deep-time 0.1.0-beta.21

High-precision, no-std, no-alloc date-time library, leap-seconds, time scales, relativistic time, and a powerful date & duration parser
Documentation
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#![allow(clippy::all, clippy::pedantic, clippy::restriction, warnings)]

#[cfg(feature = "perf-tests")]
mod perf_tests {
    use deep_time::civil_parts::Parts;
    use deep_time::{Dt, Lang, ParseCfg, Scale};
    use std::time::Instant;

    #[test]
    fn combined_perf_tests() {
        // All timing loops and test cases are left unchanged.
        // Results are captured and only two tables are emitted (via eprintln!) at the very end.

        // ── results (populated by the benchmark blocks below) ───────────────────
        let mut gps_deep_ns = 0.0f64;
        let mut gps_hifi_ns = 0.0f64;
        let mut tow_deep_ns = 0.0f64;
        let mut tow_hifi_ns = 0.0f64;

        let mut tai_utc_deep_ns = 0.0f64;
        let mut tai_utc_hifi_ns = 0.0f64;
        let mut utc_tai_deep_ns = 0.0f64;
        let mut utc_tai_hifi_ns = 0.0f64;

        let mut tai_tdb_deep_ns = 0.0f64;
        let mut tai_tdb_hifi_ns = 0.0f64;
        let mut tdb_tai_deep_ns = 0.0f64;
        let mut tdb_tai_hifi_ns = 0.0f64;

        let mut auto_ns_per = 0.0f64;

        let mut strptime_timeparts_ns = 0.0f64;
        let mut strptime_jiff_ns = 0.0f64;

        let mut zoned_deep_ns = 0.0f64;
        let mut zoned_jiff_ns = 0.0f64;

        let mut iso_deep_ns = 0.0f64;
        let mut iso_jiff_ns = 0.0f64;

        let mut strftime_deep_ns = 0.0f64;
        let mut strftime_jiff_ns = 0.0f64;

        // ═══════════════════════════════════════════════════════════════════════
        // GPS CONVERSION PERF — deep_time vs hifitime 4.x
        // ═══════════════════════════════════════════════════════════════════════
        {
            use hifitime::{Epoch, TimeScale};
            use std::hint::black_box;

            const ITERATIONS: usize = 10_000_000;

            let deep_tai = Dt::from_ymd(2000, 1, 1, Scale::UTC, 0, 0, 0, 0);
            let hifi_tai = Epoch::from_gregorian_tai(2000, 1, 1, 12, 0, 0, 0);

            let start = Instant::now();
            for _ in 0..ITERATIONS {
                let _ = black_box(deep_tai).to_gps();
            }
            gps_deep_ns = start.elapsed().as_nanos() as f64 / ITERATIONS as f64;

            let start = Instant::now();
            for _ in 0..ITERATIONS {
                let _ = black_box(hifi_tai).to_time_scale(black_box(TimeScale::GPST));
            }
            gps_hifi_ns = start.elapsed().as_nanos() as f64 / ITERATIONS as f64;

            let start = Instant::now();
            for _ in 0..ITERATIONS {
                let _ = black_box(deep_tai).to_gps_wk_and_tow();
            }
            tow_deep_ns = start.elapsed().as_nanos() as f64 / ITERATIONS as f64;
            let start = Instant::now();
            for _ in 0..ITERATIONS {
                let _ = black_box(hifi_tai).to_gpst_seconds();
            }
            tow_hifi_ns = start.elapsed().as_nanos() as f64 / ITERATIONS as f64;
        }

        // ═══════════════════════════════════════════════════════════════════════
        // TAI ↔ UTC PERF — deep_time vs hifitime 4.x
        // ═══════════════════════════════════════════════════════════════════════
        {
            use hifitime::{Epoch, TimeScale};
            use std::hint::black_box;

            const ITERATIONS: usize = 10_000_000;

            let deep_tai = Dt::from_ymd(2000, 1, 1, Scale::UTC, 0, 0, 0, 0);
            let hifi_tai = Epoch::from_gregorian_tai(2000, 1, 1, 0, 0, 0, 0);

            // TAI → UTC
            let start = Instant::now();
            for _ in 0..ITERATIONS {
                let _ = black_box(deep_tai).to(black_box(Scale::UTC));
            }
            tai_utc_deep_ns = start.elapsed().as_nanos() as f64 / ITERATIONS as f64;

            let start = Instant::now();
            for _ in 0..ITERATIONS {
                let _ = black_box(hifi_tai).to_time_scale(black_box(TimeScale::UTC));
            }
            tai_utc_hifi_ns = start.elapsed().as_nanos() as f64 / ITERATIONS as f64;

            // UTC → TAI
            let deep_utc = deep_tai.to(Scale::UTC);
            let hifi_utc = hifi_tai.to_time_scale(TimeScale::UTC);

            let start = Instant::now();
            for _ in 0..ITERATIONS {
                let _ = black_box(deep_utc).to(black_box(Scale::TAI));
            }
            utc_tai_deep_ns = start.elapsed().as_nanos() as f64 / ITERATIONS as f64;

            let start = Instant::now();
            for _ in 0..ITERATIONS {
                let _ = black_box(hifi_utc).to_time_scale(black_box(TimeScale::TAI));
            }
            utc_tai_hifi_ns = start.elapsed().as_nanos() as f64 / ITERATIONS as f64;
        }

        // ═══════════════════════════════════════════════════════════════════════
        // TAI ↔ TDB PERF — deep_time vs hifitime 4.x
        // ═══════════════════════════════════════════════════════════════════════
        {
            use hifitime::{Epoch, TimeScale};
            use std::hint::black_box;

            const ITERATIONS: usize = 1_000_000;

            // Same reference instant: J2000.0 (2000-01-01 12:00:00 TAI)
            let deep_tai = Dt::from_ymd(2000, 1, 1, Scale::UTC, 0, 0, 0, 0);
            let hifi_tai = Epoch::from_gregorian_tai(2000, 1, 1, 12, 0, 0, 0);

            // ── TAI → TDB ─────────────────────────────────────────────────────
            let start = Instant::now();
            for _ in 0..ITERATIONS {
                let _ = black_box(deep_tai).to(black_box(Scale::TDB));
            }
            tai_tdb_deep_ns = start.elapsed().as_nanos() as f64 / ITERATIONS as f64;

            let start = Instant::now();
            for _ in 0..ITERATIONS {
                let _ = black_box(hifi_tai).to_time_scale(black_box(TimeScale::TDB));
            }
            tai_tdb_hifi_ns = start.elapsed().as_nanos() as f64 / ITERATIONS as f64;

            // ── TDB → TAI ─────────────────────────────────────────────────────
            let deep_tdb = deep_tai.to(Scale::TDB);
            let hifi_tdb = hifi_tai.to_time_scale(TimeScale::TDB);

            let start = Instant::now();
            for _ in 0..ITERATIONS {
                let _ = black_box(deep_tdb).to(black_box(Scale::TAI));
            }
            tdb_tai_deep_ns = start.elapsed().as_nanos() as f64 / ITERATIONS as f64;

            let start = Instant::now();
            for _ in 0..ITERATIONS {
                let _ = black_box(hifi_tdb).to_time_scale(black_box(TimeScale::TAI));
            }
            tdb_tai_hifi_ns = start.elapsed().as_nanos() as f64 / ITERATIONS as f64;
        }

        // ═══════════════════════════════════════════════════════════════════════
        // DATE AUTO PARSER PERF
        // ═══════════════════════════════════════════════════════════════════════
        {
            let cases: Vec<&str> = vec![
                "2024-03-14",
                "14 Mar 2024",
                "Mar 14, 2024",
                "2024/03/14",
                "14.03.2024",
                "14/03/2024",
                "240314",
                "202403",
                "2024073",
                "24073",
                "60400",
                "2460000",
                "1700000000",
                "1700000000000",
                "15/03/2024 14:30:45.123456",
                "Mar 15, 2024 14:30",
                "2024-03-14T15:30:45.123456Z",
                "2024-03-14T15:30:45+01:00",
                // "Dec 31 23:59:59",
                "15/03/2024 14:30:45.123456789",
                "03/03/2024",
                "2024-074T15:30:45.123Z",
                // "YmdHMS",
                "240315",
                "-2024-03-14",
                "2024-03-14 15:30",
                "15 Mar 2024 14:30:45",
                // REMOVED: "20240314153045" (pure numeric YYYYMMDDHHMMSS case)
            ];

            const ITERATIONS: usize = 100_000;

            let start = Instant::now();
            for _ in 0..ITERATIONS {
                for &input in &cases {
                    let _ = Dt::from_str_parse(input, &ParseCfg::DEFAULT);
                }
            }
            let elapsed = start.elapsed();

            let total_parses = cases.len() * ITERATIONS;
            auto_ns_per = elapsed.as_nanos() as f64 / total_parses as f64;
        }

        // ═══════════════════════════════════════════════════════════════════════
        // strptime — Parts vs Jiff BrokenDownTime strtime
        // ═══════════════════════════════════════════════════════════════════════
        {
            const ITERATIONS: usize = 30_000_000;
            const FORMAT: &str = "%Y-%m-%dT%H:%M:%S";
            const INPUT: &str = "2024-03-14T00:00:00";

            // ── Jiff low-level BrokenDownTime strtime ───────────────────────
            use jiff::fmt::strtime::BrokenDownTime;

            let start = std::time::Instant::now();
            for _ in 0..ITERATIONS {
                let x = BrokenDownTime::parse(FORMAT, INPUT).unwrap();
            }
            strptime_jiff_ns = start.elapsed().as_nanos() as f64 / ITERATIONS as f64;

            // ── Parts ───────────────────────
            let start = std::time::Instant::now();
            for _ in 0..ITERATIONS {
                let x = Parts::from_str(FORMAT, INPUT, true, true, false).unwrap();
            }
            strptime_timeparts_ns = start.elapsed().as_nanos() as f64 / ITERATIONS as f64;
        }

        // ═══════════════════════════════════════════════════════════════════════
        // Zoned strptime — Dt vs Jiff Zoned using strtime
        // ═══════════════════════════════════════════════════════════════════════
        {
            const ITERATIONS: usize = 10_000_000;
            const INPUT: &str = "2024-03-14T00:00:00[America/New_York]";
            const FORMAT_WITH_Q: &str = "%Y-%m-%dT%H:%M:%S[%Q]";

            // ── Jiff zoned parsing via low-level strtime ───────────────────────
            use jiff::fmt::strtime::BrokenDownTime;

            let start = std::time::Instant::now();
            for _ in 0..ITERATIONS {
                let tm = BrokenDownTime::parse(FORMAT_WITH_Q, INPUT).unwrap();
                let x = tm.to_zoned().unwrap();
            }
            zoned_jiff_ns = start.elapsed().as_nanos() as f64 / ITERATIONS as f64;

            // ── deep_time with %Q directive ─────────────────
            let start = std::time::Instant::now();
            for _ in 0..ITERATIONS {
                let x = Dt::from_str(INPUT, FORMAT_WITH_Q, true, true, false).unwrap();
            }
            zoned_deep_ns = start.elapsed().as_nanos() as f64 / ITERATIONS as f64;
        }

        // ═══════════════════════════════════════════════════════════════════════
        // Datetime strptime — Dt::from_str vs Jiff to_datetime strtime
        // ═══════════════════════════════════════════════════════════════════════
        {
            const ITERATIONS: usize = 10_000_000; // lowered because IANA zone resolution is heavier
            const INPUT: &str = "2024-03-14T00:00:00";
            const FORMAT: &str = "%Y-%m-%dT%H:%M:%S";

            // ── Jiff parsing via low-level strtime ───────────────────────
            use jiff::fmt::strtime::BrokenDownTime;

            let start = std::time::Instant::now();
            for _ in 0..ITERATIONS {
                let tm = BrokenDownTime::parse(FORMAT, INPUT).unwrap();
                let x = tm.to_datetime().unwrap();
            }
            let _dt_strptime_jiff_ns = start.elapsed().as_nanos() as f64 / ITERATIONS as f64;

            // ── deep time  parsing ───────────────────────

            let start = std::time::Instant::now();
            for _ in 0..ITERATIONS {
                let x = Dt::from_str(INPUT, FORMAT, true, true, false).unwrap();
            }
            let _dt_strptime_deep_ns = start.elapsed().as_nanos() as f64 / ITERATIONS as f64;
        }

        // ═══════════════════════════════════════════════════════════════════════
        // Datetime parse — Parts::from_str_iso vs Jiff parse::DateTime
        // ═══════════════════════════════════════════════════════════════════════
        {
            const ITERATIONS: usize = 20_000_000;
            const INPUT: &str = "2024-03-14T00:00:00.123456789";

            // ── Jiff high-level DateTime parse ───────────────────────
            use jiff::civil::DateTime;

            let start = std::time::Instant::now();
            for _ in 0..ITERATIONS {
                let x = INPUT.parse::<DateTime>().unwrap();
            }
            iso_jiff_ns = start.elapsed().as_nanos() as f64 / ITERATIONS as f64;

            // ── deep_time CCSDS/ISO dedicated parser ───────────────────────
            let start = std::time::Instant::now();
            for _ in 0..ITERATIONS {
                let x = Parts::from_str_iso(INPUT).unwrap();
            }
            iso_deep_ns = start.elapsed().as_nanos() as f64 / ITERATIONS as f64;
        }

        // ═══════════════════════════════════════════════════════════════════════
        // strftime — Dt::to_str vs Jiff civil::DateTime::strftime
        // ═══════════════════════════════════════════════════════════════════════
        {
            const ITERATIONS: usize = 20_000_000;
            const FORMAT: &str = "%Y-%m-%dT%H:%M:%S";

            // ── deep_time ───────────────────────
            let dt = Dt::from_str("2024-03-14T00:00:00", FORMAT, true, true, false).unwrap();

            let start = std::time::Instant::now();
            for _ in 0..ITERATIONS {
                let x = dt.to_str_lite(FORMAT, Lang::En);
            }
            strftime_deep_ns = start.elapsed().as_nanos() as f64 / ITERATIONS as f64;

            // ── Jiff ───────────────────────
            use jiff::civil::DateTime;

            let jiff_dt: DateTime = "2024-03-14T00:00:00".parse().unwrap();

            let start = std::time::Instant::now();
            for _ in 0..ITERATIONS {
                let x = jiff_dt.strftime(FORMAT).to_string();
            }
            strftime_jiff_ns = start.elapsed().as_nanos() as f64 / ITERATIONS as f64;
        }

        // ═══════════════════════════════════════════════════════════════════════
        // Emit two neat tables (only output; using eprintln! so it is easy to capture)
        // These tables are formatted to be directly droppable into the README.
        // ═══════════════════════════════════════════════════════════════════════

        let fmt_ns = |x: f64| -> String {
            if x >= 99.5 {
                format!("{:.0} ns", x)
            } else {
                format!("{:.1} ns", x)
            }
        };

        // For parse/format table we use "% faster/slower" style (matching historical README)
        let pct = |d: f64, j: f64| -> String {
            let r = d / j;
            if r < 1.0 {
                format!("{:.1}% faster", (1.0 - r) * 100.0)
            } else {
                format!("{:.1}% slower", (r - 1.0) * 100.0)
            }
        };

        // For scale conversions we use "× faster/slower" style (matching historical README)
        let xrel = |d: f64, h: f64| -> String {
            let r = d / h;
            if r < 1.0 {
                format!("{:.1}× faster", 1.0 / r)
            } else {
                format!("{:.1}× slower", r)
            }
        };

        eprintln!();
        eprintln!("#### Parsing and Formatting");
        eprintln!();
        eprintln!(
            "| Operation                              | Time          | vs Jiff 0.2.31           |"
        );
        eprintln!(
            "|----------------------------------------|---------------|--------------------------|"
        );
        eprintln!(
            "| ISO datetime parsing                   | {:<13} | {:<24} |",
            fmt_ns(iso_deep_ns),
            pct(iso_deep_ns, iso_jiff_ns)
        );
        eprintln!(
            "| `strptime`                             | {:<13} | {:<24} |",
            fmt_ns(strptime_timeparts_ns),
            pct(strptime_timeparts_ns, strptime_jiff_ns)
        );
        eprintln!(
            "| TZ `strptime` -> `Dt` vs `jiff:Zoned`  | {:<13} | {:<24} |",
            fmt_ns(zoned_deep_ns),
            pct(zoned_deep_ns, zoned_jiff_ns)
        );
        eprintln!(
            "| `strftime`                             | {:<13} | {:<24} |",
            fmt_ns(strftime_deep_ns),
            pct(strftime_deep_ns, strftime_jiff_ns)
        );
        eprintln!(
            "| Auto parser (`from_str_parse`)         | {:<13} | —                        |",
            fmt_ns(auto_ns_per)
        );

        eprintln!();
        eprintln!("#### Time Scale Conversions");
        eprintln!();
        eprintln!(
            "| Conversion       | deep-time     | hifitime 4.3  | Relative Performance      |"
        );
        eprintln!(
            "|------------------|---------------|---------------|---------------------------|"
        );
        eprintln!(
            "| TAI → UTC        | {:<13} | {:<13} | {:<25} |",
            fmt_ns(tai_utc_deep_ns),
            fmt_ns(tai_utc_hifi_ns),
            xrel(tai_utc_deep_ns, tai_utc_hifi_ns)
        );
        eprintln!(
            "| UTC → TAI        | {:<13} | {:<13} | {:<25} |",
            fmt_ns(utc_tai_deep_ns),
            fmt_ns(utc_tai_hifi_ns),
            xrel(utc_tai_deep_ns, utc_tai_hifi_ns)
        );
        eprintln!(
            "| TAI → TDB        | {:<13} | {:<13} | {:<25} |",
            fmt_ns(tai_tdb_deep_ns),
            fmt_ns(tai_tdb_hifi_ns),
            xrel(tai_tdb_deep_ns, tai_tdb_hifi_ns)
        );
        eprintln!(
            "| TDB → TAI        | {:<13} | {:<13} | {:<25} |",
            fmt_ns(tdb_tai_deep_ns),
            fmt_ns(tdb_tai_hifi_ns),
            xrel(tdb_tai_deep_ns, tdb_tai_hifi_ns)
        );
        eprintln!(
            "| GPS conversion   | {:<13} | {:<13} | {:<25} |",
            fmt_ns(gps_deep_ns),
            fmt_ns(gps_hifi_ns),
            xrel(gps_deep_ns, gps_hifi_ns)
        );
        eprintln!(
            "| GPS week + TOW   | {:<13} | {:<13} | {:<25} |",
            fmt_ns(tow_deep_ns),
            fmt_ns(tow_hifi_ns),
            xrel(tow_deep_ns, tow_hifi_ns)
        );
        eprintln!();
    }
}