Struct CdcRing 

pub struct CdcRing { /* private fields */ }

Fixed-capacity circular buffer for CDC events.

Events are appended with push and assigned a monotonically increasing sequence number. When the buffer is full the oldest slot is silently overwritten. Consumers read batches via read and are informed through CdcReadResult::gap when events they have not yet consumed were evicted.

Implementations

impl CdcRing

pub fn new(capacity: usize) -> Self

Create a new ring buffer that can hold up to capacity events.

Panics

Panics if capacity is zero.

pub fn push( &mut self, op: CdcOp, key: Vec<u8>, value: Option<Vec<u8>>, timestamp_ms: u64, )

Append a mutation event to the ring, assigning it the next sequence number.

If the buffer is full the oldest event is overwritten and start_seq advances accordingly.

pub fn write_seq(&self) -> u64

Return the sequence number that will be assigned to the next pushed event.

pub fn start_seq(&self) -> u64

Return the earliest sequence number still available in the buffer.

pub fn len(&self) -> usize

Return the number of events currently retained in the buffer.

pub fn is_empty(&self) -> bool

Return true if no events have been pushed yet.

pub fn read(&self, from_seq: u64, limit: usize) -> CdcReadResult

Read up to limit events starting at from_seq.

If from_seq has already been evicted the read begins at the earliest available sequence and CdcReadResult::gap is set to true, signalling that the consumer missed events.

pub fn get(&self, seq: u64) -> Option<&CdcEvent>

Look up a single event by its sequence number.

Returns None if seq has been evicted or has not been written yet.