Class SnapshotChain

java.lang.Object

com.loomcache.server.persistence.SnapshotChain

public class SnapshotChain
extends Object

A chain of snapshots: one full (base) snapshot followed by zero or more delta snapshots.

materialize() replays all deltas onto the base to produce a complete StateMachineSnapshotManager.FullSnapshot suitable for restoration.

Delta ordering matters: deltas are applied in the order they were added (oldest first). Later deltas overwrite earlier ones for the same structure ID.

Constructor Summary

Constructors

Constructor	Description
SnapshotChain(StateMachineSnapshotManager.FullSnapshot base)	Create a snapshot chain with the given base snapshot and no deltas, using a dedicated default KryoSerializer for map snapshot merging.
SnapshotChain(StateMachineSnapshotManager.FullSnapshot base, KryoSerializer mapSnapshotSerializer)	Create a snapshot chain sharing a KryoSerializer with the rest of the server so that map snapshot merging sees the same registered classes.

Method Summary

Modifier and Type	Method	Description
void	addDelta(DeltaSnapshot delta)	Append a delta snapshot to this chain.
int	deltaCount()	Get the number of deltas in this chain.
List<DeltaSnapshot>	getDeltas()	Get an unmodifiable view of the deltas.
StateMachineSnapshotManager.FullSnapshot	materialize()	Materialize the chain into a single full snapshot by applying all deltas to the base in order.

Methods inherited from class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

SnapshotChain

public SnapshotChain(StateMachineSnapshotManager.FullSnapshot base)

Create a snapshot chain with the given base snapshot and no deltas, using a dedicated default KryoSerializer for map snapshot merging.

SnapshotChain

public SnapshotChain(StateMachineSnapshotManager.FullSnapshot base,
 KryoSerializer mapSnapshotSerializer)

Create a snapshot chain sharing a KryoSerializer with the rest of the server so that map snapshot merging sees the same registered classes.

Method Details

addDelta

public void addDelta(DeltaSnapshot delta)

Append a delta snapshot to this chain.

Deltas must be added in chronological order.

Parameters:

delta - the delta snapshot to append

materialize

public StateMachineSnapshotManager.FullSnapshot materialize()

Materialize the chain into a single full snapshot by applying all deltas to the base in order.

For each delta:

• Changed structures overwrite or add entries in the result map
• Deleted structures are removed from the result map

Returns:

a new FullSnapshot representing the merged state

deltaCount

public int deltaCount()

Get the number of deltas in this chain.

Returns:

the delta count

getDeltas

public List<DeltaSnapshot> getDeltas()

Get an unmodifiable view of the deltas.

Returns:

list of delta snapshots in order