1#[cfg(any(test, feature = "test-support"))]
2pub mod test;
3
4pub use backtrace::Backtrace;
5use futures::Future;
6use rand::{seq::SliceRandom, Rng};
7use std::{
8 cmp::Ordering,
9 ops::AddAssign,
10 pin::Pin,
11 task::{Context, Poll},
12};
13
14#[macro_export]
15macro_rules! debug_panic {
16 ( $($fmt_arg:tt)* ) => {
17 if cfg!(debug_assertions) {
18 panic!( $($fmt_arg)* );
19 } else {
20 let backtrace = $crate::Backtrace::new();
21 log::error!("{}\n{:?}", format_args!($($fmt_arg)*), backtrace);
22 }
23 };
24}
25
26pub fn truncate(s: &str, max_chars: usize) -> &str {
27 match s.char_indices().nth(max_chars) {
28 None => s,
29 Some((idx, _)) => &s[..idx],
30 }
31}
32
33pub fn truncate_and_trailoff(s: &str, max_chars: usize) -> String {
34 debug_assert!(max_chars >= 5);
35
36 if s.len() > max_chars {
37 format!("{}…", truncate(&s, max_chars.saturating_sub(3)))
38 } else {
39 s.to_string()
40 }
41}
42
43pub fn post_inc<T: From<u8> + AddAssign<T> + Copy>(value: &mut T) -> T {
44 let prev = *value;
45 *value += T::from(1);
46 prev
47}
48
49/// Extend a sorted vector with a sorted sequence of items, maintaining the vector's sort order and
50/// enforcing a maximum length. Sort the items according to the given callback. Before calling this,
51/// both `vec` and `new_items` should already be sorted according to the `cmp` comparator.
52pub fn extend_sorted<T, I, F>(vec: &mut Vec<T>, new_items: I, limit: usize, mut cmp: F)
53where
54 I: IntoIterator<Item = T>,
55 F: FnMut(&T, &T) -> Ordering,
56{
57 let mut start_index = 0;
58 for new_item in new_items {
59 if let Err(i) = vec[start_index..].binary_search_by(|m| cmp(m, &new_item)) {
60 let index = start_index + i;
61 if vec.len() < limit {
62 vec.insert(index, new_item);
63 } else if index < vec.len() {
64 vec.pop();
65 vec.insert(index, new_item);
66 }
67 start_index = index;
68 }
69 }
70}
71
72pub trait ResultExt {
73 type Ok;
74
75 fn log_err(self) -> Option<Self::Ok>;
76 fn warn_on_err(self) -> Option<Self::Ok>;
77}
78
79impl<T, E> ResultExt for Result<T, E>
80where
81 E: std::fmt::Debug,
82{
83 type Ok = T;
84
85 fn log_err(self) -> Option<T> {
86 match self {
87 Ok(value) => Some(value),
88 Err(error) => {
89 log::error!("{:?}", error);
90 None
91 }
92 }
93 }
94
95 fn warn_on_err(self) -> Option<T> {
96 match self {
97 Ok(value) => Some(value),
98 Err(error) => {
99 log::warn!("{:?}", error);
100 None
101 }
102 }
103 }
104}
105
106pub trait TryFutureExt {
107 fn log_err(self) -> LogErrorFuture<Self>
108 where
109 Self: Sized;
110 fn warn_on_err(self) -> LogErrorFuture<Self>
111 where
112 Self: Sized;
113}
114
115impl<F, T> TryFutureExt for F
116where
117 F: Future<Output = anyhow::Result<T>>,
118{
119 fn log_err(self) -> LogErrorFuture<Self>
120 where
121 Self: Sized,
122 {
123 LogErrorFuture(self, log::Level::Error)
124 }
125
126 fn warn_on_err(self) -> LogErrorFuture<Self>
127 where
128 Self: Sized,
129 {
130 LogErrorFuture(self, log::Level::Warn)
131 }
132}
133
134pub struct LogErrorFuture<F>(F, log::Level);
135
136impl<F, T> Future for LogErrorFuture<F>
137where
138 F: Future<Output = anyhow::Result<T>>,
139{
140 type Output = Option<T>;
141
142 fn poll(self: std::pin::Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
143 let level = self.1;
144 let inner = unsafe { Pin::new_unchecked(&mut self.get_unchecked_mut().0) };
145 match inner.poll(cx) {
146 Poll::Ready(output) => Poll::Ready(match output {
147 Ok(output) => Some(output),
148 Err(error) => {
149 log::log!(level, "{:?}", error);
150 None
151 }
152 }),
153 Poll::Pending => Poll::Pending,
154 }
155 }
156}
157
158struct Defer<F: FnOnce()>(Option<F>);
159
160impl<F: FnOnce()> Drop for Defer<F> {
161 fn drop(&mut self) {
162 if let Some(f) = self.0.take() {
163 f()
164 }
165 }
166}
167
168pub fn defer<F: FnOnce()>(f: F) -> impl Drop {
169 Defer(Some(f))
170}
171
172pub struct RandomCharIter<T: Rng>(T);
173
174impl<T: Rng> RandomCharIter<T> {
175 pub fn new(rng: T) -> Self {
176 Self(rng)
177 }
178}
179
180impl<T: Rng> Iterator for RandomCharIter<T> {
181 type Item = char;
182
183 fn next(&mut self) -> Option<Self::Item> {
184 if std::env::var("SIMPLE_TEXT").map_or(false, |v| !v.is_empty()) {
185 return if self.0.gen_range(0..100) < 5 {
186 Some('\n')
187 } else {
188 Some(self.0.gen_range(b'a'..b'z' + 1).into())
189 };
190 }
191
192 match self.0.gen_range(0..100) {
193 // whitespace
194 0..=19 => [' ', '\n', '\r', '\t'].choose(&mut self.0).copied(),
195 // two-byte greek letters
196 20..=32 => char::from_u32(self.0.gen_range(('α' as u32)..('ω' as u32 + 1))),
197 // // three-byte characters
198 33..=45 => ['✋', '✅', '❌', '❎', '⭐'].choose(&mut self.0).copied(),
199 // // four-byte characters
200 46..=58 => ['🍐', '🏀', '🍗', '🎉'].choose(&mut self.0).copied(),
201 // ascii letters
202 _ => Some(self.0.gen_range(b'a'..b'z' + 1).into()),
203 }
204 }
205}
206
207#[cfg(test)]
208mod tests {
209 use super::*;
210
211 #[test]
212 fn test_extend_sorted() {
213 let mut vec = vec![];
214
215 extend_sorted(&mut vec, vec![21, 17, 13, 8, 1, 0], 5, |a, b| b.cmp(a));
216 assert_eq!(vec, &[21, 17, 13, 8, 1]);
217
218 extend_sorted(&mut vec, vec![101, 19, 17, 8, 2], 8, |a, b| b.cmp(a));
219 assert_eq!(vec, &[101, 21, 19, 17, 13, 8, 2, 1]);
220
221 extend_sorted(&mut vec, vec![1000, 19, 17, 9, 5], 8, |a, b| b.cmp(a));
222 assert_eq!(vec, &[1000, 101, 21, 19, 17, 13, 9, 8]);
223 }
224}