mozilla
/
gecko-dev
зеркало из https://github.com/mozilla/gecko-dev.git
1
0
Форкнуть 0
Код Задачи Пакеты Проекты Релизы Вики Активность
gecko-dev/third_party/rust/smallvec/lib.rs

1425 строки
40 KiB
Rust
Исходник Ответственный История

/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
//! Small vectors in various sizes. These store a certain number of elements inline, and fall back
//! to the heap for larger allocations. This can be a useful optimization for improving cache
//! locality and reducing allocator traffic for workloads that fit within the inline buffer.
#[cfg(feature="heapsizeof")]
extern crate heapsize;
use std::borrow::{Borrow, BorrowMut};
use std::cmp;
use std::fmt;
use std::hash::{Hash, Hasher};
use std::iter::{IntoIterator, FromIterator};
use std::mem;
use std::ops;
use std::ptr;
use std::slice;
#[cfg(feature="heapsizeof")]
use std::os::raw::c_void;
#[cfg(feature="heapsizeof")]
use heapsize::{HeapSizeOf, heap_size_of};
use SmallVecData::{Inline, Heap};
/// Common operations implemented by both `Vec` and `SmallVec`.
///
/// This can be used to write generic code that works with both `Vec` and `SmallVec`.
///
/// ## Example
///
/// ```rust
/// use smallvec::{VecLike, SmallVec8};
///
/// fn initialize<V: VecLike<u8>>(v: &mut V) {
/// for i in 0..5 {
/// v.push(i);
/// }
/// }
///
/// let mut vec = Vec::new();
/// initialize(&mut vec);
///
/// let mut small_vec = SmallVec8::new();
/// initialize(&mut small_vec);
/// ```
pub trait VecLike<T>:
ops::Index<usize, Output=T> +
ops::IndexMut<usize> +
ops::Index<ops::Range<usize>, Output=[T]> +
ops::IndexMut<ops::Range<usize>> +
ops::Index<ops::RangeFrom<usize>, Output=[T]> +
ops::IndexMut<ops::RangeFrom<usize>> +
ops::Index<ops::RangeTo<usize>, Output=[T]> +
ops::IndexMut<ops::RangeTo<usize>> +
ops::Index<ops::RangeFull, Output=[T]> +
ops::IndexMut<ops::RangeFull> +
ops::DerefMut<Target = [T]> +
Extend<T> {
/// Append an element to the vector.
fn push(&mut self, value: T);
}
impl<T> VecLike<T> for Vec<T> {
#[inline]
fn push(&mut self, value: T) {
Vec::push(self, value);
}
}
unsafe fn deallocate<T>(ptr: *mut T, capacity: usize) {
let _vec: Vec<T> = Vec::from_raw_parts(ptr, 0, capacity);
// Let it drop.
}
pub struct Drain<'a, T: 'a> {
iter: slice::IterMut<'a,T>,
}
impl<'a, T: 'a> Iterator for Drain<'a,T> {
type Item = T;
#[inline]
fn next(&mut self) -> Option<T> {
match self.iter.next() {
None => None,
Some(reference) => {
unsafe {
Some(ptr::read(reference))
}
}
}
}
#[inline]
fn size_hint(&self) -> (usize, Option<usize>) {
self.iter.size_hint()
}
}
impl<'a, T: 'a> DoubleEndedIterator for Drain<'a, T> {
#[inline]
fn next_back(&mut self) -> Option<T> {
match self.iter.next_back() {
None => None,
Some(reference) => {
unsafe {
Some(ptr::read(reference))
}
}
}
}
}
impl<'a, T> ExactSizeIterator for Drain<'a, T> { }
impl<'a, T: 'a> Drop for Drain<'a,T> {
fn drop(&mut self) {
// Destroy the remaining elements.
for _ in self.by_ref() {}
}
}
enum SmallVecData<A: Array> {
Inline { array: A },
Heap { ptr: *mut A::Item, capacity: usize },
}
impl<A: Array> SmallVecData<A> {
fn ptr_mut(&mut self) -> *mut A::Item {
match *self {
Inline { ref mut array } => array.ptr_mut(),
Heap { ptr, .. } => ptr,
}
}
}
unsafe impl<A: Array + Send> Send for SmallVecData<A> {}
unsafe impl<A: Array + Sync> Sync for SmallVecData<A> {}
impl<A: Array> Drop for SmallVecData<A> {
fn drop(&mut self) {
unsafe {
match *self {
ref mut inline @ Inline { .. } => {
// Inhibit the array destructor.
ptr::write(inline, Heap {
ptr: ptr::null_mut(),
capacity: 0,
});
}
Heap { ptr, capacity } => deallocate(ptr, capacity),
}
}
}
}
/// A `Vec`-like container that can store a small number of elements inline.
///
/// `SmallVec` acts like a vector, but can store a limited amount of data inline within the
/// `Smallvec` struct rather than in a separate allocation. If the data exceeds this limit, the
/// `SmallVec` will "spill" its data onto the heap, allocating a new buffer to hold it.
///
/// The amount of data that a `SmallVec` can store inline depends on its backing store. The backing
/// store can be any type that implements the `Array` trait; usually it is a small fixed-sized
/// array. For example a `SmallVec<[u64; 8]>` can hold up to eight 64-bit integers inline.
///
/// Type aliases like `SmallVec8<T>` are provided as convenient shorthand for types like
/// `SmallVec<[T; 8]>`.
///
/// ## Example
///
/// ```rust
/// use smallvec::SmallVec;
/// let mut v = SmallVec::<[u8; 4]>::new(); // initialize an empty vector
///
/// use smallvec::SmallVec4;
/// let mut v: SmallVec4<u8> = SmallVec::new(); // alternate way to write the above
///
/// // SmallVec4 can hold up to 4 items without spilling onto the heap.
/// v.extend(0..4);
/// assert_eq!(v.len(), 4);
/// assert!(!v.spilled());
///
/// // Pushing another element will force the buffer to spill:
/// v.push(4);
/// assert_eq!(v.len(), 5);
/// assert!(v.spilled());
/// ```
pub struct SmallVec<A: Array> {
len: usize,
data: SmallVecData<A>,
}
impl<A: Array> SmallVec<A> {
/// Construct an empty vector
#[inline]
pub fn new() -> SmallVec<A> {
unsafe {
SmallVec {
len: 0,
data: Inline { array: mem::uninitialized() },
}
}
}
/// Construct a new `SmallVec` from a `Vec<A::Item>` without copying
/// elements.
///
/// ```rust
/// use smallvec::SmallVec;
///
/// let vec = vec![1, 2, 3, 4, 5];
/// let small_vec: SmallVec<[_; 3]> = SmallVec::from_vec(vec);
///
/// assert_eq!(&*small_vec, &[1, 2, 3, 4, 5]);
/// ```
#[inline]
pub fn from_vec(mut vec: Vec<A::Item>) -> SmallVec<A> {
let (ptr, cap, len) = (vec.as_mut_ptr(), vec.capacity(), vec.len());
mem::forget(vec);
SmallVec {
len: len,
data: SmallVecData::Heap {
ptr: ptr,
capacity: cap
}
}
}
/// Sets the length of a vector.
///
/// This will explicitly set the size of the vector, without actually
/// modifying its buffers, so it is up to the caller to ensure that the
/// vector is actually the specified size.
pub unsafe fn set_len(&mut self, new_len: usize) {
self.len = new_len
}
/// The maximum number of elements this vector can hold inline
#[inline]
pub fn inline_size(&self) -> usize {
A::size()
}
/// The number of elements stored in the vector
#[inline]
pub fn len(&self) -> usize {
self.len
}
/// Returns `true` if the vector is empty
#[inline]
pub fn is_empty(&self) -> bool {
self.len == 0
}
/// The number of items the vector can hold without reallocating
#[inline]
pub fn capacity(&self) -> usize {
match self.data {
Inline { .. } => A::size(),
Heap { capacity, .. } => capacity,
}
}
/// Returns `true` if the data has spilled into a separate heap-allocated buffer.
#[inline]
pub fn spilled(&self) -> bool {
match self.data {
Inline { .. } => false,
Heap { .. } => true,
}
}
/// Empty the vector and return an iterator over its former contents.
pub fn drain(&mut self) -> Drain<A::Item> {
unsafe {
let current_len = self.len();
self.set_len(0);
let ptr = self.data.ptr_mut();
let slice = slice::from_raw_parts_mut(ptr, current_len);
Drain {
iter: slice.iter_mut(),
}
}
}
/// Append an item to the vector.
#[inline]
pub fn push(&mut self, value: A::Item) {
let cap = self.capacity();
if self.len == cap {
self.grow(cmp::max(cap * 2, 1))
}
unsafe {
let end = self.as_mut_ptr().offset(self.len as isize);
ptr::write(end, value);
let len = self.len;
self.set_len(len + 1)
}
}
/// Append elements from an iterator.
///
/// This function is deprecated; it has been replaced by `Extend::extend`.
#[deprecated(note = "Use `extend` instead")]
pub fn push_all_move<V: IntoIterator<Item=A::Item>>(&mut self, other: V) {
self.extend(other)
}
/// Remove an item from the end of the vector and return it, or None if empty.
#[inline]
pub fn pop(&mut self) -> Option<A::Item> {
if self.len == 0 {
return None
}
let last_index = self.len - 1;
if (last_index as isize) < 0 {
panic!("overflow")
}
unsafe {
let end_ptr = self.as_mut_ptr().offset(last_index as isize);
let value = ptr::replace(end_ptr, mem::uninitialized());
self.set_len(last_index);
Some(value)
}
}
/// Re-allocate to set the capacity to `new_cap`.
///
/// Panics if `new_cap` is less than the vector's length.
pub fn grow(&mut self, new_cap: usize) {
assert!(new_cap >= self.len);
let mut vec: Vec<A::Item> = Vec::with_capacity(new_cap);
let new_alloc = vec.as_mut_ptr();
unsafe {
mem::forget(vec);
ptr::copy_nonoverlapping(self.as_ptr(), new_alloc, self.len);
match self.data {
Inline { .. } => {}
Heap { ptr, capacity } => deallocate(ptr, capacity),
}
ptr::write(&mut self.data, Heap {
ptr: new_alloc,
capacity: new_cap,
});
}
}
/// Reserve capacity for `additional` more elements to be inserted.
///
/// May reserve more space to avoid frequent reallocations.
///
/// If the new capacity would overflow `usize` then it will be set to `usize::max_value()`
/// instead. (This means that inserting `additional` new elements is not guaranteed to be
/// possible after calling this function.)
pub fn reserve(&mut self, additional: usize) {
let len = self.len();
if self.capacity() - len < additional {
match len.checked_add(additional).and_then(usize::checked_next_power_of_two) {
Some(cap) => self.grow(cap),
None => self.grow(usize::max_value()),
}
}
}
/// Reserve the minumum capacity for `additional` more elements to be inserted.
///
/// Panics if the new capacity overflows `usize`.
pub fn reserve_exact(&mut self, additional: usize) {
let len = self.len();
if self.capacity() - len < additional {
match len.checked_add(additional) {
Some(cap) => self.grow(cap),
None => panic!("reserve_exact overflow"),
}
}
}
/// Shrink the capacity of the vector as much as possible.
///
/// When possible, this will move data from an external heap buffer to the vector's inline
/// storage.
pub fn shrink_to_fit(&mut self) {
let len = self.len;
if self.inline_size() >= len {
unsafe {
let (ptr, capacity) = match self.data {
Inline { .. } => return,
Heap { ptr, capacity } => (ptr, capacity),
};
ptr::write(&mut self.data, Inline { array: mem::uninitialized() });
ptr::copy_nonoverlapping(ptr, self.as_mut_ptr(), len);
deallocate(ptr, capacity);
}
} else if self.capacity() > len {
self.grow(len);
}
}
/// Shorten the vector, keeping the first `len` elements and dropping the rest.
///
/// If `len` is greater than or equal to the vector's current length, this has no
/// effect.
///
/// This does not re-allocate. If you want the vector's capacity to shrink, call
/// `shrink_to_fit` after truncating.
pub fn truncate(&mut self, len: usize) {
let end_ptr = self.as_ptr();
while len < self.len {
unsafe {
let last_index = self.len - 1;
self.set_len(last_index);
ptr::read(end_ptr.offset(last_index as isize));
}
}
}
/// Remove the element at position `index`, replacing it with the last element.
///
/// This does not preserve ordering, but is O(1).
///
/// Panics if `index` is out of bounds.
#[inline]
pub fn swap_remove(&mut self, index: usize) -> A::Item {
let len = self.len;
self.swap(len - 1, index);
self.pop().unwrap()
}
/// Remove all elements from the vector.
#[inline]
pub fn clear(&mut self) {
self.truncate(0);
}
/// Remove and return the element at position `index`, shifting all elements after it to the
/// left.
///
/// Panics if `index` is out of bounds.
pub fn remove(&mut self, index: usize) -> A::Item {
let len = self.len();
assert!(index < len);
unsafe {
let ptr = self.as_mut_ptr().offset(index as isize);
let item = ptr::read(ptr);
ptr::copy(ptr.offset(1), ptr, len - index - 1);
self.set_len(len - 1);
item
}
}
/// Insert an element at position `index`, shifting all elements after it to the right.
///
/// Panics if `index` is out of bounds.
pub fn insert(&mut self, index: usize, element: A::Item) {
self.reserve(1);
let len = self.len;
assert!(index <= len);
unsafe {
let ptr = self.as_mut_ptr().offset(index as isize);
ptr::copy(ptr, ptr.offset(1), len - index);
ptr::write(ptr, element);
self.set_len(len + 1);
}
}
pub fn insert_many<I: IntoIterator<Item=A::Item>>(&mut self, index: usize, iterable: I) {
let iter = iterable.into_iter();
let (lower_size_bound, _) = iter.size_hint();
assert!(lower_size_bound <= std::isize::MAX as usize); // Ensure offset is indexable
assert!(index + lower_size_bound >= index); // Protect against overflow
self.reserve(lower_size_bound);
unsafe {
let old_len = self.len;
assert!(index <= old_len);
let ptr = self.as_mut_ptr().offset(index as isize);
ptr::copy(ptr, ptr.offset(lower_size_bound as isize), old_len - index);
for (off, element) in iter.enumerate() {
if off < lower_size_bound {
ptr::write(ptr.offset(off as isize), element);
self.len = self.len + 1;
} else {
// Iterator provided more elements than the hint.
assert!(index + off >= index); // Protect against overflow.
self.insert(index + off, element);
}
}
let num_added = self.len - old_len;
if num_added < lower_size_bound {
// Iterator provided fewer elements than the hint
ptr::copy(ptr.offset(lower_size_bound as isize), ptr.offset(num_added as isize), old_len - index);
}
}
}
/// Convert a SmallVec to a Vec, without reallocating if the SmallVec has already spilled onto
/// the heap.
pub fn into_vec(self) -> Vec<A::Item> {
match self.data {
Inline { .. } => self.into_iter().collect(),
Heap { ptr, capacity } => unsafe {
let v = Vec::from_raw_parts(ptr, self.len, capacity);
mem::forget(self);
v
}
}
}
}
impl<A: Array> SmallVec<A> where A::Item: Copy {
pub fn from_slice(slice: &[A::Item]) -> Self {
let mut vec = Self::new();
vec.extend_from_slice(slice);
vec
}
pub fn insert_from_slice(&mut self, index: usize, slice: &[A::Item]) {
self.reserve(slice.len());
let len = self.len;
assert!(index <= len);
unsafe {
let slice_ptr = slice.as_ptr();
let ptr = self.as_mut_ptr().offset(index as isize);
ptr::copy(ptr, ptr.offset(slice.len() as isize), len - index);
ptr::copy(slice_ptr, ptr, slice.len());
self.set_len(len + slice.len());
}
}
#[inline]
pub fn extend_from_slice(&mut self, slice: &[A::Item]) {
let len = self.len();
self.insert_from_slice(len, slice);
}
}
#[cfg(feature="heapsizeof")]
impl<A: Array> HeapSizeOf for SmallVec<A> where A::Item: HeapSizeOf {
fn heap_size_of_children(&self) -> usize {
match self.data {
Inline { .. } => 0,
Heap { ptr, .. } => {
self.iter().fold(
unsafe { heap_size_of(ptr as *const c_void) },
|n, elem| n + elem.heap_size_of_children())
},
}
}
}
impl<A: Array> ops::Deref for SmallVec<A> {
type Target = [A::Item];
#[inline]
fn deref(&self) -> &[A::Item] {
let ptr: *const _ = match self.data {
Inline { ref array } => array.ptr(),
Heap { ptr, .. } => ptr,
};
unsafe {
slice::from_raw_parts(ptr, self.len)
}
}
}
impl<A: Array> ops::DerefMut for SmallVec<A> {
#[inline]
fn deref_mut(&mut self) -> &mut [A::Item] {
let ptr = self.data.ptr_mut();
unsafe {
slice::from_raw_parts_mut(ptr, self.len)
}
}
}
impl<A: Array> AsRef<[A::Item]> for SmallVec<A> {
#[inline]
fn as_ref(&self) -> &[A::Item] {
self
}
}
impl<A: Array> AsMut<[A::Item]> for SmallVec<A> {
#[inline]
fn as_mut(&mut self) -> &mut [A::Item] {
self
}
}
impl<A: Array> Borrow<[A::Item]> for SmallVec<A> {
#[inline]
fn borrow(&self) -> &[A::Item] {
self
}
}
impl<A: Array> BorrowMut<[A::Item]> for SmallVec<A> {
#[inline]
fn borrow_mut(&mut self) -> &mut [A::Item] {
self
}
}
impl<'a, A: Array> From<&'a [A::Item]> for SmallVec<A> where A::Item: Clone {
#[inline]
fn from(slice: &'a [A::Item]) -> SmallVec<A> {
slice.into_iter().cloned().collect()
}
}
macro_rules! impl_index {
($index_type: ty, $output_type: ty) => {
impl<A: Array> ops::Index<$index_type> for SmallVec<A> {
type Output = $output_type;
#[inline]
fn index(&self, index: $index_type) -> &$output_type {
&(&**self)[index]
}
}
impl<A: Array> ops::IndexMut<$index_type> for SmallVec<A> {
#[inline]
fn index_mut(&mut self, index: $index_type) -> &mut $output_type {
&mut (&mut **self)[index]
}
}
}
}
impl_index!(usize, A::Item);
impl_index!(ops::Range<usize>, [A::Item]);
impl_index!(ops::RangeFrom<usize>, [A::Item]);
impl_index!(ops::RangeTo<usize>, [A::Item]);
impl_index!(ops::RangeFull, [A::Item]);
impl<A: Array> VecLike<A::Item> for SmallVec<A> {
#[inline]
fn push(&mut self, value: A::Item) {
SmallVec::push(self, value);
}
}
impl<A: Array> FromIterator<A::Item> for SmallVec<A> {
fn from_iter<I: IntoIterator<Item=A::Item>>(iterable: I) -> SmallVec<A> {
let mut v = SmallVec::new();
v.extend(iterable);
v
}
}
impl<A: Array> Extend<A::Item> for SmallVec<A> {
fn extend<I: IntoIterator<Item=A::Item>>(&mut self, iterable: I) {
let iter = iterable.into_iter();
let (lower_size_bound, _) = iter.size_hint();
let target_len = self.len + lower_size_bound;
if target_len > self.capacity() {
self.grow(target_len);
}
for elem in iter {
self.push(elem);
}
}
}
impl<A: Array> fmt::Debug for SmallVec<A> where A::Item: fmt::Debug {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
write!(f, "{:?}", &**self)
}
}
impl<A: Array> Default for SmallVec<A> {
#[inline]
fn default() -> SmallVec<A> {
SmallVec::new()
}
}
impl<A: Array> Drop for SmallVec<A> {
fn drop(&mut self) {
// Note on panic safety: dropping an element may panic,
// but the inner SmallVecData destructor will still run
unsafe {
let ptr = self.as_ptr();
for i in 0 .. self.len {
ptr::read(ptr.offset(i as isize));
}
}
}
}
impl<A: Array> Clone for SmallVec<A> where A::Item: Clone {
fn clone(&self) -> SmallVec<A> {
let mut new_vector = SmallVec::new();
for element in self.iter() {
new_vector.push((*element).clone())
}
new_vector
}
}
impl<A: Array, B: Array> PartialEq<SmallVec<B>> for SmallVec<A>
where A::Item: PartialEq<B::Item> {
#[inline]
fn eq(&self, other: &SmallVec<B>) -> bool { self[..] == other[..] }
#[inline]
fn ne(&self, other: &SmallVec<B>) -> bool { self[..] != other[..] }
}
impl<A: Array> Eq for SmallVec<A> where A::Item: Eq {}
impl<A: Array> PartialOrd for SmallVec<A> where A::Item: PartialOrd {
#[inline]
fn partial_cmp(&self, other: &SmallVec<A>) -> Option<cmp::Ordering> {
PartialOrd::partial_cmp(&**self, &**other)
}
}
impl<A: Array> Ord for SmallVec<A> where A::Item: Ord {
#[inline]
fn cmp(&self, other: &SmallVec<A>) -> cmp::Ordering {
Ord::cmp(&**self, &**other)
}
}
impl<A: Array> Hash for SmallVec<A> where A::Item: Hash {
fn hash<H: Hasher>(&self, state: &mut H) {
(**self).hash(state)
}
}
unsafe impl<A: Array> Send for SmallVec<A> where A::Item: Send {}
pub struct IntoIter<A: Array> {
data: SmallVecData<A>,
current: usize,
end: usize,
}
impl<A: Array> Drop for IntoIter<A> {
fn drop(&mut self) {
for _ in self { }
}
}
impl<A: Array> Iterator for IntoIter<A> {
type Item = A::Item;
#[inline]
fn next(&mut self) -> Option<A::Item> {
if self.current == self.end {
None
}
else {
unsafe {
let current = self.current as isize;
self.current += 1;
Some(ptr::read(self.data.ptr_mut().offset(current)))
}
}
}
#[inline]
fn size_hint(&self) -> (usize, Option<usize>) {
let size = self.end - self.current;
(size, Some(size))
}
}
impl<A: Array> DoubleEndedIterator for IntoIter<A> {
#[inline]
fn next_back(&mut self) -> Option<A::Item> {
if self.current == self.end {
None
}
else {
unsafe {
self.end -= 1;
Some(ptr::read(self.data.ptr_mut().offset(self.end as isize)))
}
}
}
}
impl<A: Array> ExactSizeIterator for IntoIter<A> { }
impl<A: Array> IntoIterator for SmallVec<A> {
type IntoIter = IntoIter<A>;
type Item = A::Item;
fn into_iter(mut self) -> Self::IntoIter {
let len = self.len();
unsafe {
// Only grab the `data` field, the `IntoIter` type handles dropping of the elements
let data = ptr::read(&mut self.data);
mem::forget(self);
IntoIter {
data: data,
current: 0,
end: len,
}
}
}
}
impl<'a, A: Array> IntoIterator for &'a SmallVec<A> {
type IntoIter = slice::Iter<'a, A::Item>;
type Item = &'a A::Item;
fn into_iter(self) -> Self::IntoIter {
self.iter()
}
}
impl<'a, A: Array> IntoIterator for &'a mut SmallVec<A> {
type IntoIter = slice::IterMut<'a, A::Item>;
type Item = &'a mut A::Item;
fn into_iter(self) -> Self::IntoIter {
self.iter_mut()
}
}
// TODO: Remove these and its users.
/// Deprecated alias to ease transition from an earlier version.
#[deprecated]
pub type SmallVec1<T> = SmallVec<[T; 1]>;
/// Deprecated alias to ease transition from an earlier version.
#[deprecated]
pub type SmallVec2<T> = SmallVec<[T; 2]>;
/// Deprecated alias to ease transition from an earlier version.
#[deprecated]
pub type SmallVec4<T> = SmallVec<[T; 4]>;
/// Deprecated alias to ease transition from an earlier version.
#[deprecated]
pub type SmallVec8<T> = SmallVec<[T; 8]>;
/// Deprecated alias to ease transition from an earlier version.
#[deprecated]
pub type SmallVec16<T> = SmallVec<[T; 16]>;
/// Deprecated alias to ease transition from an earlier version.
#[deprecated]
pub type SmallVec24<T> = SmallVec<[T; 24]>;
/// Deprecated alias to ease transition from an earlier version.
#[deprecated]
pub type SmallVec32<T> = SmallVec<[T; 32]>;
/// Types that can be used as the backing store for a SmallVec
pub unsafe trait Array {
type Item;
fn size() -> usize;
fn ptr(&self) -> *const Self::Item;
fn ptr_mut(&mut self) -> *mut Self::Item;
}
macro_rules! impl_array(
($($size:expr),+) => {
$(
unsafe impl<T> Array for [T; $size] {
type Item = T;
fn size() -> usize { $size }
fn ptr(&self) -> *const T { &self[0] }
fn ptr_mut(&mut self) -> *mut T { &mut self[0] }
}
)+
}
);
impl_array!(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 20, 24, 32, 36,
0x40, 0x80, 0x100, 0x200, 0x400, 0x800, 0x1000, 0x2000, 0x4000, 0x8000,
0x10000, 0x20000, 0x40000, 0x80000, 0x100000);
#[cfg(test)]
pub mod tests {
use SmallVec;
use std::borrow::ToOwned;
use std::iter::FromIterator;
#[cfg(feature="heapsizeof")]
use heapsize::HeapSizeOf;
#[cfg(feature="heapsizeof")]
use std::mem::size_of;
// We heap allocate all these strings so that double frees will show up under valgrind.
#[test]
pub fn test_inline() {
let mut v = SmallVec::<[_; 16]>::new();
v.push("hello".to_owned());
v.push("there".to_owned());
assert_eq!(&*v, &[
"hello".to_owned(),
"there".to_owned(),
][..]);
}
#[test]
pub fn test_spill() {
let mut v = SmallVec::<[_; 2]>::new();
v.push("hello".to_owned());
assert_eq!(v[0], "hello");
v.push("there".to_owned());
v.push("burma".to_owned());
assert_eq!(v[0], "hello");
v.push("shave".to_owned());
assert_eq!(&*v, &[
"hello".to_owned(),
"there".to_owned(),
"burma".to_owned(),
"shave".to_owned(),
][..]);
}
#[test]
pub fn test_double_spill() {
let mut v = SmallVec::<[_; 2]>::new();
v.push("hello".to_owned());
v.push("there".to_owned());
v.push("burma".to_owned());
v.push("shave".to_owned());
v.push("hello".to_owned());
v.push("there".to_owned());
v.push("burma".to_owned());
v.push("shave".to_owned());
assert_eq!(&*v, &[
"hello".to_owned(),
"there".to_owned(),
"burma".to_owned(),
"shave".to_owned(),
"hello".to_owned(),
"there".to_owned(),
"burma".to_owned(),
"shave".to_owned(),
][..]);
}
/// https://github.com/servo/rust-smallvec/issues/4
#[test]
fn issue_4() {
SmallVec::<[Box<u32>; 2]>::new();
}
/// https://github.com/servo/rust-smallvec/issues/5
#[test]
fn issue_5() {
assert!(Some(SmallVec::<[&u32; 2]>::new()).is_some());
}
#[test]
fn drain() {
let mut v: SmallVec<[u8; 2]> = SmallVec::new();
v.push(3);
assert_eq!(v.drain().collect::<Vec<_>>(), &[3]);
// spilling the vec
v.push(3);
v.push(4);
v.push(5);
assert_eq!(v.drain().collect::<Vec<_>>(), &[3, 4, 5]);
}
#[test]
fn drain_rev() {
let mut v: SmallVec<[u8; 2]> = SmallVec::new();
v.push(3);
assert_eq!(v.drain().rev().collect::<Vec<_>>(), &[3]);
// spilling the vec
v.push(3);
v.push(4);
v.push(5);
assert_eq!(v.drain().rev().collect::<Vec<_>>(), &[5, 4, 3]);
}
#[test]
fn into_iter() {
let mut v: SmallVec<[u8; 2]> = SmallVec::new();
v.push(3);
assert_eq!(v.into_iter().collect::<Vec<_>>(), &[3]);
// spilling the vec
let mut v: SmallVec<[u8; 2]> = SmallVec::new();
v.push(3);
v.push(4);
v.push(5);
assert_eq!(v.into_iter().collect::<Vec<_>>(), &[3, 4, 5]);
}
#[test]
fn into_iter_rev() {
let mut v: SmallVec<[u8; 2]> = SmallVec::new();
v.push(3);
assert_eq!(v.into_iter().rev().collect::<Vec<_>>(), &[3]);
// spilling the vec
let mut v: SmallVec<[u8; 2]> = SmallVec::new();
v.push(3);
v.push(4);
v.push(5);
assert_eq!(v.into_iter().rev().collect::<Vec<_>>(), &[5, 4, 3]);
}
#[test]
fn into_iter_drop() {
use std::cell::Cell;
struct DropCounter<'a>(&'a Cell<i32>);
impl<'a> Drop for DropCounter<'a> {
fn drop(&mut self) {
self.0.set(self.0.get() + 1);
}
}
{
let cell = Cell::new(0);
let mut v: SmallVec<[DropCounter; 2]> = SmallVec::new();
v.push(DropCounter(&cell));
v.into_iter();
assert_eq!(cell.get(), 1);
}
{
let cell = Cell::new(0);
let mut v: SmallVec<[DropCounter; 2]> = SmallVec::new();
v.push(DropCounter(&cell));
v.push(DropCounter(&cell));
assert!(v.into_iter().next().is_some());
assert_eq!(cell.get(), 2);
}
{
let cell = Cell::new(0);
let mut v: SmallVec<[DropCounter; 2]> = SmallVec::new();
v.push(DropCounter(&cell));
v.push(DropCounter(&cell));
v.push(DropCounter(&cell));
assert!(v.into_iter().next().is_some());
assert_eq!(cell.get(), 3);
}
{
let cell = Cell::new(0);
let mut v: SmallVec<[DropCounter; 2]> = SmallVec::new();
v.push(DropCounter(&cell));
v.push(DropCounter(&cell));
v.push(DropCounter(&cell));
{
let mut it = v.into_iter();
assert!(it.next().is_some());
assert!(it.next_back().is_some());
}
assert_eq!(cell.get(), 3);
}
}
#[test]
fn test_capacity() {
let mut v: SmallVec<[u8; 2]> = SmallVec::new();
v.reserve(1);
assert_eq!(v.capacity(), 2);
assert!(!v.spilled());
v.reserve_exact(0x100);
assert!(v.capacity() >= 0x100);
v.push(0);
v.push(1);
v.push(2);
v.push(3);
v.shrink_to_fit();
assert!(v.capacity() < 0x100);
}
#[test]
fn test_truncate() {
let mut v: SmallVec<[Box<u8>; 8]> = SmallVec::new();
for x in 0..8 {
v.push(Box::new(x));
}
v.truncate(4);
assert_eq!(v.len(), 4);
assert!(!v.spilled());
assert_eq!(*v.swap_remove(1), 1);
assert_eq!(*v.remove(1), 3);
v.insert(1, Box::new(3));
assert_eq!(&v.iter().map(|v| **v).collect::<Vec<_>>(), &[0, 3, 2]);
}
#[test]
fn test_insert_many() {
let mut v: SmallVec<[u8; 8]> = SmallVec::new();
for x in 0..4 {
v.push(x);
}
assert_eq!(v.len(), 4);
v.insert_many(1, [5, 6].iter().cloned());
assert_eq!(&v.iter().map(|v| *v).collect::<Vec<_>>(), &[0, 5, 6, 1, 2, 3]);
}
struct MockHintIter<T: Iterator>{x: T, hint: usize}
impl<T: Iterator> Iterator for MockHintIter<T> {
type Item = T::Item;
fn next(&mut self) -> Option<Self::Item> {self.x.next()}
fn size_hint(&self) -> (usize, Option<usize>) {(self.hint, None)}
}
#[test]
fn test_insert_many_short_hint() {
let mut v: SmallVec<[u8; 8]> = SmallVec::new();
for x in 0..4 {
v.push(x);
}
assert_eq!(v.len(), 4);
v.insert_many(1, MockHintIter{x: [5, 6].iter().cloned(), hint: 5});
assert_eq!(&v.iter().map(|v| *v).collect::<Vec<_>>(), &[0, 5, 6, 1, 2, 3]);
}
#[test]
fn test_insert_many_long_hint() {
let mut v: SmallVec<[u8; 8]> = SmallVec::new();
for x in 0..4 {
v.push(x);
}
assert_eq!(v.len(), 4);
v.insert_many(1, MockHintIter{x: [5, 6].iter().cloned(), hint: 1});
assert_eq!(&v.iter().map(|v| *v).collect::<Vec<_>>(), &[0, 5, 6, 1, 2, 3]);
}
#[test]
#[should_panic]
fn test_invalid_grow() {
let mut v: SmallVec<[u8; 8]> = SmallVec::new();
v.extend(0..8);
v.grow(5);
}
#[test]
fn test_insert_from_slice() {
let mut v: SmallVec<[u8; 8]> = SmallVec::new();
for x in 0..4 {
v.push(x);
}
assert_eq!(v.len(), 4);
v.insert_from_slice(1, &[5, 6]);
assert_eq!(&v.iter().map(|v| *v).collect::<Vec<_>>(), &[0, 5, 6, 1, 2, 3]);
}
#[test]
fn test_extend_from_slice() {
let mut v: SmallVec<[u8; 8]> = SmallVec::new();
for x in 0..4 {
v.push(x);
}
assert_eq!(v.len(), 4);
v.extend_from_slice(&[5, 6]);
assert_eq!(&v.iter().map(|v| *v).collect::<Vec<_>>(), &[0, 1, 2, 3, 5, 6]);
}
#[test]
#[should_panic]
fn test_drop_panic_smallvec() {
// This test should only panic once, and not double panic,
// which would mean a double drop
struct DropPanic;
impl Drop for DropPanic {
fn drop(&mut self) {
panic!("drop");
}
}
let mut v = SmallVec::<[_; 1]>::new();
v.push(DropPanic);
}
#[test]
fn test_eq() {
let mut a: SmallVec<[u32; 2]> = SmallVec::new();
let mut b: SmallVec<[u32; 2]> = SmallVec::new();
let mut c: SmallVec<[u32; 2]> = SmallVec::new();
// a = [1, 2]
a.push(1);
a.push(2);
// b = [1, 2]
b.push(1);
b.push(2);
// c = [3, 4]
c.push(3);
c.push(4);
assert!(a == b);
assert!(a != c);
}
#[test]
fn test_ord() {
let mut a: SmallVec<[u32; 2]> = SmallVec::new();
let mut b: SmallVec<[u32; 2]> = SmallVec::new();
let mut c: SmallVec<[u32; 2]> = SmallVec::new();
// a = [1]
a.push(1);
// b = [1, 1]
b.push(1);
b.push(1);
// c = [1, 2]
c.push(1);
c.push(2);
assert!(a < b);
assert!(b > a);
assert!(b < c);
assert!(c > b);
}
#[test]
fn test_hash() {
use std::hash::Hash;
use std::collections::hash_map::DefaultHasher;
{
let mut a: SmallVec<[u32; 2]> = SmallVec::new();
let b = [1, 2];
a.extend(b.iter().cloned());
let mut hasher = DefaultHasher::new();
assert_eq!(a.hash(&mut hasher), b.hash(&mut hasher));
}
{
let mut a: SmallVec<[u32; 2]> = SmallVec::new();
let b = [1, 2, 11, 12];
a.extend(b.iter().cloned());
let mut hasher = DefaultHasher::new();
assert_eq!(a.hash(&mut hasher), b.hash(&mut hasher));
}
}
#[test]
fn test_as_ref() {
let mut a: SmallVec<[u32; 2]> = SmallVec::new();
a.push(1);
assert_eq!(a.as_ref(), [1]);
a.push(2);
assert_eq!(a.as_ref(), [1, 2]);
a.push(3);
assert_eq!(a.as_ref(), [1, 2, 3]);
}
#[test]
fn test_as_mut() {
let mut a: SmallVec<[u32; 2]> = SmallVec::new();
a.push(1);
assert_eq!(a.as_mut(), [1]);
a.push(2);
assert_eq!(a.as_mut(), [1, 2]);
a.push(3);
assert_eq!(a.as_mut(), [1, 2, 3]);
a.as_mut()[1] = 4;
assert_eq!(a.as_mut(), [1, 4, 3]);
}
#[test]
fn test_borrow() {
use std::borrow::Borrow;
let mut a: SmallVec<[u32; 2]> = SmallVec::new();
a.push(1);
assert_eq!(a.borrow(), [1]);
a.push(2);
assert_eq!(a.borrow(), [1, 2]);
a.push(3);
assert_eq!(a.borrow(), [1, 2, 3]);
}
#[test]
fn test_borrow_mut() {
use std::borrow::BorrowMut;
let mut a: SmallVec<[u32; 2]> = SmallVec::new();
a.push(1);
assert_eq!(a.borrow_mut(), [1]);
a.push(2);
assert_eq!(a.borrow_mut(), [1, 2]);
a.push(3);
assert_eq!(a.borrow_mut(), [1, 2, 3]);
BorrowMut::<[u32]>::borrow_mut(&mut a)[1] = 4;
assert_eq!(a.borrow_mut(), [1, 4, 3]);
}
#[test]
fn test_from() {
assert_eq!(&SmallVec::<[u32; 2]>::from(&[1][..])[..], [1]);
assert_eq!(&SmallVec::<[u32; 2]>::from(&[1, 2, 3][..])[..], [1, 2, 3]);
}
#[test]
fn test_from_slice() {
assert_eq!(&SmallVec::<[u32; 2]>::from_slice(&[1][..])[..], [1]);
assert_eq!(&SmallVec::<[u32; 2]>::from_slice(&[1, 2, 3][..])[..], [1, 2, 3]);
}
#[cfg(feature="heapsizeof")]
#[test]
fn test_heap_size_of_children() {
let mut vec = SmallVec::<[u32; 2]>::new();
assert_eq!(vec.heap_size_of_children(), 0);
vec.push(1);
vec.push(2);
assert_eq!(vec.heap_size_of_children(), 0);
vec.push(3);
assert_eq!(vec.heap_size_of_children(), 16);
// Now check with reserved space
let mut vec = SmallVec::<[u32; 2]>::new();
vec.reserve(10); // Rounds up to 16
assert_eq!(vec.heap_size_of_children(), 64);
// Check with nested heap structures
let mut vec = SmallVec::<[Vec<u32>; 2]>::new();
vec.reserve(10);
vec.push(vec![2, 3, 4]);
assert_eq!(vec.heap_size_of_children(),
vec![2, 3, 4].heap_size_of_children() + 16 * size_of::<Vec<u32>>());
}
#[test]
fn test_exact_size_iterator() {
let mut vec = SmallVec::<[u32; 2]>::from(&[1, 2, 3][..]);
assert_eq!(vec.clone().into_iter().len(), 3);
assert_eq!(vec.drain().len(), 3);
}
#[test]
fn veclike_deref_slice() {
use super::VecLike;
fn test<T: VecLike<i32>>(vec: &mut T) {
assert!(!vec.is_empty());
assert_eq!(vec.len(), 3);
vec.sort();
assert_eq!(&vec[..], [1, 2, 3]);
}
let mut vec = SmallVec::<[i32; 2]>::from(&[3, 1, 2][..]);
test(&mut vec);
}
#[test]
fn shrink_to_fit_unspill() {
let mut vec = SmallVec::<[u8; 2]>::from_iter(0..3);
vec.pop();
assert!(vec.spilled());
vec.shrink_to_fit();
assert!(!vec.spilled(), "shrink_to_fit will un-spill if possible");
}
#[test]
fn test_into_vec() {
let vec = SmallVec::<[u8; 2]>::from_iter(0..2);
assert_eq!(vec.into_vec(), vec![0, 1]);
let vec = SmallVec::<[u8; 2]>::from_iter(0..3);
assert_eq!(vec.into_vec(), vec![0, 1, 2]);
}
#[test]
fn test_from_vec() {
let vec = vec![];
let small_vec: SmallVec<[u8; 3]> = SmallVec::from_vec(vec);
assert_eq!(&*small_vec, &[]);
drop(small_vec);
let vec = vec![];
let small_vec: SmallVec<[u8; 1]> = SmallVec::from_vec(vec);
assert_eq!(&*small_vec, &[]);
drop(small_vec);
let vec = vec![1];
let small_vec: SmallVec<[u8; 3]> = SmallVec::from_vec(vec);
assert_eq!(&*small_vec, &[1]);
drop(small_vec);
let vec = vec![1, 2, 3];
let small_vec: SmallVec<[u8; 3]> = SmallVec::from_vec(vec);
assert_eq!(&*small_vec, &[1, 2, 3]);
drop(small_vec);
let vec = vec![1, 2, 3, 4, 5];
let small_vec: SmallVec<[u8; 3]> = SmallVec::from_vec(vec);
assert_eq!(&*small_vec, &[1, 2, 3, 4, 5]);
drop(small_vec);
let vec = vec![1, 2, 3, 4, 5];
let small_vec: SmallVec<[u8; 1]> = SmallVec::from_vec(vec);
assert_eq!(&*small_vec, &[1, 2, 3, 4, 5]);
drop(small_vec);
}
}
Ссылка в новой задаче Показать git blame Копировать постоянную ссылку