diff options
Diffstat (limited to 'rust')
-rw-r--r-- | rust/kernel/alloc.rs | 1 | ||||
-rw-r--r-- | rust/kernel/alloc/kvec.rs | 184 |
2 files changed, 185 insertions, 0 deletions
diff --git a/rust/kernel/alloc.rs b/rust/kernel/alloc.rs index 4d7190594076..4035644b5dca 100644 --- a/rust/kernel/alloc.rs +++ b/rust/kernel/alloc.rs @@ -19,6 +19,7 @@ pub use self::kbox::KBox; pub use self::kbox::KVBox; pub use self::kbox::VBox; +pub use self::kvec::IntoIter; pub use self::kvec::KVVec; pub use self::kvec::KVec; pub use self::kvec::VVec; diff --git a/rust/kernel/alloc/kvec.rs b/rust/kernel/alloc/kvec.rs index 351c4f1702db..cc8f3c555d1e 100644 --- a/rust/kernel/alloc/kvec.rs +++ b/rust/kernel/alloc/kvec.rs @@ -11,6 +11,7 @@ use core::{ ops::DerefMut, ops::Index, ops::IndexMut, + ptr, ptr::NonNull, slice, slice::SliceIndex, @@ -611,3 +612,186 @@ __impl_slice_eq! { [A: Allocator] Vec<T, A>, [U] } __impl_slice_eq! { [A: Allocator] [T], Vec<U, A> } __impl_slice_eq! { [A: Allocator, const N: usize] Vec<T, A>, [U; N] } __impl_slice_eq! { [A: Allocator, const N: usize] Vec<T, A>, &[U; N] } + +impl<'a, T, A> IntoIterator for &'a Vec<T, A> +where + A: Allocator, +{ + type Item = &'a T; + type IntoIter = slice::Iter<'a, T>; + + fn into_iter(self) -> Self::IntoIter { + self.iter() + } +} + +impl<'a, T, A: Allocator> IntoIterator for &'a mut Vec<T, A> +where + A: Allocator, +{ + type Item = &'a mut T; + type IntoIter = slice::IterMut<'a, T>; + + fn into_iter(self) -> Self::IntoIter { + self.iter_mut() + } +} + +/// An `Iterator` implementation for `Vec<T,A>` that moves elements out of a vector. +/// +/// This structure is created by the `Vec::into_iter` method on [`Vec`] (provided by the +/// [`IntoIterator`] trait). +/// +/// # Examples +/// +/// ``` +/// let v = kernel::kvec![0, 1, 2]?; +/// let iter = v.into_iter(); +/// +/// # Ok::<(), Error>(()) +/// ``` +pub struct IntoIter<T, A: Allocator> { + ptr: *mut T, + buf: NonNull<T>, + len: usize, + cap: usize, + _p: PhantomData<A>, +} + +impl<T, A> IntoIter<T, A> +where + A: Allocator, +{ + fn as_raw_mut_slice(&mut self) -> *mut [T] { + ptr::slice_from_raw_parts_mut(self.ptr, self.len) + } +} + +impl<T, A> Iterator for IntoIter<T, A> +where + A: Allocator, +{ + type Item = T; + + /// # Examples + /// + /// ``` + /// let v = kernel::kvec![1, 2, 3]?; + /// let mut it = v.into_iter(); + /// + /// assert_eq!(it.next(), Some(1)); + /// assert_eq!(it.next(), Some(2)); + /// assert_eq!(it.next(), Some(3)); + /// assert_eq!(it.next(), None); + /// + /// # Ok::<(), Error>(()) + /// ``` + fn next(&mut self) -> Option<T> { + if self.len == 0 { + return None; + } + + let ptr = self.ptr; + if !Vec::<T, A>::is_zst() { + // SAFETY: We can't overflow; `end` is guaranteed to mark the end of the buffer. + unsafe { self.ptr = self.ptr.add(1) }; + } else { + // For ZST `ptr` has to stay where it is to remain aligned, so we just reduce `self.len` + // by 1. + } + self.len -= 1; + + // SAFETY: `ptr` is guaranteed to point at a valid element within the buffer. + Some(unsafe { ptr.read() }) + } + + /// # Examples + /// + /// ``` + /// let v: KVec<u32> = kernel::kvec![1, 2, 3]?; + /// let mut iter = v.into_iter(); + /// let size = iter.size_hint().0; + /// + /// iter.next(); + /// assert_eq!(iter.size_hint().0, size - 1); + /// + /// iter.next(); + /// assert_eq!(iter.size_hint().0, size - 2); + /// + /// iter.next(); + /// assert_eq!(iter.size_hint().0, size - 3); + /// + /// # Ok::<(), Error>(()) + /// ``` + fn size_hint(&self) -> (usize, Option<usize>) { + (self.len, Some(self.len)) + } +} + +impl<T, A> Drop for IntoIter<T, A> +where + A: Allocator, +{ + fn drop(&mut self) { + // SAFETY: Drop the remaining vector's elements in place, before we free the backing + // memory. + unsafe { ptr::drop_in_place(self.as_raw_mut_slice()) }; + + // If `cap == 0` we never allocated any memory in the first place. + if self.cap != 0 { + // SAFETY: `self.buf` was previously allocated with `A`. + unsafe { A::free(self.buf.cast()) }; + } + } +} + +impl<T, A> IntoIterator for Vec<T, A> +where + A: Allocator, +{ + type Item = T; + type IntoIter = IntoIter<T, A>; + + /// Consumes the `Vec<T, A>` and creates an `Iterator`, which moves each value out of the + /// vector (from start to end). + /// + /// # Examples + /// + /// ``` + /// let v = kernel::kvec![1, 2]?; + /// let mut v_iter = v.into_iter(); + /// + /// let first_element: Option<u32> = v_iter.next(); + /// + /// assert_eq!(first_element, Some(1)); + /// assert_eq!(v_iter.next(), Some(2)); + /// assert_eq!(v_iter.next(), None); + /// + /// # Ok::<(), Error>(()) + /// ``` + /// + /// ``` + /// let v = kernel::kvec![]; + /// let mut v_iter = v.into_iter(); + /// + /// let first_element: Option<u32> = v_iter.next(); + /// + /// assert_eq!(first_element, None); + /// + /// # Ok::<(), Error>(()) + /// ``` + #[inline] + fn into_iter(self) -> Self::IntoIter { + let (ptr, len, cap) = self.into_raw_parts(); + + IntoIter { + ptr, + // SAFETY: `ptr` is either a dangling pointer or a pointer to a valid memory + // allocation, allocated with `A`. + buf: unsafe { NonNull::new_unchecked(ptr) }, + len, + cap, + _p: PhantomData::<A>, + } + } +} |