util.rs

  1pub mod arc_cow;
  2pub mod channel;
  3pub mod fs;
  4pub mod github;
  5pub mod http;
  6pub mod paths;
  7#[cfg(any(test, feature = "test-support"))]
  8pub mod test;
  9
 10use std::{
 11    borrow::Cow,
 12    cmp::{self, Ordering},
 13    ops::{AddAssign, Range, RangeInclusive},
 14    panic::Location,
 15    pin::Pin,
 16    task::{Context, Poll},
 17};
 18
 19pub use backtrace::Backtrace;
 20use futures::Future;
 21use rand::{seq::SliceRandom, Rng};
 22
 23pub use take_until::*;
 24
 25#[macro_export]
 26macro_rules! debug_panic {
 27    ( $($fmt_arg:tt)* ) => {
 28        if cfg!(debug_assertions) {
 29            panic!( $($fmt_arg)* );
 30        } else {
 31            let backtrace = $crate::Backtrace::new();
 32            log::error!("{}\n{:?}", format_args!($($fmt_arg)*), backtrace);
 33        }
 34    };
 35}
 36
 37pub fn truncate(s: &str, max_chars: usize) -> &str {
 38    match s.char_indices().nth(max_chars) {
 39        None => s,
 40        Some((idx, _)) => &s[..idx],
 41    }
 42}
 43
 44pub fn truncate_and_trailoff(s: &str, max_chars: usize) -> String {
 45    debug_assert!(max_chars >= 5);
 46
 47    let truncation_ix = s.char_indices().map(|(i, _)| i).nth(max_chars);
 48    match truncation_ix {
 49        Some(length) => s[..length].to_string() + "",
 50        None => s.to_string(),
 51    }
 52}
 53
 54pub fn post_inc<T: From<u8> + AddAssign<T> + Copy>(value: &mut T) -> T {
 55    let prev = *value;
 56    *value += T::from(1);
 57    prev
 58}
 59
 60/// Extend a sorted vector with a sorted sequence of items, maintaining the vector's sort order and
 61/// enforcing a maximum length. This also de-duplicates items. Sort the items according to the given callback. Before calling this,
 62/// both `vec` and `new_items` should already be sorted according to the `cmp` comparator.
 63pub fn extend_sorted<T, I, F>(vec: &mut Vec<T>, new_items: I, limit: usize, mut cmp: F)
 64where
 65    I: IntoIterator<Item = T>,
 66    F: FnMut(&T, &T) -> Ordering,
 67{
 68    let mut start_index = 0;
 69    for new_item in new_items {
 70        if let Err(i) = vec[start_index..].binary_search_by(|m| cmp(m, &new_item)) {
 71            let index = start_index + i;
 72            if vec.len() < limit {
 73                vec.insert(index, new_item);
 74            } else if index < vec.len() {
 75                vec.pop();
 76                vec.insert(index, new_item);
 77            }
 78            start_index = index;
 79        }
 80    }
 81}
 82
 83pub fn merge_json_value_into(source: serde_json::Value, target: &mut serde_json::Value) {
 84    use serde_json::Value;
 85
 86    match (source, target) {
 87        (Value::Object(source), Value::Object(target)) => {
 88            for (key, value) in source {
 89                if let Some(target) = target.get_mut(&key) {
 90                    merge_json_value_into(value, target);
 91                } else {
 92                    target.insert(key.clone(), value);
 93                }
 94            }
 95        }
 96
 97        (source, target) => *target = source,
 98    }
 99}
100
101pub fn merge_non_null_json_value_into(source: serde_json::Value, target: &mut serde_json::Value) {
102    use serde_json::Value;
103    if let Value::Object(source_object) = source {
104        let target_object = if let Value::Object(target) = target {
105            target
106        } else {
107            *target = Value::Object(Default::default());
108            target.as_object_mut().unwrap()
109        };
110        for (key, value) in source_object {
111            if let Some(target) = target_object.get_mut(&key) {
112                merge_non_null_json_value_into(value, target);
113            } else if !value.is_null() {
114                target_object.insert(key.clone(), value);
115            }
116        }
117    } else if !source.is_null() {
118        *target = source
119    }
120}
121
122pub trait ResultExt<E> {
123    type Ok;
124
125    fn log_err(self) -> Option<Self::Ok>;
126    fn warn_on_err(self) -> Option<Self::Ok>;
127    fn inspect_error(self, func: impl FnOnce(&E)) -> Self;
128}
129
130impl<T, E> ResultExt<E> for Result<T, E>
131where
132    E: std::fmt::Debug,
133{
134    type Ok = T;
135
136    #[track_caller]
137    fn log_err(self) -> Option<T> {
138        match self {
139            Ok(value) => Some(value),
140            Err(error) => {
141                let caller = Location::caller();
142                log::error!("{}:{}: {:?}", caller.file(), caller.line(), error);
143                None
144            }
145        }
146    }
147
148    fn warn_on_err(self) -> Option<T> {
149        match self {
150            Ok(value) => Some(value),
151            Err(error) => {
152                log::warn!("{:?}", error);
153                None
154            }
155        }
156    }
157
158    /// https://doc.rust-lang.org/std/result/enum.Result.html#method.inspect_err
159    fn inspect_error(self, func: impl FnOnce(&E)) -> Self {
160        if let Err(err) = &self {
161            func(err);
162        }
163
164        self
165    }
166}
167
168pub trait TryFutureExt {
169    fn log_err(self) -> LogErrorFuture<Self>
170    where
171        Self: Sized;
172    fn warn_on_err(self) -> LogErrorFuture<Self>
173    where
174        Self: Sized;
175    fn unwrap(self) -> UnwrapFuture<Self>
176    where
177        Self: Sized;
178}
179
180impl<F, T, E> TryFutureExt for F
181where
182    F: Future<Output = Result<T, E>>,
183    E: std::fmt::Debug,
184{
185    fn log_err(self) -> LogErrorFuture<Self>
186    where
187        Self: Sized,
188    {
189        LogErrorFuture(self, log::Level::Error)
190    }
191
192    fn warn_on_err(self) -> LogErrorFuture<Self>
193    where
194        Self: Sized,
195    {
196        LogErrorFuture(self, log::Level::Warn)
197    }
198
199    fn unwrap(self) -> UnwrapFuture<Self>
200    where
201        Self: Sized,
202    {
203        UnwrapFuture(self)
204    }
205}
206
207pub struct LogErrorFuture<F>(F, log::Level);
208
209impl<F, T, E> Future for LogErrorFuture<F>
210where
211    F: Future<Output = Result<T, E>>,
212    E: std::fmt::Debug,
213{
214    type Output = Option<T>;
215
216    fn poll(self: Pin<&mut Self>, cx: &mut Context) -> Poll<Self::Output> {
217        let level = self.1;
218        let inner = unsafe { Pin::new_unchecked(&mut self.get_unchecked_mut().0) };
219        match inner.poll(cx) {
220            Poll::Ready(output) => Poll::Ready(match output {
221                Ok(output) => Some(output),
222                Err(error) => {
223                    log::log!(level, "{:?}", error);
224                    None
225                }
226            }),
227            Poll::Pending => Poll::Pending,
228        }
229    }
230}
231
232pub struct UnwrapFuture<F>(F);
233
234impl<F, T, E> Future for UnwrapFuture<F>
235where
236    F: Future<Output = Result<T, E>>,
237    E: std::fmt::Debug,
238{
239    type Output = T;
240
241    fn poll(self: Pin<&mut Self>, cx: &mut Context) -> Poll<Self::Output> {
242        let inner = unsafe { Pin::new_unchecked(&mut self.get_unchecked_mut().0) };
243        match inner.poll(cx) {
244            Poll::Ready(result) => Poll::Ready(result.unwrap()),
245            Poll::Pending => Poll::Pending,
246        }
247    }
248}
249
250pub struct Deferred<F: FnOnce()>(Option<F>);
251
252impl<F: FnOnce()> Deferred<F> {
253    /// Drop without running the deferred function.
254    pub fn cancel(mut self) {
255        self.0.take();
256    }
257}
258
259impl<F: FnOnce()> Drop for Deferred<F> {
260    fn drop(&mut self) {
261        if let Some(f) = self.0.take() {
262            f()
263        }
264    }
265}
266
267/// Run the given function when the returned value is dropped (unless it's cancelled).
268pub fn defer<F: FnOnce()>(f: F) -> Deferred<F> {
269    Deferred(Some(f))
270}
271
272pub struct RandomCharIter<T: Rng>(T);
273
274impl<T: Rng> RandomCharIter<T> {
275    pub fn new(rng: T) -> Self {
276        Self(rng)
277    }
278}
279
280impl<T: Rng> Iterator for RandomCharIter<T> {
281    type Item = char;
282
283    fn next(&mut self) -> Option<Self::Item> {
284        if std::env::var("SIMPLE_TEXT").map_or(false, |v| !v.is_empty()) {
285            return if self.0.gen_range(0..100) < 5 {
286                Some('\n')
287            } else {
288                Some(self.0.gen_range(b'a'..b'z' + 1).into())
289            };
290        }
291
292        match self.0.gen_range(0..100) {
293            // whitespace
294            0..=19 => [' ', '\n', '\r', '\t'].choose(&mut self.0).copied(),
295            // two-byte greek letters
296            20..=32 => char::from_u32(self.0.gen_range(('α' as u32)..('ω' as u32 + 1))),
297            // // three-byte characters
298            33..=45 => ['✋', '✅', '❌', '❎', '⭐'].choose(&mut self.0).copied(),
299            // // four-byte characters
300            46..=58 => ['🍐', '🏀', '🍗', '🎉'].choose(&mut self.0).copied(),
301            // ascii letters
302            _ => Some(self.0.gen_range(b'a'..b'z' + 1).into()),
303        }
304    }
305}
306
307/// Get an embedded file as a string.
308pub fn asset_str<A: rust_embed::RustEmbed>(path: &str) -> Cow<'static, str> {
309    match A::get(path).unwrap().data {
310        Cow::Borrowed(bytes) => Cow::Borrowed(std::str::from_utf8(bytes).unwrap()),
311        Cow::Owned(bytes) => Cow::Owned(String::from_utf8(bytes).unwrap()),
312    }
313}
314
315// copy unstable standard feature option unzip
316// https://github.com/rust-lang/rust/issues/87800
317// Remove when this ship in Rust 1.66 or 1.67
318pub fn unzip_option<T, U>(option: Option<(T, U)>) -> (Option<T>, Option<U>) {
319    match option {
320        Some((a, b)) => (Some(a), Some(b)),
321        None => (None, None),
322    }
323}
324
325/// Immediately invoked function expression. Good for using the ? operator
326/// in functions which do not return an Option or Result
327#[macro_export]
328macro_rules! iife {
329    ($block:block) => {
330        (|| $block)()
331    };
332}
333
334/// Async Immediately invoked function expression. Good for using the ? operator
335/// in functions which do not return an Option or Result. Async version of above
336#[macro_export]
337macro_rules! async_iife {
338    ($block:block) => {
339        (|| async move { $block })()
340    };
341}
342
343pub trait RangeExt<T> {
344    fn sorted(&self) -> Self;
345    fn to_inclusive(&self) -> RangeInclusive<T>;
346    fn overlaps(&self, other: &Range<T>) -> bool;
347    fn contains_inclusive(&self, other: &Range<T>) -> bool;
348}
349
350impl<T: Ord + Clone> RangeExt<T> for Range<T> {
351    fn sorted(&self) -> Self {
352        cmp::min(&self.start, &self.end).clone()..cmp::max(&self.start, &self.end).clone()
353    }
354
355    fn to_inclusive(&self) -> RangeInclusive<T> {
356        self.start.clone()..=self.end.clone()
357    }
358
359    fn overlaps(&self, other: &Range<T>) -> bool {
360        self.start < other.end && other.start < self.end
361    }
362
363    fn contains_inclusive(&self, other: &Range<T>) -> bool {
364        self.start <= other.start && other.end <= self.end
365    }
366}
367
368impl<T: Ord + Clone> RangeExt<T> for RangeInclusive<T> {
369    fn sorted(&self) -> Self {
370        cmp::min(self.start(), self.end()).clone()..=cmp::max(self.start(), self.end()).clone()
371    }
372
373    fn to_inclusive(&self) -> RangeInclusive<T> {
374        self.clone()
375    }
376
377    fn overlaps(&self, other: &Range<T>) -> bool {
378        self.start() < &other.end && &other.start <= self.end()
379    }
380
381    fn contains_inclusive(&self, other: &Range<T>) -> bool {
382        self.start() <= &other.start && &other.end <= self.end()
383    }
384}
385
386#[cfg(test)]
387mod tests {
388    use super::*;
389
390    #[test]
391    fn test_extend_sorted() {
392        let mut vec = vec![];
393
394        extend_sorted(&mut vec, vec![21, 17, 13, 8, 1, 0], 5, |a, b| b.cmp(a));
395        assert_eq!(vec, &[21, 17, 13, 8, 1]);
396
397        extend_sorted(&mut vec, vec![101, 19, 17, 8, 2], 8, |a, b| b.cmp(a));
398        assert_eq!(vec, &[101, 21, 19, 17, 13, 8, 2, 1]);
399
400        extend_sorted(&mut vec, vec![1000, 19, 17, 9, 5], 8, |a, b| b.cmp(a));
401        assert_eq!(vec, &[1000, 101, 21, 19, 17, 13, 9, 8]);
402    }
403
404    #[test]
405    fn test_iife() {
406        fn option_returning_function() -> Option<()> {
407            None
408        }
409
410        let foo = iife!({
411            option_returning_function()?;
412            Some(())
413        });
414
415        assert_eq!(foo, None);
416    }
417
418    #[test]
419    fn test_trancate_and_trailoff() {
420        assert_eq!(truncate_and_trailoff("", 5), "");
421        assert_eq!(truncate_and_trailoff("èèèèèè", 7), "èèèèèè");
422        assert_eq!(truncate_and_trailoff("èèèèèè", 6), "èèèèèè");
423        assert_eq!(truncate_and_trailoff("èèèèèè", 5), "èèèèè…");
424    }
425}