io.zeebe.logstreams.spi

Interface SnapshotStorage

All Known Implementing Classes:

FsSnapshotStorage

public interface SnapshotStorage

Storage for log snapshots.

Method Summary

Modifier and Type	Method and Description
SnapshotWriter	createSnapshot(String name, long logPosition) Returns a writer to create a new snapshot.
SnapshotWriter	createTemporarySnapshot(String name, long logPosition) Returns a writer to create a temporary snapshot.
ReadableSnapshot	getLastSnapshot(String name) Returns the last snapshot for the given name.
List<SnapshotMetadata>	listSnapshots() Returns a list of available snapshots; for each snapshot item, it returns the latest file.
boolean	purgeSnapshot(String name) Deletes all existing snapshot and checksum files.
boolean	snapshotExists(String name, long logPosition) Returns whether or not there already exists a snapshot for the given name + position.

Method Detail

getLastSnapshot

ReadableSnapshot getLastSnapshot(String name)
                          throws Exception

Returns the last snapshot for the given name.

Parameters:

name - the name of the snapshot

Returns:

the snapshot or null if none exists

Throws:

Exception - if fails to open the snapshot

createSnapshot

SnapshotWriter createSnapshot(String name,
                              long logPosition)
                       throws Exception

Returns a writer to create a new snapshot.

Parameters:

name - the name of the snapshot

logPosition - the log position at which the snapshot is taken

Returns:

the writer to create the snapshot

Throws:

Exception - if fails to create the snapshot

purgeSnapshot

boolean purgeSnapshot(String name)

Deletes all existing snapshot and checksum files.

Parameters:

name - the name of the snapshot

Returns:

true if the purging was successful otherwise false

listSnapshots

List<SnapshotMetadata> listSnapshots()

Returns a list of available snapshots; for each snapshot item, it returns the latest file.

Returns:

all available snapshots

snapshotExists

boolean snapshotExists(String name,
                       long logPosition)

Returns whether or not there already exists a snapshot for the given name + position.

createTemporarySnapshot

SnapshotWriter createTemporarySnapshot(String name,
                                       long logPosition)
                                throws Exception

Returns a writer to create a temporary snapshot.

Parameters:

name - the snapshot name

logPosition - the logPosition

Returns:

pre-configured SnapshotWriter

Throws:

Exception - if it fails to prepare the necessary resources for the temporary snapshot