Package io.debezium.crdt

Interface DeltaCounter

All Superinterfaces:

Count, DeltaCount, GCount, GCounter, PNCount, PNCounter

All Known Implementing Classes:

StateBasedPNDeltaCounter

@NotThreadSafe
public interface DeltaCounter
extends PNCounter, DeltaCount

A simple counter that maintains a single changing value by separately tracking the positive and negative changes, and by tracking recent changes in this value since last reset. It is inspired by the conflict-free replicated data type (CRDT) P-N Counter. The semantics ensure the value converges toward the global number of increments minus the number of decrements. The global total can be calculated by merging all the replicated instances, without regard to order of merging.

Method Summary

Modifier and Type	Method	Description
DeltaCounter	decrement()	Decrement the counter and get the result.
DeltaCounter	increment()	Increment the counter and get the result.
DeltaCounter	merge(Count other)	Merge the supplied counter into this counter.
void	reset()	Start a new interval and reset the DeltaCount.getChanges() to initial values.

Methods inherited from interface io.debezium.crdt.DeltaCount

getChanges, getPriorCount, hasChanges

Methods inherited from interface io.debezium.crdt.GCount

getIncrement

Methods inherited from interface io.debezium.crdt.GCounter

getAndIncrement, incrementAndGet

Methods inherited from interface io.debezium.crdt.PNCount

get, getDecrement

Methods inherited from interface io.debezium.crdt.PNCounter

decrementAndGet, getAndDecrement

Method Details

increment

DeltaCounter increment()

Increment the counter and get the result.

Specified by:

increment in interface GCounter

Specified by:

increment in interface PNCounter

Returns:

this instance so methods can be chained together; never null

decrement

DeltaCounter decrement()

Decrement the counter and get the result.

Specified by:

decrement in interface PNCounter

Returns:

this instance so methods can be chained together; never null

merge

DeltaCounter merge(Count other)

Merge the supplied counter into this counter.

Specified by:

merge in interface GCounter

Specified by:

merge in interface PNCounter

Parameters:

other - the other counter to merge into this one; may be null

Returns:

this counter so that methods can be chained

reset

void reset()

Start a new interval and reset the DeltaCount.getChanges() to initial values.