Struct WallClockState 

pub struct WallClockState { /* private fields */ }

The wall clock, as an offset from a monotonic millisecond timer.

Every method takes the current monotonic reading rather than fetching one, which is what keeps this testable without a clock at all.

Implementations

impl WallClockState

pub const UNKNOWN: Self

A device that does not know what time it is, at UTC.

pub const fn now(&self, monotonic_ms: u64) -> Option<u32>

The current time in Unix seconds, or None when unknown.

pub const fn now_ms(&self, monotonic_ms: u64) -> Option<u64>

The current time in Unix milliseconds, or None when unknown.

A clock whose offset would put it before the epoch or past what PROP_TIME can carry reads as unknown rather than as a wrapped value: those are only reachable from an absurd set, and reporting a wrapped time is worse than reporting none.

pub const fn local_now(&self, monotonic_ms: u64) -> Option<u32>

The local wall-clock reading in seconds — the time shifted by the configured zone — or None when the time is unknown.

A reading for presentation, not an instant: it does not name a point in time on its own, and nothing should send it anywhere.

pub const fn is_set(&self) -> bool

Whether the device knows what time it is.

pub const fn source(&self) -> Option<TimeSource>

Where the current reading came from, or None while unset.

pub const fn tz_offset_min(&self) -> i16

Minutes east of UTC.

pub const fn set_tz(&mut self, minutes: i16)

Set the time zone. Independent of the clock: the zone is known from commissioning, and changing it never makes the time known or unknown.

pub const fn clear(&mut self)

Return the device to not knowing what time it is.

The zone survives, because where the device is has not changed.

pub const fn apply( &mut self, epoch: u32, monotonic_ms: u64, source: TimeSource, trust_receiver: bool, ) -> Update

Offer a reading from source, applying the precedence rule.

trust_receiver is PROP_GNSS_TIME_TRUST. The rule:

• TimeSource::Manual always applies. The operator is the more authoritative source by definition, including while the receiver is distrusted — distrusting the sky is why somebody would set the clock by hand.
• TimeSource::GnssFix applies whenever the receiver is trusted, overwriting whatever was there. Every fix re-synchronizes the clock, which is what keeps it good over a long deployment.
• TimeSource::GnssRtc applies only when trusted and the clock is unset. It is a boot-time restore, not a correction: the receiver may have re-synchronized its own RTC from a bad sky while the device was running, so it must not displace a reading that is already in hand.
• TimeSource::ExternalRtc applies only when the clock is unset, for the same reason, but is not subject to the receiver trust flag — it is not the receiver.

Trait Implementations

impl Clone for WallClockState

fn clone(&self) -> WallClockState

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for WallClockState

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for WallClockState

fn default() -> Self

Returns the “default value” for a type.

impl PartialEq for WallClockState

fn eq(&self, other: &WallClockState) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Copy for WallClockState

impl Eq for WallClockState

impl StructuralPartialEq for WallClockState