Struct PartitionTracker 

pub struct PartitionTracker { /* private fields */ }

Contiguity tracker for one partition within one assignment epoch.

Sequence numbers start at 0 and must be registered contiguously; a gap is a driver bug and panics. Resolutions arrive out of order (sharded sinks ack whenever their flushes complete).

use etl_core::checkpoint::{AckStatus, PartitionTracker};

let mut t = PartitionTracker::new();
t.register(0, 99); // batch 0 covers offsets ..=99
t.register(1, 199);
let _ = t.resolve(1, AckStatus::Delivered); // out of order
assert_eq!(t.advance(), None); // batch 0 still pending
let _ = t.resolve(0, AckStatus::Delivered);
assert_eq!(t.advance(), Some(200)); // committable position

Implementations

impl PartitionTracker

pub fn new() -> Self

A fresh tracker expecting its first registration at sequence 0.

pub fn register(&mut self, seq: u64, last_offset: i64)

Register a newly issued batch. Sequences must be contiguous.

Registering after a stall is legal (batches already in flight when the failure surfaced still arrive); they will never advance the watermark.

Panics

Panics on a sequence gap — the driver issued batches out of order, which would silently corrupt watermark accounting.

pub fn resolve(&mut self, seq: u64, status: AckStatus) -> ResolveOutcome

Apply one resolution. Out-of-order and cross-batch interleavings are expected; duplicates and unknown sequences are reported (and debug_asserted) rather than corrupting state.

pub fn advance(&mut self) -> Option<i64>

Pop the contiguous delivered prefix and return the new committable offset (one past the last delivered batch), or None if the watermark did not move.

If the batch at the head has failed, the tracker stalls permanently: everything delivered before the failure is still reported (commit up to the failure is correct), but nothing past it ever will be.

pub fn stalled(&self) -> bool

Whether a failed batch has reached the head and blocked the watermark. Permanent once set.

pub fn stalled_since(&self) -> Option<Instant>

When the stall was first observed, for watermark-age alerting.

pub fn stalled_seq(&self) -> Option<u64>

Sequence number of the failed batch that caused the stall.

pub fn pending(&self) -> usize

Batches issued but not yet advanced through the watermark. This is the backpressure trigger: it bounds tracker memory and replay size.

Trait Implementations

impl Debug for PartitionTracker

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

Formats the value using the given formatter.

impl Default for PartitionTracker

fn default() -> PartitionTracker

Returns the “default value” for a type.