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use super::noop::NoopConsumer;
use super::plumbing::{Consumer, Folder, Reducer, UnindexedConsumer};
use super::{IntoParallelIterator, ParallelExtend, ParallelIterator};
use either::Either;
use std::borrow::Cow;
use std::collections::LinkedList;
use std::collections::{BTreeMap, BTreeSet, HashMap, HashSet};
use std::collections::{BinaryHeap, VecDeque};
use std::ffi::{OsStr, OsString};
use std::hash::{BuildHasher, Hash};
/// Performs a generic `par_extend` by collecting to a `LinkedList<Vec<_>>` in
/// parallel, then extending the collection sequentially.
macro_rules! extend {
($self:ident, $par_iter:ident) => {
extend!($self <- fast_collect($par_iter))
};
($self:ident <- $vecs:expr) => {
match $vecs {
Either::Left(vec) => $self.extend(vec),
Either::Right(list) => {
for vec in list {
$self.extend(vec);
}
}
}
};
}
macro_rules! extend_reserved {
($self:ident, $par_iter:ident, $len:ident) => {
let vecs = fast_collect($par_iter);
$self.reserve($len(&vecs));
extend!($self <- vecs)
};
($self:ident, $par_iter:ident) => {
extend_reserved!($self, $par_iter, len)
};
}
/// Computes the total length of a `fast_collect` result.
fn len<T>(vecs: &Either<Vec<T>, LinkedList<Vec<T>>>) -> usize {
match vecs {
Either::Left(vec) => vec.len(),
Either::Right(list) => list.iter().map(Vec::len).sum(),
}
}
/// Computes the total string length of a `fast_collect` result.
fn string_len<T: AsRef<str>>(vecs: &Either<Vec<T>, LinkedList<Vec<T>>>) -> usize {
let strs = match vecs {
Either::Left(vec) => Either::Left(vec.iter()),
Either::Right(list) => Either::Right(list.iter().flatten()),
};
strs.map(AsRef::as_ref).map(str::len).sum()
}
/// Computes the total OS-string length of a `fast_collect` result.
fn osstring_len<T: AsRef<OsStr>>(vecs: &Either<Vec<T>, LinkedList<Vec<T>>>) -> usize {
let osstrs = match vecs {
Either::Left(vec) => Either::Left(vec.iter()),
Either::Right(list) => Either::Right(list.iter().flatten()),
};
osstrs.map(AsRef::as_ref).map(OsStr::len).sum()
}
pub(super) fn fast_collect<I, T>(pi: I) -> Either<Vec<T>, LinkedList<Vec<T>>>
where
I: IntoParallelIterator<Item = T>,
T: Send,
{
let par_iter = pi.into_par_iter();
match par_iter.opt_len() {
Some(len) => {
// Pseudo-specialization. See impl of ParallelExtend for Vec for more details.
let mut vec = Vec::new();
super::collect::special_extend(par_iter, len, &mut vec);
Either::Left(vec)
}
None => Either::Right(par_iter.drive_unindexed(ListVecConsumer)),
}
}
struct ListVecConsumer;
struct ListVecFolder<T> {
vec: Vec<T>,
}
impl<T: Send> Consumer<T> for ListVecConsumer {
type Folder = ListVecFolder<T>;
type Reducer = ListReducer;
type Result = LinkedList<Vec<T>>;
fn split_at(self, _index: usize) -> (Self, Self, Self::Reducer) {
(Self, Self, ListReducer)
}
fn into_folder(self) -> Self::Folder {
ListVecFolder { vec: Vec::new() }
}
fn full(&self) -> bool {
false
}
}
impl<T: Send> UnindexedConsumer<T> for ListVecConsumer {
fn split_off_left(&self) -> Self {
Self
}
fn to_reducer(&self) -> Self::Reducer {
ListReducer
}
}
impl<T> Folder<T> for ListVecFolder<T> {
type Result = LinkedList<Vec<T>>;
fn consume(mut self, item: T) -> Self {
self.vec.push(item);
self
}
fn consume_iter<I>(mut self, iter: I) -> Self
where
I: IntoIterator<Item = T>,
{
self.vec.extend(iter);
self
}
fn complete(self) -> Self::Result {
let mut list = LinkedList::new();
if !self.vec.is_empty() {
list.push_back(self.vec);
}
list
}
fn full(&self) -> bool {
false
}
}
/// Extends a binary heap with items from a parallel iterator.
impl<T> ParallelExtend<T> for BinaryHeap<T>
where
T: Ord + Send,
{
fn par_extend<I>(&mut self, par_iter: I)
where
I: IntoParallelIterator<Item = T>,
{
extend_reserved!(self, par_iter);
}
}
/// Extends a binary heap with copied items from a parallel iterator.
impl<'a, T> ParallelExtend<&'a T> for BinaryHeap<T>
where
T: 'a + Copy + Ord + Send + Sync,
{
fn par_extend<I>(&mut self, par_iter: I)
where
I: IntoParallelIterator<Item = &'a T>,
{
extend_reserved!(self, par_iter);
}
}
/// Extends a B-tree map with items from a parallel iterator.
impl<K, V> ParallelExtend<(K, V)> for BTreeMap<K, V>
where
K: Ord + Send,
V: Send,
{
fn par_extend<I>(&mut self, par_iter: I)
where
I: IntoParallelIterator<Item = (K, V)>,
{
extend!(self, par_iter);
}
}
/// Extends a B-tree map with copied items from a parallel iterator.
impl<'a, K: 'a, V: 'a> ParallelExtend<(&'a K, &'a V)> for BTreeMap<K, V>
where
K: Copy + Ord + Send + Sync,
V: Copy + Send + Sync,
{
fn par_extend<I>(&mut self, par_iter: I)
where
I: IntoParallelIterator<Item = (&'a K, &'a V)>,
{
extend!(self, par_iter);
}
}
/// Extends a B-tree set with items from a parallel iterator.
impl<T> ParallelExtend<T> for BTreeSet<T>
where
T: Ord + Send,
{
fn par_extend<I>(&mut self, par_iter: I)
where
I: IntoParallelIterator<Item = T>,
{
extend!(self, par_iter);
}
}
/// Extends a B-tree set with copied items from a parallel iterator.
impl<'a, T> ParallelExtend<&'a T> for BTreeSet<T>
where
T: 'a + Copy + Ord + Send + Sync,
{
fn par_extend<I>(&mut self, par_iter: I)
where
I: IntoParallelIterator<Item = &'a T>,
{
extend!(self, par_iter);
}
}
/// Extends a hash map with items from a parallel iterator.
impl<K, V, S> ParallelExtend<(K, V)> for HashMap<K, V, S>
where
K: Eq + Hash + Send,
V: Send,
S: BuildHasher + Send,
{
fn par_extend<I>(&mut self, par_iter: I)
where
I: IntoParallelIterator<Item = (K, V)>,
{
// See the map_collect benchmarks in rayon-demo for different strategies.
extend_reserved!(self, par_iter);
}
}
/// Extends a hash map with copied items from a parallel iterator.
impl<'a, K: 'a, V: 'a, S> ParallelExtend<(&'a K, &'a V)> for HashMap<K, V, S>
where
K: Copy + Eq + Hash + Send + Sync,
V: Copy + Send + Sync,
S: BuildHasher + Send,
{
fn par_extend<I>(&mut self, par_iter: I)
where
I: IntoParallelIterator<Item = (&'a K, &'a V)>,
{
extend_reserved!(self, par_iter);
}
}
/// Extends a hash set with items from a parallel iterator.
impl<T, S> ParallelExtend<T> for HashSet<T, S>
where
T: Eq + Hash + Send,
S: BuildHasher + Send,
{
fn par_extend<I>(&mut self, par_iter: I)
where
I: IntoParallelIterator<Item = T>,
{
extend_reserved!(self, par_iter);
}
}
/// Extends a hash set with copied items from a parallel iterator.
impl<'a, T, S> ParallelExtend<&'a T> for HashSet<T, S>
where
T: 'a + Copy + Eq + Hash + Send + Sync,
S: BuildHasher + Send,
{
fn par_extend<I>(&mut self, par_iter: I)
where
I: IntoParallelIterator<Item = &'a T>,
{
extend_reserved!(self, par_iter);
}
}
/// Extends a linked list with items from a parallel iterator.
impl<T> ParallelExtend<T> for LinkedList<T>
where
T: Send,
{
fn par_extend<I>(&mut self, par_iter: I)
where
I: IntoParallelIterator<Item = T>,
{
let mut list = par_iter.into_par_iter().drive_unindexed(ListConsumer);
self.append(&mut list);
}
}
/// Extends a linked list with copied items from a parallel iterator.
impl<'a, T> ParallelExtend<&'a T> for LinkedList<T>
where
T: 'a + Copy + Send + Sync,
{
fn par_extend<I>(&mut self, par_iter: I)
where
I: IntoParallelIterator<Item = &'a T>,
{
self.par_extend(par_iter.into_par_iter().copied())
}
}
struct ListConsumer;
struct ListFolder<T> {
list: LinkedList<T>,
}
struct ListReducer;
impl<T: Send> Consumer<T> for ListConsumer {
type Folder = ListFolder<T>;
type Reducer = ListReducer;
type Result = LinkedList<T>;
fn split_at(self, _index: usize) -> (Self, Self, Self::Reducer) {
(Self, Self, ListReducer)
}
fn into_folder(self) -> Self::Folder {
ListFolder {
list: LinkedList::new(),
}
}
fn full(&self) -> bool {
false
}
}
impl<T: Send> UnindexedConsumer<T> for ListConsumer {
fn split_off_left(&self) -> Self {
Self
}
fn to_reducer(&self) -> Self::Reducer {
ListReducer
}
}
impl<T> Folder<T> for ListFolder<T> {
type Result = LinkedList<T>;
fn consume(mut self, item: T) -> Self {
self.list.push_back(item);
self
}
fn consume_iter<I>(mut self, iter: I) -> Self
where
I: IntoIterator<Item = T>,
{
self.list.extend(iter);
self
}
fn complete(self) -> Self::Result {
self.list
}
fn full(&self) -> bool {
false
}
}
impl<T> Reducer<LinkedList<T>> for ListReducer {
fn reduce(self, mut left: LinkedList<T>, mut right: LinkedList<T>) -> LinkedList<T> {
left.append(&mut right);
left
}
}
/// Extends an OS-string with string slices from a parallel iterator.
impl<'a> ParallelExtend<&'a OsStr> for OsString {
fn par_extend<I>(&mut self, par_iter: I)
where
I: IntoParallelIterator<Item = &'a OsStr>,
{
extend_reserved!(self, par_iter, osstring_len);
}
}
/// Extends an OS-string with strings from a parallel iterator.
impl ParallelExtend<OsString> for OsString {
fn par_extend<I>(&mut self, par_iter: I)
where
I: IntoParallelIterator<Item = OsString>,
{
extend_reserved!(self, par_iter, osstring_len);
}
}
/// Extends an OS-string with string slices from a parallel iterator.
impl<'a> ParallelExtend<Cow<'a, OsStr>> for OsString {
fn par_extend<I>(&mut self, par_iter: I)
where
I: IntoParallelIterator<Item = Cow<'a, OsStr>>,
{
extend_reserved!(self, par_iter, osstring_len);
}
}
/// Extends a string with characters from a parallel iterator.
impl ParallelExtend<char> for String {
fn par_extend<I>(&mut self, par_iter: I)
where
I: IntoParallelIterator<Item = char>,
{
// This is like `extend`, but `Vec<char>` is less efficient to deal
// with than `String`, so instead collect to `LinkedList<String>`.
let list = par_iter.into_par_iter().drive_unindexed(ListStringConsumer);
self.reserve(list.iter().map(String::len).sum());
self.extend(list);
}
}
/// Extends a string with copied characters from a parallel iterator.
impl<'a> ParallelExtend<&'a char> for String {
fn par_extend<I>(&mut self, par_iter: I)
where
I: IntoParallelIterator<Item = &'a char>,
{
self.par_extend(par_iter.into_par_iter().copied())
}
}
struct ListStringConsumer;
struct ListStringFolder {
string: String,
}
impl Consumer<char> for ListStringConsumer {
type Folder = ListStringFolder;
type Reducer = ListReducer;
type Result = LinkedList<String>;
fn split_at(self, _index: usize) -> (Self, Self, Self::Reducer) {
(Self, Self, ListReducer)
}
fn into_folder(self) -> Self::Folder {
ListStringFolder {
string: String::new(),
}
}
fn full(&self) -> bool {
false
}
}
impl UnindexedConsumer<char> for ListStringConsumer {
fn split_off_left(&self) -> Self {
Self
}
fn to_reducer(&self) -> Self::Reducer {
ListReducer
}
}
impl Folder<char> for ListStringFolder {
type Result = LinkedList<String>;
fn consume(mut self, item: char) -> Self {
self.string.push(item);
self
}
fn consume_iter<I>(mut self, iter: I) -> Self
where
I: IntoIterator<Item = char>,
{
self.string.extend(iter);
self
}
fn complete(self) -> Self::Result {
let mut list = LinkedList::new();
if !self.string.is_empty() {
list.push_back(self.string);
}
list
}
fn full(&self) -> bool {
false
}
}
/// Extends a string with string slices from a parallel iterator.
impl<'a> ParallelExtend<&'a str> for String {
fn par_extend<I>(&mut self, par_iter: I)
where
I: IntoParallelIterator<Item = &'a str>,
{
extend_reserved!(self, par_iter, string_len);
}
}
/// Extends a string with strings from a parallel iterator.
impl ParallelExtend<String> for String {
fn par_extend<I>(&mut self, par_iter: I)
where
I: IntoParallelIterator<Item = String>,
{
extend_reserved!(self, par_iter, string_len);
}
}
/// Extends a string with boxed strings from a parallel iterator.
impl ParallelExtend<Box<str>> for String {
fn par_extend<I>(&mut self, par_iter: I)
where
I: IntoParallelIterator<Item = Box<str>>,
{
extend_reserved!(self, par_iter, string_len);
}
}
/// Extends a string with string slices from a parallel iterator.
impl<'a> ParallelExtend<Cow<'a, str>> for String {
fn par_extend<I>(&mut self, par_iter: I)
where
I: IntoParallelIterator<Item = Cow<'a, str>>,
{
extend_reserved!(self, par_iter, string_len);
}
}
/// Extends a deque with items from a parallel iterator.
impl<T> ParallelExtend<T> for VecDeque<T>
where
T: Send,
{
fn par_extend<I>(&mut self, par_iter: I)
where
I: IntoParallelIterator<Item = T>,
{
extend_reserved!(self, par_iter);
}
}
/// Extends a deque with copied items from a parallel iterator.
impl<'a, T> ParallelExtend<&'a T> for VecDeque<T>
where
T: 'a + Copy + Send + Sync,
{
fn par_extend<I>(&mut self, par_iter: I)
where
I: IntoParallelIterator<Item = &'a T>,
{
extend_reserved!(self, par_iter);
}
}
/// Extends a vector with items from a parallel iterator.
impl<T> ParallelExtend<T> for Vec<T>
where
T: Send,
{
fn par_extend<I>(&mut self, par_iter: I)
where
I: IntoParallelIterator<Item = T>,
{
// See the vec_collect benchmarks in rayon-demo for different strategies.
let par_iter = par_iter.into_par_iter();
match par_iter.opt_len() {
Some(len) => {
// When Rust gets specialization, we can get here for indexed iterators
// without relying on `opt_len`. Until then, `special_extend()` fakes
// an unindexed mode on the promise that `opt_len()` is accurate.
super::collect::special_extend(par_iter, len, self);
}
None => {
// This works like `extend`, but `Vec::append` is more efficient.
let list = par_iter.drive_unindexed(ListVecConsumer);
self.reserve(list.iter().map(Vec::len).sum());
for mut other in list {
self.append(&mut other);
}
}
}
}
}
/// Extends a vector with copied items from a parallel iterator.
impl<'a, T> ParallelExtend<&'a T> for Vec<T>
where
T: 'a + Copy + Send + Sync,
{
fn par_extend<I>(&mut self, par_iter: I)
where
I: IntoParallelIterator<Item = &'a T>,
{
self.par_extend(par_iter.into_par_iter().copied())
}
}
/// Collapses all unit items from a parallel iterator into one.
impl ParallelExtend<()> for () {
fn par_extend<I>(&mut self, par_iter: I)
where
I: IntoParallelIterator<Item = ()>,
{
par_iter.into_par_iter().drive_unindexed(NoopConsumer)
}
}