io.spine.server.aggregate

Class AggregateStorage<I>

java.lang.Object

io.spine.server.storage.AbstractStorage<I,io.spine.server.aggregate.AggregateHistory,AggregateReadRequest<I>>

io.spine.server.aggregate.AggregateStorage<I>

Type Parameters:

I - the type of IDs of aggregates managed by this storage

All Implemented Interfaces:

Storage<I,io.spine.server.aggregate.AggregateHistory,AggregateReadRequest<I>>, StorageWithLifecycleFlags<I,io.spine.server.aggregate.AggregateHistory,AggregateReadRequest<I>>, java.lang.AutoCloseable

@SPI
public abstract class AggregateStorage<I>
extends AbstractStorage<I,io.spine.server.aggregate.AggregateHistory,AggregateReadRequest<I>>
implements StorageWithLifecycleFlags<I,io.spine.server.aggregate.AggregateHistory,AggregateReadRequest<I>>

An event-sourced storage of aggregate part events and snapshots.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	AggregateStorage(boolean multitenant)

Method Summary

Modifier and Type	Method and Description
protected void	checkNotClosed() Ensures the storage is not closed.
protected abstract java.util.Iterator<I>	distinctAggregateIds() Obtains distinct aggregate IDs from the stored event records.
protected abstract java.util.Iterator<io.spine.server.aggregate.AggregateEventRecord>	historyBackward(AggregateReadRequest<I> request) Creates iterator of aggregate event history with the reverse traversal.
java.util.Iterator<I>	index() Returns an iterator over identifiers of records in the storage.
java.util.Optional<io.spine.server.aggregate.AggregateHistory>	read(AggregateReadRequest<I> request) Forms and returns an AggregateHistory based on the aggregate history.
protected abstract void	truncate(int snapshotIndex) Drops all records which occur before the Nth snapshot for each entity.
protected abstract void	truncate(int snapshotIndex, com.google.protobuf.Timestamp date) Drops all records older than date but not newer than the Nth snapshot for each entity.
void	write(I id, io.spine.server.aggregate.AggregateHistory events) Writes events into the storage.
protected abstract void	writeRecord(I id, io.spine.server.aggregate.AggregateEventRecord record) Writes the passed record into the storage.

Methods inherited from class io.spine.server.storage.AbstractStorage

checkNotClosed, close, isClosed, isMultitenant, isOpen

Methods inherited from class java.lang.Object

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

Methods inherited from interface io.spine.server.storage.StorageWithLifecycleFlags

readLifecycleFlags, writeLifecycleFlags

Methods inherited from interface io.spine.server.storage.Storage

close, isMultitenant, isOpen

Constructor Detail

AggregateStorage

protected AggregateStorage(boolean multitenant)

Method Detail

checkNotClosed

protected void checkNotClosed()
                       throws java.lang.IllegalStateException

Ensures the storage is not closed.

If the storage is closed, throws IllegalStateException.

Opens the method for the package.

Overrides:

checkNotClosed in class AbstractStorage<I,io.spine.server.aggregate.AggregateHistory,AggregateReadRequest<I>>

Throws:

java.lang.IllegalStateException - if the storage is closed

index

public java.util.Iterator<I> index()

Returns an iterator over identifiers of records in the storage.

Attempts to read aggregate IDs from the MirrorRepository, as they are already stored there in a convenient form.

If an aggregate MirrorRepository is not configured to use for reads with this repository, falls back to the default method of getting distinct aggregate IDs from the event records.

Specified by:

index in interface Storage<I,io.spine.server.aggregate.AggregateHistory,AggregateReadRequest<I>>

read

public java.util.Optional<io.spine.server.aggregate.AggregateHistory> read(AggregateReadRequest<I> request)

Forms and returns an AggregateHistory based on the aggregate history.

Specified by:

read in interface Storage<I,io.spine.server.aggregate.AggregateHistory,AggregateReadRequest<I>>

Parameters:

request - the aggregate read request based on which to form a record

Returns:

the record instance or Optional.empty() if the aggregate history is empty

Throws:

java.lang.IllegalStateException - if the storage was closed before

write

public void write(I id,
                  io.spine.server.aggregate.AggregateHistory events)

Writes events into the storage.

NOTE: does not rewrite any events. Several events can be associated with one aggregate ID.

Specified by:

write in interface Storage<I,io.spine.server.aggregate.AggregateHistory,AggregateReadRequest<I>>

Parameters:

id - the ID for the record

events - non empty aggregate state record to store

writeRecord

protected abstract void writeRecord(I id,
                                    io.spine.server.aggregate.AggregateEventRecord record)

Writes the passed record into the storage.

Parameters:

id - the aggregate ID

record - the record to write

historyBackward

protected abstract java.util.Iterator<io.spine.server.aggregate.AggregateEventRecord> historyBackward(AggregateReadRequest<I> request)

Creates iterator of aggregate event history with the reverse traversal.

Records are sorted by timestamp descending (from newer to older). The iterator is empty if there's no history for the aggregate with passed ID.

Parameters:

request - the read request

Returns:

new iterator instance

truncate

protected abstract void truncate(int snapshotIndex)

Drops all records which occur before the Nth snapshot for each entity.

truncate

protected abstract void truncate(int snapshotIndex,
                                 com.google.protobuf.Timestamp date)

Drops all records older than date but not newer than the Nth snapshot for each entity.

distinctAggregateIds

protected abstract java.util.Iterator<I> distinctAggregateIds()

Obtains distinct aggregate IDs from the stored event records.