Vendor dependencies for 0.3.0 release

vendor/windows-core/src/array.rs

@@ -0,0 +1,165 @@
+use super::*;
+
+/// A WinRT array stores elements contiguously in a heap-allocated buffer.
+pub struct Array<T: Type<T>> {
+    pub(crate) data: *mut T::Default,
+    pub(crate) len: u32,
+}
+
+impl<T: Type<T>> Default for Array<T> {
+    fn default() -> Self {
+        Self {
+            data: core::ptr::null_mut(),
+            len: 0,
+        }
+    }
+}
+
+impl<T: Type<T>> Array<T> {
+    /// Creates an empty array.
+    pub fn new() -> Self {
+        Self::default()
+    }
+
+    /// Creates an array of the given length with default values.
+    pub fn with_len(len: usize) -> Self {
+        assert!(len < u32::MAX as usize);
+        let bytes_amount = len
+            .checked_mul(core::mem::size_of::<T>())
+            .expect("Attempted to allocate too large an Array");
+
+        // WinRT arrays must be allocated with CoTaskMemAlloc.
+        // SAFETY: the call to CoTaskMemAlloc is safe to perform
+        // if len is zero and overflow was checked above.
+        // We ensured we alloc enough space by multiplying len * size_of::<T>
+        let data = unsafe { imp::CoTaskMemAlloc(bytes_amount) as *mut T::Default };
+
+        assert!(!data.is_null(), "Could not successfully allocate for Array");
+
+        // SAFETY: It is by definition safe to zero-initialize WinRT types.
+        // `write_bytes` will write 0 to (len * size_of::<T>())
+        // bytes making the entire array zero initialized. We have assured
+        // above that the data ptr is not null.
+        unsafe {
+            core::ptr::write_bytes(data, 0, len);
+        }
+
+        let len = len as u32;
+        Self { data, len }
+    }
+
+    /// Creates an array by copying the elements from the slice.
+    pub fn from_slice(values: &[T::Default]) -> Self
+    where
+        T::Default: Clone,
+    {
+        let mut array = Self::with_len(values.len());
+        array.clone_from_slice(values);
+        array
+    }
+
+    /// Creates an array from a pointer and length. The `len` argument is the number of elements, not the number of bytes.
+    /// # Safety
+    /// The `data` argument must have been allocated with `CoTaskMemAlloc`.
+    pub unsafe fn from_raw_parts(data: *mut T::Default, len: u32) -> Self {
+        Self { data, len }
+    }
+
+    /// Returns a slice containing the entire array.
+    pub fn as_slice(&self) -> &[T::Default] {
+        self
+    }
+
+    /// Returns `true` if the array is empty.
+    pub fn is_empty(&self) -> bool {
+        self.len == 0
+    }
+
+    /// Returns the length of the array.
+    pub fn len(&self) -> usize {
+        self.len as usize
+    }
+
+    /// Clears the contents of the array.
+    pub fn clear(&mut self) {
+        if self.is_empty() {
+            return;
+        }
+
+        let mut data = core::ptr::null_mut();
+        let mut len = 0;
+
+        core::mem::swap(&mut data, &mut self.data);
+        core::mem::swap(&mut len, &mut self.len);
+
+        // SAFETY: At this point, self has been reset to zero so any panics in T's destructor would
+        // only leak data not leave the array in bad state.
+        unsafe {
+            // Call the destructors of all the elements of the old array
+            // SAFETY: the slice cannot be used after the call to `drop_in_place`
+            core::ptr::drop_in_place(core::ptr::slice_from_raw_parts_mut(data, len as usize));
+            // Free the data memory where the elements were
+            // SAFETY: we have unique access to the data pointer at this point
+            // so freeing it is the right thing to do
+            imp::CoTaskMemFree(data as _);
+        }
+    }
+
+    #[doc(hidden)]
+    /// Get a mutable pointer to the array's length
+    ///
+    /// # Safety
+    ///
+    /// This function is safe but writing to the pointer is not. Calling this without
+    /// a subsequent call to `set_abi` is likely to either leak memory or cause UB
+    pub unsafe fn set_abi_len(&mut self) -> *mut u32 {
+        &mut self.len
+    }
+
+    #[doc(hidden)]
+    /// Turn the array into a pointer to its data and its length
+    pub fn into_abi(self) -> (*mut T::Abi, u32) {
+        let abi = (self.data as *mut _, self.len);
+        core::mem::forget(self);
+        abi
+    }
+}
+
+impl<T: Type<T>> core::ops::Deref for Array<T> {
+    type Target = [T::Default];
+
+    fn deref(&self) -> &[T::Default] {
+        if self.is_empty() {
+            return &[];
+        }
+
+        // SAFETY: data must not be null if the array is not empty
+        unsafe { core::slice::from_raw_parts(self.data, self.len as usize) }
+    }
+}
+
+impl<T: Type<T>> core::ops::DerefMut for Array<T> {
+    fn deref_mut(&mut self) -> &mut [T::Default] {
+        if self.is_empty() {
+            return &mut [];
+        }
+
+        // SAFETY: data must not be null if the array is not empty
+        unsafe { core::slice::from_raw_parts_mut(self.data, self.len as usize) }
+    }
+}
+
+impl<T: Type<T>> Drop for Array<T> {
+    fn drop(&mut self) {
+        self.clear();
+    }
+}
+
+impl<T: Type<T>> core::fmt::Debug for Array<T>
+where
+    T::Default: core::fmt::Debug,
+{
+    fn fmt(&self, f: &mut core::fmt::Formatter) -> core::fmt::Result {
+        core::ops::Deref::deref(self).fmt(f)
+    }
+}