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use std::borrow::Borrow; use std::fmt::{self, Debug}; use std::hash::{Hash, Hasher}; use std::marker::PhantomData; use std::ops::Deref; use std::ptr::NonNull; use crate::private::{get_api, ReferenceCountedClassPlaceholder}; use crate::ref_kind::{ManuallyManaged, RefCounted, RefKind}; use crate::sys; use crate::thread_access::{ LocalThreadAccess, NonUniqueThreadAccess, Shared, ThreadAccess, ThreadLocal, Unique, }; #[cfg(feature = "nativescript")] use crate::nativescript::{Instance, NativeClass, RefInstance}; mod raw; pub use self::raw::RawObject; /// Trait for Godot API objects. This trait is sealed, and implemented for generated wrapper /// types. /// /// Bare `GodotObject` references, like `&Node`, can be used safely, but do not track thread /// access states, which limits their usefulness to some extent. It's not, for example, possible /// to pass a `&Node` into an API method because it might have came from a `Unique` reference. /// As such, it's usually better to use `Ref` and `TRef`s whenever possible. /// /// For convenience. it's possible to use bare references as `owner` arguments in exported /// methods when using NativeScript, but the limitations above should be kept in mind. See /// the `OwnerArg` for more information. /// /// IF it's ever needed to obtain persistent references out of bare references, the `assume_` /// methods can be used. pub unsafe trait GodotObject: Sized + crate::private::godot_object::Sealed { /// The memory management kind of this type. This modifies the behavior of the /// [`Ref`](struct.Ref.html) smart pointer. See its type-level documentation for more /// information. type RefKind: RefKind; fn class_name() -> &'static str; /// Creates an explicitly null reference of `Self` as a method argument. This makes type /// inference easier for the compiler compared to `Option`. #[inline] fn null() -> Null<Self> { Null::null() } /// Creates a new instance of `Self` using a zero-argument constructor, as a `Unique` /// reference. #[inline] fn new() -> Ref<Self, Unique> where Self: Instanciable, { Ref::new() } /// Performs a dynamic reference downcast to target type. /// /// The `cast` method can only be used for downcasts. For statically casting to a /// supertype, use `upcast` instead. /// /// This method is only for conversion between engine types. To downcast to a `NativeScript` /// type from its base type, see `Ref::cast_instance` and `TRef::cast_instance`. #[inline] fn cast<T>(&self) -> Option<&T> where T: GodotObject + SubClass<Self>, { self.as_raw().cast().map(T::cast_ref) } /// Performs a static reference upcast to a supertype that is guaranteed to be valid. /// /// This is guaranteed to be a no-op at runtime. #[inline(always)] fn upcast<T>(&self) -> &T where T: GodotObject, Self: SubClass<T>, { unsafe { T::cast_ref(self.as_raw().cast_unchecked()) } } /// Creates a reference to `Self` given a `RawObject` reference. This is an internal /// interface, #[doc(hidden)] #[inline] fn cast_ref(raw: &RawObject<Self>) -> &Self { unsafe { &*(raw as *const _ as *const _) } } /// Casts `self` to `RawObject`. This is an internal interface. #[doc(hidden)] #[inline] fn as_raw(&self) -> &RawObject<Self> { unsafe { &*(self as *const _ as *const _) } } /// Casts `self` to a raw pointer. This is an internal interface. #[doc(hidden)] #[inline] fn as_ptr(&self) -> *mut sys::godot_object { self.as_raw().sys().as_ptr() } /// Creates a persistent reference to the same Godot object with shared thread access. /// /// # Safety /// /// There must not be any `Unique` or `ThreadLocal` references of the object when this /// is called. This causes undefined behavior otherwise. #[inline] unsafe fn assume_shared(&self) -> Ref<Self, Shared> where Self: Sized, { Ref::from_sys(self.as_raw().sys()) } /// Creates a persistent reference to the same Godot object with thread-local thread access. /// /// # Safety /// /// There must not be any `Unique` or `Shared` references of the object when this /// is called. This causes undefined behavior otherwise. #[inline] unsafe fn assume_thread_local(&self) -> Ref<Self, ThreadLocal> where Self: Sized + GodotObject<RefKind = RefCounted>, { Ref::from_sys(self.as_raw().sys()) } /// Creates a persistent reference to the same Godot object with unique access. /// /// # Safety /// /// **Use with care.** `Unique` is a very strong assumption that can easily be /// violated. Only use this when you are **absolutely** sure you have the only reference. /// /// There must be no other references of the object when this is called. This causes /// undefined behavior otherwise. #[inline] unsafe fn assume_unique(&self) -> Ref<Self, Unique> where Self: Sized, { Ref::from_sys(self.as_raw().sys()) } } /// Marker trait for API types that are subclasses of another type. This trait is implemented /// by the bindings generator, and has no public interface. Users should not attempt to /// implement this trait. pub unsafe trait SubClass<A: GodotObject>: GodotObject {} unsafe impl<T: GodotObject> SubClass<T> for T {} /// GodotObjects that have a zero argument constructor. pub trait Instanciable: GodotObject { fn construct() -> Ref<Self, Unique>; } /// Manually managed Godot classes implementing `queue_free`. This trait has no public /// interface. See `Ref::queue_free`. pub trait QueueFree: GodotObject { /// Deallocate the object in the near future. /// /// # Safety /// /// When this function is dequeued no references to this /// object must be held and dereferenced. #[doc(hidden)] unsafe fn godot_queue_free(sys: *mut sys::godot_object); } /// A polymorphic smart pointer for Godot objects whose behavior changes depending on the /// memory management method of the underlying type and the thread access status. /// /// # Manually-managed types /// /// `Shared` references to manually-managed types, like `Ref<Node, Shared>`, act like raw /// pointers. They are safe to alias, can be sent between threads, and can also be taken as /// method arguments (converted from `Variant`). They can't be used directly. Instead, it's /// required to obtain a safe view first. See the "Obtaining a safe view" section below for /// more information. /// /// `ThreadLocal` references to manually-managed types cannot normally be obtained, since /// it does not add anything over `Shared` ones. /// /// `Unique` references to manually-managed types, like `Ref<Node, Unique>`, can't be aliased /// or sent between threads, but can be used safely. However, they *won't* be automatically /// freed on drop, and are *leaked* if not passed to the engine or freed manually with `free`. /// `Unique` references can be obtained through constructors safely, or `assume_unique` in /// unsafe contexts. /// /// # Reference-counted types /// /// `Shared` references to reference-counted types, like `Ref<Reference, Shared>`, act like /// `Arc` smart pointers. New references can be created with `Clone`, and they can be sent /// between threads. The pointer is presumed to be always valid. As such, more operations /// are available even when thread safety is not assumed. However, API methods still can't be /// used directly, and users are required to obtain a safe view first. See the "Obtaining a /// safe view" section below for more information. /// /// `ThreadLocal` reference to reference-counted types, like `Ref<Reference, ThreadLocal>`, add /// the ability to call API methods safely. Unlike `Unique` references, it's unsafe to convert /// them to `Shared` because there might be other `ThreadLocal` references in existence. /// /// # Obtaining a safe view /// /// In a lot of cases, references obtained from the engine as return values or arguments aren't /// safe to use, due to lack of pointer validity and thread safety guarantees in the API. As /// such, it's usually required to use `unsafe` code to obtain safe views of the same object /// before API methods can be called. The ways to cast between different reference types are as /// follows: /// /// | From | To | Method | Note | /// | - | - | - | - | /// | `Unique` | `&'a T` | `Deref` (API methods can be called directly) / `as_ref` | - | /// | `ThreadLocal` | `&'a T` | `Deref` (API methods can be called directly) / `as_ref` | Only if `T` is a reference-counted type. | /// | `Shared` | `&'a T` | `unsafe assume_safe::<'a>` | The underlying object must be valid, and exclusive to this thread during `'a`. | /// | `Unique` | `ThreadLocal` | `into_thread_local` | - | /// | `Unique` | `Shared` | `into_shared` | - | /// | `Shared` | `ThreadLocal` | `unsafe assume_thread_local` | The reference must be local to the current thread. | /// | `Shared` / `ThreadLocal` | `Unique` | `unsafe assume_unique` | The reference must be unique. | /// | `ThreadLocal` | `Shared` | `unsafe assume_unique().into_shared()` | The reference must be unique. | /// /// # Using as method arguments or return values /// /// In order to enforce thread safety statically, the ability to be passed to the engine is only /// given to some reference types. Specifically, they are: /// /// - All *owned* `Ref<T, Unique>` references. The `Unique` access is lost if passed into a /// method. /// - Owned and borrowed `Shared` references, including temporary ones (`TRef`). /// /// It's unsound to pass `ThreadLocal` references to the engine because there is no guarantee /// that the reference will stay on the same thread. /// /// # Conditional trait implementations /// /// Many trait implementations for `Ref` are conditional, dependent on the type parameters. /// When viewing rustdoc documentation, you may expand the documentation on their respective /// `impl` blocks for more detailed explanations of the trait bounds. pub struct Ref<T: GodotObject, Access: ThreadAccess = Shared> { ptr: <T::RefKind as RefKindSpec>::PtrWrapper, _marker: PhantomData<(*const T, Access)>, } /// `Ref` is `Send` if the thread access is `Shared` or `Unique`. unsafe impl<T: GodotObject, Access: ThreadAccess + Send> Send for Ref<T, Access> {} /// `Ref` is `Sync` if the thread access is `Shared`. unsafe impl<T: GodotObject, Access: ThreadAccess + Sync> Sync for Ref<T, Access> {} impl<T: GodotObject, Access: ThreadAccess> private::Sealed for Ref<T, Access> {} /// `Ref` is `Copy` if the underlying object is manually-managed, and the access is not /// `Unique`. impl<T, Access> Copy for Ref<T, Access> where T: GodotObject<RefKind = ManuallyManaged>, Access: NonUniqueThreadAccess, { } /// `Ref` is `Clone` if the access is not `Unique`. impl<T, Access> Clone for Ref<T, Access> where T: GodotObject, Access: NonUniqueThreadAccess, { #[inline] fn clone(&self) -> Self { unsafe { Ref::from_sys(self.ptr.as_non_null()) } } } impl<T: GodotObject + Instanciable> Ref<T, Unique> { /// Creates a new instance of `T`. /// /// The lifetime of the returned object is *not* automatically managed if `T` is a manually- /// managed type. #[inline] #[allow(clippy::new_without_default)] pub fn new() -> Self { T::construct() } } /// Method for references that can be safely used. impl<T: GodotObject, Access: ThreadAccess> Ref<T, Access> where RefImplBound: SafeDeref<T::RefKind, Access>, { /// Returns a safe temporary reference that tracks thread access. /// /// `Ref<T, Access>` can be safely dereferenced if either: /// /// - `T` is reference-counted and `Access` is not `Shared`, /// - or, `T` is manually-managed and `Access` is `Unique`. #[inline] pub fn as_ref(&self) -> TRef<'_, T, Access> { RefImplBound::impl_as_ref(self) } } /// `Ref<T, Access>` can be safely dereferenced if either: /// /// - `T` is reference-counted and `Access` is not `Shared`, /// - or, `T` is manually-managed and `Access` is `Unique`. impl<T: GodotObject, Access: ThreadAccess> Deref for Ref<T, Access> where RefImplBound: SafeDeref<T::RefKind, Access>, { type Target = T; #[inline] fn deref(&self) -> &Self::Target { RefImplBound::impl_as_ref(self).obj } } /// `Ref<T, Access>` can be safely dereferenced if either: /// /// - `T` is reference-counted and `Access` is not `Shared`, /// - or, `T` is manually-managed and `Access` is `Unique`. impl<T: GodotObject, Access: ThreadAccess> Borrow<T> for Ref<T, Access> where RefImplBound: SafeDeref<T::RefKind, Access>, { #[inline] fn borrow(&self) -> &T { RefImplBound::impl_as_ref(self).obj } } /// Methods for references that point to valid objects, but are not necessarily safe to use. /// /// - All `Ref`s to reference-counted types always point to valid objects. /// - `Ref` to manually-managed types are only guaranteed to be valid if `Unique`. impl<T: GodotObject, Access: ThreadAccess> Ref<T, Access> where RefImplBound: SafeAsRaw<T::RefKind, Access>, { /// Cast to a `RawObject` reference safely. This is an internal interface. #[inline] #[doc(hidden)] pub fn as_raw(&self) -> &RawObject<T> { unsafe { self.as_raw_unchecked() } } /// Performs a dynamic reference cast to target type, keeping the reference count. /// Shorthand for `try_cast().ok()`. /// /// The `cast` method can only be used for downcasts. For statically casting to a /// supertype, use `upcast` instead. /// /// This is only possible between types with the same `RefKind`s, since otherwise the /// reference can get leaked. Casting between `Object` and `Reference` is possible on /// `TRef` and bare references. #[inline] pub fn cast<U>(self) -> Option<Ref<U, Access>> where U: GodotObject<RefKind = T::RefKind> + SubClass<T>, { self.try_cast().ok() } /// Performs a static reference upcast to a supertype, keeping the reference count. /// This is guaranteed to be valid. /// /// This is only possible between types with the same `RefKind`s, since otherwise the /// reference can get leaked. Casting between `Object` and `Reference` is possible on /// `TRef` and bare references. #[inline] pub fn upcast<U>(self) -> Ref<U, Access> where U: GodotObject<RefKind = T::RefKind>, T: SubClass<U>, { unsafe { self.cast_unchecked() } } /// Performs a dynamic reference cast to target type, keeping the reference count. /// /// This is only possible between types with the same `RefKind`s, since otherwise the /// reference can get leaked. Casting between `Object` and `Reference` is possible on /// `TRef` and bare references. /// /// # Errors /// /// Returns `Err(self)` if the cast failed. #[inline] pub fn try_cast<U>(self) -> Result<Ref<U, Access>, Self> where U: GodotObject<RefKind = T::RefKind> + SubClass<T>, { if self.as_raw().is_class::<U>() { Ok(unsafe { self.cast_unchecked() }) } else { Err(self) } } /// Performs an unchecked cast. unsafe fn cast_unchecked<U>(self) -> Ref<U, Access> where U: GodotObject<RefKind = T::RefKind>, { let ret = Ref::move_from_sys(self.ptr.as_non_null()); std::mem::forget(self); ret } /// Performs a downcast to a `NativeClass` instance, keeping the reference count. /// Shorthand for `try_cast_instance().ok()`. /// /// The resulting `Instance` is not necessarily safe to use directly. #[inline] #[cfg(feature = "nativescript")] pub fn cast_instance<C>(self) -> Option<Instance<C, Access>> where C: NativeClass<Base = T>, { self.try_cast_instance().ok() } /// Performs a downcast to a `NativeClass` instance, keeping the reference count. /// /// # Errors /// /// Returns `Err(self)` if the cast failed. #[inline] #[cfg(feature = "nativescript")] pub fn try_cast_instance<C>(self) -> Result<Instance<C, Access>, Self> where C: NativeClass<Base = T>, { Instance::try_from_base(self) } } /// Methods for references that can't be used directly, and have to be assumed safe `unsafe`ly. impl<T: GodotObject> Ref<T, Shared> { /// Assume that `self` is safe to use, returning a reference that can be used to call API /// methods. /// /// This is guaranteed to be a no-op at runtime if `debug_assertions` is disabled. Runtime /// sanity checks may be added in debug builds to help catch bugs. /// /// # Safety /// /// Suppose that the lifetime of the returned reference is `'a`. It's safe to call /// `assume_safe` only if: /// /// 1. During the entirety of `'a`, the underlying object will always be valid. /// /// *This is always true for reference-counted types.* For them, the `'a` lifetime will /// be constrained to the lifetime of `&self`. /// /// This means that any methods called on the resulting reference will not free it, /// unless it's the last operation within the lifetime. /// /// If any script methods are called, the code ran as a consequence will also not free /// it. This can happen via virtual method calls on other objects, or signals connected /// in a non-deferred way. /// /// 2. During the entirety of 'a, the thread from which `assume_safe` is called has /// exclusive access to the underlying object. /// /// This is because all Godot objects have "interior mutability" in Rust parlance, /// and can't be shared across threads. The best way to guarantee this is to follow /// the official [thread-safety guidelines][thread-safety] across the codebase. /// /// Failure to satisfy either of the conditions will lead to undefined behavior. /// /// [thread-safety]: https://docs.godotengine.org/en/stable/tutorials/threads/thread_safe_apis.html #[inline(always)] pub unsafe fn assume_safe<'a, 'r>(&'r self) -> TRef<'a, T, Shared> where AssumeSafeLifetime<'a, 'r>: LifetimeConstraint<T::RefKind>, { T::RefKind::impl_assume_safe(self) } /// Assume that `self` is the unique reference to the underlying object. /// /// This is guaranteed to be a no-op at runtime if `debug_assertions` is disabled. Runtime /// sanity checks may be added in debug builds to help catch bugs. /// /// # Safety /// /// Calling `assume_unique` when `self` isn't the unique reference is instant undefined /// behavior. This is a much stronger assumption than `assume_safe` and should be used with /// care. #[inline(always)] pub unsafe fn assume_unique(self) -> Ref<T, Unique> { T::RefKind::impl_assume_unique(self) } } /// Extra methods with explicit sanity checks for manually-managed unsafe references. impl<T: GodotObject<RefKind = ManuallyManaged>> Ref<T, Shared> { /// Returns `true` if the pointer currently points to a valid object of the correct type. /// **This does NOT guarantee that it's safe to use this pointer.** /// /// # Safety /// /// This thread must have exclusive access to the object during the call. #[inline] #[allow(clippy::trivially_copy_pass_by_ref)] pub unsafe fn is_instance_sane(&self) -> bool { let api = get_api(); if !(api.godot_is_instance_valid)(self.as_ptr()) { return false; } self.as_raw_unchecked().is_class::<T>() } /// Assume that `self` is safe to use, if a sanity check using `is_instance_sane` passed. /// /// # Safety /// /// The same safety constraints as `assume_safe` applies. **The sanity check does NOT /// guarantee that the operation is safe.** #[inline] #[allow(clippy::trivially_copy_pass_by_ref)] pub unsafe fn assume_safe_if_sane<'a>(&self) -> Option<TRef<'a, T, Shared>> { if self.is_instance_sane() { Some(self.assume_safe_unchecked()) } else { None } } /// Assume that `self` is the unique reference to the underlying object, if a sanity check /// using `is_instance_sane` passed. /// /// # Safety /// /// Calling `assume_unique_if_sane` when `self` isn't the unique reference is instant /// undefined behavior. This is a much stronger assumption than `assume_safe` and should be /// used with care. #[inline] pub unsafe fn assume_unique_if_sane(self) -> Option<Ref<T, Unique>> { if self.is_instance_sane() { Some(self.cast_access()) } else { None } } } /// Methods for conversion from `Shared` to `ThreadLocal` access. This is only available for /// reference-counted types. impl<T: GodotObject<RefKind = RefCounted>> Ref<T, Shared> { /// Assume that all references to the underlying object is local to the current thread. /// /// This is guaranteed to be a no-op at runtime. /// /// # Safety /// /// Calling `assume_thread_local` when there are references on other threads is instant /// undefined behavior. This is a much stronger assumption than `assume_safe` and should /// be used with care. #[inline(always)] pub unsafe fn assume_thread_local(self) -> Ref<T, ThreadLocal> { self.cast_access() } } /// Methods for conversion from `Unique` to `ThreadLocal` access. This is only available for /// reference-counted types. impl<T: GodotObject<RefKind = RefCounted>> Ref<T, Unique> { /// Convert to a thread-local reference. /// /// This is guaranteed to be a no-op at runtime. #[inline(always)] pub fn into_thread_local(self) -> Ref<T, ThreadLocal> { unsafe { self.cast_access() } } } /// Methods for conversion from `Unique` to `Shared` access. impl<T: GodotObject> Ref<T, Unique> { /// Convert to a shared reference. /// /// This is guaranteed to be a no-op at runtime. #[inline(always)] pub fn into_shared(self) -> Ref<T, Shared> { unsafe { self.cast_access() } } } /// Methods for freeing `Unique` references to manually-managed objects. impl<T: GodotObject<RefKind = ManuallyManaged>> Ref<T, Unique> { /// Manually frees the object. /// /// Manually-managed objects are not free-on-drop *even when the access is unique*, because /// it's impossible to know whether methods take "ownership" of them or not. It's up to the /// user to decide when they should be freed. /// /// This is only available for `Unique` references. If you have a `Ref` with another access, /// and you are sure that it is unique, use `assume_unique` to convert it to a `Unique` one. #[inline] pub fn free(self) { unsafe { self.as_raw().free(); } } } /// Methods for freeing `Unique` references to manually-managed objects. impl<T: GodotObject<RefKind = ManuallyManaged> + QueueFree> Ref<T, Unique> { /// Queues the object for deallocation in the near future. This is preferable for `Node`s /// compared to `Ref::free`. /// /// This is only available for `Unique` references. If you have a `Ref` with another access, /// and you are sure that it is unique, use `assume_unique` to convert it to a `Unique` one. #[inline] pub fn queue_free(self) { unsafe { T::godot_queue_free(self.as_ptr()) } } } /// Reference equality. impl<T: GodotObject, Access: ThreadAccess> Eq for Ref<T, Access> {} /// Reference equality. impl<T, Access, RhsAccess> PartialEq<Ref<T, RhsAccess>> for Ref<T, Access> where T: GodotObject, Access: ThreadAccess, RhsAccess: ThreadAccess, { #[inline] fn eq(&self, other: &Ref<T, RhsAccess>) -> bool { self.ptr.as_non_null() == other.ptr.as_non_null() } } /// Ordering of the raw pointer value. impl<T: GodotObject, Access: ThreadAccess> Ord for Ref<T, Access> { #[inline] fn cmp(&self, other: &Self) -> std::cmp::Ordering { self.ptr.as_non_null().cmp(&other.ptr.as_non_null()) } } /// Ordering of the raw pointer value. impl<T: GodotObject, Access: ThreadAccess> PartialOrd for Ref<T, Access> { #[inline] fn partial_cmp(&self, other: &Self) -> Option<std::cmp::Ordering> { self.ptr.as_non_null().partial_cmp(&other.ptr.as_non_null()) } } /// Hashes the raw pointer. impl<T: GodotObject, Access: ThreadAccess> Hash for Ref<T, Access> { #[inline] fn hash<H: Hasher>(&self, state: &mut H) { state.write_usize(self.ptr.as_ptr() as usize) } } impl<T: GodotObject, Access: ThreadAccess> Debug for Ref<T, Access> { #[inline] fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { write!(f, "{}({:p})", T::class_name(), self.ptr.as_ptr()) } } impl<T: GodotObject, Access: ThreadAccess> Ref<T, Access> { /// Convert to a nullable raw pointer. #[doc(hidden)] #[inline] pub fn sys(&self) -> *mut sys::godot_object { self.ptr.as_ptr() } /// Convert to a nullable raw pointer. #[doc(hidden)] #[inline] pub fn as_ptr(&self) -> *mut sys::godot_object { self.ptr.as_ptr() } /// Convert to a `RawObject` reference. /// /// # Safety /// /// `self` must point to a valid object of the correct type. #[doc(hidden)] #[inline] pub unsafe fn as_raw_unchecked<'a>(&self) -> &'a RawObject<T> { RawObject::from_sys_ref_unchecked(self.ptr.as_non_null()) } /// Convert from a pointer returned from a ptrcall. For reference-counted types, this takes /// the ownership of the returned reference, in Rust parlance. For non-reference-counted /// types, its behavior should be exactly the same as `from_sys`. This is needed for /// reference-counted types to be properly freed, since any references returned from /// ptrcalls are leaked in the process of being cast into a pointer. /// /// # Safety /// /// `obj` must point to a valid object of the correct type. #[doc(hidden)] #[inline] pub unsafe fn move_from_sys(obj: NonNull<sys::godot_object>) -> Self { Ref { ptr: <T::RefKind as RefKindSpec>::PtrWrapper::new(obj), _marker: PhantomData, } } /// Convert from a raw pointer, incrementing the reference counter if reference-counted. /// /// # Safety /// /// `obj` must point to a valid object of the correct type. #[doc(hidden)] #[inline] pub unsafe fn from_sys(obj: NonNull<sys::godot_object>) -> Self { let ret = Self::move_from_sys(obj); <T::RefKind as RefKindSpec>::maybe_add_ref(ret.as_raw_unchecked()); ret } /// Convert from a pointer returned from a constructor of a reference-counted type. For /// non-reference-counted types, its behavior should be exactly the same as `from_sys`. /// /// # Safety /// /// `obj` must point to a valid object of the correct type, and must be the only reference. #[doc(hidden)] #[inline] pub unsafe fn init_from_sys(obj: NonNull<sys::godot_object>) -> Self { let ret = Self::move_from_sys(obj); <T::RefKind as RefKindSpec>::maybe_init_ref(ret.as_raw_unchecked()); ret } /// Casts the access type of `self` to `TargetAccess`, moving the reference. /// /// # Safety /// /// The cast must be valid. unsafe fn cast_access<TargetAccess: ThreadAccess>(self) -> Ref<T, TargetAccess> { let ret = Ref::move_from_sys(self.ptr.as_non_null()); std::mem::forget(self); ret } /// Assume that the reference is safe in an `unsafe` context even if it can be used safely. /// For internal use in macros. /// /// This is guaranteed to be a no-op at runtime. /// /// # Safety /// /// The same safety constraints as `assume_safe` applies. #[doc(hidden)] #[inline(always)] pub unsafe fn assume_safe_unchecked<'a>(&self) -> TRef<'a, T, Access> { TRef::new(T::cast_ref(self.as_raw_unchecked())) } } /// A temporary safe pointer to Godot objects that tracks thread access status. `TRef` can be /// coerced into bare references with `Deref`. /// /// See the type-level documentation on `Ref` for detailed documentation on the reference /// system of `godot-rust`. /// /// # Using as method arguments or return values /// /// `TRef<T, Shared>` can be passed into methods. /// /// # Using as `owner` arguments in NativeScript methods /// /// It's possible to use `TRef` as the `owner` argument in NativeScript methods. This can make /// passing `owner` to methods easier. pub struct TRef<'a, T: GodotObject, Access: ThreadAccess = Shared> { obj: &'a T, _marker: PhantomData<Access>, } impl<'a, T: GodotObject, Access: ThreadAccess> Copy for TRef<'a, T, Access> {} impl<'a, T: GodotObject, Access: ThreadAccess> Clone for TRef<'a, T, Access> { #[inline] fn clone(&self) -> Self { TRef::new(self.obj) } } impl<'a, T: GodotObject, Access: ThreadAccess> Debug for TRef<'a, T, Access> { #[inline] fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { write!(f, "{}({:p})", T::class_name(), self.obj) } } impl<'a, T: GodotObject, Access: ThreadAccess> Deref for TRef<'a, T, Access> { type Target = T; #[inline] fn deref(&self) -> &Self::Target { self.obj } } impl<'a, T: GodotObject, Access: ThreadAccess> AsRef<T> for TRef<'a, T, Access> { #[inline] fn as_ref(&self) -> &T { self.obj } } impl<'a, T: GodotObject, Access: ThreadAccess> Borrow<T> for TRef<'a, T, Access> { #[inline] fn borrow(&self) -> &T { self.obj } } impl<'a, T: GodotObject, Access: ThreadAccess> TRef<'a, T, Access> { pub(crate) fn new(obj: &'a T) -> Self { TRef { obj, _marker: PhantomData, } } /// Returns the underlying reference without thread access. #[inline] #[allow(clippy::should_implement_trait)] pub fn as_ref(self) -> &'a T { self.obj } /// Performs a dynamic reference cast to target type, keeping the thread access info. #[inline] pub fn cast<U>(self) -> Option<TRef<'a, U, Access>> where U: GodotObject + SubClass<T>, { self.obj.cast().map(TRef::new) } /// Performs a static reference upcast to a supertype that is guaranteed to be valid, /// keeping the thread access info. /// /// This is guaranteed to be a no-op at runtime. #[inline(always)] pub fn upcast<U>(&self) -> TRef<'a, U, Access> where U: GodotObject, T: SubClass<U>, { TRef::new(self.obj.upcast()) } /// Convenience method to downcast to `RefInstance` where `self` is the base object. #[inline] #[cfg(feature = "nativescript")] pub fn cast_instance<C>(self) -> Option<RefInstance<'a, C, Access>> where C: NativeClass<Base = T>, { RefInstance::try_from_base(self) } } impl<'a, Kind, T, Access> TRef<'a, T, Access> where Kind: RefKind, T: GodotObject<RefKind = Kind>, Access: NonUniqueThreadAccess, { /// Persists this reference into a persistent `Ref` with the same thread access. /// /// This is only available for non-`Unique` accesses. #[inline] pub fn claim(self) -> Ref<T, Access> { unsafe { Ref::from_sys(self.obj.as_raw().sys()) } } } /// Trait for safe conversion from Godot object references into API method arguments. This is /// a sealed trait with no public interface. /// /// In order to enforce thread safety statically, the ability to be passed to the engine is only /// given to some reference types. Specifically, they are: /// /// - All *owned* `Ref<T, Unique>` references. The `Unique` access is lost if passed into a /// method. /// - Owned and borrowed `Shared` references, including temporary ones (`TRef`). /// /// It's unsound to pass `ThreadLocal` references to the engine because there is no guarantee /// that the reference will stay on the same thread. /// /// To explicitly pass a null reference to the engine, use `Null::null` or `GodotObject::null`. pub trait AsArg<T>: private::Sealed { #[doc(hidden)] fn as_arg_ptr(&self) -> *mut sys::godot_object; #[doc(hidden)] #[inline] unsafe fn to_arg_variant(&self) -> crate::core_types::Variant { crate::core_types::Variant::from_object_ptr(self.as_arg_ptr()) } } /// Trait for safe conversion from Godot object references into Variant. This is /// a sealed trait with no public interface. /// /// Used for `Variant` methods and implementations as a trait bound to improve type inference. pub trait AsVariant: AsArg<<Self as AsVariant>::Target> { type Target; } /// Represents an explicit null reference in method arguments. This works around type inference /// issues with `Option`. You may create `Null`s with `Null::null` or `GodotObject::null`. pub struct Null<T>(PhantomData<T>); impl<T: GodotObject> Null<T> { /// Creates an explicitly null reference that can be used as a method argument. #[inline] pub fn null() -> Self { Null(PhantomData) } } impl<'a, T> private::Sealed for Null<T> {} impl<'a, T: GodotObject> AsArg<T> for Null<T> { #[inline] fn as_arg_ptr(&self) -> *mut sys::godot_object { std::ptr::null_mut() } } impl<'a, T: GodotObject> AsVariant for Null<T> { type Target = T; } impl<'a, T: GodotObject> private::Sealed for TRef<'a, T, Shared> {} impl<'a, T, U> AsArg<U> for TRef<'a, T, Shared> where T: GodotObject + SubClass<U>, U: GodotObject, { #[inline] fn as_arg_ptr(&self) -> *mut sys::godot_object { self.as_ptr() } } impl<'a, T: GodotObject> AsVariant for TRef<'a, T, Shared> { type Target = T; } impl<T, U> AsArg<U> for Ref<T, Shared> where T: GodotObject + SubClass<U>, U: GodotObject, { #[inline] fn as_arg_ptr(&self) -> *mut sys::godot_object { self.as_ptr() } } impl<T: GodotObject> AsVariant for Ref<T, Shared> { type Target = T; } impl<T, U> AsArg<U> for Ref<T, Unique> where T: GodotObject + SubClass<U>, U: GodotObject, { #[inline] fn as_arg_ptr(&self) -> *mut sys::godot_object { self.as_ptr() } } impl<T: GodotObject> AsVariant for Ref<T, Unique> { type Target = T; } impl<'a, T: GodotObject> private::Sealed for &'a Ref<T, Shared> {} impl<'a, T, U> AsArg<U> for &'a Ref<T, Shared> where T: GodotObject + SubClass<U>, U: GodotObject, { #[inline] fn as_arg_ptr(&self) -> *mut sys::godot_object { self.as_ptr() } } impl<'a, T: GodotObject> AsVariant for &'a Ref<T, Shared> { type Target = T; } /// Trait for combinations of `RefKind` and `ThreadAccess` that can be dereferenced safely. /// This is an internal interface. pub unsafe trait SafeDeref<Kind: RefKind, Access: ThreadAccess> { /// Returns a safe reference to the underlying object. #[doc(hidden)] fn impl_as_ref<T: GodotObject<RefKind = Kind>>(this: &Ref<T, Access>) -> TRef<'_, T, Access>; } /// Trait for persistent `Ref`s that point to valid objects. This is an internal interface. pub unsafe trait SafeAsRaw<Kind: RefKind, Access: ThreadAccess> { /// Returns a raw reference to the underlying object. #[doc(hidden)] fn impl_as_raw<T: GodotObject<RefKind = Kind>>(this: &Ref<T, Access>) -> &RawObject<T>; } /// Struct to be used for various `Ref` trait bounds. pub struct RefImplBound { _private: (), } unsafe impl SafeDeref<ManuallyManaged, Unique> for RefImplBound { #[inline] fn impl_as_ref<T: GodotObject<RefKind = ManuallyManaged>>( this: &Ref<T, Unique>, ) -> TRef<'_, T, Unique> { unsafe { this.assume_safe_unchecked() } } } unsafe impl<Access: LocalThreadAccess> SafeDeref<RefCounted, Access> for RefImplBound { #[inline] fn impl_as_ref<T: GodotObject<RefKind = RefCounted>>( this: &Ref<T, Access>, ) -> TRef<'_, T, Access> { unsafe { this.assume_safe_unchecked() } } } unsafe impl SafeAsRaw<ManuallyManaged, Unique> for RefImplBound { #[inline] fn impl_as_raw<T: GodotObject<RefKind = ManuallyManaged>>( this: &Ref<T, Unique>, ) -> &RawObject<T> { unsafe { this.as_raw_unchecked() } } } unsafe impl<Access: ThreadAccess> SafeAsRaw<RefCounted, Access> for RefImplBound { #[inline] fn impl_as_raw<T: GodotObject<RefKind = RefCounted>>(this: &Ref<T, Access>) -> &RawObject<T> { unsafe { this.as_raw_unchecked() } } } /// Specialization trait depending on `RefKind`. This is an internal interface. pub trait RefKindSpec: Sized { /// Pointer wrapper that may be `Drop` or not. #[doc(hidden)] type PtrWrapper: PtrWrapper; #[doc(hidden)] unsafe fn impl_assume_safe<'a, T: GodotObject<RefKind = Self>>( this: &Ref<T, Shared>, ) -> TRef<'a, T, Shared> where Self: RefKind; #[doc(hidden)] unsafe fn impl_assume_unique<T: GodotObject<RefKind = Self>>( this: Ref<T, Shared>, ) -> Ref<T, Unique> where Self: RefKind; #[doc(hidden)] unsafe fn maybe_add_ref<T: GodotObject<RefKind = Self>>(raw: &RawObject<T>) where Self: RefKind; #[doc(hidden)] unsafe fn maybe_init_ref<T: GodotObject<RefKind = Self>>(raw: &RawObject<T>) where Self: RefKind; } impl RefKindSpec for ManuallyManaged { type PtrWrapper = Forget; #[inline(always)] unsafe fn impl_assume_safe<'a, T: GodotObject<RefKind = Self>>( this: &Ref<T, Shared>, ) -> TRef<'a, T, Shared> { debug_assert!( this.is_instance_sane(), "assume_safe called on an invalid pointer" ); this.assume_safe_unchecked() } #[inline(always)] unsafe fn impl_assume_unique<T: GodotObject<RefKind = Self>>( this: Ref<T, Shared>, ) -> Ref<T, Unique> { debug_assert!( this.is_instance_sane(), "assume_unique called on an invalid pointer" ); this.cast_access() } #[inline] unsafe fn maybe_add_ref<T: GodotObject<RefKind = Self>>(_raw: &RawObject<T>) {} #[inline] unsafe fn maybe_init_ref<T: GodotObject<RefKind = Self>>(_raw: &RawObject<T>) {} } impl RefKindSpec for RefCounted { type PtrWrapper = UnRef; #[inline(always)] unsafe fn impl_assume_safe<'a, T: GodotObject<RefKind = Self>>( this: &Ref<T, Shared>, ) -> TRef<'a, T, Shared> { this.assume_safe_unchecked() } #[inline(always)] unsafe fn impl_assume_unique<T: GodotObject<RefKind = Self>>( this: Ref<T, Shared>, ) -> Ref<T, Unique> { this.cast_access() } #[inline] unsafe fn maybe_add_ref<T: GodotObject<RefKind = Self>>(raw: &RawObject<T>) { raw.add_ref(); } #[inline] unsafe fn maybe_init_ref<T: GodotObject<RefKind = Self>>(raw: &RawObject<T>) { raw.init_ref_count(); } } /// Specialization trait for `Drop` behavior. pub trait PtrWrapper { fn new(ptr: NonNull<sys::godot_object>) -> Self; fn as_non_null(&self) -> NonNull<sys::godot_object>; #[inline] fn as_ptr(&self) -> *mut sys::godot_object { self.as_non_null().as_ptr() } } #[derive(Copy, Clone)] pub struct Forget(NonNull<sys::godot_object>); impl PtrWrapper for Forget { #[inline] fn new(ptr: NonNull<sys::godot_object>) -> Self { Forget(ptr) } #[inline] fn as_non_null(&self) -> NonNull<sys::godot_object> { self.0 } } pub struct UnRef(NonNull<sys::godot_object>); impl PtrWrapper for UnRef { #[inline] fn new(ptr: NonNull<sys::godot_object>) -> Self { UnRef(ptr) } #[inline] fn as_non_null(&self) -> NonNull<sys::godot_object> { self.0 } } impl Drop for UnRef { #[inline] fn drop(&mut self) { unsafe { let raw = RawObject::<ReferenceCountedClassPlaceholder>::from_sys_ref_unchecked(self.0); raw.unref_and_free_if_last(); } } } /// Trait for constraining `assume_safe` lifetimes to the one of `&self` when `T` is /// reference-counted. This is an internal interface. pub trait LifetimeConstraint<Kind: RefKind> {} /// Type used to check lifetime constraint depending on `RefKind`. Internal interface. #[doc(hidden)] pub struct AssumeSafeLifetime<'a, 'r> { _marker: PhantomData<(&'a (), &'r ())>, } impl<'a, 'r> LifetimeConstraint<ManuallyManaged> for AssumeSafeLifetime<'a, 'r> {} impl<'a, 'r: 'a> LifetimeConstraint<RefCounted> for AssumeSafeLifetime<'a, 'r> {} mod private { pub trait Sealed {} }