Module aeonics.core

Package aeonics.manager

Class Snapshot

java.lang.Object

aeonics.entity.Entity

aeonics.manager.Manager.Type

aeonics.manager.Snapshot

All Implemented Interfaces:

Exportable, Snapshotable

public abstract class Snapshot
extends Manager.Type

Manages restore points of the system. This manager is responsible to create snapshots and to restore them. Entities or Plugins that want to react to such events may add a callback handler to be notified when such events happen.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
protected static class	Snapshot.ModuleAwareBiConsumer	This class is used to track the owning module of the handler.

Field Summary

Fields

Modifier and Type	Field	Description
protected static Callback<Data,Snapshot>	createCallback	The snapshot create callback
protected static Callback<Data,Snapshot>	restoreCallback	The snapshot restore callback

Constructor Summary

Constructors

Constructor	Description
Snapshot()

Method Summary

Modifier and Type	Method	Description
abstract Executor.Task<java.lang.String>	create(java.lang.String suffix)	Creates a new snapshot using the specified suffix while the prefix is usually the date of the snapshot.
abstract byte[]	download(java.lang.String snapshot)	Downloads a snapshot.
abstract boolean	exists(java.lang.String snapshot)	Checks if a snapshot exists
abstract java.lang.String	latest()	Gets the name of the latest snapshot or null if there are no snapshots.
abstract java.util.Collection<java.lang.String>	list()	Lists all available snapshots
java.lang.Class<? extends Manager.Type>	manager()	Hardcoded manager type
static void	onRestore(Functions.Consumer<Data> handler)	Adds an event handler to react to the current restore phase.
static void	onSnapshot(Functions.Consumer<Data> handler)	Adds an event handler to react to the current snapshot phase.
abstract void	remove(java.lang.String snapshot)	Permanently removes a snapshot
abstract Executor.Task<java.lang.Void>	restore(java.lang.String snapshot)	Checks if the specified snapshot exists and triggers the restore operation.
abstract void	upload(byte[] snapshot)	Uploads a snapshot in this system.

Methods inherited from class aeonics.manager.Manager.Type

category, internal

Methods inherited from class aeonics.entity.Entity

addRelation, addRelation, addRelation, cast, clearRelation, config, defineRelation, equals, export, firstRelation, hashCode, hasRelation, id, name, name, onCreate, onRemove, onUpdate, parameter, relations, relationships, removeRelation, snapshot, type, valueOf, valueOf

Methods inherited from class java.lang.Object

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

Field Detail

createCallback

protected static Callback<Data,Snapshot> createCallback

The snapshot create callback

restoreCallback

protected static Callback<Data,Snapshot> restoreCallback

The snapshot restore callback

Constructor Detail

Snapshot

public Snapshot()

Method Detail

manager

public final java.lang.Class<? extends Manager.Type> manager()

Hardcoded manager type

Specified by:

manager in class Manager.Type

Returns:

the type of manager

onSnapshot

public static void onSnapshot(Functions.Consumer<Data> handler)

Adds an event handler to react to the current snapshot phase. Implementations may store elements in the provided data object that will be persisted at the end of the snapshot phase. For isolation purposes, a new empty data object will be provided per plugin (java module scope).

Parameters:

handler - the snapshot handler

onRestore

public static void onRestore(Functions.Consumer<Data> handler)

Adds an event handler to react to the current restore phase. Implementations may fetch elements from the provided data object. For isolation purposes, each plugin (java module scope) will be given its own data object.

Parameters:

handler - the restore handler

create

public abstract Executor.Task<java.lang.String> create(java.lang.String suffix)

Creates a new snapshot using the specified suffix while the prefix is usually the date of the snapshot.

Snapshots are always performed asynchronously and handlers are called sequentially. When all onSnapshot(Consumer) handlers have executed, the returned task will complete with the final snapshot name.

Parameters:

suffix - the snapshot suffix (will be sanitized to contain 0 to 30 alpha numerical characters a-zA-Z0-9)

Returns:

the asynchronous snapshot task

restore

public abstract Executor.Task<java.lang.Void> restore(java.lang.String snapshot)

Checks if the specified snapshot exists and triggers the restore operation.

Snapshots are always performed asynchronously and handlers are called sequentially. When all onRestore(Consumer) handlers have executed, the returned task will complete.

Parameters:

snapshot - the snapshot name

Returns:

the asynchronous restore task

Throws:

java.lang.IllegalArgumentException - if the specified snapshot does not exist

upload

public abstract void upload(byte[] snapshot)

Uploads a snapshot in this system.

Parameters:

snapshot - the snapshot content

Throws:

java.lang.IllegalArgumentException - if the snapshot is not compatible with this system

download

public abstract byte[] download(java.lang.String snapshot)

Downloads a snapshot.

Parameters:

snapshot - the snapshot name

Returns:

the opaque snapshot content

Throws:

java.lang.IllegalArgumentException - if the specified snapshot does not exist

list

public abstract java.util.Collection<java.lang.String> list()

Lists all available snapshots

Returns:

the list of snapshots

remove

public abstract void remove(java.lang.String snapshot)

Permanently removes a snapshot

Parameters:

snapshot - the snapshot to remove

exists

public abstract boolean exists(java.lang.String snapshot)

Checks if a snapshot exists

Parameters:

snapshot - the snapshot to check

Returns:

true if the snapshot exists, false otherwise

latest

public abstract java.lang.String latest()

Gets the name of the latest snapshot or null if there are no snapshots.

Returns:

the the latest snapshot name