Struct SegmentManager 

pub struct SegmentManager(/* private fields */);

Keeps the public segments of every (src, dst) pair that is in use available and fresh.

A pair starts being managed the first time it is asked for, is refetched before its segments expire, and is evicted once it has not been used for SegmentManagerConfig::idle_eviction_time.

A consumer that keeps using a pair longer than that must hold a PairGuard from Self::hold_pair on it, which exempts it from eviction.

Cheap to clone; all clones share the same state.

Implementations

impl SegmentManager

pub fn new( config: SegmentManagerConfig, segment_fetcher: Box<dyn SegmentsDiscovery>, ) -> Result<Self>

Creates a new, empty segment manager with the timings of config.

Returns an error if config does not SegmentManagerConfig::validate.

pub async fn segment( &self, id: SegmentStoreId, now: SystemTime, ) -> Option<SignedPathSegment>

Returns the segment with the given fingerprint, if it is in the store.

Counts as a use of the segment’s (src, dst) pair.

pub async fn hold_pair( &self, src: IsdAsn, dst: IsdAsn, now: SystemTime, ) -> Result<PairGuard>

Keeps the given (src, dst) pair managed for as long as the returned guard is held, fetching its segments if it is not managed yet.

A guarded pair is exempt from idle eviction, so a long lived consumer cannot have the segments it depends on evicted out from under it. Refreshing is unaffected: a guarded pair keeps being refetched as its segments approach expiry.

pub async fn segments<'this>( &'this self, src: IsdAsn, dst: IsdAsn, now: SystemTime, ) -> Result<SegmentsIter<'this>>

Returns a SegmentsIter for the given (src, dst) pair, fetching segments if necessary.

Allows iterating over all core and non-core segments for the given (src, dst) pair.

pub async fn run(&self)

Runs the maintenance loop for the segment manager, which periodically evicts unused (src, dst) pairs and refetches the ones that are due for a refresh.

Reads the wall clock itself, unlike every other entry point. Never returns.

pub async fn maintain(&self, now: SystemTime) -> SystemTime

Maintains the segment store by removing unused entries and fetching new segments for (src, dst) pairs that are due for refresh.

Returns the next scheduled maintenance time, which is the earliest next refresh time of all (src, dst) pairs in the store.

If no (src, dst) pairs are due for refresh, the next maintenance time is the maximum segment fetch interval from now.

Trait Implementations

impl Clone for SegmentManager

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.