refactor generational box into multiple files

packages/generational-box/src/sync.rs

@@ -0,0 +1,135 @@
+use parking_lot::{
+    MappedRwLockReadGuard, MappedRwLockWriteGuard, Mutex, RwLock, RwLockReadGuard, RwLockWriteGuard,
+};
+use std::sync::{Arc, OnceLock};
+
+use crate::{
+    error::{self, ValueDroppedError},
+    references::{
+        GenerationalRef, GenerationalRefBorrowInfo, GenerationalRefMut,
+        GenerationalRefMutBorrowInfo,
+    },
+    AnyStorage, Mappable, MappableMut, MemoryLocation, MemoryLocationInner, Storage,
+};
+
+/// A thread safe storage. This is slower than the unsync storage, but allows you to share the value between threads.
+#[derive(Default)]
+pub struct SyncStorage(RwLock<Option<Box<dyn std::any::Any + Send + Sync>>>);
+
+static SYNC_RUNTIME: OnceLock<Arc<Mutex<Vec<MemoryLocation<SyncStorage>>>>> = OnceLock::new();
+
+fn sync_runtime() -> &'static Arc<Mutex<Vec<MemoryLocation<SyncStorage>>>> {
+    SYNC_RUNTIME.get_or_init(|| Arc::new(Mutex::new(Vec::new())))
+}
+
+impl AnyStorage for SyncStorage {
+    fn data_ptr(&self) -> *const () {
+        self.0.data_ptr() as *const ()
+    }
+
+    fn take(&self) -> bool {
+        self.0.write().take().is_some()
+    }
+
+    fn claim() -> MemoryLocation<Self> {
+        sync_runtime().lock().pop().unwrap_or_else(|| {
+            let data: &'static MemoryLocationInner<Self> =
+                &*Box::leak(Box::new(MemoryLocationInner {
+                    data: Self::default(),
+                    #[cfg(any(debug_assertions, feature = "check_generation"))]
+                    generation: 0.into(),
+                    #[cfg(any(debug_assertions, feature = "debug_borrows"))]
+                    borrow: Default::default(),
+                }));
+            MemoryLocation(data)
+        })
+    }
+
+    fn recycle(location: &MemoryLocation<Self>) {
+        location.drop();
+        sync_runtime().lock().push(*location);
+    }
+}
+
+impl<T> Mappable<T> for MappedRwLockReadGuard<'static, T> {
+    type Mapped<U: 'static> = MappedRwLockReadGuard<'static, U>;
+
+    fn map<U: 'static>(_self: Self, f: impl FnOnce(&T) -> &U) -> Self::Mapped<U> {
+        MappedRwLockReadGuard::map(_self, f)
+    }
+
+    fn try_map<U: 'static>(
+        _self: Self,
+        f: impl FnOnce(&T) -> Option<&U>,
+    ) -> Option<Self::Mapped<U>> {
+        MappedRwLockReadGuard::try_map(_self, f).ok()
+    }
+}
+
+impl<T> MappableMut<T> for MappedRwLockWriteGuard<'static, T> {
+    type Mapped<U: 'static> = MappedRwLockWriteGuard<'static, U>;
+
+    fn map<U: 'static>(_self: Self, f: impl FnOnce(&mut T) -> &mut U) -> Self::Mapped<U> {
+        MappedRwLockWriteGuard::map(_self, f)
+    }
+
+    fn try_map<U: 'static>(
+        _self: Self,
+        f: impl FnOnce(&mut T) -> Option<&mut U>,
+    ) -> Option<Self::Mapped<U>> {
+        MappedRwLockWriteGuard::try_map(_self, f).ok()
+    }
+}
+
+impl<T: Sync + Send + 'static> Storage<T> for SyncStorage {
+    type Ref = GenerationalRef<T, MappedRwLockReadGuard<'static, T>>;
+    type Mut = GenerationalRefMut<T, MappedRwLockWriteGuard<'static, T>>;
+
+    fn try_read(
+        &'static self,
+        #[cfg(any(debug_assertions, feature = "debug_ownership"))]
+        created_at: &'static std::panic::Location<'static>,
+        #[cfg(any(debug_assertions, feature = "debug_ownership"))] at: GenerationalRefBorrowInfo,
+    ) -> Result<Self::Ref, error::BorrowError> {
+        RwLockReadGuard::try_map(self.0.read(), |any| any.as_ref()?.downcast_ref())
+            .map_err(|_| {
+                error::BorrowError::Dropped(ValueDroppedError {
+                    #[cfg(any(debug_assertions, feature = "debug_ownership"))]
+                    created_at,
+                })
+            })
+            .map(|guard| {
+                GenerationalRef::new(
+                    guard,
+                    #[cfg(any(debug_assertions, feature = "debug_ownership"))]
+                    at,
+                )
+            })
+    }
+
+    fn try_write(
+        &'static self,
+        #[cfg(any(debug_assertions, feature = "debug_ownership"))]
+        created_at: &'static std::panic::Location<'static>,
+        #[cfg(any(debug_assertions, feature = "debug_ownership"))] at: GenerationalRefMutBorrowInfo,
+    ) -> Result<Self::Mut, error::BorrowMutError> {
+        RwLockWriteGuard::try_map(self.0.write(), |any| any.as_mut()?.downcast_mut())
+            .map_err(|_| {
+                error::BorrowMutError::Dropped(ValueDroppedError {
+                    #[cfg(any(debug_assertions, feature = "debug_ownership"))]
+                    created_at,
+                })
+            })
+            .map(|guard| {
+                GenerationalRefMut::new(
+                    guard,
+                    #[cfg(any(debug_assertions, feature = "debug_ownership"))]
+                    at,
+                )
+            })
+    }
+
+    fn set(&self, value: T) {
+        *self.0.write() = Some(Box::new(value));
+    }
+}