Create UserdataRefMut, create tests for UserdataRef and UserdataRefMut

.vscode/launch.json

@@ -40,6 +40,27 @@
             },
             "args": [],
             "cwd": "${workspaceFolder}"
+        },
+        {
+            "type": "lldb",
+            "request": "launch",
+            "name": "Debug a specific unit tests in executable 'lua-ffi'",
+            "cargo": {
+                "args": [
+                    "test",
+                    "--no-run",
+                    "--package=lua-ffi",
+                    "userdata::borrow::tests::ud_methods_borrow",
+                    "--",
+                    "--exact"
+                ]/* ,
+                "filter": {
+                    "name": "lua-ffi",
+                    "kind": "bin"
+                } */
+            },
+            "args": [],
+            "cwd": "${workspaceFolder}"
         }
     ]
 }

src/tests.rs

@@ -3,8 +3,8 @@ use std::cell::Ref;
 use crate::{MetaMethod, State, Userdata, UserdataBuilder};
 
 pub struct Vec2 {
-    x: f32,
+    pub x: f32,
-    y: f32,
+    pub y: f32,
 }
 
 impl Userdata for Vec2 {
@@ -28,6 +28,18 @@ impl Userdata for Vec2 {
                     y: ly + ry,
                 })
             })
+            .method_mut("mult", |_, this: &mut Vec2, scalar: f32| {
+                this.x *= scalar;
+                this.y *= scalar;
+
+                Ok(())
+            })
+            .method("mult_ret", |lua, this: &Vec2, scalar: f32| {
+                lua.create_userdata(Vec2 {
+                    x: this.x * scalar,
+                    y: this.y * scalar,
+                })
+            })
             .meta_method(MetaMethod::Add, |lua, lhs: &Vec2, (rhs,): (Ref<Vec2>,)| {
                 let lx = lhs.x;
                 let ly = lhs.y;

src/userdata/borrow.rs

@@ -1,6 +1,6 @@
 use std::{cell::Ref, mem, ops::Deref};
 
-use crate::{AnyUserdata, Result, State, Userdata, UserdataBuilder};
+use crate::{AnyUserdata, Error, Result, State, Userdata, UserdataBuilder};
 
 enum Borrow<'a, T> {
     Wrapped(Ref<'a, T>),
@@ -64,10 +64,18 @@ impl<'a, T: Userdata + 'static> Userdata for UserdataRef<'a, T> {
             Ok(ud_ptr.cast::<()>())
         };
 
+        let mut_getter: fn(AnyUserdata<'_>) -> Result<*mut ()> = move |_ud: AnyUserdata| {
+            Err(Error::Runtime(format!("cannot mutably access '{}' when its behind a non mutable reference!", T::name())))
+        };
+
         if builder.wrapped_getter.set(Box::new(getter)).is_err() {
             panic!("Somehow the wrapped getter has already been set");
         }
 
+        if builder.wrapped_getter_mut.set(Box::new(mut_getter)).is_err() {
+            panic!("Somehow the wrapped mutable getter has already been set");
+        }
+
         Ok(())
     }
 
@@ -76,3 +84,85 @@ impl<'a, T: Userdata + 'static> Userdata for UserdataRef<'a, T> {
         name
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use std::{borrow::Borrow, cell::{Ref, RefCell}};
+
+    use crate::{tests::Vec2, AnyUserdata, State, StdLibrary, Value};
+
+    use super::UserdataRef;
+
+    /// This test ensures that a Ref of userdata can be provided to Lua, and it that it can access fields on the userdata.
+    #[test]
+    fn ud_fields_borrow() -> crate::Result<()> {
+        let lua = State::new();
+        lua.expose_libraries(&[StdLibrary::Debug, StdLibrary::Package]);
+    
+        let globals = lua.globals()?;
+    
+        let v1 = RefCell::new(Vec2 { x: 50.0, y: 5.0 });
+        let ud = lua.create_userdata(UserdataRef::from(v1.borrow()))?;
+        globals.set("v1", ud)?;
+
+        let chunk = lua.load(
+            "text.lua",
+            r#"
+            print("v1: (" .. v1.x .. ", " .. v1.y .. ")")
+        "#)?;
+    
+        for _ in 0..40 {
+            let res = lua.execute_chunk::<_, Value>(&chunk, ());
+    
+            if let Err(e) = res {
+                panic!("{}", e);
+            }
+            
+            //println!("i = {}", i);
+            globals.set("v1", Value::Nil)?;
+            lua.gc_collect()?; // must collect here to drop the Ref
+    
+            let mut t = v1.borrow_mut();
+            t.x += 50.0;
+            t.y += 5.0;
+            drop(t); 
+    
+            let ud = lua.create_userdata(UserdataRef::from(v1.borrow()))?;
+            globals.raw_set("v1", ud)?;
+        }
+
+        Ok(())
+    }
+
+    /// This test ensures that a raw borrow of userdata can be provided to Lua, and it that it can run non-mutating methods on the userdata.
+    #[test]
+    fn ud_methods_borrow() -> crate::Result<()> {
+        let lua = State::new();
+        lua.expose_libraries(&[StdLibrary::Debug, StdLibrary::Package]);
+    
+        let globals = lua.globals()?;
+    
+        let v1 = RefCell::new(Vec2 { x: 50.0, y: 5.0 });
+        let ud = lua.create_userdata(UserdataRef::from(v1.borrow()))?;
+        globals.set("v1", ud)?;
+
+        let chunk = lua.load(
+            "text.lua",
+            r#"
+                v2 = v1:mult_ret(2.0)
+                print("v2: (" .. v2.x .. ", " .. v2.y .. ")")
+        "#)?;
+
+        let res = lua.execute_chunk::<_, Value>(&chunk, ());
+    
+        if let Err(e) = res {
+            panic!("{}", e);
+        }
+
+        let v2 = globals.get::<_, Ref<Vec2>>("v2")?;
+        assert_eq!(v2.x, 100.0);
+        assert_eq!(v2.y, 10.0);
+
+        Ok(())
+    }
+}

src/userdata/borrow_mut.rs

@@ -0,0 +1,195 @@
+use std::{cell::RefMut, mem, ops::{Deref, DerefMut}};
+
+use crate::{AnyUserdata, Result, State, Userdata, UserdataBuilder};
+
+enum BorrowMut<'a, T> {
+    Wrapped(RefMut<'a, T>),
+    Raw(&'a mut T),
+}
+
+impl<'a, T> Deref for BorrowMut<'a, T> {
+    type Target = T;
+
+    fn deref(&self) -> &Self::Target {
+        match self {
+            BorrowMut::Wrapped(w) => w,
+            BorrowMut::Raw(w) => w,
+        }
+    }
+}
+
+impl<'a, T> DerefMut for BorrowMut<'a, T> {
+    fn deref_mut(&mut self) -> &mut Self::Target {
+        match self {
+            BorrowMut::Wrapped(w) => w,
+            BorrowMut::Raw(w) => w,
+        }
+    }
+}
+
+pub struct UserdataRefMut<'a, T: Userdata> {
+    borrow: BorrowMut<'a, T>,
+}
+
+impl<'a, T: Userdata> From<&'a mut T> for UserdataRefMut<'static, T> {
+    fn from(value: &'a mut T) -> Self {
+        let ud = BorrowMut::Raw(value);
+
+        Self {
+            borrow: unsafe {
+                mem::transmute(ud)
+            }
+        }
+    }
+}
+
+impl<'a, T: Userdata> From<RefMut<'a, T>> for UserdataRefMut<'static, T> {
+    fn from(value: RefMut<'a, T>) -> Self {
+        let ud = BorrowMut::Wrapped(value);
+
+        Self {
+            borrow: unsafe {
+                mem::transmute(ud)
+            },
+        }
+    }
+}
+
+impl<'a, T: Userdata + 'static> Userdata for UserdataRefMut<'a, T> {
+    fn build<'b>(state: &State, builder: &mut UserdataBuilder<'b, Self>) -> crate::Result<()> {
+        let mut other = UserdataBuilder::<T>::new();
+        T::build(state, &mut other)?;
+
+        builder.expand_with(other);
+
+        let getter: fn(AnyUserdata<'_>) -> Result<*const ()> = move |ud: AnyUserdata| {
+            let ud_ptr = {
+                let ud = ud.as_ref::<UserdataRefMut<T>>()?;
+
+                let ud_ptr: *const T = &*ud.borrow;
+                ud_ptr
+            };
+
+            Ok(ud_ptr.cast::<()>())
+        };
+
+        let getter_mut: fn(AnyUserdata<'_>) -> Result<*mut ()> = move |ud: AnyUserdata| {
+            let ud_ptr = {
+                let mut ud = ud.as_mut::<UserdataRefMut<T>>()?;
+
+                let ud_ptr: *mut T = &mut *ud.borrow;
+                ud_ptr
+            };
+
+            Ok(ud_ptr.cast::<()>())
+        };
+
+        if builder.wrapped_getter.set(Box::new(getter)).is_err() {
+            panic!("Somehow the wrapped getter has already been set");
+        }
+
+        if builder.wrapped_getter_mut.set(Box::new(getter_mut)).is_err() {
+            panic!("Somehow the wrapped mutable getter has already been set");
+        }
+
+        Ok(())
+    }
+
+    fn name() -> String {
+        let name = format!("{}RefMut", T::name());
+        name
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use std::cell::RefCell;
+
+    use crate::{tests::Vec2, State, StdLibrary, Value};
+
+    use super::UserdataRefMut;
+
+    /// This test ensures that you can provide Lua a RefMut and it that it can set the fields on the userdata.
+    #[test]
+    fn ud_fields_borrow_mut() -> crate::Result<()> {
+        let lua = State::new();
+        lua.expose_libraries(&[StdLibrary::Debug, StdLibrary::Package]);
+    
+        let globals = lua.globals()?;
+    
+        let v1 = RefCell::new(Vec2 { x: 50.0, y: 5.0 });
+        let ud = lua.create_userdata(UserdataRefMut::from(v1.borrow_mut()))?;
+        globals.set("v1", ud)?;
+
+        let mut x = 50.0;
+        let mut y = 5.0;
+
+        let chunk = lua.load(
+            "text.lua",
+            r#"
+            v1.x = v1.x + 50
+            v1.y = v1.y + 5
+            print("v1: (" .. v1.x .. ", " .. v1.y .. ")")
+        "#)?;
+    
+        for _ in 0..40 {
+            let res = lua.execute_chunk::<_, Value>(&chunk, ());
+    
+            if let Err(e) = res {
+                panic!("{}", e);
+            }
+            
+            //println!("i = {}", i);
+            globals.set("v1", Value::Nil)?;
+            lua.gc_collect()?; // must collect here to drop the RefMut
+    
+            x += 50.0;
+            y += 5.0;
+            
+            let t = v1.borrow();
+            assert_eq!(x, t.x);
+            assert_eq!(y, t.y);
+            drop(t);
+
+            let ud = lua.create_userdata(UserdataRefMut::from(v1.borrow_mut()))?;
+            globals.raw_set("v1", ud)?;
+        }
+
+        Ok(())
+    }
+
+    /// This test ensures that a RefMut of userdata can be provided to Lua, and it that it can run mutating methods on the userdata.
+    #[test]
+    fn ud_methods_borrow_mut() -> crate::Result<()> {
+        let lua = State::new();
+        lua.expose_libraries(&[StdLibrary::Debug, StdLibrary::Package]);
+    
+        let globals = lua.globals()?;
+    
+        let v1 = RefCell::new(Vec2 { x: 50.0, y: 5.0 });
+        let ud = lua.create_userdata(UserdataRefMut::from(v1.borrow_mut()))?;
+        globals.set("v1", ud)?;
+
+        let chunk = lua.load(
+            "text.lua",
+            r#"
+            v1:mult(2.0)
+            print("v1: (" .. v1.x .. ", " .. v1.y .. ")")
+        "#)?;
+    
+        let res = lua.execute_chunk::<_, Value>(&chunk, ());
+
+        if let Err(e) = res {
+            panic!("{}", e);
+        }
+        
+        globals.set("v1", Value::Nil)?;
+        lua.gc_collect()?; // must collect here to drop the RefMut
+
+        let t = v1.borrow();
+        assert_eq!(100.0, t.x);
+        assert_eq!(10.0, t.y);
+
+        Ok(())
+    }
+}

src/userdata/mod.rs

@@ -1,4 +1,4 @@
-use std::{cell::{OnceCell, Ref, RefCell, RefMut}, collections::HashMap, ffi::CStr, marker::PhantomData, mem, ops::{Deref, DerefMut}, sync::Arc};
+use std::{cell::{OnceCell, Ref, RefCell, RefMut}, collections::HashMap, ffi::CStr, marker::PhantomData, mem, ops::DerefMut, sync::Arc};
 
 use crate::{ensure_type, AsLua, FromLua, FromLuaStack, FromLuaVec, Function, IntoLuaVec, LuaRef, PushToLuaStack, StackGuard, State, Table, Value, ValueVec};
 
@@ -15,6 +15,11 @@ pub mod borrow;
 #[allow(unused_imports)]
 use borrow::*;
 
+pub mod borrow_mut;
+#[allow(unused_imports)]
+use borrow_mut::*;
+
+
 /// An enum representing all Lua MetaMethods
 /// https://gist.github.com/oatmealine/655c9e64599d0f0dd47687c1186de99f
 pub enum MetaMethod {
@@ -101,6 +106,8 @@ impl<'a> PushToLuaStack<'a> for MetaMethod {
 }
 
 pub type UserdataFn<'a> = Box<dyn Fn(&'a State, ValueVec<'a>) -> crate::Result<Value<'a>>>;
+pub type UserdataGetterFn<'a> = Arc<OnceCell<Box<dyn Fn(AnyUserdata<'a>) -> crate::Result<*const ()>>>>;
+pub type UserdataMutGetterFn<'a> = Arc<OnceCell<Box<dyn Fn(AnyUserdata<'a>) -> crate::Result<*mut ()>>>>;
 
 pub struct UserdataBuilder<'a, T> {
     pub(crate) name: String,
@@ -110,6 +117,7 @@ pub struct UserdataBuilder<'a, T> {
     pub(crate) meta_methods: HashMap<String, UserdataFn<'a>>,
 
     pub(crate) wrapped_getter: Arc<OnceCell<Box<dyn Fn(AnyUserdata<'a>) -> crate::Result<*const ()>>>>,
+    pub(crate) wrapped_getter_mut: Arc<OnceCell<Box<dyn Fn(AnyUserdata<'a>) -> crate::Result<*mut ()>>>>,
 
     _marker: PhantomData<T>,
 }
@@ -123,6 +131,7 @@ impl<'a, T: Userdata> UserdataBuilder<'a, T> {
             functions: HashMap::new(),
             meta_methods: HashMap::new(),
             wrapped_getter: Arc::new(OnceCell::new()),
+            wrapped_getter_mut: Arc::new(OnceCell::new()),
             _marker: PhantomData,
         }
     }
@@ -135,24 +144,22 @@ impl<'a, T: Userdata> UserdataBuilder<'a, T> {
     {
         let wrapped = self.wrapped_getter.clone();
         let wrapped: Arc<OnceCell<Box<dyn Fn(AnyUserdata<'_>) -> Result<*const (), crate::Error>>>> = unsafe { mem::transmute(wrapped) };
-        let fn_name = Arc::new(name.to_string());
+        
+        let ud_name = self.name.clone();
+        let fn_name = name.to_string();
 
         let wrap = move |lua: &'a State, mut val: ValueVec<'a>| {
             let val = val.pop_front().unwrap();
             let this = val.as_userdata().unwrap(); // if this panics, its a bug
 
             if let Some(getter) = wrapped.get() {
-                let this_ptr = match getter(this.clone()) {
+                let this_ptr = Self::result_to_bad_arg(
-                    Ok(v) => v,
+                    getter(this.clone()),
-                    Err(e) => {
+                    &ud_name,
-                        return Err(crate::Error::BadArgument {
+                    &fn_name,
-                            func: Some(fn_name.deref().clone()),
+                    1,
-                            arg_index: 1,
+                    Some("self")
-                            arg_name: Some("self".to_string()),
+                )?;
-                            error: Arc::new(e),
-                        });
-                    }
-                };
                 let this_ptr = this_ptr.cast::<T>();
                 let this = unsafe { &*this_ptr };
 
@@ -173,22 +180,43 @@ impl<'a, T: Userdata> UserdataBuilder<'a, T> {
         V: FromLua<'a>,
         T: Userdata + 'static
     {
+        let wrapped = self.wrapped_getter_mut.clone();
+        let wrapped: Arc<OnceCell<Box<dyn Fn(AnyUserdata<'_>) -> Result<*mut (), crate::Error>>>> = unsafe { mem::transmute(wrapped) };
+        
+        let ud_name = self.name.clone();
+        let fn_name = name.to_string();
+
         let wrap = move |lua: &'a State, mut val: ValueVec<'a>| {
             let lua_val = val.pop_front().unwrap();
             let this = lua_val.as_userdata().unwrap(); // if this panics, its a bug
-            let mut this = this.as_mut::<T>()?;
 
             let lua_val = val.pop_front().unwrap();
             let v_arg = V::from_lua(lua, lua_val)?;
 
+            if let Some(mut_getter) = wrapped.get() {
+                let this_ptr = Self::result_to_bad_arg(
+                    mut_getter(this.clone()),
+                    &ud_name,
+                    &fn_name,
+                    1,
+                    Some("self")
+                )?;
+                let this_ptr = this_ptr.cast::<T>();
+                let this = unsafe { this_ptr.as_mut().unwrap() };
+
+                f(lua, this, v_arg).as_lua(lua)
+            } else {
+                let mut this = this.as_mut::<T>()?;
+
                 f(lua, this.deref_mut(), v_arg).as_lua(lua)
+            }
         };
         self.field_setters.insert(name.to_string(), Box::new(wrap));
 
         self
     }
 
-    fn result_to_bad_arg<R>(res: crate::Result<R>, ud_name: &str, fn_name: &str) -> crate::Result<R> {
+    fn arg_result_to_bad_arg<R>(res: crate::Result<R>, ud_name: &str, fn_name: &str) -> crate::Result<R> {
         res.map_err(|e| match e {
             crate::Error::ValueVecError { value_idx, error } => {
                 let full_name = format!("{}.{}", ud_name, fn_name);
@@ -200,17 +228,27 @@ impl<'a, T: Userdata> UserdataBuilder<'a, T> {
         })
     }
 
+    fn result_to_bad_arg<R>(res: crate::Result<R>, ud_name: &str, fn_name: &str, arg_idx: i32, arg_name: Option<&str>) -> crate::Result<R> {
+        res.map_err(|e| {
+            let full_name = format!("{}.{}", ud_name, fn_name);
+            let arg_name = arg_name.map(|s| s.to_string());
+
+            crate::Error::BadArgument { func: Some(full_name), arg_index: arg_idx, arg_name, error: Arc::new(e), }
+        })
+    }
+
     pub fn function<F, R, A>(&mut self, name: &str, f: F) -> &mut Self
     where
         F: Fn(&'a State, A) -> crate::Result<R> + 'static,
         A: FromLuaVec<'a>,
         R: AsLua<'a>,
     {
+        let ud_name = self.name.clone();
         let fn_name = name.to_string();
         let wrap = move |lua: &'a State, val: ValueVec<'a>| {
-            let args = Self::result_to_bad_arg(
+            let args = Self::arg_result_to_bad_arg(
                 A::from_lua_value_vec(lua, val),
-                &T::name(), &fn_name
+                &ud_name, &fn_name
             )?;
             f(lua, args).and_then(|r| r.as_lua(lua))
         };
@@ -226,20 +264,83 @@ impl<'a, T: Userdata> UserdataBuilder<'a, T> {
         R: AsLua<'a>,
         T: Userdata + 'static
     {
+        let wrapped = self.wrapped_getter.clone();
+        let wrapped: Arc<OnceCell<Box<dyn Fn(AnyUserdata<'_>) -> Result<*const (), crate::Error>>>> = unsafe { mem::transmute(wrapped) };
+
+        let ud_name = self.name.clone();
         let fn_name = name.to_string();
+        
         let wrap = move |lua: &'a State, mut val: ValueVec<'a>| {
             let this_val = val.pop_front().unwrap();
             let this = this_val.as_userdata().unwrap(); // if this panics, its a bug
-            //this.unsafe_ud.as_ptr_unchecked()
-            let this = this.as_ref::<T>()?;
 
-            let this_name = T::name();
+            let args = Self::arg_result_to_bad_arg(
-            let args = Self::result_to_bad_arg(
                 A::from_lua_value_vec(lua, val),
-                &this_name, &fn_name
+                &ud_name, &fn_name
             )?;
 
+            if let Some(mut_getter) = wrapped.get() {
+                let this_ptr = Self::result_to_bad_arg(
+                    mut_getter(this.clone()),
+                    &ud_name,
+                    &fn_name,
+                    1,
+                    Some("self")
+                )?;
+                let this_ptr = this_ptr.cast::<T>();
+                let this = unsafe { this_ptr.as_ref().unwrap() };
+
+                f(lua, this, args).and_then(|r| r.as_lua(lua))
+            } else {
+                let this = this.as_ref::<T>()?;
+
                 f(lua, &*this, args).and_then(|r| r.as_lua(lua))
+            }
+        };
+        self.functions.insert(name.to_string(), Box::new(wrap));
+
+        self
+    }
+
+    pub fn method_mut<F, R, A>(&mut self, name: &str, f: F) -> &mut Self
+    where
+        F: Fn(&'a State, &mut T, A) -> crate::Result<R> + 'static,
+        A: FromLuaVec<'a>,
+        R: AsLua<'a>,
+        T: Userdata + 'static
+    {
+        let wrapped = self.wrapped_getter_mut.clone();
+        let wrapped: Arc<OnceCell<Box<dyn Fn(AnyUserdata<'_>) -> Result<*mut (), crate::Error>>>> = unsafe { mem::transmute(wrapped) };
+
+        let ud_name = self.name.clone();
+        let fn_name = name.to_string();
+        
+        let wrap = move |lua: &'a State, mut val: ValueVec<'a>| {
+            let this_val = val.pop_front().unwrap();
+            let this = this_val.as_userdata().unwrap(); // if this panics, its a bug
+
+            let args = Self::arg_result_to_bad_arg(
+                A::from_lua_value_vec(lua, val),
+                &ud_name, &fn_name
+            )?;
+
+            if let Some(mut_getter) = wrapped.get() {
+                let this_ptr = Self::result_to_bad_arg(
+                    mut_getter(this.clone()),
+                    &ud_name,
+                    &fn_name,
+                    1,
+                    Some("self")
+                )?;
+                let this_ptr = this_ptr.cast::<T>();
+                let this = unsafe { this_ptr.as_mut().unwrap() };
+
+                f(lua, this, args).and_then(|r| r.as_lua(lua))
+            } else {
+                let mut this = this.as_mut::<T>()?;
+
+                f(lua, this.deref_mut(), args).and_then(|r| r.as_lua(lua))
+            }
         };
         self.functions.insert(name.to_string(), Box::new(wrap));
 
@@ -254,16 +355,16 @@ impl<'a, T: Userdata> UserdataBuilder<'a, T> {
         R: AsLua<'a>,
         T: Userdata + 'static
     {
+        let ud_name = self.name.clone();
         let fn_name = name.as_ref().to_string();
         let wrap = move |lua: &'a State, mut val: ValueVec<'a>| {
             let this_val = val.pop_front().unwrap();
             let this = this_val.as_userdata().unwrap(); // if this panics, its a bug
             let this = this.as_ref::<T>()?;
 
-            let this_name = T::name();
+            let args = Self::arg_result_to_bad_arg(
-            let args = Self::result_to_bad_arg(
                 A::from_lua_value_vec(lua, val),
-                &this_name, &fn_name
+                &ud_name, &fn_name
             )?;
             
             f(lua, &*this, args).and_then(|r| r.as_lua(lua))
@@ -280,6 +381,7 @@ impl<'a, T: Userdata> UserdataBuilder<'a, T> {
         self.functions = other.functions;
         self.meta_methods = other.meta_methods;
         self.wrapped_getter = other.wrapped_getter;
+        self.wrapped_getter_mut = other.wrapped_getter_mut;
     }
 }