util.rs

  1pub mod arc_cow;
  2pub mod fs;
  3pub mod github;
  4pub mod http;
  5pub mod paths;
  6#[cfg(any(test, feature = "test-support"))]
  7pub mod test;
  8
  9pub use backtrace::Backtrace;
 10use futures::Future;
 11use lazy_static::lazy_static;
 12use rand::{seq::SliceRandom, Rng};
 13use std::{
 14    borrow::Cow,
 15    cmp::{self, Ordering},
 16    env,
 17    ops::{AddAssign, Range, RangeInclusive},
 18    panic::Location,
 19    pin::Pin,
 20    task::{Context, Poll},
 21    time::Instant,
 22};
 23
 24pub use take_until::*;
 25
 26#[macro_export]
 27macro_rules! debug_panic {
 28    ( $($fmt_arg:tt)* ) => {
 29        if cfg!(debug_assertions) {
 30            panic!( $($fmt_arg)* );
 31        } else {
 32            let backtrace = $crate::Backtrace::new();
 33            log::error!("{}\n{:?}", format_args!($($fmt_arg)*), backtrace);
 34        }
 35    };
 36}
 37
 38pub fn truncate(s: &str, max_chars: usize) -> &str {
 39    match s.char_indices().nth(max_chars) {
 40        None => s,
 41        Some((idx, _)) => &s[..idx],
 42    }
 43}
 44
 45/// Removes characters from the end of the string if its length is greater than `max_chars` and
 46/// appends "..." to the string. Returns string unchanged if its length is smaller than max_chars.
 47pub fn truncate_and_trailoff(s: &str, max_chars: usize) -> String {
 48    debug_assert!(max_chars >= 5);
 49
 50    let truncation_ix = s.char_indices().map(|(i, _)| i).nth(max_chars);
 51    match truncation_ix {
 52        Some(length) => s[..length].to_string() + "",
 53        None => s.to_string(),
 54    }
 55}
 56
 57/// Removes characters from the front of the string if its length is greater than `max_chars` and
 58/// prepends the string with "...". Returns string unchanged if its length is smaller than max_chars.
 59pub fn truncate_and_remove_front(s: &str, max_chars: usize) -> String {
 60    debug_assert!(max_chars >= 5);
 61
 62    let truncation_ix = s.char_indices().map(|(i, _)| i).nth_back(max_chars);
 63    match truncation_ix {
 64        Some(length) => "".to_string() + &s[length..],
 65        None => s.to_string(),
 66    }
 67}
 68
 69pub fn post_inc<T: From<u8> + AddAssign<T> + Copy>(value: &mut T) -> T {
 70    let prev = *value;
 71    *value += T::from(1);
 72    prev
 73}
 74
 75/// Extend a sorted vector with a sorted sequence of items, maintaining the vector's sort order and
 76/// enforcing a maximum length. This also de-duplicates items. Sort the items according to the given callback. Before calling this,
 77/// both `vec` and `new_items` should already be sorted according to the `cmp` comparator.
 78pub fn extend_sorted<T, I, F>(vec: &mut Vec<T>, new_items: I, limit: usize, mut cmp: F)
 79where
 80    I: IntoIterator<Item = T>,
 81    F: FnMut(&T, &T) -> Ordering,
 82{
 83    let mut start_index = 0;
 84    for new_item in new_items {
 85        if let Err(i) = vec[start_index..].binary_search_by(|m| cmp(m, &new_item)) {
 86            let index = start_index + i;
 87            if vec.len() < limit {
 88                vec.insert(index, new_item);
 89            } else if index < vec.len() {
 90                vec.pop();
 91                vec.insert(index, new_item);
 92            }
 93            start_index = index;
 94        }
 95    }
 96}
 97
 98pub fn merge_json_value_into(source: serde_json::Value, target: &mut serde_json::Value) {
 99    use serde_json::Value;
100
101    match (source, target) {
102        (Value::Object(source), Value::Object(target)) => {
103            for (key, value) in source {
104                if let Some(target) = target.get_mut(&key) {
105                    merge_json_value_into(value, target);
106                } else {
107                    target.insert(key.clone(), value);
108                }
109            }
110        }
111
112        (source, target) => *target = source,
113    }
114}
115
116pub fn merge_non_null_json_value_into(source: serde_json::Value, target: &mut serde_json::Value) {
117    use serde_json::Value;
118    if let Value::Object(source_object) = source {
119        let target_object = if let Value::Object(target) = target {
120            target
121        } else {
122            *target = Value::Object(Default::default());
123            target.as_object_mut().unwrap()
124        };
125        for (key, value) in source_object {
126            if let Some(target) = target_object.get_mut(&key) {
127                merge_non_null_json_value_into(value, target);
128            } else if !value.is_null() {
129                target_object.insert(key.clone(), value);
130            }
131        }
132    } else if !source.is_null() {
133        *target = source
134    }
135}
136
137pub fn measure<R>(label: &str, f: impl FnOnce() -> R) -> R {
138    lazy_static! {
139        pub static ref ZED_MEASUREMENTS: bool = env::var("ZED_MEASUREMENTS")
140            .map(|measurements| measurements == "1" || measurements == "true")
141            .unwrap_or(false);
142    }
143
144    if *ZED_MEASUREMENTS {
145        let start = Instant::now();
146        let result = f();
147        let elapsed = start.elapsed();
148        eprintln!("{}: {:?}", label, elapsed);
149        result
150    } else {
151        f()
152    }
153}
154
155pub trait ResultExt<E> {
156    type Ok;
157
158    fn log_err(self) -> Option<Self::Ok>;
159    /// Assert that this result should never be an error in development or tests.
160    fn debug_assert_ok(self, reason: &str) -> Self;
161    fn warn_on_err(self) -> Option<Self::Ok>;
162    fn inspect_error(self, func: impl FnOnce(&E)) -> Self;
163}
164
165impl<T, E> ResultExt<E> for Result<T, E>
166where
167    E: std::fmt::Debug,
168{
169    type Ok = T;
170
171    #[track_caller]
172    fn log_err(self) -> Option<T> {
173        match self {
174            Ok(value) => Some(value),
175            Err(error) => {
176                let caller = Location::caller();
177                log::error!("{}:{}: {:?}", caller.file(), caller.line(), error);
178                None
179            }
180        }
181    }
182
183    #[track_caller]
184    fn debug_assert_ok(self, reason: &str) -> Self {
185        if let Err(error) = &self {
186            debug_panic!("{reason} - {error:?}");
187        }
188        self
189    }
190
191    fn warn_on_err(self) -> Option<T> {
192        match self {
193            Ok(value) => Some(value),
194            Err(error) => {
195                log::warn!("{:?}", error);
196                None
197            }
198        }
199    }
200
201    /// https://doc.rust-lang.org/std/result/enum.Result.html#method.inspect_err
202    fn inspect_error(self, func: impl FnOnce(&E)) -> Self {
203        if let Err(err) = &self {
204            func(err);
205        }
206
207        self
208    }
209}
210
211pub trait TryFutureExt {
212    fn log_err(self) -> LogErrorFuture<Self>
213    where
214        Self: Sized;
215
216    fn log_tracked_err(self, location: core::panic::Location<'static>) -> LogErrorFuture<Self>
217    where
218        Self: Sized;
219
220    fn warn_on_err(self) -> LogErrorFuture<Self>
221    where
222        Self: Sized;
223    fn unwrap(self) -> UnwrapFuture<Self>
224    where
225        Self: Sized;
226}
227
228impl<F, T, E> TryFutureExt for F
229where
230    F: Future<Output = Result<T, E>>,
231    E: std::fmt::Debug,
232{
233    #[track_caller]
234    fn log_err(self) -> LogErrorFuture<Self>
235    where
236        Self: Sized,
237    {
238        let location = Location::caller();
239        LogErrorFuture(self, log::Level::Error, *location)
240    }
241
242    fn log_tracked_err(self, location: core::panic::Location<'static>) -> LogErrorFuture<Self>
243    where
244        Self: Sized,
245    {
246        LogErrorFuture(self, log::Level::Error, location)
247    }
248
249    #[track_caller]
250    fn warn_on_err(self) -> LogErrorFuture<Self>
251    where
252        Self: Sized,
253    {
254        let location = Location::caller();
255        LogErrorFuture(self, log::Level::Warn, *location)
256    }
257
258    fn unwrap(self) -> UnwrapFuture<Self>
259    where
260        Self: Sized,
261    {
262        UnwrapFuture(self)
263    }
264}
265
266#[must_use]
267pub struct LogErrorFuture<F>(F, log::Level, core::panic::Location<'static>);
268
269impl<F, T, E> Future for LogErrorFuture<F>
270where
271    F: Future<Output = Result<T, E>>,
272    E: std::fmt::Debug,
273{
274    type Output = Option<T>;
275
276    fn poll(self: Pin<&mut Self>, cx: &mut Context) -> Poll<Self::Output> {
277        let level = self.1;
278        let location = self.2;
279        let inner = unsafe { Pin::new_unchecked(&mut self.get_unchecked_mut().0) };
280        match inner.poll(cx) {
281            Poll::Ready(output) => Poll::Ready(match output {
282                Ok(output) => Some(output),
283                Err(error) => {
284                    log::log!(
285                        level,
286                        "{}:{}: {:?}",
287                        location.file(),
288                        location.line(),
289                        error
290                    );
291                    None
292                }
293            }),
294            Poll::Pending => Poll::Pending,
295        }
296    }
297}
298
299pub struct UnwrapFuture<F>(F);
300
301impl<F, T, E> Future for UnwrapFuture<F>
302where
303    F: Future<Output = Result<T, E>>,
304    E: std::fmt::Debug,
305{
306    type Output = T;
307
308    fn poll(self: Pin<&mut Self>, cx: &mut Context) -> Poll<Self::Output> {
309        let inner = unsafe { Pin::new_unchecked(&mut self.get_unchecked_mut().0) };
310        match inner.poll(cx) {
311            Poll::Ready(result) => Poll::Ready(result.unwrap()),
312            Poll::Pending => Poll::Pending,
313        }
314    }
315}
316
317pub struct Deferred<F: FnOnce()>(Option<F>);
318
319impl<F: FnOnce()> Deferred<F> {
320    /// Drop without running the deferred function.
321    pub fn abort(mut self) {
322        self.0.take();
323    }
324}
325
326impl<F: FnOnce()> Drop for Deferred<F> {
327    fn drop(&mut self) {
328        if let Some(f) = self.0.take() {
329            f()
330        }
331    }
332}
333
334/// Run the given function when the returned value is dropped (unless it's cancelled).
335pub fn defer<F: FnOnce()>(f: F) -> Deferred<F> {
336    Deferred(Some(f))
337}
338
339pub struct RandomCharIter<T: Rng> {
340    rng: T,
341    simple_text: bool,
342}
343
344impl<T: Rng> RandomCharIter<T> {
345    pub fn new(rng: T) -> Self {
346        Self {
347            rng,
348            simple_text: std::env::var("SIMPLE_TEXT").map_or(false, |v| !v.is_empty()),
349        }
350    }
351
352    pub fn with_simple_text(mut self) -> Self {
353        self.simple_text = true;
354        self
355    }
356}
357
358impl<T: Rng> Iterator for RandomCharIter<T> {
359    type Item = char;
360
361    fn next(&mut self) -> Option<Self::Item> {
362        if self.simple_text {
363            return if self.rng.gen_range(0..100) < 5 {
364                Some('\n')
365            } else {
366                Some(self.rng.gen_range(b'a'..b'z' + 1).into())
367            };
368        }
369
370        match self.rng.gen_range(0..100) {
371            // whitespace
372            0..=19 => [' ', '\n', '\r', '\t'].choose(&mut self.rng).copied(),
373            // two-byte greek letters
374            20..=32 => char::from_u32(self.rng.gen_range(('α' as u32)..('ω' as u32 + 1))),
375            // // three-byte characters
376            33..=45 => ['✋', '✅', '❌', '❎', '⭐']
377                .choose(&mut self.rng)
378                .copied(),
379            // // four-byte characters
380            46..=58 => ['🍐', '🏀', '🍗', '🎉'].choose(&mut self.rng).copied(),
381            // ascii letters
382            _ => Some(self.rng.gen_range(b'a'..b'z' + 1).into()),
383        }
384    }
385}
386
387/// Get an embedded file as a string.
388pub fn asset_str<A: rust_embed::RustEmbed>(path: &str) -> Cow<'static, str> {
389    match A::get(path).unwrap().data {
390        Cow::Borrowed(bytes) => Cow::Borrowed(std::str::from_utf8(bytes).unwrap()),
391        Cow::Owned(bytes) => Cow::Owned(String::from_utf8(bytes).unwrap()),
392    }
393}
394
395// copy unstable standard feature option unzip
396// https://github.com/rust-lang/rust/issues/87800
397// Remove when this ship in Rust 1.66 or 1.67
398pub fn unzip_option<T, U>(option: Option<(T, U)>) -> (Option<T>, Option<U>) {
399    match option {
400        Some((a, b)) => (Some(a), Some(b)),
401        None => (None, None),
402    }
403}
404
405/// Evaluates to an immediately invoked function expression. Good for using the ? operator
406/// in functions which do not return an Option or Result
407#[macro_export]
408macro_rules! maybe {
409    ($block:block) => {
410        (|| $block)()
411    };
412}
413
414/// Evaluates to an immediately invoked function expression. Good for using the ? operator
415/// in functions which do not return an Option or Result, but async.
416#[macro_export]
417macro_rules! async_maybe {
418    ($block:block) => {
419        (|| async move { $block })()
420    };
421}
422
423pub trait RangeExt<T> {
424    fn sorted(&self) -> Self;
425    fn to_inclusive(&self) -> RangeInclusive<T>;
426    fn overlaps(&self, other: &Range<T>) -> bool;
427    fn contains_inclusive(&self, other: &Range<T>) -> bool;
428}
429
430impl<T: Ord + Clone> RangeExt<T> for Range<T> {
431    fn sorted(&self) -> Self {
432        cmp::min(&self.start, &self.end).clone()..cmp::max(&self.start, &self.end).clone()
433    }
434
435    fn to_inclusive(&self) -> RangeInclusive<T> {
436        self.start.clone()..=self.end.clone()
437    }
438
439    fn overlaps(&self, other: &Range<T>) -> bool {
440        self.start < other.end && other.start < self.end
441    }
442
443    fn contains_inclusive(&self, other: &Range<T>) -> bool {
444        self.start <= other.start && other.end <= self.end
445    }
446}
447
448impl<T: Ord + Clone> RangeExt<T> for RangeInclusive<T> {
449    fn sorted(&self) -> Self {
450        cmp::min(self.start(), self.end()).clone()..=cmp::max(self.start(), self.end()).clone()
451    }
452
453    fn to_inclusive(&self) -> RangeInclusive<T> {
454        self.clone()
455    }
456
457    fn overlaps(&self, other: &Range<T>) -> bool {
458        self.start() < &other.end && &other.start <= self.end()
459    }
460
461    fn contains_inclusive(&self, other: &Range<T>) -> bool {
462        self.start() <= &other.start && &other.end <= self.end()
463    }
464}
465
466#[cfg(test)]
467mod tests {
468    use super::*;
469
470    #[test]
471    fn test_extend_sorted() {
472        let mut vec = vec![];
473
474        extend_sorted(&mut vec, vec![21, 17, 13, 8, 1, 0], 5, |a, b| b.cmp(a));
475        assert_eq!(vec, &[21, 17, 13, 8, 1]);
476
477        extend_sorted(&mut vec, vec![101, 19, 17, 8, 2], 8, |a, b| b.cmp(a));
478        assert_eq!(vec, &[101, 21, 19, 17, 13, 8, 2, 1]);
479
480        extend_sorted(&mut vec, vec![1000, 19, 17, 9, 5], 8, |a, b| b.cmp(a));
481        assert_eq!(vec, &[1000, 101, 21, 19, 17, 13, 9, 8]);
482    }
483
484    #[test]
485    fn test_iife() {
486        fn option_returning_function() -> Option<()> {
487            None
488        }
489
490        let foo = maybe!({
491            option_returning_function()?;
492            Some(())
493        });
494
495        assert_eq!(foo, None);
496    }
497
498    #[test]
499    fn test_trancate_and_trailoff() {
500        assert_eq!(truncate_and_trailoff("", 5), "");
501        assert_eq!(truncate_and_trailoff("èèèèèè", 7), "èèèèèè");
502        assert_eq!(truncate_and_trailoff("èèèèèè", 6), "èèèèèè");
503        assert_eq!(truncate_and_trailoff("èèèèèè", 5), "èèèèè…");
504    }
505}