continuwuity/src/core/utils/stream/wideband.rs
Jason Volk 7a6d657558 configurable dynamic stream concurrency scalar
Signed-off-by: Jason Volk <jason@zemos.net>
2025-01-01 23:28:01 -05:00

82 lines
1.9 KiB
Rust

//! Wideband stream combinator extensions to futures::Stream
use std::convert::identity;
use futures::{
stream::{Stream, StreamExt},
Future,
};
use super::{automatic_width, ReadyExt};
/// Concurrency extensions to augment futures::StreamExt. wideband_ combinators
/// produce in-order.
pub trait WidebandExt<Item>
where
Self: Stream<Item = Item> + Send + Sized,
{
/// Concurrent filter_map(); ordered results
fn widen_filter_map<F, Fut, U, N>(self, n: N, f: F) -> impl Stream<Item = U> + Send
where
N: Into<Option<usize>>,
F: Fn(Item) -> Fut + Send,
Fut: Future<Output = Option<U>> + Send,
U: Send;
fn widen_then<F, Fut, U, N>(self, n: N, f: F) -> impl Stream<Item = U> + Send
where
N: Into<Option<usize>>,
F: Fn(Item) -> Fut + Send,
Fut: Future<Output = U> + Send,
U: Send;
#[inline]
fn wide_filter_map<F, Fut, U>(self, f: F) -> impl Stream<Item = U> + Send
where
F: Fn(Item) -> Fut + Send,
Fut: Future<Output = Option<U>> + Send,
U: Send,
{
self.widen_filter_map(None, f)
}
#[inline]
fn wide_then<F, Fut, U>(self, f: F) -> impl Stream<Item = U> + Send
where
F: Fn(Item) -> Fut + Send,
Fut: Future<Output = U> + Send,
U: Send,
{
self.widen_then(None, f)
}
}
impl<Item, S> WidebandExt<Item> for S
where
S: Stream<Item = Item> + Send + Sized,
{
#[inline]
fn widen_filter_map<F, Fut, U, N>(self, n: N, f: F) -> impl Stream<Item = U> + Send
where
N: Into<Option<usize>>,
F: Fn(Item) -> Fut + Send,
Fut: Future<Output = Option<U>> + Send,
U: Send,
{
self.map(f)
.buffered(n.into().unwrap_or_else(automatic_width))
.ready_filter_map(identity)
}
#[inline]
fn widen_then<F, Fut, U, N>(self, n: N, f: F) -> impl Stream<Item = U> + Send
where
N: Into<Option<usize>>,
F: Fn(Item) -> Fut + Send,
Fut: Future<Output = U> + Send,
U: Send,
{
self.map(f)
.buffered(n.into().unwrap_or_else(automatic_width))
}
}