Enum WatchEvent 

#[non_exhaustive]
pub enum WatchEvent {
    #[non_exhaustive]
    Snapshot {
        state: WatchState,
    },
    #[non_exhaustive]
    Error {
        error: Error,
        state: WatchState,
    },
}

Stream item of ProxyWatcher: a state snapshot or a failed re-read, each stamped with the watcher’s WatchState as it stood at delivery.

A snapshot arrives when the configuration changed, when the health changed, or both, so a lost notification route reaches a subscriber rather than only ProxyWatcher::health.

Variants (Non-exhaustive)

Non-exhaustive enums could have additional variants added in future. Therefore, when matching against variants of non-exhaustive enums, an extra wildcard arm must be added to account for any future variants.

#[non_exhaustive]

Snapshot

The configuration, the liveness of the routes, or both moved.

Consecutive undelivered snapshots fold into the newest one, so a subscriber that stops polling loses the history between snapshots, never the current answer.

Fields

Non-exhaustive enum variants could have additional fields added in future. Therefore, non-exhaustive enum variants cannot be constructed in external crates and cannot be matched against.

state: WatchState

Configuration and liveness at delivery.

#[non_exhaustive]

Error

Re-reading the OS settings failed. This does not end the subscription.

Nothing is guaranteed to follow, and no event reports the recovery. If the next successful read returns the same configuration and no route changed, the equality skip publishes nothing, and ProxyWatcher::current and ProxyWatcher::state return what they returned before the failure, captured_at included, so there is nothing to wait for: what they hold is what that read agreed with. A Snapshot does follow whenever the configuration or the health moved.

Fields

Non-exhaustive enum variants could have additional fields added in future. Therefore, non-exhaustive enum variants cannot be constructed in external crates and cannot be matched against.

error: Error

Why the re-read failed.

state: WatchState

Liveness at delivery, and the last configuration that did read cleanly.

Implementations

impl WatchEvent

pub fn state(&self) -> &WatchState

The state stamped on this event, whichever variant it is.

Trait Implementations

impl Debug for WatchEvent

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

Formats the value using the given formatter.