| use super::plumbing::*; |
| use super::*; |
| use std::fmt; |
| use std::sync::atomic::{AtomicBool, Ordering}; |
| |
| /// `TakeAnyWhile` is an iterator that iterates over elements from anywhere in `I` |
| /// until the callback returns `false`. |
| /// This struct is created by the [`take_any_while()`] method on [`ParallelIterator`] |
| /// |
| /// [`take_any_while()`]: trait.ParallelIterator.html#method.take_any_while |
| /// [`ParallelIterator`]: trait.ParallelIterator.html |
| #[must_use = "iterator adaptors are lazy and do nothing unless consumed"] |
| #[derive(Clone)] |
| pub struct TakeAnyWhile<I: ParallelIterator, P> { |
| base: I, |
| predicate: P, |
| } |
| |
| impl<I: ParallelIterator + fmt::Debug, P> fmt::Debug for TakeAnyWhile<I, P> { |
| fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { |
| f.debug_struct("TakeAnyWhile") |
| .field("base", &self.base) |
| .finish() |
| } |
| } |
| |
| impl<I, P> TakeAnyWhile<I, P> |
| where |
| I: ParallelIterator, |
| { |
| /// Creates a new `TakeAnyWhile` iterator. |
| pub(super) fn new(base: I, predicate: P) -> Self { |
| TakeAnyWhile { base, predicate } |
| } |
| } |
| |
| impl<I, P> ParallelIterator for TakeAnyWhile<I, P> |
| where |
| I: ParallelIterator, |
| P: Fn(&I::Item) -> bool + Sync + Send, |
| { |
| type Item = I::Item; |
| |
| fn drive_unindexed<C>(self, consumer: C) -> C::Result |
| where |
| C: UnindexedConsumer<Self::Item>, |
| { |
| let consumer1 = TakeAnyWhileConsumer { |
| base: consumer, |
| predicate: &self.predicate, |
| taking: &AtomicBool::new(true), |
| }; |
| self.base.drive_unindexed(consumer1) |
| } |
| } |
| |
| /// //////////////////////////////////////////////////////////////////////// |
| /// Consumer implementation |
| |
| struct TakeAnyWhileConsumer<'p, C, P> { |
| base: C, |
| predicate: &'p P, |
| taking: &'p AtomicBool, |
| } |
| |
| impl<'p, T, C, P> Consumer<T> for TakeAnyWhileConsumer<'p, C, P> |
| where |
| C: Consumer<T>, |
| P: Fn(&T) -> bool + Sync, |
| { |
| type Folder = TakeAnyWhileFolder<'p, C::Folder, P>; |
| type Reducer = C::Reducer; |
| type Result = C::Result; |
| |
| fn split_at(self, index: usize) -> (Self, Self, Self::Reducer) { |
| let (left, right, reducer) = self.base.split_at(index); |
| ( |
| TakeAnyWhileConsumer { base: left, ..self }, |
| TakeAnyWhileConsumer { |
| base: right, |
| ..self |
| }, |
| reducer, |
| ) |
| } |
| |
| fn into_folder(self) -> Self::Folder { |
| TakeAnyWhileFolder { |
| base: self.base.into_folder(), |
| predicate: self.predicate, |
| taking: self.taking, |
| } |
| } |
| |
| fn full(&self) -> bool { |
| !self.taking.load(Ordering::Relaxed) || self.base.full() |
| } |
| } |
| |
| impl<'p, T, C, P> UnindexedConsumer<T> for TakeAnyWhileConsumer<'p, C, P> |
| where |
| C: UnindexedConsumer<T>, |
| P: Fn(&T) -> bool + Sync, |
| { |
| fn split_off_left(&self) -> Self { |
| TakeAnyWhileConsumer { |
| base: self.base.split_off_left(), |
| ..*self |
| } |
| } |
| |
| fn to_reducer(&self) -> Self::Reducer { |
| self.base.to_reducer() |
| } |
| } |
| |
| struct TakeAnyWhileFolder<'p, C, P> { |
| base: C, |
| predicate: &'p P, |
| taking: &'p AtomicBool, |
| } |
| |
| fn take<T>(item: &T, taking: &AtomicBool, predicate: &impl Fn(&T) -> bool) -> bool { |
| if !taking.load(Ordering::Relaxed) { |
| return false; |
| } |
| if predicate(item) { |
| return true; |
| } |
| taking.store(false, Ordering::Relaxed); |
| false |
| } |
| |
| impl<'p, T, C, P> Folder<T> for TakeAnyWhileFolder<'p, C, P> |
| where |
| C: Folder<T>, |
| P: Fn(&T) -> bool + 'p, |
| { |
| type Result = C::Result; |
| |
| fn consume(mut self, item: T) -> Self { |
| if take(&item, self.taking, self.predicate) { |
| self.base = self.base.consume(item); |
| } |
| self |
| } |
| |
| fn consume_iter<I>(mut self, iter: I) -> Self |
| where |
| I: IntoIterator<Item = T>, |
| { |
| self.base = self.base.consume_iter( |
| iter.into_iter() |
| .take_while(move |x| take(x, self.taking, self.predicate)), |
| ); |
| self |
| } |
| |
| fn complete(self) -> C::Result { |
| self.base.complete() |
| } |
| |
| fn full(&self) -> bool { |
| !self.taking.load(Ordering::Relaxed) || self.base.full() |
| } |
| } |