1#[cfg(feature = "test-support")]
2pub mod test;
3
4use futures::Future;
5use std::{
6 cmp::Ordering,
7 ops::AddAssign,
8 pin::Pin,
9 task::{Context, Poll},
10};
11
12pub fn post_inc<T: From<u8> + AddAssign<T> + Copy>(value: &mut T) -> T {
13 let prev = *value;
14 *value += T::from(1);
15 prev
16}
17
18/// Extend a sorted vector with a sorted sequence of items, maintaining the vector's sort order and
19/// enforcing a maximum length. Sort the items according to the given callback. Before calling this,
20/// both `vec` and `new_items` should already be sorted according to the `cmp` comparator.
21pub fn extend_sorted<T, I, F>(vec: &mut Vec<T>, new_items: I, limit: usize, mut cmp: F)
22where
23 I: IntoIterator<Item = T>,
24 F: FnMut(&T, &T) -> Ordering,
25{
26 let mut start_index = 0;
27 for new_item in new_items {
28 if let Err(i) = vec[start_index..].binary_search_by(|m| cmp(m, &new_item)) {
29 let index = start_index + i;
30 if vec.len() < limit {
31 vec.insert(index, new_item);
32 } else if index < vec.len() {
33 vec.pop();
34 vec.insert(index, new_item);
35 }
36 start_index = index;
37 }
38 }
39}
40
41pub trait ResultExt {
42 type Ok;
43
44 fn log_err(self) -> Option<Self::Ok>;
45 fn warn_on_err(self) -> Option<Self::Ok>;
46}
47
48impl<T, E> ResultExt for Result<T, E>
49where
50 E: std::fmt::Debug,
51{
52 type Ok = T;
53
54 fn log_err(self) -> Option<T> {
55 match self {
56 Ok(value) => Some(value),
57 Err(error) => {
58 log::error!("{:?}", error);
59 None
60 }
61 }
62 }
63
64 fn warn_on_err(self) -> Option<T> {
65 match self {
66 Ok(value) => Some(value),
67 Err(error) => {
68 log::warn!("{:?}", error);
69 None
70 }
71 }
72 }
73}
74
75pub trait TryFutureExt {
76 fn log_err(self) -> LogErrorFuture<Self>
77 where
78 Self: Sized;
79 fn warn_on_err(self) -> LogErrorFuture<Self>
80 where
81 Self: Sized;
82}
83
84impl<F, T> TryFutureExt for F
85where
86 F: Future<Output = anyhow::Result<T>>,
87{
88 fn log_err(self) -> LogErrorFuture<Self>
89 where
90 Self: Sized,
91 {
92 LogErrorFuture(self, log::Level::Error)
93 }
94
95 fn warn_on_err(self) -> LogErrorFuture<Self>
96 where
97 Self: Sized,
98 {
99 LogErrorFuture(self, log::Level::Warn)
100 }
101}
102
103pub struct LogErrorFuture<F>(F, log::Level);
104
105impl<F, T> Future for LogErrorFuture<F>
106where
107 F: Future<Output = anyhow::Result<T>>,
108{
109 type Output = Option<T>;
110
111 fn poll(self: std::pin::Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
112 let level = self.1;
113 let inner = unsafe { Pin::new_unchecked(&mut self.get_unchecked_mut().0) };
114 match inner.poll(cx) {
115 Poll::Ready(output) => Poll::Ready(match output {
116 Ok(output) => Some(output),
117 Err(error) => {
118 log::log!(level, "{:?}", error);
119 None
120 }
121 }),
122 Poll::Pending => Poll::Pending,
123 }
124 }
125}
126
127struct Defer<F: FnOnce()>(Option<F>);
128
129impl<F: FnOnce()> Drop for Defer<F> {
130 fn drop(&mut self) {
131 self.0.take().map(|f| f());
132 }
133}
134
135pub fn defer<F: FnOnce()>(f: F) -> impl Drop {
136 Defer(Some(f))
137}
138
139#[cfg(test)]
140mod tests {
141 use super::*;
142
143 #[test]
144 fn test_extend_sorted() {
145 let mut vec = vec![];
146
147 extend_sorted(&mut vec, vec![21, 17, 13, 8, 1, 0], 5, |a, b| b.cmp(a));
148 assert_eq!(vec, &[21, 17, 13, 8, 1]);
149
150 extend_sorted(&mut vec, vec![101, 19, 17, 8, 2], 8, |a, b| b.cmp(a));
151 assert_eq!(vec, &[101, 21, 19, 17, 13, 8, 2, 1]);
152
153 extend_sorted(&mut vec, vec![1000, 19, 17, 9, 5], 8, |a, b| b.cmp(a));
154 assert_eq!(vec, &[1000, 101, 21, 19, 17, 13, 9, 8]);
155 }
156}