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use crate::prelude::*;
use crate::{complete_proxy_impl, error_proxy_impl};
#[derive(Clone)]
pub struct FilterOp<S, F> {
pub(crate) source: S,
pub(crate) filter: F,
}
#[doc(hidden)]
macro_rules! observable_impl {
($subscription:ty, $source:ident, $($marker:ident +)* $lf: lifetime) => {
type Unsub = $source::Unsub;
fn actual_subscribe<O>(
self,
subscriber: Subscriber<O, $subscription>,
) -> Self::Unsub
where O: Observer<Item=Self::Item,Err= Self::Err> + $($marker +)* $lf {
let filter = self.filter;
self.source.actual_subscribe(Subscriber {
observer: FilterObserver {
filter,
observer: subscriber.observer,
},
subscription: subscriber.subscription,
})
}
}
}
impl<S, F> Observable for FilterOp<S, F>
where
S: Observable,
F: FnMut(&S::Item) -> bool,
{
type Item = S::Item;
type Err = S::Err;
}
impl<'a, S, F> LocalObservable<'a> for FilterOp<S, F>
where
S: LocalObservable<'a>,
F: FnMut(&S::Item) -> bool + 'a,
{
observable_impl!(LocalSubscription, S, 'a);
}
impl<S, F> SharedObservable for FilterOp<S, F>
where
S: SharedObservable,
F: FnMut(&S::Item) -> bool + Send + Sync + 'static,
{
observable_impl!(SharedSubscription, S, Send + Sync + 'static);
}
pub struct FilterObserver<S, F> {
observer: S,
filter: F,
}
impl<Item, Err, O, F> Observer for FilterObserver<O, F>
where
O: Observer<Item = Item, Err = Err>,
F: FnMut(&Item) -> bool,
{
type Item = Item;
type Err = Err;
fn next(&mut self, value: Item) {
if (self.filter)(&value) {
self.observer.next(value)
}
}
error_proxy_impl!(Err, observer);
complete_proxy_impl!(observer);
#[inline]
fn is_stopped(&self) -> bool { self.observer.is_stopped() }
}
#[cfg(test)]
mod test {
use crate::prelude::*;
#[test]
fn fork_and_shared() {
observable::from_iter(0..10)
.filter(|v| v % 2 == 0)
.clone()
.filter(|_| true)
.clone()
.into_shared()
.subscribe(|_| {});
}
#[test]
fn smoke() {
observable::from_iter(0..1000)
.filter(|v| v % 2 == 0)
.subscribe(|v| {
assert!(v % 2 == 0);
});
}
#[test]
fn bench() { do_bench(); }
benchmark_group!(do_bench, bench_filter);
fn bench_filter(b: &mut bencher::Bencher) { b.iter(smoke); }
}