Trait Clock 

pub trait Clock: Debug {
    // Required methods
    fn timestamp_ns(&self) -> UnixNanos;
    fn timestamp_us(&self) -> u64;
    fn timestamp_ms(&self) -> u64;
    fn timestamp(&self) -> f64;
    fn timer_names(&self) -> Vec<&str>;
    fn timer_count(&self) -> usize;
    fn timer_exists(&self, name: &Ustr) -> bool;
    fn register_default_handler(&mut self, callback: TimeEventCallback);
    fn get_handler(&self, event: TimeEvent) -> TimeEventHandlerV2;
    fn set_time_alert_ns(
        &mut self,
        name: &str,
        alert_time_ns: UnixNanos,
        callback: Option<TimeEventCallback>,
        allow_past: Option<bool>,
    ) -> Result<()>;
    fn set_timer_ns(
        &mut self,
        name: &str,
        interval_ns: u64,
        start_time_ns: Option<UnixNanos>,
        stop_time_ns: Option<UnixNanos>,
        callback: Option<TimeEventCallback>,
        allow_past: Option<bool>,
        fire_immediately: Option<bool>,
    ) -> Result<()>;
    fn next_time_ns(&self, name: &str) -> Option<UnixNanos>;
    fn cancel_timer(&mut self, name: &str);
    fn cancel_timers(&mut self);
    fn reset(&mut self);

    // Provided methods
    fn utc_now(&self) -> DateTime<Utc> { ... }
    fn set_time_alert(
        &mut self,
        name: &str,
        alert_time: DateTime<Utc>,
        callback: Option<TimeEventCallback>,
        allow_past: Option<bool>,
    ) -> Result<()> { ... }
    fn set_timer(
        &mut self,
        name: &str,
        interval: Duration,
        start_time: Option<DateTime<Utc>>,
        stop_time: Option<DateTime<Utc>>,
        callback: Option<TimeEventCallback>,
        allow_past: Option<bool>,
        fire_immediately: Option<bool>,
    ) -> Result<()> { ... }
}

Represents a type of clock.

Notes

An active timer is one which has not expired (timer.is_expired == False).

Required Methods

fn timestamp_ns(&self) -> UnixNanos

Returns the current UNIX timestamp in nanoseconds (ns).

fn timestamp_us(&self) -> u64

Returns the current UNIX timestamp in microseconds (μs).

fn timestamp_ms(&self) -> u64

Returns the current UNIX timestamp in milliseconds (ms).

fn timestamp(&self) -> f64

Returns the current UNIX timestamp in seconds.

fn timer_names(&self) -> Vec<&str>

Returns the names of active timers in the clock.

fn timer_count(&self) -> usize

Returns the count of active timers in the clock.

fn timer_exists(&self, name: &Ustr) -> bool

If a timer with the name exists.

fn register_default_handler(&mut self, callback: TimeEventCallback)

Register a default event handler for the clock. If a timer does not have an event handler, then this handler is used.

fn get_handler(&self, event: TimeEvent) -> TimeEventHandlerV2

Get handler for TimeEvent.

Note: Panics if the event does not have an associated handler

fn set_time_alert_ns( &mut self, name: &str, alert_time_ns: UnixNanos, callback: Option<TimeEventCallback>, allow_past: Option<bool>, ) -> Result<()>

Set a timer to alert at the specified time.

Any existing timer registered under the same name is cancelled with a warning before the new alert is scheduled.

Flags

allow_past	Behavior
true	If alert time is in the past, the alert fires immediately; otherwise at alert time.
false	Returns an error if alert time is earlier than now.

Callback

• callback: Some, then callback handles the time event.
• callback: None, then the clock’s default time event callback is used.

Errors

Returns an error if name is invalid, alert_time_ns is earlier than now when not allowed, or any predicate check fails.

fn set_timer_ns( &mut self, name: &str, interval_ns: u64, start_time_ns: Option<UnixNanos>, stop_time_ns: Option<UnixNanos>, callback: Option<TimeEventCallback>, allow_past: Option<bool>, fire_immediately: Option<bool>, ) -> Result<()>

Set a timer to fire time events at every interval between start and stop time.

Any existing timer registered under the same name is cancelled before the new timer is scheduled.

Start Time

• None or Some(0): Uses the current time as start time.
• Some(non_zero): Uses the specified timestamp as start time.

Flags

allow_past	fire_immediately	Behavior
true	true	First event fires immediately at start time, even if start time is in the past.
true	false	First event fires at start time + interval, even if start time is in the past.
false	true	Returns error if start time is in the past (first event would be immediate but past).
false	false	Returns error if start time + interval is in the past.

Callback

• callback: Some, then callback handles the time event.
• callback: None, then the clock’s default time event callback is used.

Errors

Returns an error if name is invalid, interval_ns is not positive, or if any predicate check fails.

fn next_time_ns(&self, name: &str) -> Option<UnixNanos>

Returns the time interval in which the timer name is triggered.

If the timer doesn’t exist None is returned.

fn cancel_timer(&mut self, name: &str)

Cancels the timer with name.

fn cancel_timers(&mut self)

Cancels all timers.

fn reset(&mut self)

Resets the clock by clearing it’s internal state.

Provided Methods

fn utc_now(&self) -> DateTime<Utc>

Returns the current date and time as a timezone-aware DateTime<UTC>.

fn set_time_alert( &mut self, name: &str, alert_time: DateTime<Utc>, callback: Option<TimeEventCallback>, allow_past: Option<bool>, ) -> Result<()>

Set a timer to alert at the specified time.

See Clock::set_time_alert_ns for flag semantics.

Callback

• callback: Some, then callback handles the time event.
• callback: None, then the clock’s default time event callback is used.

Errors

Returns an error if name is invalid, alert_time is in the past when not allowed, or any predicate check fails.

fn set_timer( &mut self, name: &str, interval: Duration, start_time: Option<DateTime<Utc>>, stop_time: Option<DateTime<Utc>>, callback: Option<TimeEventCallback>, allow_past: Option<bool>, fire_immediately: Option<bool>, ) -> Result<()>

Set a timer to fire time events at every interval between start and stop time.

Any existing timer registered under the same name is cancelled with a warning before the new timer is scheduled.

See Clock::set_timer_ns for flag semantics.

Callback

• callback: Some, then callback handles the time event.
• callback: None, then the clock’s default time event callback is used.

Errors

Returns an error if name is invalid, interval is not positive, or if any predicate check fails.

Implementors

impl Clock for LiveClock

impl Clock for TestClock