Struct ProtectedHeaderJournal 

pub struct ProtectedHeaderJournal { /* private fields */ }

The in-memory protected headers of every cluster, and the unresolved proposals that may still replace them.

A proposal is effective at once. A rejection drops it, so the newest remaining proposal, else the confirmed state, is effective: an ancestor’s rejection leaves a live descendant alone. An acceptance confirms the proposal and supersedes every older one, which can no longer change the outcome. Resolved proposals are forgotten; versions are never reused, so a late or repeated resolution finds nothing and changes nothing.

There is no serde, no Clone and Debug prints counts only: the journal never reaches a state file, a task snapshot or a log.

Implementations

impl ProtectedHeaderJournal

pub fn propose( &mut self, cluster: &str, change: ProtectedHeaderChange, ) -> Result<ProtectedHeaderVersion, VersionExhausted>

Record change as the effective state of cluster until it is resolved. Nothing is touched when the versions are exhausted.

pub fn holds_values(&self) -> bool

Whether the journal retains a non-empty header set anywhere: confirmed, or in any unresolved proposal, for any cluster. A later Clear or Remove hides the headers beneath it without dropping them, so this looks at every retained state and not only Self::effective.

pub fn confirmed_bootstrap<'m>( &self, metadata: impl Fn(&str) -> Option<&'m [HealthCheckHeader]>, ) -> Result<Option<ConfirmedBootstrap>, TransferError>

What a fresh worker must be given to hold the confirmed values: the clusters whose confirmed set is not empty, in lexical order, and the version they are all staged under. None when no value is held.

Read-only: it proposes, accepts and rejects nothing, and returns no byte of a value. A fresh worker store is empty, so the last version the journal issued is acceptable for every cluster: it is at least 1 as soon as a value was ever held, and no cluster was confirmed under a newer one. Refused while any proposal is unresolved, and when a confirmed set is not the one metadata names.

pub fn effective(&self, cluster: &str) -> Option<&ProtectedHeaderSet>

The effective protected headers of cluster: None when it is absent, an empty set when it was cleared.

pub fn proposed( &self, cluster: &str, version: ProtectedHeaderVersion, ) -> Option<Option<&ProtectedHeaderSet>>

The state version proposed for cluster while it is unresolved: None when the version is unknown or resolved, Some(None) for a removal.

pub fn accept( &mut self, cluster: &str, version: ProtectedHeaderVersion, ) -> Resolution

Every targeted worker acknowledged version. It becomes the confirmed state and supersedes the proposals older than it.

pub fn reject( &mut self, cluster: &str, version: ProtectedHeaderVersion, ) -> Resolution

version failed: drop it and fall back to what is left.

Trait Implementations

impl Debug for ProtectedHeaderJournal

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

Formats the value using the given formatter.

impl Default for ProtectedHeaderJournal

fn default() -> Self

Returns the “default value” for a type.