nautilus_core/
nanos.rs

1// -------------------------------------------------------------------------------------------------
2//  Copyright (C) 2015-2025 Nautech Systems Pty Ltd. All rights reserved.
3//  https://nautechsystems.io
4//
5//  Licensed under the GNU Lesser General Public License Version 3.0 (the "License");
6//  You may not use this file except in compliance with the License.
7//  You may obtain a copy of the License at https://www.gnu.org/licenses/lgpl-3.0.en.html
8//
9//  Unless required by applicable law or agreed to in writing, software
10//  distributed under the License is distributed on an "AS IS" BASIS,
11//  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12//  See the License for the specific language governing permissions and
13//  limitations under the License.
14// -------------------------------------------------------------------------------------------------
15
16//! A `UnixNanos` type for working with timestamps in nanoseconds since the UNIX epoch.
17//!
18//! This module provides a strongly-typed representation of timestamps as nanoseconds
19//! since the UNIX epoch (January 1, 1970, 00:00:00 UTC). The `UnixNanos` type offers
20//! conversion utilities, arithmetic operations, and comparison methods.
21//!
22//! # Features
23//!
24//! - Zero-cost abstraction with appropriate operator implementations.
25//! - Conversion to/from `DateTime<Utc>`.
26//! - RFC 3339 string formatting.
27//! - Duration calculations.
28//! - Flexible parsing and serialization.
29//!
30//! # Parsing and Serialization
31#![allow(
32    clippy::cast_possible_truncation,
33    clippy::cast_sign_loss,
34    clippy::cast_precision_loss,
35    clippy::cast_possible_wrap
36)]
37//!
38//! `UnixNanos` can be created from and serialized to various formats:
39//!
40//! * Integer values are interpreted as nanoseconds since the UNIX epoch.
41//! * Floating-point values are interpreted as seconds since the UNIX epoch (converted to nanoseconds).
42//! * String values may be:
43//!   - A numeric string (interpreted as nanoseconds).
44//!   - A floating-point string (interpreted as seconds, converted to nanoseconds).
45//!   - An RFC 3339 formatted timestamp (ISO 8601 with timezone).
46//!   - A simple date string in YYYY-MM-DD format (interpreted as midnight UTC on that date).
47//!
48//! # Limitations
49//!
50//! * Negative timestamps are invalid and will result in an error.
51//! * Arithmetic operations will panic on overflow/underflow rather than wrapping.
52
53use std::{
54    cmp::Ordering,
55    fmt::Display,
56    ops::{Add, AddAssign, Deref, Sub, SubAssign},
57    str::FromStr,
58};
59
60use chrono::{DateTime, NaiveDate, Utc};
61use serde::{
62    Deserialize, Deserializer, Serialize,
63    de::{self, Visitor},
64};
65
66/// Represents a duration in nanoseconds.
67pub type DurationNanos = u64;
68
69/// Represents a timestamp in nanoseconds since the UNIX epoch.
70#[repr(C)]
71#[derive(Clone, Copy, Debug, Default, PartialEq, Eq, PartialOrd, Ord, Hash, Serialize)]
72pub struct UnixNanos(u64);
73
74impl UnixNanos {
75    /// Creates a new [`UnixNanos`] instance.
76    #[must_use]
77    pub const fn new(value: u64) -> Self {
78        Self(value)
79    }
80
81    /// Creates a new [`UnixNanos`] instance with the maximum valid value.
82    #[must_use]
83    pub const fn max() -> Self {
84        Self(u64::MAX)
85    }
86
87    /// Returns `true` if the value of this instance is zero.
88    #[must_use]
89    pub const fn is_zero(&self) -> bool {
90        self.0 == 0
91    }
92
93    /// Returns the underlying value as `u64`.
94    #[must_use]
95    pub const fn as_u64(&self) -> u64 {
96        self.0
97    }
98
99    /// Returns the underlying value as `i64`.
100    ///
101    /// # Panics
102    ///
103    /// Panics if the value exceeds `i64::MAX` (approximately year 2262).
104    #[must_use]
105    pub const fn as_i64(&self) -> i64 {
106        assert!(
107            self.0 <= i64::MAX as u64,
108            "UnixNanos value exceeds i64::MAX"
109        );
110        self.0 as i64
111    }
112
113    /// Returns the underlying value as `f64`.
114    #[must_use]
115    pub const fn as_f64(&self) -> f64 {
116        self.0 as f64
117    }
118
119    /// Converts the underlying value to a datetime (UTC).
120    ///
121    /// # Panics
122    ///
123    /// Panics if the value exceeds `i64::MAX` (approximately year 2262).
124    #[must_use]
125    pub const fn to_datetime_utc(&self) -> DateTime<Utc> {
126        DateTime::from_timestamp_nanos(self.as_i64())
127    }
128
129    /// Converts the underlying value to an ISO 8601 (RFC 3339) string.
130    #[must_use]
131    pub fn to_rfc3339(&self) -> String {
132        self.to_datetime_utc().to_rfc3339()
133    }
134
135    /// Calculates the duration in nanoseconds since another [`UnixNanos`] instance.
136    ///
137    /// Returns `Some(duration)` if `self` is later than `other`, otherwise `None` if `other` is
138    /// greater than `self` (indicating a negative duration is not possible with `DurationNanos`).
139    #[must_use]
140    pub const fn duration_since(&self, other: &Self) -> Option<DurationNanos> {
141        self.0.checked_sub(other.0)
142    }
143
144    fn parse_string(s: &str) -> Result<Self, String> {
145        // Try parsing as an integer (nanoseconds)
146        if let Ok(int_value) = s.parse::<u64>() {
147            return Ok(Self(int_value));
148        }
149
150        // If the string is composed solely of digits but didn't fit in a u64 we
151        // treat that as an overflow error rather than attempting to interpret
152        // it as seconds in floating-point form. This avoids the surprising
153        // situation where a caller provides nanoseconds but gets an out-of-
154        // range float interpretation instead.
155        if s.chars().all(|c| c.is_ascii_digit()) {
156            return Err("Unix timestamp is out of range".into());
157        }
158
159        // Try parsing as a floating point number (seconds)
160        if let Ok(float_value) = s.parse::<f64>() {
161            if !float_value.is_finite() {
162                return Err("Unix timestamp must be finite".into());
163            }
164
165            if float_value < 0.0 {
166                return Err("Unix timestamp cannot be negative".into());
167            }
168
169            // Convert seconds to nanoseconds while checking for overflow
170            // We perform the multiplication in `f64`, then validate the
171            // result fits inside `u64` *before* rounding / casting.
172            const MAX_NS_F64: f64 = u64::MAX as f64;
173            let nanos_f64 = float_value * 1_000_000_000.0;
174
175            if nanos_f64 > MAX_NS_F64 {
176                return Err("Unix timestamp is out of range".into());
177            }
178
179            let nanos = nanos_f64.round() as u64;
180            return Ok(Self(nanos));
181        }
182
183        // Try parsing as an RFC 3339 timestamp
184        if let Ok(datetime) = DateTime::parse_from_rfc3339(s) {
185            let nanos = datetime
186                .timestamp_nanos_opt()
187                .ok_or_else(|| "Timestamp out of range".to_string())?;
188
189            if nanos < 0 {
190                return Err("Unix timestamp cannot be negative".into());
191            }
192
193            // SAFETY: Checked that nanos >= 0, so cast to u64 is safe
194            return Ok(Self(nanos as u64));
195        }
196
197        // Try parsing as a simple date string (YYYY-MM-DD format)
198        if let Ok(datetime) = NaiveDate::parse_from_str(s, "%Y-%m-%d")
199            // SAFETY: unwrap() is safe here because and_hms_opt(0, 0, 0) always succeeds
200            // for valid dates (midnight is always a valid time)
201            .map(|date| date.and_hms_opt(0, 0, 0).unwrap())
202            .map(|naive_dt| DateTime::<Utc>::from_naive_utc_and_offset(naive_dt, Utc))
203        {
204            let nanos = datetime
205                .timestamp_nanos_opt()
206                .ok_or_else(|| "Timestamp out of range".to_string())?;
207            // SAFETY: timestamp_nanos_opt() returns >= 0 for valid dates
208            return Ok(Self(nanos as u64));
209        }
210
211        Err(format!("Invalid format: {s}"))
212    }
213
214    /// Returns `Some(self + rhs)` or `None` if the addition would overflow
215    #[must_use]
216    pub fn checked_add<T: Into<u64>>(self, rhs: T) -> Option<Self> {
217        self.0.checked_add(rhs.into()).map(Self)
218    }
219
220    /// Returns `Some(self - rhs)` or `None` if the subtraction would underflow
221    #[must_use]
222    pub fn checked_sub<T: Into<u64>>(self, rhs: T) -> Option<Self> {
223        self.0.checked_sub(rhs.into()).map(Self)
224    }
225
226    /// Saturating addition – if overflow occurs the value is clamped to `u64::MAX`.
227    #[must_use]
228    pub fn saturating_add_ns<T: Into<u64>>(self, rhs: T) -> Self {
229        Self(self.0.saturating_add(rhs.into()))
230    }
231
232    /// Saturating subtraction – if underflow occurs the value is clamped to `0`.
233    #[must_use]
234    pub fn saturating_sub_ns<T: Into<u64>>(self, rhs: T) -> Self {
235        Self(self.0.saturating_sub(rhs.into()))
236    }
237}
238
239impl Deref for UnixNanos {
240    type Target = u64;
241
242    fn deref(&self) -> &Self::Target {
243        &self.0
244    }
245}
246
247impl PartialEq<u64> for UnixNanos {
248    fn eq(&self, other: &u64) -> bool {
249        self.0 == *other
250    }
251}
252
253impl PartialOrd<u64> for UnixNanos {
254    fn partial_cmp(&self, other: &u64) -> Option<Ordering> {
255        self.0.partial_cmp(other)
256    }
257}
258
259impl PartialEq<Option<u64>> for UnixNanos {
260    fn eq(&self, other: &Option<u64>) -> bool {
261        match other {
262            Some(value) => self.0 == *value,
263            None => false,
264        }
265    }
266}
267
268impl PartialOrd<Option<u64>> for UnixNanos {
269    fn partial_cmp(&self, other: &Option<u64>) -> Option<Ordering> {
270        match other {
271            Some(value) => self.0.partial_cmp(value),
272            None => Some(Ordering::Greater),
273        }
274    }
275}
276
277impl PartialEq<UnixNanos> for u64 {
278    fn eq(&self, other: &UnixNanos) -> bool {
279        *self == other.0
280    }
281}
282
283impl PartialOrd<UnixNanos> for u64 {
284    fn partial_cmp(&self, other: &UnixNanos) -> Option<Ordering> {
285        self.partial_cmp(&other.0)
286    }
287}
288
289impl From<u64> for UnixNanos {
290    fn from(value: u64) -> Self {
291        Self(value)
292    }
293}
294
295impl From<UnixNanos> for u64 {
296    fn from(value: UnixNanos) -> Self {
297        value.0
298    }
299}
300
301impl From<&str> for UnixNanos {
302    fn from(value: &str) -> Self {
303        value
304            .parse()
305            .unwrap_or_else(|e| panic!("Failed to parse string into UnixNanos: {e}"))
306    }
307}
308
309impl From<String> for UnixNanos {
310    fn from(value: String) -> Self {
311        value
312            .parse()
313            .unwrap_or_else(|e| panic!("Failed to parse string into UnixNanos: {e}"))
314    }
315}
316
317impl From<DateTime<Utc>> for UnixNanos {
318    fn from(value: DateTime<Utc>) -> Self {
319        let nanos = value
320            .timestamp_nanos_opt()
321            .expect("DateTime timestamp out of range for UnixNanos");
322
323        assert!(nanos >= 0, "DateTime timestamp cannot be negative: {nanos}");
324
325        Self::from(nanos as u64)
326    }
327}
328
329impl FromStr for UnixNanos {
330    type Err = Box<dyn std::error::Error>;
331
332    fn from_str(s: &str) -> Result<Self, Self::Err> {
333        Self::parse_string(s).map_err(std::convert::Into::into)
334    }
335}
336
337impl Add for UnixNanos {
338    type Output = Self;
339
340    fn add(self, rhs: Self) -> Self::Output {
341        Self(
342            self.0
343                .checked_add(rhs.0)
344                .expect("Error adding with overflow"),
345        )
346    }
347}
348
349impl Sub for UnixNanos {
350    type Output = Self;
351
352    fn sub(self, rhs: Self) -> Self::Output {
353        Self(
354            self.0
355                .checked_sub(rhs.0)
356                .expect("Error subtracting with underflow"),
357        )
358    }
359}
360
361impl Add<u64> for UnixNanos {
362    type Output = Self;
363
364    fn add(self, rhs: u64) -> Self::Output {
365        Self(self.0.checked_add(rhs).expect("Error adding with overflow"))
366    }
367}
368
369impl Sub<u64> for UnixNanos {
370    type Output = Self;
371
372    fn sub(self, rhs: u64) -> Self::Output {
373        Self(
374            self.0
375                .checked_sub(rhs)
376                .expect("Error subtracting with underflow"),
377        )
378    }
379}
380
381impl<T: Into<u64>> AddAssign<T> for UnixNanos {
382    fn add_assign(&mut self, other: T) {
383        let other_u64 = other.into();
384        self.0 = self
385            .0
386            .checked_add(other_u64)
387            .expect("Error adding with overflow");
388    }
389}
390
391impl<T: Into<u64>> SubAssign<T> for UnixNanos {
392    fn sub_assign(&mut self, other: T) {
393        let other_u64 = other.into();
394        self.0 = self
395            .0
396            .checked_sub(other_u64)
397            .expect("Error subtracting with underflow");
398    }
399}
400
401impl Display for UnixNanos {
402    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
403        write!(f, "{}", self.0)
404    }
405}
406
407impl From<UnixNanos> for DateTime<Utc> {
408    fn from(value: UnixNanos) -> Self {
409        value.to_datetime_utc()
410    }
411}
412
413impl<'de> Deserialize<'de> for UnixNanos {
414    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
415    where
416        D: Deserializer<'de>,
417    {
418        struct UnixNanosVisitor;
419
420        impl Visitor<'_> for UnixNanosVisitor {
421            type Value = UnixNanos;
422
423            fn expecting(&self, formatter: &mut std::fmt::Formatter) -> std::fmt::Result {
424                formatter.write_str("an integer, a string integer, or an RFC 3339 timestamp")
425            }
426
427            fn visit_u64<E>(self, value: u64) -> Result<Self::Value, E>
428            where
429                E: de::Error,
430            {
431                Ok(UnixNanos(value))
432            }
433
434            fn visit_i64<E>(self, value: i64) -> Result<Self::Value, E>
435            where
436                E: de::Error,
437            {
438                if value < 0 {
439                    return Err(E::custom("Unix timestamp cannot be negative"));
440                }
441                Ok(UnixNanos(value as u64))
442            }
443
444            fn visit_f64<E>(self, value: f64) -> Result<Self::Value, E>
445            where
446                E: de::Error,
447            {
448                if value < 0.0 {
449                    return Err(E::custom("Unix timestamp cannot be negative"));
450                }
451                // Convert from seconds to nanoseconds
452                let nanos = (value * 1_000_000_000.0).round() as u64;
453                Ok(UnixNanos(nanos))
454            }
455
456            fn visit_str<E>(self, value: &str) -> Result<Self::Value, E>
457            where
458                E: de::Error,
459            {
460                UnixNanos::parse_string(value).map_err(E::custom)
461            }
462        }
463
464        deserializer.deserialize_any(UnixNanosVisitor)
465    }
466}
467
468////////////////////////////////////////////////////////////////////////////////
469// Tests
470////////////////////////////////////////////////////////////////////////////////
471#[cfg(test)]
472mod tests {
473    use chrono::{Duration, TimeZone};
474    use rstest::rstest;
475
476    use super::*;
477
478    #[rstest]
479    fn test_new() {
480        let nanos = UnixNanos::new(123);
481        assert_eq!(nanos.as_u64(), 123);
482        assert_eq!(nanos.as_i64(), 123);
483    }
484
485    #[rstest]
486    fn test_max() {
487        let nanos = UnixNanos::max();
488        assert_eq!(nanos.as_u64(), u64::MAX);
489    }
490
491    #[rstest]
492    fn test_is_zero() {
493        assert!(UnixNanos::default().is_zero());
494        assert!(!UnixNanos::max().is_zero());
495    }
496
497    #[rstest]
498    fn test_from_u64() {
499        let nanos = UnixNanos::from(123);
500        assert_eq!(nanos.as_u64(), 123);
501        assert_eq!(nanos.as_i64(), 123);
502    }
503
504    #[rstest]
505    fn test_default() {
506        let nanos = UnixNanos::default();
507        assert_eq!(nanos.as_u64(), 0);
508        assert_eq!(nanos.as_i64(), 0);
509    }
510
511    #[rstest]
512    fn test_into_from() {
513        let nanos: UnixNanos = 456.into();
514        let value: u64 = nanos.into();
515        assert_eq!(value, 456);
516    }
517
518    #[rstest]
519    #[case(0, "1970-01-01T00:00:00+00:00")]
520    #[case(1_000_000_000, "1970-01-01T00:00:01+00:00")]
521    #[case(1_000_000_000_000_000_000, "2001-09-09T01:46:40+00:00")]
522    #[case(1_500_000_000_000_000_000, "2017-07-14T02:40:00+00:00")]
523    #[case(1_707_577_123_456_789_000, "2024-02-10T14:58:43.456789+00:00")]
524    fn test_to_datetime_utc(#[case] nanos: u64, #[case] expected: &str) {
525        let nanos = UnixNanos::from(nanos);
526        let datetime = nanos.to_datetime_utc();
527        assert_eq!(datetime.to_rfc3339(), expected);
528    }
529
530    #[rstest]
531    #[case(0, "1970-01-01T00:00:00+00:00")]
532    #[case(1_000_000_000, "1970-01-01T00:00:01+00:00")]
533    #[case(1_000_000_000_000_000_000, "2001-09-09T01:46:40+00:00")]
534    #[case(1_500_000_000_000_000_000, "2017-07-14T02:40:00+00:00")]
535    #[case(1_707_577_123_456_789_000, "2024-02-10T14:58:43.456789+00:00")]
536    fn test_to_rfc3339(#[case] nanos: u64, #[case] expected: &str) {
537        let nanos = UnixNanos::from(nanos);
538        assert_eq!(nanos.to_rfc3339(), expected);
539    }
540
541    #[rstest]
542    fn test_from_str() {
543        let nanos: UnixNanos = "123".parse().unwrap();
544        assert_eq!(nanos.as_u64(), 123);
545    }
546
547    #[rstest]
548    fn test_from_str_invalid() {
549        let result = "abc".parse::<UnixNanos>();
550        assert!(result.is_err());
551    }
552
553    #[rstest]
554    fn test_try_from_datetime_valid() {
555        use chrono::TimeZone;
556        let datetime = Utc.timestamp_opt(1_000_000_000, 0).unwrap(); // 1 billion seconds since epoch
557        let nanos = UnixNanos::from(datetime);
558        assert_eq!(nanos.as_u64(), 1_000_000_000_000_000_000);
559    }
560
561    #[rstest]
562    fn test_eq() {
563        let nanos = UnixNanos::from(100);
564        assert_eq!(nanos, 100);
565        assert_eq!(nanos, Some(100));
566        assert_ne!(nanos, 200);
567        assert_ne!(nanos, Some(200));
568        assert_ne!(nanos, None);
569    }
570
571    #[rstest]
572    fn test_partial_cmp() {
573        let nanos = UnixNanos::from(100);
574        assert_eq!(nanos.partial_cmp(&100), Some(Ordering::Equal));
575        assert_eq!(nanos.partial_cmp(&200), Some(Ordering::Less));
576        assert_eq!(nanos.partial_cmp(&50), Some(Ordering::Greater));
577        assert_eq!(nanos.partial_cmp(&None), Some(Ordering::Greater));
578    }
579
580    #[rstest]
581    fn test_edge_case_max_value() {
582        let nanos = UnixNanos::from(u64::MAX);
583        assert_eq!(format!("{nanos}"), format!("{}", u64::MAX));
584    }
585
586    #[rstest]
587    fn test_display() {
588        let nanos = UnixNanos::from(123);
589        assert_eq!(format!("{nanos}"), "123");
590    }
591
592    #[rstest]
593    fn test_addition() {
594        let nanos1 = UnixNanos::from(100);
595        let nanos2 = UnixNanos::from(200);
596        let result = nanos1 + nanos2;
597        assert_eq!(result.as_u64(), 300);
598    }
599
600    #[rstest]
601    fn test_add_assign() {
602        let mut nanos = UnixNanos::from(100);
603        nanos += 50_u64;
604        assert_eq!(nanos.as_u64(), 150);
605    }
606
607    #[rstest]
608    fn test_subtraction() {
609        let nanos1 = UnixNanos::from(200);
610        let nanos2 = UnixNanos::from(100);
611        let result = nanos1 - nanos2;
612        assert_eq!(result.as_u64(), 100);
613    }
614
615    #[rstest]
616    fn test_sub_assign() {
617        let mut nanos = UnixNanos::from(200);
618        nanos -= 50_u64;
619        assert_eq!(nanos.as_u64(), 150);
620    }
621
622    #[rstest]
623    #[should_panic(expected = "Error adding with overflow")]
624    fn test_overflow_add() {
625        let nanos = UnixNanos::from(u64::MAX);
626        let _ = nanos + UnixNanos::from(1); // This should panic due to overflow
627    }
628
629    #[rstest]
630    #[should_panic(expected = "Error adding with overflow")]
631    fn test_overflow_add_u64() {
632        let nanos = UnixNanos::from(u64::MAX);
633        let _ = nanos + 1_u64; // This should panic due to overflow
634    }
635
636    #[rstest]
637    #[should_panic(expected = "Error subtracting with underflow")]
638    fn test_overflow_sub() {
639        let _ = UnixNanos::default() - UnixNanos::from(1); // This should panic due to underflow
640    }
641
642    #[rstest]
643    #[should_panic(expected = "Error subtracting with underflow")]
644    fn test_overflow_sub_u64() {
645        let _ = UnixNanos::default() - 1_u64; // This should panic due to underflow
646    }
647
648    #[rstest]
649    #[case(100, 50, Some(50))]
650    #[case(1_000_000_000, 500_000_000, Some(500_000_000))]
651    #[case(u64::MAX, u64::MAX - 1, Some(1))]
652    #[case(50, 50, Some(0))]
653    #[case(50, 100, None)]
654    #[case(0, 1, None)]
655    fn test_duration_since(
656        #[case] time1: u64,
657        #[case] time2: u64,
658        #[case] expected: Option<DurationNanos>,
659    ) {
660        let nanos1 = UnixNanos::from(time1);
661        let nanos2 = UnixNanos::from(time2);
662        assert_eq!(nanos1.duration_since(&nanos2), expected);
663    }
664
665    #[rstest]
666    fn test_duration_since_same_moment() {
667        let moment = UnixNanos::from(1_707_577_123_456_789_000);
668        assert_eq!(moment.duration_since(&moment), Some(0));
669    }
670
671    #[rstest]
672    fn test_duration_since_chronological() {
673        // Create a reference time (Feb 10, 2024)
674        let earlier = Utc.with_ymd_and_hms(2024, 2, 10, 12, 0, 0).unwrap();
675
676        // Create a time 1 hour, 30 minutes, and 45 seconds later (with nanoseconds)
677        let later = earlier
678            + Duration::hours(1)
679            + Duration::minutes(30)
680            + Duration::seconds(45)
681            + Duration::nanoseconds(500_000_000);
682
683        let earlier_nanos = UnixNanos::from(earlier);
684        let later_nanos = UnixNanos::from(later);
685
686        // Calculate expected duration in nanoseconds
687        let expected_duration = 60 * 60 * 1_000_000_000 + // 1 hour
688        30 * 60 * 1_000_000_000 + // 30 minutes
689        45 * 1_000_000_000 + // 45 seconds
690        500_000_000; // 500 million nanoseconds
691
692        assert_eq!(
693            later_nanos.duration_since(&earlier_nanos),
694            Some(expected_duration)
695        );
696        assert_eq!(earlier_nanos.duration_since(&later_nanos), None);
697    }
698
699    #[rstest]
700    fn test_duration_since_with_edge_cases() {
701        // Test with maximum value
702        let max = UnixNanos::from(u64::MAX);
703        let smaller = UnixNanos::from(u64::MAX - 1000);
704
705        assert_eq!(max.duration_since(&smaller), Some(1000));
706        assert_eq!(smaller.duration_since(&max), None);
707
708        // Test with minimum value
709        let min = UnixNanos::default(); // Zero timestamp
710        let larger = UnixNanos::from(1000);
711
712        assert_eq!(min.duration_since(&min), Some(0));
713        assert_eq!(larger.duration_since(&min), Some(1000));
714        assert_eq!(min.duration_since(&larger), None);
715    }
716
717    #[rstest]
718    fn test_serde_json() {
719        let nanos = UnixNanos::from(123);
720        let json = serde_json::to_string(&nanos).unwrap();
721        let deserialized: UnixNanos = serde_json::from_str(&json).unwrap();
722        assert_eq!(deserialized, nanos);
723    }
724
725    #[rstest]
726    fn test_serde_edge_cases() {
727        let nanos = UnixNanos::from(u64::MAX);
728        let json = serde_json::to_string(&nanos).unwrap();
729        let deserialized: UnixNanos = serde_json::from_str(&json).unwrap();
730        assert_eq!(deserialized, nanos);
731    }
732
733    #[rstest]
734    #[case("123", 123)] // Integer string
735    #[case("1234.567", 1_234_567_000_000)] // Float string (seconds to nanos)
736    #[case("2024-02-10", 1_707_523_200_000_000_000)] // Simple date (midnight UTC)
737    #[case("2024-02-10T14:58:43Z", 1_707_577_123_000_000_000)] // RFC3339 without fractions
738    #[case("2024-02-10T14:58:43.456789Z", 1_707_577_123_456_789_000)] // RFC3339 with fractions
739    fn test_from_str_formats(#[case] input: &str, #[case] expected: u64) {
740        let parsed: UnixNanos = input.parse().unwrap();
741        assert_eq!(parsed.as_u64(), expected);
742    }
743
744    #[rstest]
745    #[case("abc")] // Random string
746    #[case("not a timestamp")] // Non-timestamp string
747    #[case("2024-02-10 14:58:43")] // Space-separated format (not RFC3339)
748    fn test_from_str_invalid_formats(#[case] input: &str) {
749        let result = input.parse::<UnixNanos>();
750        assert!(result.is_err());
751    }
752
753    #[rstest]
754    fn test_from_str_integer_overflow() {
755        // One more digit than u64::MAX (20 digits) so definitely overflows
756        let input = "184467440737095516160";
757        let result = input.parse::<UnixNanos>();
758        assert!(result.is_err());
759    }
760
761    // ---------- checked / saturating arithmetic ----------
762
763    #[rstest]
764    fn test_checked_add_overflow_returns_none() {
765        let max = UnixNanos::from(u64::MAX);
766        assert_eq!(max.checked_add(1_u64), None);
767    }
768
769    #[rstest]
770    fn test_checked_sub_underflow_returns_none() {
771        let zero = UnixNanos::default();
772        assert_eq!(zero.checked_sub(1_u64), None);
773    }
774
775    #[rstest]
776    fn test_saturating_add_overflow() {
777        let max = UnixNanos::from(u64::MAX);
778        let result = max.saturating_add_ns(1_u64);
779        assert_eq!(result, UnixNanos::from(u64::MAX));
780    }
781
782    #[rstest]
783    fn test_saturating_sub_underflow() {
784        let zero = UnixNanos::default();
785        let result = zero.saturating_sub_ns(1_u64);
786        assert_eq!(result, UnixNanos::default());
787    }
788
789    #[rstest]
790    fn test_from_str_float_overflow() {
791        // Use scientific notation so we take the floating-point parsing path.
792        let input = "2e10"; // 20 billion seconds ~ 634 years (> u64::MAX nanoseconds)
793        let result = input.parse::<UnixNanos>();
794        assert!(result.is_err());
795    }
796
797    #[rstest]
798    fn test_deserialize_u64() {
799        let json = "123456789";
800        let deserialized: UnixNanos = serde_json::from_str(json).unwrap();
801        assert_eq!(deserialized.as_u64(), 123_456_789);
802    }
803
804    #[rstest]
805    fn test_deserialize_string_with_int() {
806        let json = "\"123456789\"";
807        let deserialized: UnixNanos = serde_json::from_str(json).unwrap();
808        assert_eq!(deserialized.as_u64(), 123_456_789);
809    }
810
811    #[rstest]
812    fn test_deserialize_float() {
813        let json = "1234.567";
814        let deserialized: UnixNanos = serde_json::from_str(json).unwrap();
815        assert_eq!(deserialized.as_u64(), 1_234_567_000_000);
816    }
817
818    #[rstest]
819    fn test_deserialize_string_with_float() {
820        let json = "\"1234.567\"";
821        let deserialized: UnixNanos = serde_json::from_str(json).unwrap();
822        assert_eq!(deserialized.as_u64(), 1_234_567_000_000);
823    }
824
825    #[rstest]
826    #[case("\"2024-02-10T14:58:43.456789Z\"", 1_707_577_123_456_789_000)]
827    #[case("\"2024-02-10T14:58:43Z\"", 1_707_577_123_000_000_000)]
828    fn test_deserialize_timestamp_strings(#[case] input: &str, #[case] expected: u64) {
829        let deserialized: UnixNanos = serde_json::from_str(input).unwrap();
830        assert_eq!(deserialized.as_u64(), expected);
831    }
832
833    #[rstest]
834    fn test_deserialize_negative_int_fails() {
835        let json = "-123456789";
836        let result: Result<UnixNanos, _> = serde_json::from_str(json);
837        assert!(result.is_err());
838    }
839
840    #[rstest]
841    fn test_deserialize_negative_float_fails() {
842        let json = "-1234.567";
843        let result: Result<UnixNanos, _> = serde_json::from_str(json);
844        assert!(result.is_err());
845    }
846
847    #[rstest]
848    fn test_deserialize_invalid_string_fails() {
849        let json = "\"not a timestamp\"";
850        let result: Result<UnixNanos, _> = serde_json::from_str(json);
851        assert!(result.is_err());
852    }
853
854    #[rstest]
855    fn test_deserialize_edge_cases() {
856        // Test zero
857        let json = "0";
858        let deserialized: UnixNanos = serde_json::from_str(json).unwrap();
859        assert_eq!(deserialized.as_u64(), 0);
860
861        // Test large value
862        let json = "18446744073709551615"; // u64::MAX
863        let deserialized: UnixNanos = serde_json::from_str(json).unwrap();
864        assert_eq!(deserialized.as_u64(), u64::MAX);
865    }
866
867    #[rstest]
868    #[should_panic(expected = "UnixNanos value exceeds i64::MAX")]
869    fn test_as_i64_overflow_panics() {
870        let nanos = UnixNanos::from(u64::MAX);
871        let _ = nanos.as_i64(); // Should panic
872    }
873
874    ////////////////////////////////////////////////////////////////////////////////
875    // Property-based testing
876    ////////////////////////////////////////////////////////////////////////////////
877
878    use proptest::prelude::*;
879
880    fn unix_nanos_strategy() -> impl Strategy<Value = UnixNanos> {
881        prop_oneof![
882            // Small values
883            0u64..1_000_000u64,
884            // Medium values (microseconds range)
885            1_000_000u64..1_000_000_000_000u64,
886            // Large values (nanoseconds since 1970, but safe for arithmetic)
887            1_000_000_000_000u64..=i64::MAX as u64,
888            // Edge cases
889            Just(0u64),
890            Just(1u64),
891            Just(1_000_000_000u64),             // 1 second in nanos
892            Just(1_000_000_000_000u64),         // ~2001 timestamp
893            Just(1_700_000_000_000_000_000u64), // ~2023 timestamp
894            Just((i64::MAX / 2) as u64),        // Safe for doubling
895        ]
896        .prop_map(UnixNanos::from)
897    }
898
899    fn unix_nanos_pair_strategy() -> impl Strategy<Value = (UnixNanos, UnixNanos)> {
900        (unix_nanos_strategy(), unix_nanos_strategy())
901    }
902
903    proptest! {
904        #[rstest]
905        fn prop_unix_nanos_construction_roundtrip(value in 0u64..=i64::MAX as u64) {
906            let nanos = UnixNanos::from(value);
907            prop_assert_eq!(nanos.as_u64(), value);
908            prop_assert_eq!(nanos.as_f64(), value as f64);
909
910            // Test i64 conversion only for values within i64 range
911            if i64::try_from(value).is_ok() {
912                prop_assert_eq!(nanos.as_i64(), value as i64);
913            }
914        }
915
916        #[rstest]
917        fn prop_unix_nanos_addition_commutative(
918            (nanos1, nanos2) in unix_nanos_pair_strategy()
919        ) {
920            // Addition should be commutative when no overflow occurs
921            if let (Some(sum1), Some(sum2)) = (
922                nanos1.checked_add(nanos2.as_u64()),
923                nanos2.checked_add(nanos1.as_u64())
924            ) {
925                prop_assert_eq!(sum1, sum2, "Addition should be commutative");
926            }
927        }
928
929        #[rstest]
930        fn prop_unix_nanos_addition_associative(
931            nanos1 in unix_nanos_strategy(),
932            nanos2 in unix_nanos_strategy(),
933            nanos3 in unix_nanos_strategy(),
934        ) {
935            // Addition should be associative when no overflow occurs
936            if let (Some(sum1), Some(sum2)) = (
937                nanos1.as_u64().checked_add(nanos2.as_u64()),
938                nanos2.as_u64().checked_add(nanos3.as_u64())
939            )
940                && let (Some(left), Some(right)) = (
941                    sum1.checked_add(nanos3.as_u64()),
942                    nanos1.as_u64().checked_add(sum2)
943                ) {
944                    let left_result = UnixNanos::from(left);
945                    let right_result = UnixNanos::from(right);
946                    prop_assert_eq!(left_result, right_result, "Addition should be associative");
947                }
948        }
949
950        #[rstest]
951        fn prop_unix_nanos_subtraction_inverse(
952            (nanos1, nanos2) in unix_nanos_pair_strategy()
953        ) {
954            // Subtraction should be the inverse of addition when no underflow occurs
955            if let Some(sum) = nanos1.checked_add(nanos2.as_u64()) {
956                let diff = sum - nanos2;
957                prop_assert_eq!(diff, nanos1, "Subtraction should be inverse of addition");
958            }
959        }
960
961        #[rstest]
962        fn prop_unix_nanos_zero_identity(nanos in unix_nanos_strategy()) {
963            // Zero should be additive identity
964            let zero = UnixNanos::default();
965            prop_assert_eq!(nanos + zero, nanos, "Zero should be additive identity");
966            prop_assert_eq!(zero + nanos, nanos, "Zero should be additive identity (commutative)");
967            prop_assert!(zero.is_zero(), "Zero should be recognized as zero");
968        }
969
970        #[rstest]
971        fn prop_unix_nanos_ordering_consistency(
972            (nanos1, nanos2) in unix_nanos_pair_strategy()
973        ) {
974            // Ordering operations should be consistent
975            let eq = nanos1 == nanos2;
976            let lt = nanos1 < nanos2;
977            let gt = nanos1 > nanos2;
978            let le = nanos1 <= nanos2;
979            let ge = nanos1 >= nanos2;
980
981            // Exactly one of eq, lt, gt should be true
982            let exclusive_count = [eq, lt, gt].iter().filter(|&&x| x).count();
983            prop_assert_eq!(exclusive_count, 1, "Exactly one of ==, <, > should be true");
984
985            // Consistency checks
986            prop_assert_eq!(le, eq || lt, "<= should equal == || <");
987            prop_assert_eq!(ge, eq || gt, ">= should equal == || >");
988            prop_assert_eq!(lt, nanos2 > nanos1, "< should be symmetric with >");
989            prop_assert_eq!(le, nanos2 >= nanos1, "<= should be symmetric with >=");
990        }
991
992        #[rstest]
993        fn prop_unix_nanos_string_roundtrip(nanos in unix_nanos_strategy()) {
994            // String serialization should round-trip correctly
995            let string_repr = nanos.to_string();
996            let parsed = UnixNanos::from_str(&string_repr);
997            prop_assert!(parsed.is_ok(), "String parsing should succeed for valid UnixNanos");
998            if let Ok(parsed_nanos) = parsed {
999                prop_assert_eq!(parsed_nanos, nanos, "String should round-trip exactly");
1000            }
1001        }
1002
1003        #[rstest]
1004        fn prop_unix_nanos_datetime_conversion(nanos in unix_nanos_strategy()) {
1005            // DateTime conversion should be consistent (only test values within i64 range)
1006            if i64::try_from(nanos.as_u64()).is_ok() {
1007                let datetime = nanos.to_datetime_utc();
1008                let converted_back = UnixNanos::from(datetime);
1009                prop_assert_eq!(converted_back, nanos, "DateTime conversion should round-trip");
1010
1011                // RFC3339 string should also round-trip for valid dates
1012                let rfc3339 = nanos.to_rfc3339();
1013                if let Ok(parsed_from_rfc3339) = UnixNanos::from_str(&rfc3339) {
1014                    prop_assert_eq!(parsed_from_rfc3339, nanos, "RFC3339 string should round-trip");
1015                }
1016            }
1017        }
1018
1019        #[rstest]
1020        fn prop_unix_nanos_duration_since(
1021            (nanos1, nanos2) in unix_nanos_pair_strategy()
1022        ) {
1023            // duration_since should be consistent with comparison and arithmetic
1024            let duration = nanos1.duration_since(&nanos2);
1025
1026            if nanos1 >= nanos2 {
1027                // If nanos1 >= nanos2, duration should be Some and equal to difference
1028                prop_assert!(duration.is_some(), "Duration should be Some when first >= second");
1029                if let Some(dur) = duration {
1030                    prop_assert_eq!(dur, nanos1.as_u64() - nanos2.as_u64(),
1031                        "Duration should equal the difference");
1032                    prop_assert_eq!(nanos2 + dur, nanos1.as_u64(),
1033                        "second + duration should equal first");
1034                }
1035            } else {
1036                // If nanos1 < nanos2, duration should be None
1037                prop_assert!(duration.is_none(), "Duration should be None when first < second");
1038            }
1039        }
1040
1041        #[rstest]
1042        fn prop_unix_nanos_checked_arithmetic(
1043            (nanos1, nanos2) in unix_nanos_pair_strategy()
1044        ) {
1045            // Checked arithmetic should be consistent with regular arithmetic when no overflow/underflow
1046            let checked_add = nanos1.checked_add(nanos2.as_u64());
1047            let checked_sub = nanos1.checked_sub(nanos2.as_u64());
1048
1049            // If checked_add succeeds, regular addition should produce the same result
1050            if let Some(sum) = checked_add
1051                && nanos1.as_u64().checked_add(nanos2.as_u64()).is_some() {
1052                    prop_assert_eq!(sum, nanos1 + nanos2, "Checked add should match regular add when no overflow");
1053                }
1054
1055            // If checked_sub succeeds, regular subtraction should produce the same result
1056            if let Some(diff) = checked_sub
1057                && nanos1.as_u64() >= nanos2.as_u64() {
1058                    prop_assert_eq!(diff, nanos1 - nanos2, "Checked sub should match regular sub when no underflow");
1059                }
1060        }
1061
1062        #[rstest]
1063        fn prop_unix_nanos_saturating_arithmetic(
1064            (nanos1, nanos2) in unix_nanos_pair_strategy()
1065        ) {
1066            // Saturating arithmetic should never panic and produce reasonable results
1067            let sat_add = nanos1.saturating_add_ns(nanos2.as_u64());
1068            let sat_sub = nanos1.saturating_sub_ns(nanos2.as_u64());
1069
1070            // Saturating add should be >= both operands
1071            prop_assert!(sat_add >= nanos1, "Saturating add result should be >= first operand");
1072            prop_assert!(sat_add.as_u64() >= nanos2.as_u64(), "Saturating add result should be >= second operand");
1073
1074            // Saturating sub should be <= first operand
1075            prop_assert!(sat_sub <= nanos1, "Saturating sub result should be <= first operand");
1076
1077            // If no overflow/underflow would occur, saturating should match checked
1078            if let Some(checked_sum) = nanos1.checked_add(nanos2.as_u64()) {
1079                prop_assert_eq!(sat_add, checked_sum, "Saturating add should match checked add when no overflow");
1080            } else {
1081                prop_assert_eq!(sat_add, UnixNanos::from(u64::MAX), "Saturating add should be MAX on overflow");
1082            }
1083
1084            if let Some(checked_diff) = nanos1.checked_sub(nanos2.as_u64()) {
1085                prop_assert_eq!(sat_sub, checked_diff, "Saturating sub should match checked sub when no underflow");
1086            } else {
1087                prop_assert_eq!(sat_sub, UnixNanos::default(), "Saturating sub should be zero on underflow");
1088            }
1089        }
1090    }
1091}
nautilus_core/nanos.rs

nautilus_core/
nanos.rs
