class DistributedImmutableMap<K : Any, V : Any> : StateMachine, Snapshottable
A distributed map state machine that doesn't allow overriding values. The state machine is replicated across a Copycat Raft cluster.
The map contents are backed by a JDBC table. State re-synchronisation is achieved by periodically persisting snapshots to disk, and sharing them across the cluster. A new node joining the cluster will have to obtain and install a snapshot containing the entire JDBC table contents.
Commands |
object Commands |
<init> |
DistributedImmutableMap(db: Database, tableName: String)
A distributed map state machine that doesn't allow overriding values. The state machine is replicated across a Copycat Raft cluster. |
db |
val db: Database |
get |
fun get(commit: Commit<Get<K, V>>): V?
Gets a value for the given Commands.Get.key |
install |
fun install(reader: SnapshotReader): Unit
Reads entries from disk and adds them to map. |
put |
fun put(commit: Commit<PutAll<K, V>>): Map<K, V>
Stores the given Commands.PutAll.entries if no entry key already exists. |
size |
fun size(commit: Commit<Size>): Int |
snapshot |
fun snapshot(writer: SnapshotWriter): Unit
Writes out all map entries to disk. Note that this operation does not load all entries into memory, as the SnapshotWriter is using a disk-backed buffer internally, and iterating map entries results in only a fixed number of recently accessed entries to ever be kept in memory. |