantees and would allow to load C modules.
pub unsafe fn unsafe_new() -> Lua {
Self::unsafe_new_with(StdLib::ALL, LuaOptions::default())
}
/// Creates a new Lua state and loads the specified safe subset of the standard libraries.
///
/// Use the [`StdLib`] flags to specify the libraries you want to load.
///
/// # Safety
/// The created Lua state would have _some_ safety guarantees and would not allow to load unsafe
/// standard libraries or C modules.
///
/// See [`StdLib`] documentation for a list of unsafe modules that cannot be loaded.
///
/// [`StdLib`]: crate::StdLib
pub fn new_with(libs: StdLib, options: LuaOptions) -> Result<Lua> {
if libs.contains(StdLib::DEBUG) {
return Err(Error::SafetyError(
"the unsafe `debug` module can't be loaded using safe `new_with`".to_string(),
));
}
#[cfg(feature = "luajit")]
{
if libs.contains(StdLib::FFI) {
return Err(Error::SafetyError(
"the unsafe `ffi` module can't be loaded using safe `new_with`".to_string(),
));
}
}
let mut lua = unsafe { Self::inner_new(libs, options) };
#[cfg(not(feature = "luau"))]
if libs.contains(StdLib::PACKAGE) {
mlua_expect!(lua.disable_c_modules(), "Error during disabling C modules");
}
lua.safe = true;
unsafe { (*lua.extra.get()).safe = true };
Ok(lua)
}
/// Creates a new Lua state and loads the specified subset of the standard libraries.
///
/// Use the [`StdLib`] flags to specify the libraries you want to load.
///
/// # Safety
/// The created Lua state will not have safety guarantees and allow to load C modules.
///
/// [`StdLib`]: crate::StdLib
pub unsafe fn unsafe_new_with(libs: StdLib, options: LuaOptions) -> Lua {
#[cfg(not(feature = "luau"))]
ffi::keep_lua_symbols();
Self::inner_new(libs, options)
}
unsafe fn inner_new(libs: StdLib, options: LuaOptions) -> Lua {
#[cfg_attr(
any(feature = "lua51", feature = "luajit", feature = "luau"),
allow(dead_code)
)]
unsafe extern "C" fn allocator(
extra_data: *mut c_void,
ptr: *mut c_void,
osize: usize,
nsize: usize,
) -> *mut c_void {
use std::alloc;
let mem_info = &mut *(extra_data as *mut MemoryInfo);
if nsize == 0 {
// Free memory
if !ptr.is_null() {
let layout =
alloc::Layout::from_size_align_unchecked(osize, ffi::SYS_MIN_ALIGN);
alloc::dealloc(ptr as *mut u8, layout);
mem_info.used_memory -= osize as isize;
}
return ptr::null_mut();
}
// Are we fit to the memory limits?
let mut mem_diff = nsize as isize;
if !ptr.is_null() {
mem_diff -= osize as isize;
}
let new_used_memory = mem_info.used_memory + mem_diff;
if mem_info.memory_limit > 0 && new_used_memory > mem_info.memory_limit {
return ptr::null_mut();
}
let new_layout = alloc::Layout::from_size_align_unchecked(nsize, ffi::SYS_MIN_ALIGN);
if ptr.is_null() {
// Allocate new memory
let new_ptr = alloc::alloc(new_layout) as *mut c_void;
if !new_ptr.is_null() {
mem_info.used_memory += mem_diff;
}
return new_ptr;
}
// Reallocate memory
let old_layout = alloc::Layout::from_size_align_unchecked(osize, ffi::SYS_MIN_ALIGN);
let new_ptr = alloc::realloc(ptr as *mut u8, old_layout, nsize) as *mut c_void;
if !new_ptr.is_null() {
mem_info.used_memory += mem_diff;
} else if !ptr.is_null() && nsize < osize {
// Should not happen
alloc::handle_alloc_error(new_layout);
}
new_ptr
}
#[cfg(any(feature = "lua54", feature = "lua53", feature = "lua52"))]
let mem_info = Box::into_raw(Box::new(MemoryInfo {
used_memory: 0,
memory_limit: 0,
}));
#[cfg(any(feature = "lua54", feature = "lua53", feature = "lua52"))]
let state = ffi::lua_newstate(allocator, mem_info as *mut c_void);
#[cfg(any(feature = "lua51", feature = "luajit", feature = "luau"))]
let state = ffi::luaL_newstate();
// #[cfg(feature = "luau")]
// {
// ffi::luaL_sandbox(state);
// }
ffi::luaL_requiref(state, cstr!("_G"), ffi::luaopen_base, 1);
ffi::lua_pop(state, 1);
let mut lua = Lua::init_from_ptr(state);
lua.ephemeral = false;
let extra = &mut *lua.extra.get();
#[cfg(any(feature = "lua54", feature = "lua53", feature = "lua52"))]
{
extra.mem_info = ptr::NonNull::new(mem_info);
}
mlua_expect!(
load_from_std_lib(state, libs),
"Error during loading standard libraries"
);
extra.libs |= libs;
if !options.catch_rust_panics {
mlua_expect!(
(|| -> Result<()> {
let _sg = StackGuard::new(lua.state);
#[cfg(any(feature = "lua54", feature = "lua53", feature = "lua52"))]
ffi::lua_rawgeti(lua.state, ffi::LUA_REGISTRYINDEX, ffi::LUA_RIDX_GLOBALS);
#[cfg(any(feature = "lua51", feature = "luajit", feature = "luau"))]
ffi::lua_pushvalue(lua.state, ffi::LUA_GLOBALSINDEX);
ffi::lua_pushcfunction(lua.state, safe_pcall);
rawset_field(lua.state, -2, "pcall")?;
ffi::lua_pushcfunction(lua.state, safe_xpcall);
rawset_field(lua.state, -2, "xpcall")?;
Ok(())
})(),
"Error during applying option `catch_rust_panics`"
)
}
#[cfg(feature = "async")]
if options.thread_cache_size > 0 {
extra.recycled_thread_cache = Vec::with_capacity(options.thread_cache_size);
}
#[cfg(feature = "luau")]
mlua_expect!(lua.prepare_luau_state(), "Error preparing Luau state");
lua
}
/// Constructs a new Lua instance from an existing raw state.
///
/// Once called, a returned Lua state is cached in the registry and can be retrieved
/// by calling this function again.
#[allow(clippy::missing_safety_doc)]
pub unsafe fn init_from_ptr(state: *mut ffi::lua_State) -> Lua {
let maybe_main_state = get_main_state(state);
let main_state = maybe_main_state.unwrap_or(state);
let main_state_top = ffi::lua_gettop(main_state);
if let Some(lua) = Lua::make_from_ptr(state) {
return lua;
}
mlua_expect!(
(|state| {
init_error_registry(state)?;
// Create the internal metatables and place them in the registry
// to prevent them from being garbage collected.
init_gc_metatable::<Arc<UnsafeCell<ExtraData>>>(state, None)?;
init_gc_metatable::<Callback>(state, None)?;
init_gc_metatable::<CallbackUpvalue>(state, None)?;
#[cfg(feature = "async")]
{
init_gc_metatable::<AsyncCallback>(state, None)?;
init_gc_metatable::<AsyncCallbackUpvalue>(state, None)?;
init_gc_metatable::<AsyncPollUpvalue>(state, None)?;
init_gc_metatable::<Option<Waker>>(state, None)?;
}
// Init serde metatables
#[cfg(feature = "serialize")]
crate::serde::init_metatables(state)?;
Ok::<_, Error>(())
})(main_state),
"Error during Lua construction",
);
// Create ref stack thread and place it in the registry to prevent it from being garbage
// collected.
let ref_thread = mlua_expect!(
protect_lua!(state, 0, 0, |state| {
let thread = ffi::lua_newthread(state);
ffi::luaL_ref(state, ffi::LUA_REGISTRYINDEX);
thread
}),
"Error while creating ref thread",
);
// Create empty Waker slot on the ref thread
#[cfg(feature = "async")]
let ref_waker_idx = {
mlua_expect!(
push_gc_userdata::<Option<Waker>>(ref_thread, None),
"Error while creating Waker slot"
);
ffi::lua_gettop(ref_thread)
};
let ref_stack_top = ffi::lua_gettop(ref_thread);
// Create ExtraData
let extra = Arc::new(UnsafeCell::new(ExtraData {
registered_userdata: FxHashMap::default(),
registered_userdata_mt: FxHashMap::default(),
registry_unref_list: Arc::new(Mutex::new(Some(Vec::new()))),
app_data: RefCell::new(HashMap::new()),
ref_thread,
libs: StdLib::NONE,
mem_info: None,
safe: false,
// We need 1 extra stack space to move values in and out of the ref stack.
ref_stack_size: ffi::LUA_MINSTACK - 1,
ref_stack_top,
ref_free: Vec::new(),
wrapped_failures_cache: Vec::with_capacity(WRAPPED_FAILURES_CACHE_SIZE),
multivalue_cache: Vec::with_capacity(MULTIVALUE_CACHE_SIZE),
#[cfg(feature = "async")]
recycled_thread_cache: Vec::new(),
#[cfg(feature = "async")]
ref_waker_idx,
#[cfg(not(feature = "luau"))]
hook_callback: None,
#[cfg(feature = "lua54")]
warn_callback: None,
}));
mlua_expect!(
(|state| {
push_gc_userdata(state, Arc::clone(&extra))?;
protect_lua!(main_state, 1, 0, fn(state) {
let extra_key = &EXTRA_REGISTRY_KEY as *const u8 as *const c_void;
ffi::lua_rawsetp(state, ffi::LUA_REGISTRYINDEX, extra_key);
})
})(main_state),
"Error while storing extra data",
);
// Register `DestructedUserdataMT` type
get_destructed_userdata_metatable(main_state);
let destructed_mt_ptr = ffi::lua_topointer(main_state, -1);
(*extra.get()).registered_userdata_mt.insert(
destructed_mt_ptr,
Some(TypeId::of::<DestructedUserdataMT>()),
);
ffi::lua_pop(main_state, 1);
mlua_debug_assert!(
ffi::lua_gettop(main_state) == main_state_top,
"stack leak during creation"
);
assert_stack(main_state, ffi::LUA_MINSTACK);
Lua {
state,
main_state: maybe_main_state,
extra,
ephemeral: true,
safe: false,
_no_ref_unwind_safe: PhantomData,
}
}
/// Loads the specified subset of the standard libraries into an existing Lua state.
///
/// Use the [`StdLib`] flags to specify the libraries you want to load.
///
/// [`StdLib`]: crate::StdLib
pub fn load_from_std_lib(&self, libs: StdLib) -> Result<()> {
if self.safe && libs.contains(StdLib::DEBUG) {
return Err(Error::SafetyError(
"the unsafe `debug` module can't be loaded in safe mode".to_string(),
));
}
#[cfg(feature = "luajit")]
{
if self.safe && libs.contains(StdLib::FFI) {
return Err(Error::SafetyError(
"the unsafe `ffi` module can't be loaded in safe mode".to_string(),
));
}
}
let state = self.main_state.unwrap_or(self.state);
let res = unsafe { load_from_std_lib(state, libs) };
// If `package` library loaded into a safe lua state then disable C modules
let extra = unsafe { &mut *self.extra.get() };
#[cfg(not(feature = "luau"))]
{
let curr_libs = extra.libs;
if self.safe && (curr_libs ^ (curr_libs | libs)).contains(StdLib::PACKAGE) {
mlua_expect!(self.disable_c_modules(), "Error during disabling C modules");
}
}
extra.libs |= libs;
res
}
/// Loads module `modname` into an existing Lua state using the specified entrypoint
/// function.
///
/// Internally calls the Lua function `func` with the string `modname` as an argument,
/// sets the call result to `package.loaded[modname]` and returns copy of the result.
///
/// If `package.loaded[modname]` value is not nil, returns copy of the value without
/// calling the function.
///
/// If the function does not return a non-nil value then this method assigns true to
/// `package.loaded[modname]`.
///
/// Behavior is similar to Lua's [`require`] function.
///
/// [`require`]: https://www.lua.org/manual/5.4/manual.html#pdf-require
pub fn load_from_function<'lua, S, T>(
&'lua self,
modname: &S,
func: Function<'lua>,
) -> Result<T>
where
S: AsRef<[u8]> + ?Sized,
T: FromLua<'lua>,
{
let loaded = unsafe {
let _sg = StackGuard::new(self.state);
check_stack(self.state, 2)?;
protect_lua!(self.state, 0, 1, fn(state) {
ffi::luaL_getsubtable(state, ffi::LUA_REGISTRYINDEX, cstr!("_LOADED"));
})?;
Table(self.pop_ref())
};
let modname = self.create_string(modname)?;
let value = match loaded.raw_get(modname.clone())? {
Value::Nil => {
let result = match func.call(modname.clone())? {
Value::Nil => Value::Boolean(true),
res => res,
};
loaded.raw_set(modname, result.clone())?;
result
}
res => res,
};
T::from_lua(value, self)
}
/// Unloads module `modname`.
///
/// Removes module from the [`package.loaded`] table which allows to load it again.
/// It does not support unloading binary Lua modules since they are internally cached and can be
/// unloaded only by closing Lua state.
///
/// [`package.loaded`]: https://www.lua.org/manual/5.4/manual.html#pdf-package.loaded
pub fn unload<S>(&self, modname: &S) -> Result<()>
where
S: AsRef<[u8]> + ?Sized,
{
let loaded = unsafe {
let _sg = StackGuard::new(self.state);
check_stack(self.state, 2)?;
protect_lua!(self.state, 0, 1, fn(state) {
ffi::luaL_getsubtable(state, ffi::LUA_REGISTRYINDEX, cstr!("_LOADED"));
})?;
Table(self.pop_ref())
};
let modname = self.create_string(modname)?;
loaded.raw_remove(modname)?;
Ok(())
}
/// Consumes and leaks `Lua` object, returning a static reference `&'static Lua`.
///
/// This function is useful when the `Lua` object is supposed to live for the remainder
/// of the program's life.
/// In particular in asynchronous context this will allow to spawn Lua tasks to execute
/// in background.
///
/// Dropping the returned reference will cause a memory leak. If this is not acceptable,
/// the reference should first be wrapped with the [`Lua::from_static`] function producing a `Lua`.
/// This `Lua` object can then be dropped which will properly release the allocated memory.
///
/// [`Lua::from_static`]: #method.from_static
#[doc(hidden)]
pub fn into_static(self) -> &'static Self {
Box::leak(Box::new(self))
}
/// Constructs a `Lua` from a static reference to it.
///
/// # Safety
/// This function is unsafe because improper use may lead to memory problems or undefined behavior.
#[doc(hidden)]
pub unsafe fn from_static(lua: &'static Lua) -> Self {
*Box::from_raw(lua as *const Lua as *mut Lua)
}
// Executes module entrypoint function, which returns only one Value.
// The returned value then pushed onto the stack.
#[doc(hidden)]
#[cfg(not(tarpaulin_include))]
pub unsafe fn entrypoint<'lua, A, R, F>(self, func: F) -> Result<c_int>
where
A: FromLuaMulti<'lua>,
R: ToLua<'lua>,
F: 'static + MaybeSend + Fn(&'lua Lua, A) -> Result<R>,
{
let entrypoint_inner = |lua: &'lua Lua, func: F| {
let nargs = ffi::lua_gettop(lua.state);
check_stack(lua.state, 3)?;
let mut args = MultiValue::new();
args.reserve(nargs as usize);
for _ in 0..nargs {
args.push_front(lua.pop_value());
}
// We create callback rather than call `func` directly to catch errors
// with attached stacktrace.
let callback = lua.create_callback(Box::new(move |lua, args| {
func(lua, A::from_lua_multi(args, lua)?)?.to_lua_multi(lua)
}))?;
callback.call(args)
};
match entrypoint_inner(mem::transmute(&self), func) {
Ok(res) => {
self.push_value(res)?;
Ok(1)
}
Err(err) => {
self.push_value(Value::Error(err))?;
let state = self.state;
// Lua (self) must be dropped before triggering longjmp
drop(self);
ffi::lua_error(state)
}
}
}
// A simple module entrypoint without arguments
#[doc(hidden)]
#[cfg(not(tarpaulin_include))]
pub unsafe fn entrypoint1<'lua, R, F>(self, func: F) -> Result<c_int>
where
R: ToLua<'lua>,
F: 'static + MaybeSend + Fn(&'lua Lua) -> Result<R>,
{
self.entrypoint(move |lua, _: ()| func(lua))
}
/// Sets a 'hook' function that will periodically be called as Lua code executes.
///
/// When exactly the hook function is called depends on the contents of the `triggers`
/// parameter, see [`HookTriggers`] for more details.
///
/// The provided hook function can error, and this error will be propagated through the Lua code
/// that was executing at the time the hook was triggered. This can be used to implement a
/// limited form of execution limits by setting [`HookTriggers.every_nth_instruction`] and
/// erroring once an instruction limit has been reached.
///
/// # Example
///
/// Shows each line number of code being executed by the Lua interpreter.
///
/// ```
/// # use mlua::{Lua, HookTriggers, Result};
/// # fn main() -> Result<()> {
/// let lua = Lua::new();
/// lua.set_hook(HookTriggers::every_line(), |_lua, debug| {
/// println!("line {}", debug.curr_line());
/// Ok(())
/// })?;
///
/// lua.load(r#"
/// local x = 2 + 3
/// local y = x * 63
/// local z = string.len(x..", "..y)
/// "#).exec()
/// # }
/// ```
///
/// [`HookTriggers`]: crate::HookTriggers
/// [`HookTriggers.every_nth_instruction`]: crate::HookTriggers::every_nth_instruction
#[cfg(not(feature = "luau"))]
pub fn set_hook<F>(&self, triggers: HookTriggers, callback: F) -> Result<()>
where
F: 'static + MaybeSend + FnMut(&Lua, Debug) -> Result<()>,
{
unsafe extern "C" fn hook_proc(state: *mut ffi::lua_State, ar: *mut ffi::lua_Debug) {
let lua = match Lua::make_from_ptr(state) {
Some(lua) => lua,
None => return,
};
let extra = lua.extra.get();
callback_error_ext(state, extra, move |_| {
let debug = Debug::new(&lua, ar);
let hook_cb = (*lua.extra.get()).hook_callback.clone();
let hook_cb = mlua_expect!(hook_cb, "no hook callback set in hook_proc");
#[allow(clippy::match_wild_err_arm)]
match hook_cb.try_lock() {
Ok(mut cb) => cb(&lua, debug),
Err(_) => {
mlua_panic!("Lua should not allow hooks to be called within another hook")
}
}?;
Ok(())
})
}
let state = self.main_state.ok_or(Error::MainThreadNotAvailable)?;
unsafe {
(*self.extra.get()).hook_callback = Some(Arc::new(Mutex::new(callback)));
ffi::lua_sethook(state, Some(hook_proc), triggers.mask(), triggers.count());
}
Ok(())
}
/// Remove any hook previously set by `set_hook`. This function has no effect if a hook was not
/// previously set.
#[cfg(not(feature = "luau"))]
pub fn remove_hook(&self) {
// If main_state is not available, then sethook wasn't called.
let state = match self.main_state {
Some(state) => state,
None => return,
};
unsafe {
(*self.extra.get()).hook_callback = None;
ffi::lua_sethook(state, None, 0, 0);
}
}
/// Sets the warning function to be used by Lua to emit warnings.
///
/// Requires `feature = "lua54"`
#[cfg(feature = "lua54")]
pub fn set_warning_function<F>(&self, callback: F)
where
F: 'static + MaybeSend + Fn(&Lua, &CStr, bool) -> Result<()>,
{
unsafe extern "C" fn warn_proc(ud: *mut c_void, msg: *const c_char, tocont: c_int) {
let state = ud as *mut ffi::lua_State;
let lua = match Lua::make_from_ptr(state) {
Some(lua) => lua,
None => return,
};
let extra = lua.extra.get();
callback_error_ext(state, extra, move |_| {
let cb = mlua_expect!(
(*lua.extra.get()).warn_callback.as_ref(),
"no warning callback set in warn_proc"
);
let msg = CStr::from_ptr(msg);
cb(&lua, msg, tocont != 0)
});
}
let state = self.main_state.unwrap_or(self.state);
unsafe {
(*self.extra.get()).warn_callback = Some(Box::new(callback));
ffi::lua_setwarnf(state, Some(warn_proc), state as *mut c_void);
}
}
/// Removes warning function previously set by `set_warning_function`.
///
/// This function has no effect if a warning function was not previously set.
///
/// Requires `feature = "lua54"`
#[cfg(feature = "lua54")]
pub fn remove_warning_function(&self) {
let state = self.main_state.unwrap_or(self.state);
unsafe {
(*self.extra.get()).warn_callback = None;
ffi::lua_setwarnf(state, None, ptr::null_mut());
}
}
/// Emits a warning with the given message.
///
/// A message in a call with `tocont` set to `true` should be continued in another call to this function.
///
/// Requires `feature = "lua54"`
#[cfg(feature = "lua54")]
pub fn warning<S: Into<Vec<u8>>>(&self, msg: S, tocont: bool) -> Result<()> {
let msg = CString::new(msg).map_err(|err| Error::RuntimeError(err.to_string()))?;
unsafe { ffi::lua_warning(self.state, msg.as_ptr(), if tocont { 1 } else { 0 }) };
Ok(())
}
/// Gets information about the interpreter runtime stack.
///
/// This function returns [`Debug`] structure that can be used to get information about the function
/// executing at a given level. Level `0` is the current running function, whereas level `n+1` is the
/// function that has called level `n` (except for tail calls, which do not count in the stack).
///
/// [`Debug`]: crate::hook::Debug
#[cfg(not(feature = "luau"))]
pub fn inspect_stack(&self, level: usize) -> Option<Debug> {
unsafe {
let mut ar: ffi::lua_Debug = mem::zeroed();
if ffi::lua_getstack(self.state, level as c_int, &mut ar) == 0 {
return None;
}
Some(Debug::new_owned(self, ar))
}
}
/// Returns the amount of memory (in bytes) currently used inside this Lua state.
pub fn used_memory(&self) -> usize {
unsafe {
let state = self.main_state.unwrap_or(self.state);
match (*self.extra.get()).mem_info.map(|x| x.as_ref()) {
Some(mem_info) => mem_info.used_memory as usize,
None => {
// Get data from the Lua GC
let used_kbytes = ffi::lua_gc(state, ffi::LUA_GCCOUNT, 0);
let used_kbytes_rem = ffi::lua_gc(state, ffi::LUA_GCCOUNTB, 0);
(used_kbytes as usize) * 1024 + (used_kbytes_rem as usize)
}
}
}
}
/// Sets a memory limit (in bytes) on this Lua state.
///
/// Once an allocation occurs that would pass this memory limit,
/// a `Error::MemoryError` is generated instead.
/// Returns previous limit (zero means no limit).
///
/// Does not work on module mode where Lua state is managed externally.
///
/// Requires `feature = "lua54/lua53/lua52"`
#[cfg(any(feature = "lua54", feature = "lua53", feature = "lua52"))]
pub fn set_memory_limit(&self, memory_limit: usize) -> Result<usize> {
unsafe {
match (*self.extra.get()).mem_info.map(|mut x| x.as_mut()) {
Some(mem_info) => {
let prev_limit = mem_info.memory_limit as usize;
mem_info.memory_limit = memory_limit as isize;
Ok(prev_limit)
}
None => Err(Error::MemoryLimitNotAvailable),
}
}
}
/// Returns true if the garbage collector is currently running automatically.
///
/// Requires `feature = "lua54/lua53/lua52"`
#[cfg(any(
feature = "lua54",
feature = "lua53",
feature = "lua52",
feature = "luau"
))]
pub fn gc_is_running(&self) -> bool {
let state = self.main_state.unwrap_or(self.state);
unsafe { ffi::lua_gc(state, ffi::LUA_GCISRUNNING, 0) != 0 }
}
/// Stop the Lua GC from running
pub fn gc_stop(&self) {
let state = self.main_state.unwrap_or(self.state);
unsafe { ffi::lua_gc(state, ffi::LUA_GCSTOP, 0) };
}
/// Restarts the Lua GC if it is not running
pub fn gc_restart(&self) {
let state = self.main_state.unwrap_or(self.state);
unsafe { ffi::lua_gc(state, ffi::LUA_GCRESTART, 0) };
}
/// Perform a full garbage-collection cycle.
///
/// It may be necessary to call this function twice to collect all currently unreachable
/// objects. Once to finish the current gc cycle, and once to start and finish the next cycle.
pub fn gc_collect(&self) -> Result<()> {
let state = self.main_state.unwrap_or(self.state);
unsafe {
check_stack(state, 3)?;
protect_lua!(state, 0, 0, fn(state) ffi::lua_gc(state, ffi::LUA_GCCOLLECT, 0))
}
}
/// Steps the garbage collector one indivisible step.
///
/// Returns true if this has finished a collection cycle.
pub fn gc_step(&self) -> Result<bool> {
self.gc_step_kbytes(0)
}
/// Steps the garbage collector as though memory had been allocated.
///
/// if `kbytes` is 0, then this is the same as calling `gc_step`. Returns true if this step has
/// finished a collection cycle.
pub fn gc_step_kbytes(&self, kbytes: c_int) -> Result<bool> {
let state = self.main_state.unwrap_or(self.state);
unsafe {
check_stack(state, 3)?;
protect_lua!(state, 0, 0, |state| {
ffi::lua_gc(state, ffi::LUA_GCSTEP, kbytes) != 0
})
}
}
/// Sets the 'pause' value of the collector.
///
/// Returns the previous value of 'pause'. More information can be found in the Lua
/// [documentation][lua_doc].
///
/// [lua_doc]: https://www.lua.org/manual/5.4/manual.html#2.5
#[cfg(not(feature = "luau"))]
pub fn gc_set_pause(&self, pause: c_int) -> c_int {
let state = self.main_state.unwrap_or(self.state);
unsafe { ffi::lua_gc(state, ffi::LUA_GCSETPAUSE, pause) }
}
/// Sets the 'step multiplier' value of the collector.
///
/// Returns the previous value of the 'step multiplier'. More information can be found in the
/// Lua [documentation][lua_doc].
///
/// [lua_doc]: https://www.lua.org/manual/5.4/manual.html#2.5
pub fn gc_set_step_multiplier(&self, step_multiplier: c_int) -> c_int {
let state = self.main_state.unwrap_or(self.state);
unsafe { ffi::lua_gc(state, ffi::LUA_GCSETSTEPMUL, step_multiplier) }
}
/// Changes the collector to incremental mode with the given parameters.
///
/// Returns the previous mode (always `GCMode::Incremental` in Lua < 5.4).
/// More information can be found in the Lua [documentation][lua_doc].
///
/// [lua_doc]: https://www.lua.org/manual/5.4/manual.html#2.5.1
#[cfg(not(feature = "luau"))]
pub fn gc_inc(&self, pause: c_int, step_multiplier: c_int, step_size: c_int) -> GCMode {
let state = self.main_state.unwrap_or(self.state);
#[cfg(any(
feature = "lua53",
feature = "lua52",
feature = "lua51",
feature = "luajit"
))]
{
if pause > 0 {
unsafe { ffi::lua_gc(state, ffi::LUA_GCSETPAUSE, pause) };
}
if step_multiplier > 0 {
unsafe { ffi::lua_gc(state, ffi::LUA_GCSETSTEPMUL, step_multiplier) };
}
let _ = step_size; // Ignored
GCMode::Incremental
}
#[cfg(feature = "lua54")]
let prev_mode =
unsafe { ffi::lua_gc(state, ffi::LUA_GCINC, pause, step_multiplier, step_size) };
#[cfg(feature = "lua54")]
match prev_mode {
ffi::LUA_GCINC => GCMode::Incremental,
ffi::LUA_GCGEN => GCMode::Generational,
_ => unreachable!(),
}
}
/// Changes the collector to generational mode with the given parameters.
///
/// Returns the previous mode. More information about the generational GC
/// can be found in the Lua 5.4 [documentation][lua_doc].
///
/// Requires `feature = "lua54"`
///
/// [lua_doc]: https://www.lua.org/manual/5.4/manual.html#2.5.2
#[cfg(any(feature = "lua54"))]
pub fn gc_gen(&self, minor_multiplier: c_int, major_multiplier: c_int) -> GCMode {
let state = self.main_state.unwrap_or(self.state);
let prev_mode =
unsafe { ffi::lua_gc(state, ffi::LUA_GCGEN, minor_multiplier, major_multiplier) };
match prev_mode {
ffi::LUA_GCGEN => GCMode::Generational,
ffi::LUA_GCINC => GCMode::Incremental,
_ => unreachable!(),
}
}
/// Returns Lua source code as a `Chunk` builder type.
///
/// In order to actually compile or run the resulting code, you must call [`Chunk::exec`] or
/// similar on the returned builder. Code is not even parsed until one of these methods is
/// called.
///
/// If this `Lua` was created with [`unsafe_new`], `load` will automatically detect and load
/// chunks of either text or binary type, as if passing `bt` mode to `luaL_loadbufferx`.
///
/// [`Chunk::exec`]: crate::Chunk::exec
/// [`unsafe_new`]: #method.unsafe_new
#[track_caller]
pub fn load<'lua, 'a, S>(&'lua self, source: &'a S) -> Chunk<'lua, 'a>
where
S: AsChunk<'lua> + ?Sized,
{
Chunk {
lua: self,
source: source.source(),
name: match source.name() {
Some(name) => Some(name),
None => CString::new(Location::caller().to_string()).ok(),
},
env: source.env(self),
mode: source.mode(),
}
}
fn load_chunk<'lua>(
&'lua self,
source: &[u8],
name: Option<&CString>,
env: Option<Value<'lua>>,
mode: Option<ChunkMode>,
) -> Result<Function<'lua>> {
unsafe {
let _sg = StackGuard::new(self.state);
check_stack(self.state, 1)?;
let mode_str = match mode {
Some(ChunkMode::Binary) if self.safe => {
return Err(Error::SafetyError(
"binary chunks are disabled in safe mode".to_string(),
))
}
Some(ChunkMode::Binary) => cstr!("b"),
Some(ChunkMode::Text) => cstr!("t"),
#[cfg(not(feature = "luau"))]
None if source.starts_with(ffi::LUA_SIGNATURE) && self.safe => {
return Err(Error::SafetyError(
"binary chunks are disabled in safe mode".to_string(),
))
}
None => cstr!("bt"),
};
match ffi::luaL_loadbufferx(
self.state,
source.as_ptr() as *const c_char,
source.len(),
name.map(|n| n.as_ptr()).unwrap_or_else(ptr::null),
mode_str,
) {
ffi::LUA_OK => {
if let Some(env) = env {
self.push_value(env)?;
#[cfg(any(feature = "lua54", feature = "lua53", feature = "lua52"))]
ffi::lua_setupvalue(self.state, -2, 1);
#[cfg(any(feature = "lua51", feature = "luajit", feature = "luau"))]
ffi::lua_setfenv(self.state, -2);
}
Ok(Function(self.pop_ref()))
}
err => Err(pop_error(self.state, err)),
}
}
}
/// Create and return an interned Lua string. Lua strings can be arbitrary [u8] data including
/// embedded nulls, so in addition to `&str` and `&String`, you can also pass plain `&[u8]`
/// here.
pub fn create_string<S>(&self, s: &S) -> Result<String>
where
S: AsRef<[u8]> + ?Sized,
{
unsafe {
let _sg = StackGuard::new(self.state);
check_stack(self.state, 3)?;
push_string(self.state, s)?;
Ok(String(self.pop_ref()))
}
}
/// Creates and returns a new empty table.
pub fn create_table(&self) -> Result<Table> {
unsafe {
let _sg = StackGuard::new(self.state);
check_stack(self.state, 2)?;
protect_lua!(self.state, 0, 1, fn(state) ffi::lua_newtable(state))?;
Ok(Table(self.pop_ref()))
}
}
/// Creates and returns a new empty table, with the specified capacity.
/// `narr` is a hint for how many elements the table will have as a sequence;
/// `nrec` is a hint for how many other elements the table will have.
/// Lua may use these hints to preallocate memory for the new table.
pub fn create_table_with_capacity(&self, narr: c_int, nrec: c_int) -> Result<Table> {
unsafe {
let _sg = StackGuard::new(self.state);
check_stack(self.state, 3)?;
push_table(self.state, narr, nrec)?;
Ok(Table(self.pop_ref()))
}
}
/// Creates a table and fills it with values from an iterator.
pub fn create_table_from<'lua, K, V, I>(&'lua self, iter: I) -> Result<Table<'lua>>
where
K: ToLua<'lua>,
V: ToLua<'lua>,
I: IntoIterator<Item = (K, V)>,
{
unsafe {
let _sg = StackGuard::new(self.state);
check_stack(self.state, 6)?;
let iter = iter.into_iter();
let lower_bound = iter.size_hint().0;
push_table(self.state, 0, lower_bound as c_int)?;
for (k, v) in iter {
self.push_value(k.to_lua(self)?)?;
self.push_value(v.to_lua(self)?)?;
protect_lua!(self.state, 3, 1, fn(state) ffi::lua_rawset(state, -3))?;
}
Ok(Table(self.pop_ref()))
}
}
/// Creates a table from an iterator of values, using `1..` as the keys.
pub fn create_sequence_from<'lua, T, I>(&'lua self, iter: I) -> Result<Table<'lua>>
where
T: ToLua<'lua>,
I: IntoIterator<Item = T>,
{
unsafe {
let _sg = StackGuard::new(self.state);
check_stack(self.state, 5)?;
let iter = iter.into_iter();
let lower_bound = iter.size_hint().0;
push_table(self.state, lower_bound as c_int, 0)?;
for (i, v) in iter.enumerate() {
self.push_value(v.to_lua(self)?)?;
protect_lua!(self.state, 2, 1, |state| {
ffi::lua_rawseti(state, -2, (i + 1) as Integer);
})?;
}
Ok(Table(self.pop_ref()))
}
}
/// Wraps a Rust function or closure, creating a callable Lua function handle to it.
///
/// The function's return value is always a `Result`: If the function returns `Err`, the error
/// is raised as a Lua error, which can be caught using `(x)pcall` or bubble up to the Rust code
/// that invoked the Lua code. This allows using the `?` operator to propagate errors through
/// intermediate Lua code.
///
/// If the function returns `Ok`, the contained value will be converted to one or more Lua
/// values. For details on Rust-to-Lua conversions, refer to the [`ToLua`] and [`ToLuaMulti`]
/// traits.
///
/// # Examples
///
/// Create a function which prints its argument:
///
/// ```
/// # use mlua::{Lua, Result};
/// # fn main() -> Result<()> {
/// # let lua = Lua::new();
/// let greet = lua.create_function(|_, name: String| {
/// println!("Hello, {}!", name);
/// Ok(())
/// });
/// # let _ = greet; // used
/// # Ok(())
/// # }
/// ```
///
/// Use tuples to accept multiple arguments:
///
/// ```
/// # use mlua::{Lua, Result};
/// # fn main() -> Result<()> {
/// # let lua = Lua::new();
/// let print_person = lua.create_function(|_, (name, age): (String, u8)| {
/// println!("{} is {} years old!", name, age);
/// Ok(())
/// });
/// # let _ = print_person; // used
/// # Ok(())
/// # }
/// ```
///
/// [`ToLua`]: crate::ToLua
/// [`ToLuaMulti`]: crate::ToLuaMulti
pub fn create_function<'lua, 'callback, A, R, F>(&'lua self, func: F) -> Result<Function<'lua>>
where
'lua: 'callback,
A: FromLuaMulti<'callback>,
R: ToLuaMulti<'callback>,
F: 'static + MaybeSend + Fn(&'callback Lua, A) -> Result<R>,
{
self.create_callback(Box::new(move |lua, args| {
func(lua, A::from_lua_multi(args, lua)?)?.to_lua_multi(lua)
}))
}
/// Wraps a Rust mutable closure, creating a callable Lua function handle to it.
///
/// This is a version of [`create_function`] that accepts a FnMut argument. Refer to
/// [`create_function`] for more information about the implementation.
///
/// [`create_function`]: #method.create_function
pub fn create_function_mut<'lua, 'callback, A, R, F>(
&'lua self,
func: F,
) -> Result<Function<'lua>>
where
'lua: 'callback,
A: FromLuaMulti<'callback>,
R: ToLuaMulti<'callback>,
F: 'static + MaybeSend + FnMut(&'callback Lua, A) -> Result<R>,
{
let func = RefCell::new(func);
self.create_function(move |lua, args| {
(&mut *func
.try_borrow_mut()
.map_err(|_| Error::RecursiveMutCallback)?)(lua, args)
})
}
/// Wraps a C function, creating a callable Lua function handle to it.
///
/// # Safety
/// This function is unsafe because provides a way to execute unsafe C function.
pub unsafe fn create_c_function(&self, func: ffi::lua_CFunction) -> Result<Function> {
check_stack(self.state, 1)?;
ffi::lua_pushcfunction(self.state, func);
Ok(Function(self.pop_ref()))
}
/// Wraps a Rust async function or closure, creating a callable Lua function handle to it.
///
/// While executing the function Rust will poll Future and if the result is not ready, call
/// `yield()` passing internal representation of a `Poll::Pending` value.
///
/// The function must be called inside Lua coroutine ([`Thread`]) to be able to suspend its execution.
/// An executor should be used to poll [`AsyncThread`] and mlua will take a provided Waker
/// in that case. Otherwise noop waker will be used if try to call the function outside of Rust
/// executors.
///
/// The family of `call_async()` functions takes care about creating [`Thread`].
///
/// Requires `feature = "async"`
///
/// # Examples
///
/// Non blocking sleep:
///
/// ```
/// use std::time::Duration;
/// use futures_timer::Delay;
/// use mlua::{Lua, Result};
///
/// async fn sleep(_lua: &Lua, n: u64) -> Result<&'static str> {
/// Delay::new(Duration::from_millis(n)).await;
/// Ok("done")
/// }
///
/// #[tokio::main]
/// async fn main() -> Result<()> {
/// let lua = Lua::new();
/// lua.globals().set("sleep", lua.create_async_function(sleep)?)?;
/// let res: String = lua.load("return sleep(...)").call_async(100).await?; // Sleep 100ms
/// assert_eq!(res, "done");
/// Ok(())
/// }
/// ```
///
/// [`Thread`]: crate::Thread
/// [`AsyncThread`]: crate::AsyncThread
#[cfg(feature = "async")]
#[cfg_attr(docsrs, doc(cfg(feature = "async")))]
pub fn create_async_function<'lua, 'callback, A, R, F, FR>(
&'lua self,
func: F,
) -> Result<Function<'lua>>
where
'lua: 'callback,
A: FromLuaMulti<'callback>,
R: ToLuaMulti<'callback>,
F: 'static + MaybeSend + Fn(&'callback Lua, A) -> FR,
FR: 'lua + Future<Output = Result<R>>,
{
self.create_async_callback(Box::new(move |lua, args| {
let args = match A::from_lua_multi(args, lua) {
Ok(args) => args,
Err(e) => return Box::pin(future::err(e)),
};
Box::pin(func(lua, args).and_then(move |ret| future::ready(ret.to_lua_multi(lua))))
}))
}
/// Wraps a Lua function into a new thread (or coroutine).
///
/// Equivalent to `coroutine.create`.
pub fn create_thread<'lua>(&'lua self, func: Function<'lua>) -> Result<Thread<'lua>> {
unsafe {
let _sg = StackGuard::new(self.state);
check_stack(self.state, 3)?;
let thread_state = protect_lua!(self.state, 0, 1, |state| ffi::lua_newthread(state))?;
self.push_ref(&func.0);
ffi::lua_xmove(self.state, thread_state, 1);
Ok(Thread(self.pop_ref()))
}
}
/// Wraps a Lua function into a new or recycled thread (coroutine).
#[cfg(feature = "async")]
pub(crate) fn create_recycled_thread<'lua>(
&'lua self,
func: Function<'lua>,
) -> Result<Thread<'lua>> {
#[cfg(any(feature = "lua54", all(feature = "luajit", feature = "vendored")))]
unsafe {
let _sg = StackGuard::new(self.state);
check_stack(self.state, 1)?;
let extra = &mut *self.extra.get();
if let Some(index) = extra.recycled_thread_cache.pop() {
let thread_state = ffi::lua_tothread(extra.ref_thread, index);
self.push_ref(&func.0);
ffi::lua_xmove(self.state, thread_state, 1);
return Ok(Thread(LuaRef { lua: self, index }));
}
};
self.create_thread(func)
}
/// Resets thread (coroutine) and returns to the cache for later use.
#[cfg(feature = "async")]
#[cfg(any(feature = "lua54", all(feature = "luajit", feature = "vendored")))]
pub(crate) unsafe fn recycle_thread(&self, thread: &mut Thread) {
let extra = &mut *self.extra.get();
let thread_state = ffi::lua_tothread(extra.ref_thread, thread.0.index);
if extra.recycled_thread_cache.len() < extra.recycled_thread_cache.capacity() {
#[cfg(feature = "lua54")]
let status = ffi::lua_resetthread(thread_state);
#[cfg(feature = "lua54")]
if status != ffi::LUA_OK {
return;
}
#[cfg(all(feature = "luajit", feature = "vendored"))]
ffi::lua_resetthread(self.state, thread_state);
#[cfg(feature = "luau")]
ffi::lua_resetthread(thread_state);
extra.recycled_thread_cache.push(thread.0.index);
thread.0.index = 0;
}
}
/// Create a Lua userdata object from a custom userdata type.
pub fn create_userdata<T>(&self, data: T) -> Result<AnyUserData>
where
T: 'static + MaybeSend + UserData,
{
unsafe { self.make_userdata(UserDataCell::new(data)) }
}
/// Create a Lua userdata object from a custom serializable userdata type.
///
/// Requires `feature = "serialize"`
#[cfg(feature = "serialize")]
#[cfg_attr(docsrs, doc(cfg(feature = "serialize")))]
pub fn create_ser_userdata<T>(&self, data: T) -> Result<AnyUserData>
where
T: 'static + MaybeSend + UserData + Serialize,
{
unsafe { self.make_userdata(UserDataCell::new_ser(data)) }
}
/// Returns a handle to the global environment.
pub fn globals(&self) -> Table {
unsafe {
let _sg = StackGuard::new(self.state);
assert_stack(self.state, 1);
#[cfg(any(feature = "lua54", feature = "lua53", feature = "lua52"))]
ffi::lua_rawgeti(self.state, ffi::LUA_REGISTRYINDEX, ffi::LUA_RIDX_GLOBALS);
#[cfg(any(feature = "lua51", feature = "luajit", feature = "luau"))]
ffi::lua_pushvalue(self.state, ffi::LUA_GLOBALSINDEX);
Table(self.pop_ref())
}
}
/// Returns a handle to the active `Thread`. For calls to `Lua` this will be the main Lua thread,
/// for parameters given to a callback, this will be whatever Lua thread called the callback.
pub fn current_thread(&self) -> Thread {
unsafe {
let _sg = StackGuard::new(self.state);
assert_stack(self.state, 1);
ffi::lua_pushthread(self.state);
Thread(self.pop_ref())
}
}
/// Calls the given function with a `Scope` parameter, giving the function the ability to create
/// userdata and callbacks from rust types that are !Send or non-'static.
///
/// The lifetime of any function or userdata created through `Scope` lasts only until the
/// completion of this method call, on completion all such created values are automatically
/// dropped and Lua references to them are invalidated. If a script accesses a value created
/// through `Scope` outside of this method, a Lua error will result. Since we can ensure the
/// lifetime of values created through `Scope`, and we know that `Lua` cannot be sent to another
/// thread while `Scope` is live, it is safe to allow !Send datatypes and whose lifetimes only
/// outlive the scope lifetime.
///
/// Inside the scope callback, all handles created through Scope will share the same unique 'lua
/// lifetime of the parent `Lua`. This allows scoped and non-scoped values to be mixed in
/// API calls, which is very useful (e.g. passing a scoped userdata to a non-scoped function).
/// However, this also enables handles to scoped values to be trivially leaked from the given
/// callback. This is not dangerous, though! After the callback returns, all scoped values are
/// invalidated, which means that though references may exist, the Rust types backing them have
/// dropped. `Function` types will error when called, and `AnyUserData` will be typeless. It
/// would be impossible to prevent handles to scoped values from escaping anyway, since you
/// would always be able to smuggle them through Lua state.
pub fn scope<'lua, 'scope, R, F>(&'lua self, f: F) -> Result<R>
where
'lua: 'scope,
R: 'static,
F: FnOnce(&Scope<'lua, 'scope>) -> Result<R>,
{
f(&Scope::new(self))
}
/// An asynchronous version of [`scope`] that allows to create scoped async functions and
/// execute them.
///
/// Requires `feature = "async"`
///
/// [`scope`]: #method.scope
#[cfg(feature = "async")]
#[cfg_attr(docsrs, doc(cfg(feature = "async")))]
pub fn async_scope<'lua, 'scope, R, F, FR>(
&'lua self,
f: F,
) -> LocalBoxFuture<'scope, Result<R>>
where
'lua: 'scope,
R: 'static,
F: FnOnce(Scope<'lua, 'scope>) -> FR,
FR: 'scope + Future<Output = Result<R>>,
{
Box::pin(f(Scope::new(self)))
}
/// Attempts to coerce a Lua value into a String in a manner consistent with Lua's internal
/// behavior.
///
/// To succeed, the value must be a string (in which case this is a no-op), an integer, or a
/// number.
pub fn coerce_string<'lua>(&'lua self, v: Value<'lua>) -> Result<Option<String<'lua>>> {
Ok(match v {
Value::String(s) => Some(s),
v => unsafe {
let _sg = StackGuard::new(self.state);
check_stack(self.state, 4)?;
self.push_value(v)?;
let res = protect_lua!(self.state, 1, 1, |state| {
ffi::lua_tolstring(state, -1, ptr::null_mut())
})?;
if !res.is_null() {
Some(String(self.pop_ref()))
} else {
None
}
},
})
}
/// Attempts to coerce a Lua value into an integer in a manner consistent with Lua's internal
/// behavior.
///
/// To succeed, the value must be an integer, a floating point number that has an exact
/// representation as an integer, or a string that can be converted to an integer. Refer to the
/// Lua manual for details.
pub fn coerce_integer(&self, v: Value) -> Result<Option<Integer>> {
Ok(match v {
Value::Integer(i) => Some(i),
v => unsafe {
let _sg = StackGuard::new(self.state);
check_stack(self.state, 2)?;
self.push_value(v)?;
let mut isint = 0;
let i = ffi::lua_tointegerx(self.state, -1, &mut isint);
if isint == 0 {
None
} else {
Some(i)
}
},
})
}
/// Attempts to coerce a Lua value into a Number in a manner consistent with Lua's internal
/// behavior.
///
/// To succeed, the value must be a number or a string that can be converted to a number. Refer
/// to the Lua manual for details.
pub fn coerce_number(&self, v: Value) -> Result<Option<Number>> {
Ok(match v {
Value::Number(n) => Some(n),
v => unsafe {
let _sg = StackGuard::new(self.state);
check_stack(self.state, 2)?;
self.push_value(v)?;
let mut isnum = 0;
let n = ffi::lua_tonumberx(self.state, -1, &mut isnum);
if isnum == 0 {
None
} else {
Some(n)
}
},
})
}
/// Converts a value that implements `ToLua` into a `Value` instance.
pub fn pack<'lua, T: ToLua<'lua>>(&'lua self, t: T) -> Result<Value<'lua>> {
t.to_lua(self)
}
/// Converts a `Value` instance into a value that implements `FromLua`.
pub fn unpack<'lua, T: FromLua<'lua>>(&'lua self, value: Value<'lua>) -> Result<T> {
T::from_lua(value, self)
}
/// Converts a value that implements `ToLuaMulti` into a `MultiValue` instance.
pub fn pack_multi<'lua, T: ToLuaMulti<'lua>>(&'lua self, t: T) -> Result<MultiValue<'lua>> {
t.to_lua_multi(self)
}
/// Converts a `MultiValue` instance into a value that implements `FromLuaMulti`.
pub fn unpack_multi<'lua, T: FromLuaMulti<'lua>>(
&'lua self,
value: MultiValue<'lua>,
) -> Result<T> {
T::from_lua_multi(value, self)
}
/// Set a value in the Lua registry based on a string name.
///
/// This value will be available to rust from all `Lua` instances which share the same main
/// state.
pub fn set_named_registry_value<'lua, S, T>(&'lua self, name: &S, t: T) -> Result<()>
where
S: AsRef<[u8]> + ?Sized,
T: ToLua<'lua>,
{
let t = t.to_lua(self)?;
unsafe {
let _sg = StackGuard::new(self.state);
check_stack(self.state, 5)?;
self.push_value(t)?;
rawset_field(self.state, ffi::LUA_REGISTRYINDEX, name)
}
}
/// Get a value from the Lua registry based on a string name.
///
/// Any Lua instance which shares the underlying main state may call this method to
/// get a value previously set by [`set_named_registry_value`].
///
/// [`set_named_registry_value`]: #method.set_named_registry_value
pub fn named_registry_value<'lua, S, T>(&'lua self, name: &S) -> Result<T>
where
S: AsRef<[u8]> + ?Sized,
T: FromLua<'lua>,
{
let value = unsafe {
let _sg = StackGuard::new(self.state);
check_stack(self.state, 3)?;
push_string(self.state, name)?;
ffi::lua_rawget(self.state, ffi::LUA_REGISTRYINDEX);
self.pop_value()
};
T::from_lua(value, self)
}
/// Removes a named value in the Lua registry.
///
/// Equivalent to calling [`set_named_registry_value`] with a value of Nil.
///
/// [`set_named_registry_value`]: #method.set_named_registry_value
pub fn unset_named_registry_value<S>(&self, name: &S) -> Result<()>
where
S: AsRef<[u8]> + ?Sized,
{
self.set_named_registry_value(name, Nil)
}
/// Place a value in the Lua registry with an auto-generated key.
///
/// This value will be available to Rust from all `Lua` instances which share the same main
/// state.
///
/// Be warned, garbage collection of values held inside the registry is not automatic, see
/// [`RegistryKey`] for more details.
/// However, dropped [`RegistryKey`]s automatically reused to store new values.
///
/// [`RegistryKey`]: crate::RegistryKey
pub fn create_registry_value<'lua, T: ToLua<'lua>>(&'lua self, t: T) -> Result<RegistryKey> {
let t = t.to_lua(self)?;
unsafe {
let _sg = StackGuard::new(self.state);
check_stack(self.state, 4)?;
let unref_list = (*self.extra.get()).registry_unref_list.clone();
self.push_value(t)?;
// Try to reuse previously allocated RegistryKey
let unref_list2 = unref_list.clone();
let mut unref_list2 = mlua_expect!(unref_list2.lock(), "unref list poisoned");
if let Some(registry_id) = unref_list2.as_mut().and_then(|x| x.pop()) {
// It must be safe to replace the value without triggering memory error
ffi::lua_rawseti(self.state, ffi::LUA_REGISTRYINDEX, registry_id as Integer);
return Ok(RegistryKey {
registry_id,
unref_list,
});
}
// Allocate a new RegistryKey
let registry_id = protect_lua!(self.state, 1, 0, |state| {
ffi::luaL_ref(state, ffi::LUA_REGISTRYINDEX)
})?;
Ok(RegistryKey {
registry_id,
unref_list,
})
}
}
/// Get a value from the Lua registry by its `RegistryKey`
///
/// Any Lua instance which shares the underlying main state may call this method to get a value
/// previously placed by [`create_registry_value`].
///
/// [`create_registry_value`]: #method.create_registry_value
pub fn registry_value<'lua, T: FromLua<'lua>>(&'lua self, key: &RegistryKey) -> Result<T> {
if !self.owns_registry_value(key) {
return Err(Error::MismatchedRegistryKey);
}
let value = unsafe {
let _sg = StackGuard::new(self.state);
check_stack(self.state, 1)?;
ffi::lua_rawgeti(
self.state,
ffi::LUA_REGISTRYINDEX,
key.registry_id as Integer,
);
self.pop_value()
};
T::from_lua(value, self)
}
/// Removes a value from the Lua registry.
///
/// You may call this function to manually remove a value placed in the registry with
/// [`create_registry_value`]. In addition to manual `RegistryKey` removal, you can also call
/// [`expire_registry_values`] to automatically remove values from the registry whose
/// `RegistryKey`s have been dropped.
///
/// [`create_registry_value`]: #method.create_registry_value
/// [`expire_registry_values`]: #method.expire_registry_values
pub fn remove_registry_value(&self, key: RegistryKey) -> Result<()> {
if !self.owns_registry_value(&key) {
return Err(Error::MismatchedRegistryKey);
}
unsafe {
ffi::luaL_unref(self.state, ffi::LUA_REGISTRYINDEX, key.take());
}
Ok(())
}
/// Replaces a value in the Lua registry by its `RegistryKey`.
///
/// See [`create_registry_value`] for more details.
///
/// [`create_registry_value`]: #method.create_registry_value
pub fn replace_registry_value<'lua, T: ToLua<'lua>>(
&'lua self,
key: &RegistryKey,
t: T,
) -> Result<()> {
if !self.owns_registry_value(key) {
return Err(Error::MismatchedRegistryKey);
}
let t = t.to_lua(self)?;
unsafe {
let _sg = StackGuard::new(self.state);
check_stack(self.state, 2)?;
self.push_value(t)?;
// It must be safe to replace the value without triggering memory error
ffi::lua_rawseti(
self.state,
ffi::LUA_REGISTRYINDEX,
key.registry_id as Integer,
);
Ok(())
}
}
/// Returns true if the given `RegistryKey` was created by a `Lua` which shares the underlying
/// main state with this `Lua` instance.
///
/// Other than this, methods that accept a `RegistryKey` will return
/// `Error::MismatchedRegistryKey` if passed a `RegistryKey` that was not created with a
/// matching `Lua` state.
pub fn owns_registry_value(&self, key: &RegistryKey) -> bool {
let registry_unref_list = unsafe { &(*self.extra.get()).registry_unref_list };
Arc::ptr_eq(&key.unref_list, registry_unref_list)
}
/// Remove any registry values whose `RegistryKey`s have all been dropped.
///
/// Unlike normal handle values, `RegistryKey`s do not automatically remove themselves on Drop,
/// but you can call this method to remove any unreachable registry values not manually removed
/// by `Lua::remove_registry_value`.
pub fn expire_registry_values(&self) {
unsafe {
let mut unref_list = mlua_expect!(
(*self.extra.get()).registry_unref_list.lock(),
"unref list poisoned"
);
let unref_list = mem::replace(&mut *unref_list, Some(Vec::new()));
for id in mlua_expect!(unref_list, "unref list not set") {
ffi::luaL_unref(self.state, ffi::LUA_REGISTRYINDEX, id);
}
}
}
/// Sets or replaces an application data object of type `T`.
///
/// Application data could be accessed at any time by using [`Lua::app_data_ref()`] or [`Lua::app_data_mut()`]
/// methods where `T` is the data type.
///
/// # Examples
///
/// ```
/// use mlua::{Lua, Result};
///
/// fn hello(lua: &Lua, _: ()) -> Result<()> {
/// let mut s = lua.app_data_mut::<&str>().unwrap();
/// assert_eq!(*s, "hello");
/// *s = "world";
/// Ok(())
/// }
///
/// fn main() -> Result<()> {
/// let lua = Lua::new();
/// lua.set_app_data("hello");
/// lua.create_function(hello)?.call(())?;
/// let s = lua.app_data_ref::<&str>().unwrap();
/// assert_eq!(*s, "world");
/// Ok(())
/// }
/// ```
pub fn set_app_data<T: 'static + MaybeSend>(&self, data: T) {
let extra = unsafe { &mut (*self.extra.get()) };
extra
.app_data
.try_borrow_mut()
.expect("cannot borrow mutably app data container")
.insert(TypeId::of::<T>(), Box::new(data));
}
/// Gets a reference to an application data object stored by [`Lua::set_app_data()`] of type `T`.
pub fn app_data_ref<T: 'static>(&self) -> Option<Ref<T>> {
let extra = unsafe { &(*self.extra.get()) };
let app_data = extra
.app_data
.try_borrow()
.expect("cannot borrow app data container");
let value = app_data.get(&TypeId::of::<T>())?.downcast_ref::<T>()? as *const _;
Some(Ref::map(app_data, |_| unsafe { &*value }))
}
/// Gets a mutable reference to an application data object stored by [`Lua::set_app_data()`] of type `T`.
pub fn app_data_mut<T: 'static>(&self) -> Option<RefMut<T>> {
let extra = unsafe { &(*self.extra.get()) };
let mut app_data = extra
.app_data
.try_borrow_mut()
.expect("cannot mutably borrow app data container");
let value = app_data.get_mut(&TypeId::of::<T>())?.downcast_mut::<T>()? as *mut _;
Some(RefMut::map(app_data, |_| unsafe { &mut *value }))
}
/// Removes an application data of type `T`.
pub fn remove_app_data<T: 'static>(&self) -> Option<T> {
let extra = unsafe { &mut (*self.extra.get()) };
extra
.app_data
.try_borrow_mut()
.expect("cannot mutably borrow app data container")
.remove(&TypeId::of::<T>())
.and_then(|data| data.downcast().ok().map(|data| *data))
}
// Uses 2 stack spaces, does not call checkstack
pub(crate) unsafe fn push_value(&self, value: Value) -> Result<()> {
match value {
Value::Nil => {
ffi::lua_pushnil(self.state);
}
Value::Boolean(b) => {
ffi::lua_pushboolean(self.state, if b { 1 } else { 0 });
}
Value::LightUserData(ud) => {
ffi::lua_pushlightuserdata(self.state, ud.0);
}
Value::Integer(i) => {
ffi::lua_pushinteger(self.state, i);
}
Value::Number(n) => {
ffi::lua_pushnumber(self.state, n);
}
Value::String(s) => {
self.push_ref(&s.0);
}
Value::Table(t) => {
self.push_ref(&t.0);
}
Value::Function(f) => {
self.push_ref(&f.0);
}
Value::Thread(t) => {
self.push_ref(&t.0);
}
Value::UserData(ud) => {
self.push_ref(&ud.0);
}
Value::Error(err) => {
push_gc_userdata(self.state, WrappedFailure::Error(err))?;
}
}
Ok(())
}
// Uses 2 stack spaces, does not call checkstack
pub(crate) unsafe fn pop_value(&self) -> Value {
let state = self.state;
match ffi::lua_type(state, -1) {
ffi::LUA_TNIL => {
ffi::lua_pop(state, 1);
Nil
}
ffi::LUA_TBOOLEAN => {
let b = Value::Boolean(ffi::lua_toboolean(state, -1) != 0);
ffi::lua_pop(state, 1);
b
}
ffi::LUA_TLIGHTUSERDATA => {
let ud = Value::LightUserData(LightUserData(ffi::lua_touserdata(state, -1)));
ffi::lua_pop(state, 1);
ud
}
ffi::LUA_TNUMBER => {
if ffi::lua_isinteger(state, -1) != 0 {
let i = Value::Integer(ffi::lua_tointeger(state, -1));
ffi::lua_pop(state, 1);
i
} else {
let n = Value::Number(ffi::lua_tonumber(state, -1));
ffi::lua_pop(state, 1);
n
}
}
ffi::LUA_TSTRING => Value::String(String(self.pop_ref())),
ffi::LUA_TTABLE => Value::Table(Table(self.pop_ref())),
ffi::LUA_TFUNCTION => Value::Function(Function(self.pop_ref())),
ffi::LUA_TUSERDATA => {
// We must prevent interaction with userdata types other than UserData OR a WrappedError.
// WrappedPanics are automatically resumed.
match get_gc_userdata::<WrappedFailure>(state, -1).as_mut() {
Some(WrappedFailure::Error(err)) => {
let err = err.clone();
ffi::lua_pop(state, 1);
Value::Error(err)
}
Some(WrappedFailure::Panic(panic)) => {
if let Some(panic) = panic.take() {
ffi::lua_pop(state, 1);
resume_unwind(panic);
}
// Previously resumed panic?
ffi::lua_pop(state, 1);
Nil
}
_ => Value::UserData(AnyUserData(self.pop_ref())),
}
}
ffi::LUA_TTHREAD => Value::Thread(Thread(self.pop_ref())),
#[cfg(feature = "luajit")]
ffi::LUA_TCDATA => {
ffi::lua_pop(state, 1);
// TODO: Fix this in a next major release
panic!("cdata objects cannot be handled by mlua yet");
}
_ => mlua_panic!("LUA_TNONE in pop_value"),
}
}
// Pushes a LuaRef value onto the stack, uses 1 stack space, does not call checkstack
pub(crate) unsafe fn push_ref(&self, lref: &LuaRef) {
assert!(
Arc::ptr_eq(&lref.lua.extra, &self.extra),
"Lua instance passed Value created from a different main Lua state"
);
let extra = &*self.extra.get();
ffi::lua_pushvalue(extra.ref_thread, lref.index);
ffi::lua_xmove(extra.ref_thread, self.state, 1);
}
// Pops the topmost element of the stack and stores a reference to it. This pins the object,
// preventing garbage collection until the returned `LuaRef` is dropped.
//
// References are stored in the stack of a specially created auxiliary thread that exists only
// to store reference values. This is much faster than storing these in the registry, and also
// much more flexible and requires less bookkeeping than storing them directly in the currently
// used stack. The implementation is somewhat biased towards the use case of a relatively small
// number of short term references being created, and `RegistryKey` being used for long term
// references.
pub(crate) unsafe fn pop_ref(&self) -> LuaRef {
let extra = &mut *self.extra.get();
ffi::lua_xmove(self.state, extra.ref_thread, 1);
let index = ref_stack_pop(extra);
LuaRef { lua: self, index }
}
pub(crate) fn clone_ref<'lua>(&'lua self, lref: &LuaRef<'lua>) -> LuaRef<'lua> {
unsafe {
let extra = &mut *self.extra.get();
ffi::lua_pushvalue(extra.ref_thread, lref.index);
let index = ref_stack_pop(extra);
LuaRef { lua: self, index }
}
}
pub(crate) fn drop_ref(&self, lref: &LuaRef) {
unsafe {
let extra = &mut *self.extra.get();
ffi::lua_pushnil(extra.ref_thread);
ffi::lua_replace(extra.ref_thread, lref.index);
extra.ref_free.push(lref.index);
}
}
/// Executes the function provided on the ref thread
#[inline]
pub(crate) unsafe fn ref_thread_exec<F, R>(&self, f: F) -> R
where
F: FnOnce(*mut ffi::lua_State) -> R,
{
let ref_thread = (*self.extra.get()).ref_thread;
f(ref_thread)
}
pub(crate) unsafe fn push_userdata_metatable<T: 'static + UserData>(&self) -> Result<()> {
let extra = &mut *self.extra.get();
let type_id = TypeId::of::<T>();
if let Some(&table_id) = extra.registered_userdata.get(&type_id) {
ffi::lua_rawgeti(self.state, ffi::LUA_REGISTRYINDEX, table_id as Integer);
return Ok(());
}
let _sg = StackGuard::new_extra(self.state, 1);
check_stack(self.state, 13)?;
let mut fields = StaticUserDataFields::default();
let mut methods = StaticUserDataMethods::default();
T::add_fields(&mut fields);
T::add_methods(&mut methods);
// Prepare metatable, add meta methods first and then meta fields
let metatable_nrec = methods.meta_methods.len() + fields.meta_fields.len();
#[cfg(feature = "async")]
let metatable_nrec = metatable_nrec + methods.async_meta_methods.len();
push_table(self.state, 0, metatable_nrec as c_int)?;
for (k, m) in methods.meta_methods {
self.push_value(Value::Function(self.create_callback(m)?))?;
rawset_field(self.state, -2, k.validate()?.name())?;
}
#[cfg(feature = "async")]
for (k, m) in methods.async_meta_methods {
self.push_value(Value::Function(self.create_async_callback(m)?))?;
rawset_field(self.state, -2, k.validate()?.name())?;
}
for (k, f) in fields.meta_fields {
self.push_value(f(self)?)?;
rawset_field(self.state, -2, k.validate()?.name())?;
}
let metatable_index = ffi::lua_absindex(self.state, -1);
let mut extra_tables_count = 0;
let mut field_getters_index = None;
let field_getters_nrec = fields.field_getters.len();
if field_getters_nrec > 0 {
push_table(self.state, 0, field_getters_nrec as c_int)?;
for (k, m) in fields.field_getters {
self.push_value(Value::Function(self.create_callback(m)?))?;
rawset_field(self.state, -2, &k)?;
}
field_getters_index = Some(ffi::lua_absindex(self.state, -1));
extra_tables_count += 1;
}
let mut field_setters_index = None;
let field_setters_nrec = fields.field_setters.len();
if field_setters_nrec > 0 {
push_table(self.state, 0, field_setters_nrec as c_int)?;
for (k, m) in fields.field_setters {
self.push_value(Value::Function(self.create_callback(m)?))?;
rawset_field(self.state, -2, &k)?;
}
field_setters_index = Some(ffi::lua_absindex(self.state, -1));
extra_tables_count += 1;
}
let mut methods_index = None;
let methods_nrec = methods.methods.len();
#[cfg(feature = "async")]
let methods_nrec = methods_nrec + methods.async_methods.len();
if methods_nrec > 0 {
push_table(self.state, 0, methods_nrec as c_int)?;
for (k, m) in methods.methods {
self.push_value(Value::Function(self.create_callback(m)?))?;
rawset_field(self.state, -2, &k)?;
}
#[cfg(feature = "async")]
for (k, m) in methods.async_methods {
self.push_value(Value::Function(self.create_async_callback(m)?))?;
rawset_field(self.state, -2, &k)?;
}
methods_index = Some(ffi::lua_absindex(self.state, -1));
extra_tables_count += 1;
}
init_userdata_metatable::<UserDataCell<T>>(
self.state,
metatable_index,
field_getters_index,
field_setters_index,
methods_index,
)?;
// Pop extra tables to get metatable on top of the stack
ffi::lua_pop(self.state, extra_tables_count);
let mt_ptr = ffi::lua_topointer(self.state, -1);
ffi::lua_pushvalue(self.state, -1);
let id = protect_lua!(self.state, 1, 0, |state| {
ffi::luaL_ref(state, ffi::LUA_REGISTRYINDEX)
})?;
extra.registered_userdata.insert(type_id, id);
extra.registered_userdata_mt.insert(mt_ptr, Some(type_id));
Ok(())
}
pub(crate) unsafe fn register_userdata_metatable(
&self,
ptr: *const c_void,
type_id: Option<TypeId>,
) {
let extra = &mut *self.extra.get();
extra.registered_userdata_mt.insert(ptr, type_id);
}
pub(crate) unsafe fn deregister_userdata_metatable(&self, ptr: *const c_void) {
(*self.extra.get()).registered_userdata_mt.remove(&ptr);
}
// Pushes a LuaRef value onto the stack, checking that it's a registered
// and not destructed UserData.
// Uses 2 stack spaces, does not call checkstack.
pub(crate) unsafe fn push_userdata_ref(&self, lref: &LuaRef) -> Result<Option<TypeId>> {
self.push_ref(lref);
if ffi::lua_getmetatable(self.state, -1) == 0 {
return Err(Error::UserDataTypeMismatch);
}
let mt_ptr = ffi::lua_topointer(self.state, -1);
ffi::lua_pop(self.state, 1);
let extra = &*self.extra.get();
match extra.registered_userdata_mt.get(&mt_ptr) {
Some(&type_id) if type_id == Some(TypeId::of::<DestructedUserdataMT>()) => {
Err(Error::UserDataDestructed)
}
Some(&type_id) => Ok(type_id),
None => Err(Error::UserDataTypeMismatch),
}
}
#[inline]
unsafe fn get_userdata_ref<T>(&self) -> Result<Ref<T>> {
(*get_userdata::<UserDataCell<T>>(self.state, -1)).try_borrow()
}
#[inline]
unsafe fn get_userdata_mut<T>(&self) -> Result<RefMut<T>> {
(*get_userdata::<UserDataCell<T>>(self.state, -1)).try_borrow_mut()
}
// Creates a Function out of a Callback containing a 'static Fn. This is safe ONLY because the
// Fn is 'static, otherwise it could capture 'callback arguments improperly. Without ATCs, we
// cannot easily deal with the "correct" callback type of:
//
// Box<for<'lua> Fn(&'lua Lua, MultiValue<'lua>) -> Result<MultiValue<'lua>>)>
//
// So we instead use a caller provided lifetime, which without the 'static requirement would be
// unsafe.
pub(crate) fn create_callback<'lua, 'callback>(
&'lua self,
func: Callback<'callback, 'static>,
) -> Result<Function<'lua>>
where
'lua: 'callback,
{
unsafe extern "C" fn call_callback(state: *mut ffi::lua_State) -> c_int {
let extra = match ffi::lua_type(state, ffi::lua_upvalueindex(1)) {
ffi::LUA_TUSERDATA => {
let upvalue = get_userdata::<CallbackUpvalue>(state, ffi::lua_upvalueindex(1));
(*upvalue).lua.extra.get()
}
_ => ptr::null_mut(),
};
callback_error_ext(state, extra, |nargs| {
let upvalue_idx = ffi::lua_upvalueindex(1);
if ffi::lua_type(state, upvalue_idx) == ffi::LUA_TNIL {
return Err(Error::CallbackDestructed);
}
let upvalue = get_userdata::<CallbackUpvalue>(state, upvalue_idx);
if nargs < ffi::LUA_MINSTACK {
check_stack(state, ffi::LUA_MINSTACK - nargs)?;
}
let mut lua = (*upvalue).lua.clone();
lua.state = state;
let mut args = MultiValue::new_or_cached(&lua);
args.reserve(nargs as usize);
for _ in 0..nargs {
args.push_front(lua.pop_value());
}
let mut results = ((*upvalue).func)(&lua, args)?;
let nresults = results.len() as c_int;
check_stack(state, nresults)?;
for r in results.drain_all() {
lua.push_value(r)?;
}
lua.cache_multivalue(results);
Ok(nresults)
})
}
unsafe {
let _sg = StackGuard::new(self.state);
check_stack(self.state, 4)?;
let lua = self.clone();
let func = mem::transmute(func);
push_gc_userdata(self.state, CallbackUpvalue { lua, func })?;
protect_lua!(self.state, 1, 1, fn(state) {
ffi::lua_pushcclosure(state, call_callback, 1);
})?;
Ok(Function(self.pop_ref()))
}
}
#[cfg(feature = "async")]
pub(crate) fn create_async_callback<'lua, 'callback>(
&'lua self,
func: AsyncCallback<'callback, 'static>,
) -> Result<Function<'lua>>
where
'lua: 'callback,
{
#[cfg(any(
feature = "lua54",
feature = "lua53",
feature = "lua52",
feature = "luau"
))]
unsafe {
let libs = (*self.extra.get()).libs;
if !libs.contains(StdLib::COROUTINE) {
self.load_from_std_lib(StdLib::COROUTINE)?;
}
}
struct StateGuard(*mut Lua, *mut ffi::lua_State);
impl StateGuard {
unsafe fn new(lua: *mut Lua, state: *mut ffi::lua_State) -> Self {
let orig_state = (*lua).state;
(*lua).state = state;
Self(lua, orig_state)
}
}
impl Drop for StateGuard {
fn drop(&mut self) {
unsafe { (*self.0).state = self.1 }
}
}
unsafe extern "C" fn call_callback(state: *mut ffi::lua_State) -> c_int {
let extra = match ffi::lua_type(state, ffi::lua_upvalueindex(1)) {
ffi::LUA_TUSERDATA => {
let upvalue =
get_userdata::<AsyncCallbackUpvalue>(state, ffi::lua_upvalueindex(1));
(*upvalue).lua.extra.get()
}
_ => ptr::null_mut(),
};
callback_error_ext(state, extra, |nargs| {
let upvalue_idx = ffi::lua_upvalueindex(1);
if ffi::lua_type(state, upvalue_idx) == ffi::LUA_TNIL {
return Err(Error::CallbackDestructed);
}
let upvalue = get_userdata::<AsyncCallbackUpvalue>(state, upvalue_idx);
if nargs < ffi::LUA_MINSTACK {
check_stack(state, ffi::LUA_MINSTACK - nargs)?;
}
let lua = &mut (*upvalue).lua;
let _guard = StateGuard::new(lua, state);
let mut args = MultiValue::new_or_cached(lua);
args.reserve(nargs as usize);
for _ in 0..nargs {
args.push_front(lua.pop_value());
}
let fut = ((*upvalue).func)(lua, args);
let lua = lua.clone();
push_gc_userdata(state, AsyncPollUpvalue { lua, fut })?;
protect_lua!(state, 1, 1, fn(state) {
ffi::lua_pushcclosure(state, poll_future, 1);
})?;
Ok(1)
})
}
unsafe extern "C" fn poll_future(state: *mut ffi::lua_State) -> c_int {
let extra = match ffi::lua_type(state, ffi::lua_upvalueindex(1)) {
ffi::LUA_TUSERDATA => {
let upvalue = get_userdata::<AsyncPollUpvalue>(state, ffi::lua_upvalueindex(1));
(*upvalue).lua.extra.get()
}
_ => ptr::null_mut(),
};
callback_error_ext(state, extra, |nargs| {
let upvalue_idx = ffi::lua_upvalueindex(1);
if ffi::lua_type(state, upvalue_idx) == ffi::LUA_TNIL {
return Err(Error::CallbackDestructed);
}
let upvalue = get_userdata::<AsyncPollUpvalue>(state, upvalue_idx);
if nargs < ffi::LUA_MINSTACK {
check_stack(state, ffi::LUA_MINSTACK - nargs)?;
}
let lua = &mut (*upvalue).lua;
lua.state = state;
// Try to get an outer poll waker
let waker = lua.waker().unwrap_or_else(noop_waker);
let mut ctx = Context::from_waker(&waker);
let fut = &mut (*upvalue).fut;
match fut.as_mut().poll(&mut ctx) {
Poll::Pending => {
check_stack(state, 1)?;
ffi::lua_pushboolean(state, 0);
Ok(1)
}
Poll::Ready(results) => {
let results = results?;
let nresults = results.len() as Integer;
let results = lua.create_sequence_from(results)?;
check_stack(state, 3)?;
ffi::lua_pushboolean(state, 1);
lua.push_value(Value::Table(results))?;
lua.push_value(Value::Integer(nresults))?;
Ok(3)
}
}
})
}
let get_poll = unsafe {
let _sg = StackGuard::new(self.state);
check_stack(self.state, 4)?;
let lua = self.clone();
let func = mem::transmute(func);
push_gc_userdata(self.state, AsyncCallbackUpvalue { lua, func })?;
protect_lua!(self.state, 1, 1, fn(state) {
ffi::lua_pushcclosure(state, call_callback, 1);
})?;
Function(self.pop_ref())
};
unsafe extern "C" fn unpack(state: *mut ffi::lua_State) -> c_int {
let len = ffi::lua_tointeger(state, 2);
ffi::luaL_checkstack(state, len as c_int, ptr::null());
for i in 1..=len {
ffi::lua_rawgeti(state, 1, i);
}
len as c_int
}
let coroutine = self.globals().get::<_, Table>("coroutine")?;
let env = self.create_table_with_capacity(0, 4)?;
env.set("get_poll", get_poll)?;
env.set("yield", coroutine.get::<_, Function>("yield")?)?;
unsafe {
env.set("unpack", self.create_c_function(unpack)?)?;
}
env.set("pending", {
LightUserData(&ASYNC_POLL_PENDING as *const u8 as *mut c_void)
})?;
// We set `poll` variable in the env table to be able to destroy upvalues
self.load(
r#"
poll = get_poll(...)
local poll, pending, yield, unpack = poll, pending, yield, unpack
while true do
local ready, res, nres = poll()
if ready then
return unpack(res, nres)
end
yield(pending)
end
"#,
)
.set_name("_mlua_async_poll")?
.set_environment(env)?
.into_function()
}
#[cfg(feature = "async")]
#[inline]
pub(crate) unsafe fn waker(&self) -> Option<Waker> {
let extra = &*self.extra.get();
(*get_userdata::<Option<Waker>>(extra.ref_thread, extra.ref_waker_idx)).clone()
}
#[cfg(feature = "async")]
#[inline]
pub(crate) unsafe fn set_waker(&self, waker: Option<Waker>) -> Option<Waker> {
let extra = &*self.extra.get();
let waker_slot = &mut *get_userdata::<Option<Waker>>(extra.ref_thread, extra.ref_waker_idx);
match waker {
Some(waker) => waker_slot.replace(waker),
None => waker_slot.take(),
}
}
pub(crate) unsafe fn make_userdata<T>(&self, data: UserDataCell<T>) -> Result<AnyUserData>
where
T: 'static + UserData,
{
let _sg = StackGuard::new(self.state);
check_stack(self.state, 3)?;
// We push metatable first to ensure having correct metatable with `__gc` method
ffi::lua_pushnil(self.state);
self.push_userdata_metatable::<T>()?;
#[cfg(not(feature = "lua54"))]
push_userdata(self.state, data)?;
#[cfg(feature = "lua54")]
push_userdata_uv(self.state, data, USER_VALUE_MAXSLOT as c_int)?;
ffi::lua_replace(self.state, -3);
ffi::lua_setmetatable(self.state, -2);
// Set empty environment for Lua 5.1
#[cfg(any(feature = "lua51", feature = "luajit"))]
protect_lua!(self.state, 1, 1, fn(state) {
ffi::lua_newtable(state);
ffi::lua_setuservalue(state, -2);
})?;
Ok(AnyUserData(self.pop_ref()))
}
#[inline]
pub(crate) fn clone(&self) -> Self {
Lua {
state: self.state,
main_state: self.main_state,
extra: Arc::clone(&self.extra),
ephemeral: true,
safe: self.safe,
_no_ref_unwind_safe: PhantomData,
}
}
#[cfg(not(feature = "luau"))]
fn disable_c_modules(&self) -> Result<()> {
let package: Table = self.globals().get("package")?;
package.set(
"loadlib",
self.create_function(|_, ()| -> Result<()> {
Err(Error::SafetyError(
"package.loadlib is disabled in safe mode".to_string(),
))
})?,
)?;
#[cfg(any(feature = "lua54", feature = "lua53", feature = "lua52"))]
let searchers: Table = package.get("searchers")?;
#[cfg(any(feature = "lua51", feature = "luajit"))]
let searchers: Table = package.get("loaders")?;
let loader = self.create_function(|_, ()| Ok("\n\tcan't load C modules in safe mode"))?;
// The third and fourth searchers looks for a loader as a C library
searchers.raw_set(3, loader.clone())?;
searchers.raw_remove(4)?;
Ok(())
}
#[cfg(feature = "luau")]
unsafe fn prepare_luau_state(&self) -> Result<()> {
use std::ffi::CStr;
// Since Luau has some missing standard function, we re-implement them here
// They are: collectgarbage, loadstring, require
unsafe extern "C" fn lua_collectgarbage(state: *mut ffi::lua_State) -> c_int {
let option = ffi::luaL_optstring(state, 1, cstr!("collect"));
let option = CStr::from_ptr(option);
match option.to_str() {
Ok("collect") => {
ffi::lua_gc(state, ffi::LUA_GCCOLLECT, 0);
return 0;
}
Ok("count") => {
let n = ffi::lua_gc(state, ffi::LUA_GCCOUNT, 0);
ffi::lua_pushnumber(state, n as ffi::lua_Number);
return 1;
}
// TODO: More variants
_ => ffi::luaL_error(
state,
cstr!("collectgarbage must be called with 'count' or 'collect'"),
),
}
}
self.globals().raw_set(
"collectgarbage",
self.create_c_function(lua_collectgarbage)?,
)?;
Ok(())
}
pub(crate) unsafe fn make_from_ptr(state: *mut ffi::lua_State) -> Option<Self> {
let _sg = StackGuard::new(state);
assert_stack(state, 1);
let extra_key = &EXTRA_REGISTRY_KEY as *const u8 as *const c_void;
if ffi::lua_rawgetp(state, ffi::LUA_REGISTRYINDEX, extra_key) != ffi::LUA_TUSERDATA {
return None;
}
let extra_ptr = ffi::lua_touserdata(state, -1) as *mut Arc<UnsafeCell<ExtraData>>;
let extra = Arc::clone(&*extra_ptr);
ffi::lua_pop(state, 1);
let safe = (*extra.get()).safe;
Some(Lua {
state,
main_state: get_main_state(state),
extra,
ephemeral: true,
safe,
_no_ref_unwind_safe: PhantomData,
})
}
#[inline]
pub(crate) fn new_or_cached_multivalue(&self) -> MultiValue {
unsafe {
let extra = &mut *self.extra.get();
extra.multivalue_cache.pop().unwrap_or_default()
}
}
#[inline]
pub(crate) fn cache_multivalue(&self, mut multivalue: MultiValue) {
unsafe {
let extra = &mut *self.extra.get();
if extra.multivalue_cache.len() < MULTIVALUE_CACHE_SIZE {
multivalue.clear();
extra.multivalue_cache.push(mem::transmute(multivalue));
}
}
}
}
/// Returned from [`Lua::load`] and is used to finalize loading and executing Lua main chunks.
///
/// [`Lua::load`]: crate::Lua::load
#[must_use = "`Chunk`s do nothing unless one of `exec`, `eval`, `call`, or `into_function` are called on them"]
pub struct Chunk<'lua, 'a> {
lua: &'lua Lua,
source: &'a [u8],
name: Option<CString>,
env: Result<Option<Value<'lua>>>,
mode: Option<ChunkMode>,
}
/// Represents chunk mode (text or binary).
#[derive(Clone, Copy, Debug)]
pub enum ChunkMode {
Text,
Binary,
}
/// Trait for types [loadable by Lua] and convertible to a [`Chunk`]
///
/// [loadable by Lua]: https://www.lua.org/manual/5.4/manual.html#3.3.2
/// [`Chunk`]: crate::Chunk
pub trait AsChunk<'lua> {
/// Returns chunk data (can be text or binary)
fn source(&self) -> &[u8];
/// Returns optional chunk name
fn name(&self) -> Option<CString> {
None
}
/// Returns optional chunk [environment]
///
/// [environment]: https://www.lua.org/manual/5.4/manual.html#2.2
fn env(&self, _lua: &'lua Lua) -> Result<Option<Value<'lua>>> {
Ok(None)
}
/// Returns optional chunk mode (text or binary)
fn mode(&self) -> Option<ChunkMode> {
None
}
}
impl<'lua, 'a> Chunk<'lua, 'a> {
/// Sets the name of this chunk, which results in more informative error traces.
pub fn set_name<S: AsRef<[u8]> + ?Sized>(mut self, name: &S) -> Result<Chunk<'lua, 'a>> {
let name =
CString::new(name.as_ref().to_vec()).map_err(|e| Error::ToLuaConversionError {
from: "&str",
to: "string",
message: Some(e.to_string()),
})?;
self.name = Some(name);
Ok(self)
}
/// Sets the first upvalue (`_ENV`) of the loaded chunk to the given value.
///
/// Lua main chunks always have exactly one upvalue, and this upvalue is used as the `_ENV`
/// variable inside the chunk. By default this value is set to the global environment.
///
/// Calling this method changes the `_ENV` upvalue to the value provided, and variables inside
/// the chunk will refer to the given environment rather than the global one.
///
/// All global variables (including the standard library!) are looked up in `_ENV`, so it may be
/// necessary to populate the environment in order for scripts using custom environments to be
/// useful.
pub fn set_environment<V: ToLua<'lua>>(mut self, env: V) -> Result<Chunk<'lua, 'a>> {
// Prefer to propagate errors here and wrap to `Ok`
self.env = Ok(Some(env.to_lua(self.lua)?));
Ok(self)
}
/// Sets whether the chunk is text or binary (autodetected by default).
///
/// Lua does not check the consistency of binary chunks, therefore this mode is allowed only
/// for instances created with [`Lua::unsafe_new`].
///
/// [`Lua::unsafe_new`]: crate::Lua::unsafe_new
pub fn set_mode(mut self, mode: ChunkMode) -> Chunk<'lua, 'a> {
self.mode = Some(mode);
self
}
/// Execute this chunk of code.
///
/// This is equivalent to calling the chunk function with no arguments and no return values.
pub fn exec(self) -> Result<()> {
self.call(())?;
Ok(())
}
/// Asynchronously execute this chunk of code.
///
/// See [`exec`] for more details.
///
/// Requires `feature = "async"`
///
/// [`exec`]: #method.exec
#[cfg(feature = "async")]
#[cfg_attr(docsrs, doc(cfg(feature = "async")))]
pub fn exec_async<'fut>(self) -> LocalBoxFuture<'fut, Result<()>>
where
'lua: 'fut,
{
self.call_async(())
}
/// Evaluate the chunk as either an expression or block.
///
/// If the chunk can be parsed as an expression, this loads and executes the chunk and returns
/// the value that it evaluates to. Otherwise, the chunk is interpreted as a block as normal,
/// and this is equivalent to calling `exec`.
pub fn eval<R: FromLuaMulti<'lua>>(self) -> Result<R> {
// Bytecode is always interpreted as a statement.
// For source code, first try interpreting the lua as an expression by adding
// "return", then as a statement. This is the same thing the
// actual lua repl does.
if self.source[0] < b'\n' {
self.call(())
} else if let Ok(function) = self.lua.load_chunk(
&self.expression_source(),
self.name.as_ref(),
self.env()?,
self.mode,
) {
function.call(())
} else {
self.call(())
}
}
/// Asynchronously evaluate the chunk as either an expression or block.
///
/// See [`eval`] for more details.
///
/// Requires `feature = "async"`
///
/// [`eval`]: #method.eval
#[cfg(feature = "async")]
#[cfg_attr(docsrs, doc(cfg(feature = "async")))]
pub fn eval_async<'fut, R>(self) -> LocalBoxFuture<'fut, Result<R>>
where
'lua: 'fut,
R: FromLuaMulti<'lua> + 'fut,
{
if self.source[0] < b'\n' {
self.call_async(())
} else if let Ok(function) = self.lua.load_chunk(
&self.expression_source(),
self.name.as_ref(),
match self.env() {
Ok(env) => env,
Err(e) => return Box::pin(future::err(e)),
},
self.mode,
) {
function.call_async(())
} else {
self.call_async(())
}
}
/// Load the chunk function and call it with the given arguments.
///
/// This is equivalent to `into_function` and calling the resulting function.
pub fn call<A: ToLuaMulti<'lua>, R: FromLuaMulti<'lua>>(self, args: A) -> Result<R> {
self.into_function()?.call(args)
}
/// Load the chunk function and asynchronously call it with the given arguments.
///
/// See [`call`] for more details.
///
/// Requires `feature = "async"`
///
/// [`call`]: #method.call
#[cfg(feature = "async")]
#[cfg_attr(docsrs, doc(cfg(feature = "async")))]
pub fn call_async<'fut, A, R>(self, args: A) -> LocalBoxFuture<'fut, Result<R>>
where
'lua: 'fut,
A: ToLuaMulti<'lua>,
R: FromLuaMulti<'lua> + 'fut,
{
match self.into_function() {
Ok(func) => func.call_async(args),
Err(e) => Box::pin(future::err(e)),
}
}
/// Load this chunk into a regular `Function`.
///
/// This simply compiles the chunk without actually executing it.
pub fn into_function(self) -> Result<Function<'lua>> {
self.lua
.load_chunk(self.source, self.name.as_ref(), self.env()?, self.mode)
}
fn env(&self) -> Result<Option<Value<'lua>>> {
self.env.clone()
}
fn expression_source(&self) -> Vec<u8> {
let mut buf = Vec::with_capacity(b"return ".len() + self.source.len());
buf.extend(b"return ");
buf.extend(self.source);
buf
}
}
impl<'lua, T: AsRef<[u8]> + ?Sized> AsChunk<'lua> for T {
fn source(&self) -> &[u8] {
self.as_ref()
}
}
// Creates required entries in the metatable cache (see `util::METATABLE_CACHE`)
pub(crate) fn init_metatable_cache(cache: &mut FxHashMap<TypeId, u8>) {
cache.insert(TypeId::of::<Arc<UnsafeCell<ExtraData>>>(), 0);
cache.insert(TypeId::of::<Callback>(), 0);
cache.insert(TypeId::of::<CallbackUpvalue>(), 0);
#[cfg(feature = "async")]
{
cache.insert(TypeId::of::<AsyncCallback>(), 0);
cache.insert(TypeId::of::<AsyncCallbackUpvalue>(), 0);
cache.insert(TypeId::of::<AsyncPollUpvalue>(), 0);
cache.insert(TypeId::of::<Option<Waker>>(), 0);
}
}
// An optimized version of `callback_error` that does not allocate `WrappedFailure` userdata
// and instead reuses unsed and cached values from previous calls (or allocates new).
// It requires `get_extra` function to return `ExtraData` value.
unsafe fn callback_error_ext<F, R>(state: *mut ffi::lua_State, extra: *mut ExtraData, f: F) -> R
where
F: FnOnce(c_int) -> Result<R>,
{
if extra.is_null() {
return callback_error(state, f);
}
let extra = &mut *extra;
let nargs = ffi::lua_gettop(state);
// We need 2 extra stack spaces to store preallocated memory and error/panic metatable.
let extra_stack = if nargs < 2 { 2 - nargs } else { 1 };
ffi::luaL_checkstack(
state,
extra_stack,
cstr!("not enough stack space for callback error handling"),
);
enum PreallocatedFailure {
New(*mut WrappedFailure),
Cached(i32),
}
// We cannot shadow Rust errors with Lua ones, so we need to obtain pre-allocated memory
// to store a wrapped failure (error or panic) *before* we proceed.
let prealloc_failure = match extra.wrapped_failures_cache.pop() {
Some(index) => PreallocatedFailure::Cached(index),
None => {
let ud = WrappedFailure::new_userdata(state);
ffi::lua_rotate(state, 1, 1);
PreallocatedFailure::New(ud)
}
};
let mut get_wrapped_failure = || match prealloc_failure {
PreallocatedFailure::New(ud) => {
ffi::lua_settop(state, 1);
ud
}
PreallocatedFailure::Cached(index) => {
ffi::lua_settop(state, 0);
ffi::lua_pushvalue(extra.ref_thread, index);
ffi::lua_xmove(extra.ref_thread, state, 1);
ffi::lua_pushnil(extra.ref_thread);
ffi::lua_replace(extra.ref_thread, index);
extra.ref_free.push(index);
ffi::lua_touserdata(state, -1) as *mut WrappedFailure
}
};
match catch_unwind(AssertUnwindSafe(|| f(nargs))) {
Ok(Ok(r)) => {
// Return unused WrappedFailure to the cache
match prealloc_failure {
PreallocatedFailure::New(_)
if extra.wrapped_failures_cache.len() < WRAPPED_FAILURES_CACHE_SIZE =>
{
ffi::lua_rotate(state, 1, -1);
ffi::lua_xmove(state, extra.ref_thread, 1);
let index = ref_stack_pop(extra);
extra.wrapped_failures_cache.push(index);
}
PreallocatedFailure::New(_) => {
ffi::lua_remove(state, 1);
}
PreallocatedFailure::Cached(index)
if extra.wrapped_failures_cache.len() < WRAPPED_FAILURES_CACHE_SIZE =>
{
extra.wrapped_failures_cache.push(index);
}
PreallocatedFailure::Cached(index) => {
ffi::lua_pushnil(extra.ref_thread);
ffi::lua_replace(extra.ref_thread, index);
extra.ref_free.push(index);
}
}
r
}
Ok(Err(err)) => {
let wrapped_error = get_wrapped_failure();
// Build `CallbackError` with traceback
let traceback = if ffi::lua_checkstack(state, ffi::LUA_TRACEBACK_STACK) != 0 {
ffi::luaL_traceback(state, state, ptr::null(), 0);
let traceback = util::to_string(state, -1);
ffi::lua_pop(state, 1);
traceback
} else {
"<not enough stack space for traceback>".to_string()
};
let cause = Arc::new(err);
ptr::write(
wrapped_error,
WrappedFailure::Error(Error::CallbackError { traceback, cause }),
);
get_gc_metatable::<WrappedFailure>(state);
ffi::lua_setmetatable(state, -2);
ffi::lua_error(state)
}
Err(p) => {
let wrapped_panic = get_wrapped_failure();
ptr::write(wrapped_panic, WrappedFailure::Panic(Some(p)));
get_gc_metatable::<WrappedFailure>(state);
ffi::lua_setmetatable(state, -2);
ffi::lua_error(state)
}
}
}
// Uses 3 stack spaces
unsafe fn load_from_std_lib(state: *mut ffi::lua_State, libs: StdLib) -> Result<()> {
#[inline(always)]
pub unsafe fn requiref<S: AsRef<[u8]> + ?Sized>(
state: *mut ffi::lua_State,
modname: &S,
openf: ffi::lua_CFunction,
glb: c_int,
) -> Result<()> {
let modname = mlua_expect!(CString::new(modname.as_ref()), "modname contains nil bytes");
protect_lua!(state, 0, 1, |state| {
ffi::luaL_requiref(state, modname.as_ptr() as *const c_char, openf, glb)
})
}
#[cfg(feature = "luajit")]
struct GcGuard(*mut ffi::lua_State);
#[cfg(feature = "luajit")]
impl GcGuard {
fn new(state: *mut ffi::lua_State) -> Self {
// Stop collector during library initialization
unsafe { ffi::lua_gc(state, ffi::LUA_GCSTOP, 0) };
GcGuard(state)
}
}
#[cfg(feature = "luajit")]
impl Drop for GcGuard {
fn drop(&mut self) {
unsafe { ffi::lua_gc(self.0, ffi::LUA_GCRESTART, -1) };
}
}
// Stop collector during library initialization
#[cfg(feature = "luajit")]
let _gc_guard = GcGuard::new(state);
#[cfg(any(
feature = "lua54",
feature = "lua53",
feature = "lua52",
feature = "luau"
))]
{
if libs.contains(StdLib::COROUTINE) {
requiref(state, ffi::LUA_COLIBNAME, ffi::luaopen_coroutine, 1)?;
ffi::lua_pop(state, 1);
}
}
if libs.contains(StdLib::TABLE) {
requiref(state, ffi::LUA_TABLIBNAME, ffi::luaopen_table, 1)?;
ffi::lua_pop(state, 1);
}
#[cfg(not(feature = "luau"))]
if libs.contains(StdLib::IO) {
requiref(state, ffi::LUA_IOLIBNAME, ffi::luaopen_io, 1)?;
ffi::lua_pop(state, 1);
}
if libs.contains(StdLib::OS) {
requiref(state, ffi::LUA_OSLIBNAME, ffi::luaopen_os, 1)?;
ffi::lua_pop(state, 1);
}
if libs.contains(StdLib::STRING) {
requiref(state, ffi::LUA_STRLIBNAME, ffi::luaopen_string, 1)?;
ffi::lua_pop(state, 1);
}
#[cfg(any(feature = "lua54", feature = "lua53", feature = "luau"))]
{
if libs.contains(StdLib::UTF8) {
requiref(state, ffi::LUA_UTF8LIBNAME, ffi::luaopen_utf8, 1)?;
ffi::lua_pop(state, 1);
}
}
#[cfg(any(feature = "lua52", feature = "luau"))]
{
if libs.contains(StdLib::BIT) {
requiref(state, ffi::LUA_BITLIBNAME, ffi::luaopen_bit32, 1)?;
ffi::lua_pop(state, 1);
}
}
#[cfg(feature = "luajit")]
{
if libs.contains(StdLib::BIT) {
requiref(state, ffi::LUA_BITLIBNAME, ffi::luaopen_bit, 1)?;
ffi::lua_pop(state, 1);
}
}
if libs.contains(StdLib::MATH) {
requiref(state, ffi::LUA_MATHLIBNAME, ffi::luaopen_math, 1)?;
ffi::lua_pop(state, 1);
}
if libs.contains(StdLib::DEBUG) {
requiref(state, ffi::LUA_DBLIBNAME, ffi::luaopen_debug, 1)?;
ffi::lua_pop(state, 1);
}
#[cfg(not(feature = "luau"))]
if libs.contains(StdLib::PACKAGE) {
requiref(state, ffi::LUA_LOADLIBNAME, ffi::luaopen_package, 1)?;
ffi::lua_pop(state, 1);
}
#[cfg(feature = "luajit")]
{
if libs.contains(StdLib::JIT) {
requiref(state, ffi::LUA_JITLIBNAME, ffi::luaopen_jit, 1)?;
ffi::lua_pop(state, 1);
}
if libs.contains(StdLib::FFI) {
requiref(state, ffi::LUA_FFILIBNAME, ffi::luaopen_ffi, 1)?;
ffi::lua_pop(state, 1);
}
}
Ok(())
}
unsafe fn ref_stack_pop(extra: &mut ExtraData) -> c_int {
if let Some(free) = extra.ref_free.pop() {
ffi::lua_replace(extra.ref_thread, free);
return free;
}
// Try to grow max stack size
if extra.ref_stack_top >= extra.ref_stack_size {
let mut inc = extra.ref_stack_size; // Try to double stack size
while inc > 0 && ffi::lua_checkstack(extra.ref_thread, inc) == 0 {
inc /= 2;
}
if inc == 0 {
// Pop item on top of the stack to avoid stack leaking and successfully run destructors
// during unwinding.
ffi::lua_pop(extra.ref_thread, 1);
let top = extra.ref_stack_top;
// It is a user error to create enough references to exhaust the Lua max stack size for
// the ref thread.
panic!(
"cannot create a Lua reference, out of auxiliary stack space (used {} slots)",
top
);
}
extra.ref_stack_size += inc;
}
extra.ref_stack_top += 1;
extra.ref_stack_top
}
struct StaticUserDataMethods<'lua, T: 'static + UserData> {
methods: Vec<(Vec<u8>, Callback<'lua, 'static>)>,
#[cfg(feature = "async")]
async_methods: Vec<(Vec<u8>, AsyncCallback<'lua, 'static>)>,
meta_methods: Vec<(MetaMethod, Callback<'lua, 'static>)>,
#[cfg(feature = "async")]
async_meta_methods: Vec<(MetaMethod, AsyncCallback<'lua, 'static>)>,
_type: PhantomData<T>,
}
impl<'lua, T: 'static + UserData> Default for StaticUserDataMethods<'lua, T> {
fn default() -> StaticUserDataMethods<'lua, T> {
StaticUserDataMethods {
methods: Vec::new(),
#[cfg(feature = "async")]
async_methods: Vec::new(),
meta_methods: Vec::new(),
#[cfg(feature = "async")]
async_meta_methods: Vec::new(),
_type: PhantomData,
}
}
}
impl<'lua, T: 'static + UserData> UserDataMethods<'lua, T> for StaticUserDataMethods<'lua, T> {
fn add_method<S, A, R, M>(&mut self, name: &S, method: M)
where
S: AsRef<[u8]> + ?Sized,
A: FromLuaMulti<'lua>,
R: ToLuaMulti<'lua>,
M: 'static + MaybeSend + Fn(&'lua Lua, &T, A) -> Result<R>,
{
self.methods
.push((name.as_ref().to_vec(), Self::box_method(method)));
}
fn add_method_mut<S, A, R, M>(&mut self, name: &S, method: M)
where
S: AsRef<[u8]> + ?Sized,
A: FromLuaMulti<'lua>,
R: ToLuaMulti<'lua>,
M: 'static + MaybeSend + FnMut(&'lua Lua, &mut T, A) -> Result<R>,
{
self.methods
.push((name.as_ref().to_vec(), Self::box_method_mut(method)));
}
#[cfg(feature = "async")]
fn add_async_method<S, A, R, M, MR>(&mut self, name: &S, method: M)
where
T: Clone,
S: AsRef<[u8]> + ?Sized,
A: FromLuaMulti<'lua>,
R: ToLuaMulti<'lua>,
M: 'static + MaybeSend + Fn(&'lua Lua, T, A) -> MR,
MR: 'lua + Future<Output = Result<R>>,
{
self.async_methods
.push((name.as_ref().to_vec(), Self::box_async_method(method)));
}
fn add_function<S, A, R, F>(&mut self, name: &S, function: F)
where
S: AsRef<[u8]> + ?Sized,
A: FromLuaMulti<'lua>,
R: ToLuaMulti<'lua>,
F: 'static + MaybeSend + Fn(&'lua Lua, A) -> Result<R>,
{
self.methods
.push((name.as_ref().to_vec(), Self::box_function(function)));
}
fn add_function_mut<S, A, R, F>(&mut self, name: &S, function: F)
where
S: AsRef<[u8]> + ?Sized,
A: FromLuaMulti<'lua>,
R: ToLuaMulti<'lua>,
F: 'static + MaybeSend + FnMut(&'lua Lua, A) -> Result<R>,
{
self.methods
.push((name.as_ref().to_vec(), Self::box_function_mut(function)));
}
#[cfg(feature = "async")]
fn add_async_function<S, A, R, F, FR>(&mut self, name: &S, function: F)
where
S: AsRef<[u8]> + ?Sized,
A: FromLuaMulti<'lua>,
R: ToLuaMulti<'lua>,
F: 'static + MaybeSend + Fn(&'lua Lua, A) -> FR,
FR: 'lua + Future<Output = Result<R>>,
{
self.async_methods
.push((name.as_ref().to_vec(), Self::box_async_function(function)));
}
fn add_meta_method<S, A, R, M>(&mut self, meta: S, method: M)
where
S: Into<MetaMethod>,
A: FromLuaMulti<'lua>,
R: ToLuaMulti<'lua>,
M: 'static + MaybeSend + Fn(&'lua Lua, &T, A) -> Result<R>,
{
self.meta_methods
.push((meta.into(), Self::box_method(method)));
}
fn add_meta_method_mut<S, A, R, M>(&mut self, meta: S, method: M)
where
S: Into<MetaMethod>,
A: FromLuaMulti<'lua>,
R: ToLuaMulti<'lua>,
M: 'static + MaybeSend + FnMut(&'lua Lua, &mut T, A) -> Result<R>,
{
self.meta_methods
.push((meta.into(), Self::box_method_mut(method)));
}
#[cfg(all(feature = "async", not(any(feature = "lua51", feature = "luau"))))]
fn add_async_meta_method<S, A, R, M, MR>(&mut self, meta: S, method: M)
where
T: Clone,
S: Into<MetaMethod>,
A: FromLuaMulti<'lua>,
R: ToLuaMulti<'lua>,
M: 'static + MaybeSend + Fn(&'lua Lua, T, A) -> MR,
MR: 'lua + Future<Output = Result<R>>,
{
self.async_meta_methods
.push((meta.into(), Self::box_async_method(method)));
}
fn add_meta_function<S, A, R, F>(&mut self, meta: S, function: F)
where
S: Into<MetaMethod>,
A: FromLuaMulti<'lua>,
R: ToLuaMulti<'lua>,
F: 'static + MaybeSend + Fn(&'lua Lua, A) -> Result<R>,
{
self.meta_methods
.push((meta.into(), Self::box_function(function)));
}
fn add_meta_function_mut<S, A, R, F>(&mut self, meta: S, function: F)
where
S: Into<MetaMethod>,
A: FromLuaMulti<'lua>,
R: ToLuaMulti<'lua>,
F: 'static + MaybeSend + FnMut(&'lua Lua, A) -> Result<R>,
{
self.meta_methods
.push((meta.into(), Self::box_function_mut(function)));
}
#[cfg(all(feature = "async", not(any(feature = "lua51", feature = "luau"))))]
fn add_async_meta_function<S, A, R, F, FR>(&mut self, meta: S, function: F)
where
S: Into<MetaMethod>,
A: FromLuaMulti<'lua>,
R: ToLuaMulti<'lua>,
F: 'static + MaybeSend + Fn(&'lua Lua, A) -> FR,
FR: 'lua + Future<Output = Result<R>>,
{
self.async_meta_methods
.push((meta.into(), Self::box_async_function(function)));
}
// Below are internal methods used in generated code
fn add_callback(&mut self, name: Vec<u8>, callback: Callback<'lua, 'static>) {
self.methods.push((name, callback));
}
#[cfg(feature = "async")]
fn add_async_callback(&mut self, name: Vec<u8>, callback: AsyncCallback<'lua, 'static>) {
self.async_methods.push((name, callback));
}
fn add_meta_callback(&mut self, meta: MetaMethod, callback: Callback<'lua, 'static>) {
self.meta_methods.push((meta, callback));
}
#[cfg(feature = "async")]
fn add_async_meta_callback(
&mut self,
meta: MetaMethod,
callback: AsyncCallback<'lua, 'static>,
) {
self.async_meta_methods.push((meta, callback))
}
}
impl<'lua, T: 'static + UserData> StaticUserDataMethods<'lua, T> {
fn box_method<A, R, M>(method: M) -> Callback<'lua, 'static>
where
A: FromLuaMulti<'lua>,
R: ToLuaMulti<'lua>,
M: 'static + MaybeSend + Fn(&'lua Lua, &T, A) -> Result<R>,
{
Box::new(move |lua, mut args| {
if let Some(front) = args.pop_front() {
let userdata = AnyUserData::from_lua(front, lua)?;
unsafe {
let _sg = StackGuard::new(lua.state);
check_stack(lua.state, 2)?;
let type_id = lua.push_userdata_ref(&userdata.0)?;
match type_id {
Some(id) if id == TypeId::of::<T>() => {
let ud = lua.get_userdata_ref::<T>()?;
method(lua, &ud, A::from_lua_multi(args, lua)?)?.to_lua_multi(lua)
}
#[cfg(not(feature = "send"))]
Some(id) if id == TypeId::of::<Rc<RefCell<T>>>() => {
let ud = lua.get_userdata_ref::<Rc<RefCell<T>>>()?;
let ud = ud.try_borrow().map_err(|_| Error::UserDataBorrowError)?;
method(lua, &ud, A::from_lua_multi(args, lua)?)?.to_lua_multi(lua)
}
Some(id) if id == TypeId::of::<Arc<Mutex<T>>>() => {
let ud = lua.get_userdata_ref::<Arc<Mutex<T>>>()?;
let ud = ud.try_lock().map_err(|_| Error::UserDataBorrowError)?;
method(lua, &ud, A::from_lua_multi(args, lua)?)?.to_lua_multi(lua)
}
Some(id) if id == TypeId::of::<Arc<RwLock<T>>>() => {
let ud = lua.get_userdata_ref::<Arc<RwLock<T>>>()?;
let ud = ud.try_read().map_err(|_| Error::UserDataBorrowError)?;
method(lua, &ud, A::from_lua_multi(args, lua)?)?.to_lua_multi(lua)
}
_ => Err(Error::UserDataTypeMismatch),
}
}
} else {
Err(Error::FromLuaConversionError {
from: "missing argument",
to: "userdata",
message: None,
})
}
})
}
fn box_method_mut<A, R, M>(method: M) -> Callback<'lua, 'static>
where
A: FromLuaMulti<'lua>,
R: ToLuaMulti<'lua>,
M: 'static + MaybeSend + FnMut(&'lua Lua, &mut T, A) -> Result<R>,
{
let method = RefCell::new(method);
Box::new(move |lua, mut args| {
if let Some(front) = args.pop_front() {
let userdata = AnyUserData::from_lua(front, lua)?;
let mut method = method
.try_borrow_mut()
.map_err(|_| Error::RecursiveMutCallback)?;
unsafe {
let _sg = StackGuard::new(lua.state);
check_stack(lua.state, 2)?;
let type_id = lua.push_userdata_ref(&userdata.0)?;
match type_id {
Some(id) if id == TypeId::of::<T>() => {
let mut ud = lua.get_userdata_mut::<T>()?;
method(lua, &mut ud, A::from_lua_multi(args, lua)?)?.to_lua_multi(lua)
}
#[cfg(not(feature = "send"))]
Some(id) if id == TypeId::of::<Rc<RefCell<T>>>() => {
let ud = lua.get_userdata_mut::<Rc<RefCell<T>>>()?;
let mut ud = ud
.try_borrow_mut()
.map_err(|_| Error::UserDataBorrowMutError)?;
method(lua, &mut ud, A::from_lua_multi(args, lua)?)?.to_lua_multi(lua)
}
Some(id) if id == TypeId::of::<Arc<Mutex<T>>>() => {
let ud = lua.get_userdata_mut::<Arc<Mutex<T>>>()?;
let mut ud =
ud.try_lock().map_err(|_| Error::UserDataBorrowMutError)?;
method(lua, &mut ud, A::from_lua_multi(args, lua)?)?.to_lua_multi(lua)
}
Some(id) if id == TypeId::of::<Arc<RwLock<T>>>() => {
let ud = lua.get_userdata_mut::<Arc<RwLock<T>>>()?;
let mut ud =
ud.try_write().map_err(|_| Error::UserDataBorrowMutError)?;
method(lua, &mut ud, A::from_lua_multi(args, lua)?)?.to_lua_multi(lua)
}
_ => Err(Error::UserDataTypeMismatch),
}
}
} else {
Err(Error::FromLuaConversionError {
from: "missing argument",
to: "userdata",
message: None,
})
}
})
}
#[cfg(feature = "async")]
fn box_async_method<A, R, M, MR>(method: M) -> AsyncCallback<'lua, 'static>
where
T: Clone,
A: FromLuaMulti<'lua>,
R: ToLuaMulti<'lua>,
M: 'static + MaybeSend + Fn(&'lua Lua, T, A) -> MR,
MR: 'lua + Future<Output = Result<R>>,
{
Box::new(move |lua, mut args| {
let fut_res = || {
if let Some(front) = args.pop_front() {
let userdata = AnyUserData::from_lua(front, lua)?;
unsafe {
let _sg = StackGuard::new(lua.state);
check_stack(lua.state, 2)?;
let type_id = lua.push_userdata_ref(&userdata.0)?;
match type_id {
Some(id) if id == TypeId::of::<T>() => {
let ud = lua.get_userdata_ref::<T>()?;
Ok(method(lua, ud.clone(), A::from_lua_multi(args, lua)?))
}
#[cfg(not(feature = "send"))]
Some(id) if id == TypeId::of::<Rc<RefCell<T>>>() => {
let ud = lua.get_userdata_ref::<Rc<RefCell<T>>>()?;
let ud = ud.try_borrow().map_err(|_| Error::UserDataBorrowError)?;
Ok(method(lua, ud.clone(), A::from_lua_multi(args, lua)?))
}
Some(id) if id == TypeId::of::<Arc<Mutex<T>>>() => {
let ud = lua.get_userdata_ref::<Arc<Mutex<T>>>()?;
let ud = ud.try_lock().map_err(|_| Error::UserDataBorrowError)?;
Ok(method(lua, ud.clone(), A::from_lua_multi(args, lua)?))
}
Some(id) if id == TypeId::of::<Arc<RwLock<T>>>() => {
let ud = lua.get_userdata_ref::<Arc<RwLock<T>>>()?;
let ud = ud.try_read().map_err(|_| Error::UserDataBorrowError)?;
Ok(method(lua, ud.clone(), A::from_lua_multi(args, lua)?))
}
_ => Err(Error::UserDataTypeMismatch),
}
}
} else {
Err(Error::FromLuaConversionError {
from: "missing argument",
to: "userdata",
message: None,
})
}
};
match fut_res() {
Ok(fut) => Box::pin(fut.and_then(move |ret| future::ready(ret.to_lua_multi(lua)))),
Err(e) => Box::pin(future::err(e)),
}
})
}
fn box_function<A, R, F>(function: F) -> Callback<'lua, 'static>
where
A: FromLuaMulti<'lua>,
R: ToLuaMulti<'lua>,
F: 'static + MaybeSend + Fn(&'lua Lua, A) -> Result<R>,
{
Box::new(move |lua, args| function(lua, A::from_lua_multi(args, lua)?)?.to_lua_multi(lua))
}
fn box_function_mut<A, R, F>(function: F) -> Callback<'lua, 'static>
where
A: FromLuaMulti<'lua>,
R: ToLuaMulti<'lua>,
F: 'static + MaybeSend + FnMut(&'lua Lua, A) -> Result<R>,
{
let function = RefCell::new(function);
Box::new(move |lua, args| {
let function = &mut *function
.try_borrow_mut()
.map_err(|_| Error::RecursiveMutCallback)?;
function(lua, A::from_lua_multi(args, lua)?)?.to_lua_multi(lua)
})
}
#[cfg(feature = "async")]
fn box_async_function<A, R, F, FR>(function: F) -> AsyncCallback<'lua, 'static>
where
A: FromLuaMulti<'lua>,
R: ToLuaMulti<'lua>,
F: 'static + MaybeSend + Fn(&'lua Lua, A) -> FR,
FR: 'lua + Future<Output = Result<R>>,
{
Box::new(move |lua, args| {
let args = match A::from_lua_multi(args, lua) {
Ok(args) => args,
Err(e) => return Box::pin(future::err(e)),
};
Box::pin(function(lua, args).and_then(move |ret| future::ready(ret.to_lua_multi(lua))))
})
}
}
struct StaticUserDataFields<'lua, T: 'static + UserData> {
field_getters: Vec<(Vec<u8>, Callback<'lua, 'static>)>,
field_setters: Vec<(Vec<u8>, Callback<'lua, 'static>)>,
#[allow(clippy::type_complexity)]
meta_fields: Vec<(
MetaMethod,
Box<dyn Fn(&'lua Lua) -> Result<Value<'lua>> + 'static>,
)>,
_type: PhantomData<T>,
}
impl<'lua, T: 'static + UserData> Default for StaticUserDataFields<'lua, T> {
fn default() -> StaticUserDataFields<'lua, T> {
StaticUserDataFields {
field_getters: Vec::new(),
field_setters: Vec::new(),
meta_fields: Vec::new(),
_type: PhantomData,
}
}
}
impl<'lua, T: 'static + UserData> UserDataFields<'lua, T> for StaticUserDataFields<'lua, T> {
fn add_field_method_get<S, R, M>(&mut self, name: &S, method: M)
where
S: AsRef<[u8]> + ?Sized,
R: ToLua<'lua>,
M: 'static + MaybeSend + Fn(&'lua Lua, &T) -> Result<R>,
{
self.field_getters.push((
name.as_ref().to_vec(),
StaticUserDataMethods::box_method(move |lua, data, ()| method(lua, data)),
));
}
fn add_field_method_set<S, A, M>(&mut self, name: &S, method: M)
where
S: AsRef<[u8]> + ?Sized,
A: FromLua<'lua>,
M: 'static + MaybeSend + FnMut(&'lua Lua, &mut T, A) -> Result<()>,
{
self.field_setters.push((
name.as_ref().to_vec(),
StaticUserDataMethods::box_method_mut(method),
));
}
fn add_field_function_get<S, R, F>(&mut self, name: &S, function: F)
where
S: AsRef<[u8]> + ?Sized,
R: ToLua<'lua>,
F: 'static + MaybeSend + Fn(&'lua Lua, AnyUserData<'lua>) -> Result<R>,
{
self.field_getters.push((
name.as_ref().to_vec(),
StaticUserDataMethods::<T>::box_function(function),
));
}
fn add_field_function_set<S, A, F>(&mut self, name: &S, mut function: F)
where
S: AsRef<[u8]> + ?Sized,
A: FromLua<'lua>,
F: 'static + MaybeSend + FnMut(&'lua Lua, AnyUserData<'lua>, A) -> Result<()>,
{
self.field_setters.push((
name.as_ref().to_vec(),
StaticUserDataMethods::<T>::box_function_mut(move |lua, (data, val)| {
function(lua, data, val)
}),
));
}
fn add_meta_field_with<S, R, F>(&mut self, meta: S, f: F)
where
S: Into<MetaMethod>,
R: ToLua<'lua>,
F: 'static + MaybeSend + Fn(&'lua Lua) -> Result<R>,
{
let meta = meta.into();
self.meta_fields.push((
meta.clone(),
Box::new(move |lua| {
let value = f(lua)?.to_lua(lua)?;
if meta == MetaMethod::Index || meta == MetaMethod::NewIndex {
match value {
Value::Nil | Value::Table(_) | Value::Function(_) => {}
_ => {
return Err(Error::MetaMethodTypeError {
method: meta.to_string(),
type_name: value.type_name(),
message: Some("expected nil, table or function".to_string()),
})
}
}
}
Ok(value)
}),
));
}
// Below are internal methods
fn add_field_getter(&mut self, name: Vec<u8>, callback: Callback<'lua, 'static>) {
self.field_getters.push((name, callback));
}
fn add_field_setter(&mut self, name: Vec<u8>, callback: Callback<'lua, 'static>) {
self.field_setters.push((name, callback));
}
}
macro_rules! lua_userdata_impl {
($type:ty) => {
impl<T: 'static + UserData> UserData for $type {
fn add_fields<'lua, F: UserDataFields<'lua, Self>>(fields: &mut F) {
let mut orig_fields = StaticUserDataFields::default();
T::add_fields(&mut orig_fields);
for (name, callback) in orig_fields.field_getters {
fields.add_field_getter(name, callback);
}
for (name, callback) in orig_fields.field_setters {
fields.add_field_setter(name, callback);
}
}
fn add_methods<'lua, M: UserDataMethods<'lua, Self>>(methods: &mut M) {
let mut orig_methods = StaticUserDataMethods::default();
T::add_methods(&mut orig_methods);
for (name, callback) in orig_methods.methods {
methods.add_callback(name, callback);
}
#[cfg(feature = "async")]
for (name, callback) in orig_methods.async_methods {
methods.add_async_callback(name, callback);
}
for (meta, callback) in orig_methods.meta_methods {
methods.add_meta_callback(meta, callback);
}
#[cfg(feature = "async")]
for (meta, callback) in orig_methods.async_meta_methods {
methods.add_async_meta_callback(meta, callback);
}
}
}
};
}
#[cfg(not(feature = "send"))]
lua_userdata_impl!(Rc<RefCell<T>>);
lua_userdata_impl!(Arc<Mutex<T>>);
lua_userdata_impl!(Arc<RwLock<T>>);
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