use crate::prelude::*;
use crate::{complete_proxy_impl, error_proxy_impl};
#[derive(Clone)]
pub struct SkipOp<S> {
pub(crate) source: S,
pub(crate) count: u32,
}
#[doc(hidden)]
macro_rules! observable_impl {
($subscription:ty, $($marker:ident +)* $lf: lifetime) => {
fn actual_subscribe<O>(
self,
subscriber: Subscriber<O, $subscription>,
) -> Self::Unsub
where O: Observer<Item=Self::Item,Err= Self::Err> + $($marker +)* $lf {
let subscriber = Subscriber {
observer: SkipObserver {
observer: subscriber.observer,
subscription: subscriber.subscription.clone(),
count: self.count,
hits: 0,
},
subscription: subscriber.subscription,
};
self.source.actual_subscribe(subscriber)
}
}
}
observable_proxy_impl!(SkipOp, S);
impl<'a, S> LocalObservable<'a> for SkipOp<S>
where
S: LocalObservable<'a>,
{
type Unsub = S::Unsub;
observable_impl!(LocalSubscription, 'a);
}
impl<S> SharedObservable for SkipOp<S>
where
S: SharedObservable,
{
type Unsub = S::Unsub;
observable_impl!(SharedSubscription, Send + Sync + 'static);
}
pub struct SkipObserver<O, S> {
observer: O,
subscription: S,
count: u32,
hits: u32,
}
impl<Item, Err, O, U> Observer for SkipObserver<O, U>
where
O: Observer<Item = Item, Err = Err>,
U: SubscriptionLike,
{
type Item = Item;
type Err = Err;
fn next(&mut self, value: Item) {
self.hits += 1;
if self.hits > self.count {
self.observer.next(value);
if self.hits == self.count {
self.complete();
self.subscription.unsubscribe();
}
}
}
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 base_function() {
let mut completed = false;
let mut next_count = 0;
observable::from_iter(0..100)
.skip(5)
.subscribe_complete(|_| next_count += 1, || completed = true);
assert_eq!(next_count, 95);
assert!(completed);
}
#[test]
fn base_empty_function() {
let mut completed = false;
let mut next_count = 0;
observable::from_iter(0..100)
.skip(101)
.subscribe_complete(|_| next_count += 1, || completed = true);
assert_eq!(next_count, 0);
assert!(completed);
}
#[test]
fn skip_support_fork() {
let mut nc1 = 0;
let mut nc2 = 0;
{
let skip5 = observable::from_iter(0..100).skip(5);
let f1 = skip5.clone();
let f2 = skip5;
f1.skip(5).subscribe(|_| nc1 += 1);
f2.skip(5).subscribe(|_| nc2 += 1);
}
assert_eq!(nc1, 90);
assert_eq!(nc2, 90);
}
#[test]
fn ininto_shared() {
observable::from_iter(0..100)
.skip(5)
.skip(5)
.into_shared()
.subscribe(|_| {});
}
#[test]
fn benchmark() { do_bench(); }
benchmark_group!(do_bench, bench);
fn bench(b: &mut bencher::Bencher) { b.iter(base_function); }
}