io.atomix.copycat.server.storage.snapshot

Class SnapshotDescriptor

java.lang.Object

io.atomix.copycat.server.storage.snapshot.SnapshotDescriptor

All Implemented Interfaces:

AutoCloseable

public final class SnapshotDescriptor
extends Object
implements AutoCloseable

Stores information about a Snapshot of the state machine.

Snapshot descriptors represent the header of a snapshot file which stores metadata about the snapshot contents. This API provides methods for reading and a builder for writing snapshot headers/descriptors.

Author:

Jordan Halterman

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	SnapshotDescriptor.Builder Snapshot descriptor builder.

Field Summary

Fields

Modifier and Type	Field and Description
static int	BYTES

Constructor Summary

Constructors

Constructor and Description
SnapshotDescriptor(Buffer buffer)

Method Summary

Modifier and Type	Method and Description
static SnapshotDescriptor.Builder	builder() Returns a descriptor builder.
static SnapshotDescriptor.Builder	builder(Buffer buffer) Returns a descriptor builder for the given descriptor buffer.
void	close()
void	delete() Deletes the descriptor.
long	index() Returns the snapshot index.
void	lock() Locks the segment.
boolean	locked() Returns whether the snapshot has been locked by commitment.
long	timestamp() Returns the snapshot timestamp.

Methods inherited from class java.lang.Object

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

Field Detail

BYTES

public static final int BYTES

See Also:

Constant Field Values

Constructor Detail

SnapshotDescriptor

public SnapshotDescriptor(Buffer buffer)

Throws:

NullPointerException - if buffer is null

Method Detail

builder

public static SnapshotDescriptor.Builder builder()

Returns a descriptor builder.

The descriptor builder will write segment metadata to a 48 byte in-memory buffer.

Returns:

The descriptor builder.

builder

public static SnapshotDescriptor.Builder builder(Buffer buffer)

Returns a descriptor builder for the given descriptor buffer.

Parameters:

buffer - The descriptor buffer.

Returns:

The descriptor builder.

Throws:

NullPointerException - if buffer is null

index

public long index()

Returns the snapshot index.

Returns:

The snapshot index.

timestamp

public long timestamp()

Returns the snapshot timestamp.

Returns:

The snapshot timestamp.

locked

public boolean locked()

Returns whether the snapshot has been locked by commitment.

A snapshot will be locked once it has been fully written.

Returns:

Indicates whether the snapshot has been locked.

lock

public void lock()

Locks the segment.

close

public void close()

Specified by:

close in interface AutoCloseable

delete

public void delete()

Deletes the descriptor.