use core::slice;
use crate::alloc::{
- handle_alloc_error, AllocErr,
+ handle_alloc_error,
AllocInit::{self, *},
AllocRef, Global, Layout,
ReallocPlacement::{self, *},
/// `#[rustc_force_min_const_fn]` attribute which requires conformance
/// with `min_const_fn` but does not necessarily allow calling it in
/// `stable(...) const fn` / user code not enabling `foo` when
- /// `#[rustc_const_unstable(feature = "foo", ..)]` is present.
+ /// `#[rustc_const_unstable(feature = "foo", issue = "01234")]` is present.
pub const NEW: Self = Self::new();
/// Creates the biggest possible `RawVec` (on the system heap)
///
/// # Panics
///
- /// * Panics if the requested capacity exceeds `usize::MAX` bytes.
- /// * Panics on 32-bit platforms if the requested capacity exceeds
- /// `isize::MAX` bytes.
+ /// Panics if the requested capacity exceeds `isize::MAX` bytes.
///
/// # Aborts
///
/// If the `ptr` and `capacity` come from a `RawVec`, then this is guaranteed.
#[inline]
pub unsafe fn from_raw_parts(ptr: *mut T, capacity: usize) -> Self {
- Self::from_raw_parts_in(ptr, capacity, Global)
+ unsafe { Self::from_raw_parts_in(ptr, capacity, Global) }
}
/// Converts a `Box<[T]>` into a `RawVec<T>`.
RawVec::from_raw_parts(slice.as_mut_ptr(), slice.len())
}
}
+
+ /// Converts the entire buffer into `Box<[MaybeUninit<T>]>` with the specified `len`.
+ ///
+ /// Note that this will correctly reconstitute any `cap` changes
+ /// that may have been performed. (See description of type for details.)
+ ///
+ /// # Safety
+ ///
+ /// * `len` must be greater than or equal to the most recently requested capacity, and
+ /// * `len` must be less than or equal to `self.capacity()`.
+ ///
+ /// Note, that the requested capacity and `self.capacity()` could differ, as
+ /// an allocator could overallocate and return a greater memory block than requested.
+ pub unsafe fn into_box(self, len: usize) -> Box<[MaybeUninit<T>]> {
+ // Sanity-check one half of the safety requirement (we cannot check the other half).
+ debug_assert!(
+ len <= self.capacity(),
+ "`len` must be smaller than or equal to `self.capacity()`"
+ );
+
+ let me = ManuallyDrop::new(self);
+ unsafe {
+ let slice = slice::from_raw_parts_mut(me.ptr() as *mut MaybeUninit<T>, len);
+ Box::from_raw(slice)
+ }
+ }
}
impl<T, A: AllocRef> RawVec<T, A> {
if mem::size_of::<T>() == 0 {
Self::new_in(alloc)
} else {
- let layout = Layout::array::<T>(capacity).unwrap_or_else(|_| capacity_overflow());
- alloc_guard(layout.size()).unwrap_or_else(|_| capacity_overflow());
+ // We avoid `unwrap_or_else` here because it bloats the amount of
+ // LLVM IR generated.
+ let layout = match Layout::array::<T>(capacity) {
+ Ok(layout) => layout,
+ Err(_) => capacity_overflow(),
+ };
+ match alloc_guard(layout.size()) {
+ Ok(_) => {}
+ Err(_) => capacity_overflow(),
+ }
+ let memory = match alloc.alloc(layout, init) {
+ Ok(memory) => memory,
+ Err(_) => handle_alloc_error(layout),
+ };
- let memory = alloc.alloc(layout, init).unwrap_or_else(|_| handle_alloc_error(layout));
Self {
ptr: unsafe { Unique::new_unchecked(memory.ptr.cast().as_ptr()) },
cap: Self::capacity_from_bytes(memory.size),
/// If the `ptr` and `capacity` come from a `RawVec` created via `a`, then this is guaranteed.
#[inline]
pub unsafe fn from_raw_parts_in(ptr: *mut T, capacity: usize, a: A) -> Self {
- Self { ptr: Unique::new_unchecked(ptr), cap: capacity, alloc: a }
+ Self { ptr: unsafe { Unique::new_unchecked(ptr) }, cap: capacity, alloc: a }
}
/// Gets a raw pointer to the start of the allocation. Note that this is
}
}
- /// Ensures that the buffer contains at least enough space to hold
- /// `used_capacity + needed_extra_capacity` elements. If it doesn't already have
- /// enough capacity, will reallocate enough space plus comfortable slack
- /// space to get amortized `O(1)` behavior. Will limit this behavior
- /// if it would needlessly cause itself to panic.
+ /// Ensures that the buffer contains at least enough space to hold `len +
+ /// additional` elements. If it doesn't already have enough capacity, will
+ /// reallocate enough space plus comfortable slack space to get amortized
+ /// `O(1)` behavior. Will limit this behavior if it would needlessly cause
+ /// itself to panic.
///
- /// If `used_capacity` exceeds `self.capacity()`, this may fail to actually allocate
+ /// If `len` exceeds `self.capacity()`, this may fail to actually allocate
/// the requested space. This is not really unsafe, but the unsafe
/// code *you* write that relies on the behavior of this function may break.
///
///
/// # Panics
///
- /// * Panics if the requested capacity exceeds `usize::MAX` bytes.
- /// * Panics on 32-bit platforms if the requested capacity exceeds
- /// `isize::MAX` bytes.
+ /// Panics if the new capacity exceeds `isize::MAX` bytes.
///
/// # Aborts
///
/// # vector.push_all(&[1, 3, 5, 7, 9]);
/// # }
/// ```
- pub fn reserve(&mut self, used_capacity: usize, needed_extra_capacity: usize) {
- match self.try_reserve(used_capacity, needed_extra_capacity) {
+ pub fn reserve(&mut self, len: usize, additional: usize) {
+ match self.try_reserve(len, additional) {
Err(CapacityOverflow) => capacity_overflow(),
Err(AllocError { layout, .. }) => handle_alloc_error(layout),
Ok(()) => { /* yay */ }
}
/// The same as `reserve`, but returns on errors instead of panicking or aborting.
- pub fn try_reserve(
- &mut self,
- used_capacity: usize,
- needed_extra_capacity: usize,
- ) -> Result<(), TryReserveError> {
- if self.needs_to_grow(used_capacity, needed_extra_capacity) {
- self.grow_amortized(used_capacity, needed_extra_capacity, MayMove)
+ pub fn try_reserve(&mut self, len: usize, additional: usize) -> Result<(), TryReserveError> {
+ if self.needs_to_grow(len, additional) {
+ self.grow_amortized(len, additional)
} else {
Ok(())
}
}
- /// Attempts to ensure that the buffer contains at least enough space to hold
- /// `used_capacity + needed_extra_capacity` elements. If it doesn't already have
- /// enough capacity, will reallocate in place enough space plus comfortable slack
- /// space to get amortized `O(1)` behavior. Will limit this behaviour
- /// if it would needlessly cause itself to panic.
- ///
- /// If `used_capacity` exceeds `self.capacity()`, this may fail to actually allocate
- /// the requested space. This is not really unsafe, but the unsafe
- /// code *you* write that relies on the behavior of this function may break.
+ /// Ensures that the buffer contains at least enough space to hold `len +
+ /// additional` elements. If it doesn't already, will reallocate the
+ /// minimum possible amount of memory necessary. Generally this will be
+ /// exactly the amount of memory necessary, but in principle the allocator
+ /// is free to give back more than we asked for.
///
- /// Returns `true` if the reallocation attempt has succeeded.
+ /// If `len` exceeds `self.capacity()`, this may fail to actually allocate
+ /// the requested space. This is not really unsafe, but the unsafe code
+ /// *you* write that relies on the behavior of this function may break.
///
/// # Panics
///
- /// * Panics if the requested capacity exceeds `usize::MAX` bytes.
- /// * Panics on 32-bit platforms if the requested capacity exceeds
- /// `isize::MAX` bytes.
- pub fn reserve_in_place(&mut self, used_capacity: usize, needed_extra_capacity: usize) -> bool {
- // This is more readable than putting this in one line:
- // `!self.needs_to_grow(...) || self.grow(...).is_ok()`
- if self.needs_to_grow(used_capacity, needed_extra_capacity) {
- self.grow_amortized(used_capacity, needed_extra_capacity, InPlace).is_ok()
- } else {
- true
- }
- }
-
- /// Ensures that the buffer contains at least enough space to hold
- /// `used_capacity + needed_extra_capacity` elements. If it doesn't already,
- /// will reallocate the minimum possible amount of memory necessary.
- /// Generally this will be exactly the amount of memory necessary,
- /// but in principle the allocator is free to give back more than what
- /// we asked for.
- ///
- /// If `used_capacity` exceeds `self.capacity()`, this may fail to actually allocate
- /// the requested space. This is not really unsafe, but the unsafe
- /// code *you* write that relies on the behavior of this function may break.
- ///
- /// # Panics
- ///
- /// * Panics if the requested capacity exceeds `usize::MAX` bytes.
- /// * Panics on 32-bit platforms if the requested capacity exceeds
- /// `isize::MAX` bytes.
+ /// Panics if the new capacity exceeds `isize::MAX` bytes.
///
/// # Aborts
///
/// Aborts on OOM.
- pub fn reserve_exact(&mut self, used_capacity: usize, needed_extra_capacity: usize) {
- match self.try_reserve_exact(used_capacity, needed_extra_capacity) {
+ pub fn reserve_exact(&mut self, len: usize, additional: usize) {
+ match self.try_reserve_exact(len, additional) {
Err(CapacityOverflow) => capacity_overflow(),
Err(AllocError { layout, .. }) => handle_alloc_error(layout),
Ok(()) => { /* yay */ }
/// The same as `reserve_exact`, but returns on errors instead of panicking or aborting.
pub fn try_reserve_exact(
&mut self,
- used_capacity: usize,
- needed_extra_capacity: usize,
+ len: usize,
+ additional: usize,
) -> Result<(), TryReserveError> {
- if self.needs_to_grow(used_capacity, needed_extra_capacity) {
- self.grow_exact(used_capacity, needed_extra_capacity)
- } else {
- Ok(())
- }
+ if self.needs_to_grow(len, additional) { self.grow_exact(len, additional) } else { Ok(()) }
}
/// Shrinks the allocation down to the specified amount. If the given amount
impl<T, A: AllocRef> RawVec<T, A> {
/// Returns if the buffer needs to grow to fulfill the needed extra capacity.
/// Mainly used to make inlining reserve-calls possible without inlining `grow`.
- fn needs_to_grow(&self, used_capacity: usize, needed_extra_capacity: usize) -> bool {
- needed_extra_capacity > self.capacity().wrapping_sub(used_capacity)
+ fn needs_to_grow(&self, len: usize, additional: usize) -> bool {
+ additional > self.capacity().wrapping_sub(len)
}
fn capacity_from_bytes(excess: usize) -> usize {
// so that all of the code that depends on `T` is within it, while as much
// of the code that doesn't depend on `T` as possible is in functions that
// are non-generic over `T`.
- fn grow_amortized(
- &mut self,
- used_capacity: usize,
- needed_extra_capacity: usize,
- placement: ReallocPlacement,
- ) -> Result<(), TryReserveError> {
+ fn grow_amortized(&mut self, len: usize, additional: usize) -> Result<(), TryReserveError> {
// This is ensured by the calling contexts.
- debug_assert!(needed_extra_capacity > 0);
+ debug_assert!(additional > 0);
if mem::size_of::<T>() == 0 {
// Since we return a capacity of `usize::MAX` when `elem_size` is
}
// Nothing we can really do about these checks, sadly.
- let required_cap =
- used_capacity.checked_add(needed_extra_capacity).ok_or(CapacityOverflow)?;
+ let required_cap = len.checked_add(additional).ok_or(CapacityOverflow)?;
// This guarantees exponential growth. The doubling cannot overflow
// because `cap <= isize::MAX` and the type of `cap` is `usize`.
let new_layout = Layout::array::<T>(cap);
// `finish_grow` is non-generic over `T`.
- let memory = finish_grow(new_layout, placement, self.current_memory(), &mut self.alloc)?;
+ let memory = finish_grow(new_layout, self.current_memory(), &mut self.alloc)?;
self.set_memory(memory);
Ok(())
}
// The constraints on this method are much the same as those on
// `grow_amortized`, but this method is usually instantiated less often so
// it's less critical.
- fn grow_exact(
- &mut self,
- used_capacity: usize,
- needed_extra_capacity: usize,
- ) -> Result<(), TryReserveError> {
+ fn grow_exact(&mut self, len: usize, additional: usize) -> Result<(), TryReserveError> {
if mem::size_of::<T>() == 0 {
// Since we return a capacity of `usize::MAX` when the type size is
// 0, getting to here necessarily means the `RawVec` is overfull.
return Err(CapacityOverflow);
}
- let cap = used_capacity.checked_add(needed_extra_capacity).ok_or(CapacityOverflow)?;
+ let cap = len.checked_add(additional).ok_or(CapacityOverflow)?;
let new_layout = Layout::array::<T>(cap);
// `finish_grow` is non-generic over `T`.
- let memory = finish_grow(new_layout, MayMove, self.current_memory(), &mut self.alloc)?;
+ let memory = finish_grow(new_layout, self.current_memory(), &mut self.alloc)?;
self.set_memory(memory);
Ok(())
}
// much smaller than the number of `T` types.)
fn finish_grow<A>(
new_layout: Result<Layout, LayoutErr>,
- placement: ReallocPlacement,
current_memory: Option<(NonNull<u8>, Layout)>,
alloc: &mut A,
) -> Result<MemoryBlock, TryReserveError>
let memory = if let Some((ptr, old_layout)) = current_memory {
debug_assert_eq!(old_layout.align(), new_layout.align());
- unsafe { alloc.grow(ptr, old_layout, new_layout.size(), placement, Uninitialized) }
+ unsafe { alloc.grow(ptr, old_layout, new_layout.size(), MayMove, Uninitialized) }
} else {
- match placement {
- MayMove => alloc.alloc(new_layout, Uninitialized),
- InPlace => Err(AllocErr),
- }
+ alloc.alloc(new_layout, Uninitialized)
}
.map_err(|_| AllocError { layout: new_layout, non_exhaustive: () })?;
Ok(memory)
}
-impl<T> RawVec<T, Global> {
- /// Converts the entire buffer into `Box<[MaybeUninit<T>]>` with the specified `len`.
- ///
- /// Note that this will correctly reconstitute any `cap` changes
- /// that may have been performed. (See description of type for details.)
- ///
- /// # Safety
- ///
- /// * `len` must be greater than or equal to the most recently requested capacity, and
- /// * `len` must be less than or equal to `self.capacity()`.
- ///
- /// Note, that the requested capacity and `self.capacity()` could differ, as
- /// an allocator could overallocate and return a greater memory block than requested.
- pub unsafe fn into_box(self, len: usize) -> Box<[MaybeUninit<T>]> {
- // Sanity-check one half of the safety requirement (we cannot check the other half).
- debug_assert!(
- len <= self.capacity(),
- "`len` must be smaller than or equal to `self.capacity()`"
- );
-
- let me = ManuallyDrop::new(self);
- let slice = slice::from_raw_parts_mut(me.ptr() as *mut MaybeUninit<T>, len);
- Box::from_raw(slice)
- }
-}
-
unsafe impl<#[may_dangle] T, A: AllocRef> Drop for RawVec<T, A> {
/// Frees the memory owned by the `RawVec` *without* trying to drop its contents.
fn drop(&mut self) {
projects / rustc.git / blobdiff