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SsoHashSet reimplemented as a wrapper on top of SsoHashMap

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SsoHashSet::replace had to be removed because
it requires missing API from SsoHashMap.
It's not a widely used function, so I think it's ok
to omit it for now.

EitherIter moved into its own file.

Also sprinkled code with #[inline] attributes where appropriate.
This commit is contained in:
Valerii Lashmanov 2020-09-26 14:28:26 -05:00
parent 0600b178aa
commit 41942fac7d
4 changed files with 158 additions and 228 deletions
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75
compiler/rustc_data_structures/src/sso/either_iter.rs Normal file
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@ -0,0 +1,75 @@
use std::fmt;
use std::iter::ExactSizeIterator;
use std::iter::FusedIterator;
use std::iter::Iterator;
/// Iterator which may contain instance of
/// one of two specific implementations.
///
/// Note: For most methods providing custom
/// implementation may margianlly
/// improve performance by avoiding
/// doing Left/Right match on every step
/// and doing it only once instead.
#[derive(Clone)]
pub enum EitherIter<L, R> {
Left(L),
Right(R),
}
impl<L, R> Iterator for EitherIter<L, R>
where
L: Iterator,
R: Iterator<Item = L::Item>,
{
type Item = L::Item;
fn next(&mut self) -> Option<Self::Item> {
match self {
EitherIter::Left(l) => l.next(),
EitherIter::Right(r) => r.next(),
}
}
fn size_hint(&self) -> (usize, Option<usize>) {
match self {
EitherIter::Left(l) => l.size_hint(),
EitherIter::Right(r) => r.size_hint(),
}
}
}
impl<L, R> ExactSizeIterator for EitherIter<L, R>
where
L: ExactSizeIterator,
R: ExactSizeIterator,
EitherIter<L, R>: Iterator,
{
fn len(&self) -> usize {
match self {
EitherIter::Left(l) => l.len(),
EitherIter::Right(r) => r.len(),
}
}
}
impl<L, R> FusedIterator for EitherIter<L, R>
where
L: FusedIterator,
R: FusedIterator,
EitherIter<L, R>: Iterator,
{
}
impl<L, R> fmt::Debug for EitherIter<L, R>
where
L: fmt::Debug,
R: fmt::Debug,
{
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
match self {
EitherIter::Left(l) => l.fmt(f),
EitherIter::Right(r) => r.fmt(f),
}
}
}

18
compiler/rustc_data_structures/src/sso/map.rs
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@ -1,4 +1,4 @@
use super::EitherIter;
use super::either_iter::EitherIter;
use crate::fx::FxHashMap;
use arrayvec::ArrayVec;
use std::borrow::Borrow;
@ -32,6 +32,7 @@ pub enum SsoHashMap<K, V> {
impl<K, V> SsoHashMap<K, V> {
/// Creates an empty `SsoHashMap`.
#[inline]
pub fn new() -> Self {
SsoHashMap::Array(ArrayVec::new())
}
@ -81,13 +82,15 @@ impl<K, V> SsoHashMap<K, V> {
/// An iterator visiting all key-value pairs in arbitrary order.
/// The iterator element type is `(&'a K, &'a V)`.
pub fn iter(&self) -> impl Iterator<Item = (&'_ K, &'_ V)> {
#[inline]
pub fn iter(&self) -> <&Self as IntoIterator>::IntoIter {
self.into_iter()
}
/// An iterator visiting all key-value pairs in arbitrary order,
/// with mutable references to the values.
/// The iterator element type is `(&'a K, &'a mut V)`.
#[inline]
pub fn iter_mut(&mut self) -> impl Iterator<Item = (&'_ K, &'_ mut V)> {
self.into_iter()
}
@ -319,12 +322,14 @@ impl<K: Eq + Hash, V> SsoHashMap<K, V> {
}
/// Gets the given key's corresponding entry in the map for in-place manipulation.
#[inline]
pub fn entry(&mut self, key: K) -> Entry<'_, K, V> {
Entry { ssomap: self, key }
}
}
impl<K, V> Default for SsoHashMap<K, V> {
#[inline]
fn default() -> Self {
Self::new()
}
@ -348,6 +353,7 @@ impl<K: Eq + Hash, V> Extend<(K, V)> for SsoHashMap<K, V> {
}
}
#[inline]
fn extend_one(&mut self, (k, v): (K, V)) {
self.insert(k, v);
}
@ -375,10 +381,12 @@ where
self.extend(iter.into_iter().map(|(k, v)| (k.clone(), v.clone())))
}
#[inline]
fn extend_one(&mut self, (&k, &v): (&'a K, &'a V)) {
self.insert(k, v);
}
#[inline]
fn extend_reserve(&mut self, additional: usize) {
Extend::<(K, V)>::extend_reserve(self, additional)
}
@ -400,12 +408,14 @@ impl<K, V> IntoIterator for SsoHashMap<K, V> {
}
/// adapts Item of array reference iterator to Item of hashmap reference iterator.
#[inline(always)]
fn adapt_array_ref_it<K, V>(pair: &'a (K, V)) -> (&'a K, &'a V) {
let (a, b) = pair;
(a, b)
}
/// adapts Item of array mut reference iterator to Item of hashmap mut reference iterator.
#[inline(always)]
fn adapt_array_mut_it<K, V>(pair: &'a mut (K, V)) -> (&'a K, &'a mut V) {
let (a, b) = pair;
(a, b)
@ -464,6 +474,7 @@ where
{
type Output = V;
#[inline]
fn index(&self, key: &Q) -> &V {
self.get(key).expect("no entry found for key")
}
@ -490,6 +501,7 @@ impl<'a, K: Eq + Hash, V> Entry<'a, K, V> {
/// Ensures a value is in the entry by inserting the default if empty, and returns
/// a mutable reference to the value in the entry.
#[inline]
pub fn or_insert(self, value: V) -> &'a mut V {
self.or_insert_with(|| value)
}
@ -515,6 +527,7 @@ impl<'a, K: Eq + Hash, V> Entry<'a, K, V> {
}
/// Returns a reference to this entry's key.
#[inline]
pub fn key(&self) -> &K {
&self.key
}
@ -523,6 +536,7 @@ impl<'a, K: Eq + Hash, V> Entry<'a, K, V> {
impl<'a, K: Eq + Hash, V: Default> Entry<'a, K, V> {
/// Ensures a value is in the entry by inserting the default value if empty,
/// and returns a mutable reference to the value in the entry.
#[inline]
pub fn or_default(self) -> &'a mut V {
self.or_insert_with(Default::default)
}

73
compiler/rustc_data_structures/src/sso/mod.rs
View File

@ -1,75 +1,4 @@
use std::fmt;
use std::iter::ExactSizeIterator;
use std::iter::FusedIterator;
use std::iter::Iterator;
/// Iterator which may contain instance of
/// one of two specific implementations.
///
/// Used by both SsoHashMap and SsoHashSet.
#[derive(Clone)]
pub enum EitherIter<L, R> {
Left(L),
Right(R),
}
impl<L, R> Iterator for EitherIter<L, R>
where
L: Iterator,
R: Iterator<Item = L::Item>,
{
type Item = L::Item;
fn next(&mut self) -> Option<Self::Item> {
match self {
EitherIter::Left(l) => l.next(),
EitherIter::Right(r) => r.next(),
}
}
fn size_hint(&self) -> (usize, Option<usize>) {
match self {
EitherIter::Left(l) => l.size_hint(),
EitherIter::Right(r) => r.size_hint(),
}
}
}
impl<L, R> ExactSizeIterator for EitherIter<L, R>
where
L: ExactSizeIterator,
R: ExactSizeIterator,
EitherIter<L, R>: Iterator,
{
fn len(&self) -> usize {
match self {
EitherIter::Left(l) => l.len(),
EitherIter::Right(r) => r.len(),
}
}
}
impl<L, R> FusedIterator for EitherIter<L, R>
where
L: FusedIterator,
R: FusedIterator,
EitherIter<L, R>: Iterator,
{
}
impl<L, R> fmt::Debug for EitherIter<L, R>
where
L: fmt::Debug,
R: fmt::Debug,
{
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
match self {
EitherIter::Left(l) => l.fmt(f),
EitherIter::Right(r) => r.fmt(f),
}
}
}
mod either_iter;
mod map;
mod set;

220
compiler/rustc_data_structures/src/sso/set.rs
View File

@ -1,11 +1,10 @@
use super::EitherIter;
use crate::fx::FxHashSet;
use arrayvec::ArrayVec;
use std::borrow::Borrow;
use std::fmt;
use std::hash::Hash;
use std::iter::FromIterator;
use super::map::SsoHashMap;
/// Small-storage-optimized implementation of a set.
///
/// Stores elements in a small array up to a certain length
@ -18,77 +17,73 @@ use std::iter::FromIterator;
/// try_reserve (unstable)
/// shrink_to (unstable)
/// drain_filter (unstable)
/// replace
/// get_or_insert/get_or_insert_owned/get_or_insert_with (unstable)
/// difference/symmetric_difference/intersection/union
/// is_disjoint/is_subset/is_superset
/// PartialEq/Eq (requires sorting the array)
/// PartialEq/Eq (requires SsoHashMap implementation)
/// BitOr/BitAnd/BitXor/Sub
#[derive(Clone)]
pub enum SsoHashSet<T> {
Array(ArrayVec<[T; 8]>),
Set(FxHashSet<T>),
pub struct SsoHashSet<T> {
map: SsoHashMap<T, ()>,
}
/// Adapter function used ot return
/// result if SsoHashMap functions into
/// result SsoHashSet should return.
#[inline(always)]
fn entry_to_key<K, V>((k, _v): (K, V)) -> K {
k
}
impl<T> SsoHashSet<T> {
/// Creates an empty `SsoHashSet`.
#[inline]
pub fn new() -> Self {
SsoHashSet::Array(ArrayVec::new())
Self { map: SsoHashMap::new() }
}
/// Creates an empty `SsoHashSet` with the specified capacity.
#[inline]
pub fn with_capacity(cap: usize) -> Self {
let array = ArrayVec::new();
if array.capacity() >= cap {
SsoHashSet::Array(array)
} else {
SsoHashSet::Set(FxHashSet::with_capacity_and_hasher(cap, Default::default()))
}
Self { map: SsoHashMap::with_capacity(cap) }
}
/// Clears the set, removing all values.
#[inline]
pub fn clear(&mut self) {
match self {
SsoHashSet::Array(array) => array.clear(),
SsoHashSet::Set(set) => set.clear(),
}
self.map.clear()
}
/// Returns the number of elements the set can hold without reallocating.
#[inline]
pub fn capacity(&self) -> usize {
match self {
SsoHashSet::Array(array) => array.capacity(),
SsoHashSet::Set(set) => set.capacity(),
}
self.map.capacity()
}
/// Returns the number of elements in the set.
#[inline]
pub fn len(&self) -> usize {
match self {
SsoHashSet::Array(array) => array.len(),
SsoHashSet::Set(set) => set.len(),
}
self.map.len()
}
/// Returns `true` if the set contains no elements.
#[inline]
pub fn is_empty(&self) -> bool {
match self {
SsoHashSet::Array(array) => array.is_empty(),
SsoHashSet::Set(set) => set.is_empty(),
}
self.map.is_empty()
}
/// An iterator visiting all elements in arbitrary order.
/// The iterator element type is `&'a T`.
#[inline]
pub fn iter(&'a self) -> impl Iterator<Item = &'a T> {
self.into_iter()
}
/// Clears the set, returning all elements in an iterator.
#[inline]
pub fn drain(&mut self) -> impl Iterator<Item = T> + '_ {
match self {
SsoHashSet::Array(array) => EitherIter::Left(array.drain(..)),
SsoHashSet::Set(set) => EitherIter::Right(set.drain()),
}
self.map.drain().map(entry_to_key)
}
}
@ -96,95 +91,46 @@ impl<T: Eq + Hash> SsoHashSet<T> {
/// Reserves capacity for at least `additional` more elements to be inserted
/// in the `SsoHashSet`. The collection may reserve more space to avoid
/// frequent reallocations.
#[inline]
pub fn reserve(&mut self, additional: usize) {
match self {
SsoHashSet::Array(array) => {
if array.capacity() < (array.len() + additional) {
let mut set: FxHashSet<T> = array.drain(..).collect();
set.reserve(additional);
*self = SsoHashSet::Set(set);
}
}
SsoHashSet::Set(set) => set.reserve(additional),
}
self.map.reserve(additional)
}
/// Shrinks the capacity of the set as much as possible. It will drop
/// down as much as possible while maintaining the internal rules
/// and possibly leaving some space in accordance with the resize policy.
#[inline]
pub fn shrink_to_fit(&mut self) {
if let SsoHashSet::Set(set) = self {
let mut array = ArrayVec::new();
if set.len() <= array.capacity() {
array.extend(set.drain());
*self = SsoHashSet::Array(array);
} else {
set.shrink_to_fit();
}
}
self.map.shrink_to_fit()
}
/// Retains only the elements specified by the predicate.
#[inline]
pub fn retain<F>(&mut self, mut f: F)
where
F: FnMut(&T) -> bool,
{
match self {
SsoHashSet::Array(array) => array.retain(|v| f(v)),
SsoHashSet::Set(set) => set.retain(f),
}
self.map.retain(|k, _v| f(k))
}
/// Removes and returns the value in the set, if any, that is equal to the given one.
#[inline]
pub fn take<Q: ?Sized>(&mut self, value: &Q) -> Option<T>
where
T: Borrow<Q>,
Q: Hash + Eq,
{
match self {
SsoHashSet::Array(array) => {
if let Some(index) = array.iter().position(|val| val.borrow() == value) {
Some(array.swap_remove(index))
} else {
None
}
}
SsoHashSet::Set(set) => set.take(value),
}
}
/// Adds a value to the set, replacing the existing value, if any, that is equal to the given
/// one. Returns the replaced value.
pub fn replace(&mut self, value: T) -> Option<T> {
match self {
SsoHashSet::Array(array) => {
if let Some(index) = array.iter().position(|val| *val == value) {
let old_value = std::mem::replace(&mut array[index], value);
Some(old_value)
} else {
None
}
}
SsoHashSet::Set(set) => set.replace(value),
}
self.map.remove_entry(value).map(entry_to_key)
}
/// Returns a reference to the value in the set, if any, that is equal to the given value.
#[inline]
pub fn get<Q: ?Sized>(&self, value: &Q) -> Option<&T>
where
T: Borrow<Q>,
Q: Hash + Eq,
{
match self {
SsoHashSet::Array(array) => {
if let Some(index) = array.iter().position(|val| val.borrow() == value) {
Some(&array[index])
} else {
None
}
}
SsoHashSet::Set(set) => set.get(value),
}
self.map.get_key_value(value).map(entry_to_key)
}
/// Adds a value to the set.
@ -192,60 +138,30 @@ impl<T: Eq + Hash> SsoHashSet<T> {
/// If the set did not have this value present, `true` is returned.
///
/// If the set did have this value present, `false` is returned.
#[inline]
pub fn insert(&mut self, elem: T) -> bool {
match self {
SsoHashSet::Array(array) => {
if array.iter().any(|e| *e == elem) {
false
} else {
if let Err(error) = array.try_push(elem) {
let mut set: FxHashSet<T> = array.drain(..).collect();
set.insert(error.element());
*self = SsoHashSet::Set(set);
}
true
}
}
SsoHashSet::Set(set) => set.insert(elem),
}
self.map.insert(elem, ()).is_none()
}
/// Removes a value from the set. Returns whether the value was
/// present in the set.
#[inline]
pub fn remove<Q: ?Sized>(&mut self, value: &Q) -> bool
where
T: Borrow<Q>,
Q: Hash + Eq,
{
match self {
SsoHashSet::Array(array) => {
if let Some(index) = array.iter().position(|val| val.borrow() == value) {
array.swap_remove(index);
true
} else {
false
}
}
SsoHashSet::Set(set) => set.remove(value),
}
self.map.remove(value).is_some()
}
/// Returns `true` if the set contains a value.
#[inline]
pub fn contains<Q: ?Sized>(&self, value: &Q) -> bool
where
T: Borrow<Q>,
Q: Hash + Eq,
{
match self {
SsoHashSet::Array(array) => array.iter().any(|v| v.borrow() == value),
SsoHashSet::Set(set) => set.contains(value),
}
}
}
impl<T> Default for SsoHashSet<T> {
fn default() -> Self {
Self::new()
self.map.contains_key(value)
}
}
@ -257,6 +173,13 @@ impl<T: Eq + Hash> FromIterator<T> for SsoHashSet<T> {
}
}
impl<T> Default for SsoHashSet<T> {
#[inline]
fn default() -> Self {
Self::new()
}
}
impl<T: Eq + Hash> Extend<T> for SsoHashSet<T> {
fn extend<I>(&mut self, iter: I)
where
@ -267,21 +190,14 @@ impl<T: Eq + Hash> Extend<T> for SsoHashSet<T> {
}
}
#[inline]
fn extend_one(&mut self, item: T) {
self.insert(item);
}
#[inline]
fn extend_reserve(&mut self, additional: usize) {
match self {
SsoHashSet::Array(array) => {
if array.capacity() < (array.len() + additional) {
let mut set: FxHashSet<T> = array.drain(..).collect();
set.extend_reserve(additional);
*self = SsoHashSet::Set(set);
}
}
SsoHashSet::Set(set) => set.extend_reserve(additional),
}
self.map.extend_reserve(additional)
}
}
@ -289,46 +205,42 @@ impl<'a, T> Extend<&'a T> for SsoHashSet<T>
where
T: 'a + Eq + Hash + Copy,
{
#[inline]
fn extend<I: IntoIterator<Item = &'a T>>(&mut self, iter: I) {
self.extend(iter.into_iter().cloned());
}
#[inline]
fn extend_one(&mut self, &item: &'a T) {
self.insert(item);
}
#[inline]
fn extend_reserve(&mut self, additional: usize) {
Extend::<T>::extend_reserve(self, additional)
}
}
impl<T> IntoIterator for SsoHashSet<T> {
type IntoIter = EitherIter<
<ArrayVec<[T; 8]> as IntoIterator>::IntoIter,
<FxHashSet<T> as IntoIterator>::IntoIter,
>;
type IntoIter = std::iter::Map<<SsoHashMap<T, ()> as IntoIterator>::IntoIter, fn((T, ())) -> T>;
type Item = <Self::IntoIter as Iterator>::Item;
#[inline]
fn into_iter(self) -> Self::IntoIter {
match self {
SsoHashSet::Array(array) => EitherIter::Left(array.into_iter()),
SsoHashSet::Set(set) => EitherIter::Right(set.into_iter()),
}
self.map.into_iter().map(entry_to_key)
}
}
impl<'a, T> IntoIterator for &'a SsoHashSet<T> {
type IntoIter = EitherIter<
<&'a ArrayVec<[T; 8]> as IntoIterator>::IntoIter,
<&'a FxHashSet<T> as IntoIterator>::IntoIter,
type IntoIter = std::iter::Map<
<&'a SsoHashMap<T, ()> as IntoIterator>::IntoIter,
fn((&'a T, &'a ())) -> &'a T,
>;
type Item = <Self::IntoIter as Iterator>::Item;
#[inline]
fn into_iter(self) -> Self::IntoIter {
match self {
SsoHashSet::Array(array) => EitherIter::Left(array.into_iter()),
SsoHashSet::Set(set) => EitherIter::Right(set.into_iter()),
}
self.map.iter().map(entry_to_key)
}
}