1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133

use derive_new::new;
use futures::Stream;
use pin_project::pin_project;
use serde::{Deserialize, Serialize};
use serde_closure::traits::FnMut;
use std::{
	pin::Pin, task::{Context, Poll}
};

use super::{ParallelPipe, ParallelStream, PipeTask, StreamTask};
use crate::pipe::Pipe;

#[pin_project]
#[derive(new)]
#[must_use]
pub struct Inspect<P, F> {
	#[pin]
	pipe: P,
	f: F,
}

impl_par_dist! {
	impl<P: ParallelStream, F> ParallelStream for Inspect<P, F>
	where
		F: for<'a> FnMut<(&'a P::Item,), Output = ()> + Clone + Send + 'static,
	{
		type Item = P::Item;
		type Task = InspectTask<P::Task, F>;

		fn size_hint(&self) -> (usize, Option<usize>) {
			self.pipe.size_hint()
		}
		fn next_task(self: Pin<&mut Self>, cx: &mut Context) -> Poll<Option<Self::Task>> {
			let self_ = self.project();
			let f = self_.f;
			self_.pipe.next_task(cx).map(|task| {
				task.map(|task| {
					let f = f.clone();
					InspectTask { task, f }
				})
			})
		}
	}

	impl<P: ParallelPipe<Input>, F, Input> ParallelPipe<Input> for Inspect<P, F>
	where
		F: for<'a> FnMut<(&'a P::Output,), Output = ()> + Clone + Send + 'static,
	{
		type Output = P::Output;
		type Task = InspectTask<P::Task, F>;

		fn task(&self) -> Self::Task {
			let task = self.pipe.task();
			let f = self.f.clone();
			InspectTask { task, f }
		}
	}
}

#[pin_project]
#[derive(Serialize, Deserialize)]
pub struct InspectTask<T, F> {
	#[pin]
	task: T,
	f: F,
}

impl<C: StreamTask, F> StreamTask for InspectTask<C, F>
where
	F: for<'a> FnMut<(&'a C::Item,), Output = ()> + Clone,
{
	type Item = C::Item;
	type Async = InspectTask<C::Async, F>;

	fn into_async(self) -> Self::Async {
		InspectTask {
			task: self.task.into_async(),
			f: self.f,
		}
	}
}
impl<C: PipeTask<Input>, F, Input> PipeTask<Input> for InspectTask<C, F>
where
	F: for<'a> FnMut<(&'a C::Output,), Output = ()> + Clone,
{
	type Output = C::Output;
	type Async = InspectTask<C::Async, F>;

	fn into_async(self) -> Self::Async {
		InspectTask {
			task: self.task.into_async(),
			f: self.f,
		}
	}
}

impl<C: Stream, F> Stream for InspectTask<C, F>
where
	F: for<'a> FnMut<(&'a C::Item,), Output = ()> + Clone,
{
	type Item = C::Item;

	fn poll_next(self: Pin<&mut Self>, cx: &mut Context) -> Poll<Option<Self::Item>> {
		let mut self_ = self.project();
		let (task, f) = (self_.task, &mut self_.f);
		task.poll_next(cx).map(|item| {
			item.map(|item| {
				f.call_mut((&item,));
				item
			})
		})
	}
}

impl<C: Pipe<Input>, F, Input> Pipe<Input> for InspectTask<C, F>
where
	F: for<'a> FnMut<(&'a C::Output,), Output = ()> + Clone,
{
	type Output = C::Output;

	fn poll_next(
		self: Pin<&mut Self>, cx: &mut Context, stream: Pin<&mut impl Stream<Item = Input>>,
	) -> Poll<Option<Self::Output>> {
		let mut self_ = self.project();
		let (task, f) = (self_.task, &mut self_.f);
		task.poll_next(cx, stream).map(|item| {
			item.map(|item| {
				f.call_mut((&item,));
				item
			})
		})
	}
}