Struct RangeProgressTracker 

pub struct RangeProgressTracker { /* private fields */ }

Tracks streaming progress for many ranges over the one physical WAL. A data member feeds every derived record through index_record to maintain each range’s primary frontier without splitting the log, and notes shipped/applied LSNs per range. Every range advances independently, so one lagging range does not skew another’s lag or failover eligibility.

All updates are monotonic (max): out-of-order or replayed observations never move a frontier backward.

Implementations

impl RangeProgressTracker

pub fn new() -> RangeProgressTracker

pub fn index_record(&mut self, record: &ChangeRecord)

Index one derived record by its range identity, bumping that range’s primary frontier. Records that carry no range identity (legacy / non-range-replicated) are ignored — they belong to no range’s stream.

pub fn note_streamed(&mut self, range_id: u64, lsn: u64)

Note that records for range_id up to lsn have been shipped to the follower. Also raises the primary frontier if it lagged behind, since you cannot stream past what was produced.

pub fn note_applied(&mut self, range_id: u64, lsn: u64)

Note that the follower has durably applied records for range_id up to lsn. Raises the streamed and primary frontiers if they lagged, since an applied record was necessarily streamed and produced.

pub fn observe_position(&mut self, position: &RangeStreamPosition)

Adopt a follower’s reported position for range_id as the applied frontier — the inbound counterpart to note_applied when a follower acks with a RangeStreamPosition.

pub fn progress(&self, range_id: u64) -> Option<&RangeStreamProgress>

pub fn apply_lag(&self, range_id: u64) -> Option<u64>

Apply lag for one range, or None if the range is unknown.

pub fn iter(&self) -> impl Iterator<Item = &RangeStreamProgress>

Iterate every tracked range’s progress, ascending by range id.

pub fn len(&self) -> usize

pub fn is_empty(&self) -> bool

pub fn failover_eligible(&self, max_lag: u64) -> Vec<u64>

The ranges currently within max_lag of their primary frontier — candidates a later per-range failover decision may promote. Ascending by range id.

Trait Implementations

impl Clone for RangeProgressTracker

fn clone(&self) -> RangeProgressTracker

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for RangeProgressTracker

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

Formats the value using the given formatter.

impl Default for RangeProgressTracker

fn default() -> RangeProgressTracker

Returns the “default value” for a type.