eu.ehri.project.persistence

Class ActionManager

java.lang.Object

eu.ehri.project.persistence.ActionManager

public final class ActionManager
extends Object

Class for dealing with actions.

Events are captured as a linked list with new events placed at the head. The head event is connected to a node called the SystemEventQueue. Events can have subjects (the thing the event is happening to) and actioners (the person initiating the event.) A subject's events and an actioner's actions likewise for a linked list so it is possible to fetch new events easily and prevent having to sort by timestamp, etc. Schematically, the graph thus formed looks something like:

 
 Actioner              SystemEventQueue             Subject
 \/                        \/                      \/
 [lifecycleAction]     [lifecycleActionStream]     [lifecycleEvent]
 |                         |                       |
 e3--[actionHasEvent]->-- Event 3 ---[hasEvent]--<--e3
 \/                        \/                      \/
 [lifecycleAction]         [lifecycleAction]       [lifecycleEvent]
 |                         |                       |
 e2--[actionHasEvent]->-- Event 2 ---[hasEvent]--<--e2
 \/                        \/                      \/
 [lifecycleAction]         [lifecycleAction]       [lifecycleEvent]
 |                         |                       |
 e1--[actionHasEvent]->-- Event 1 ---[hasEvent]--<--e1
 
 

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
class	ActionManager.EventContext EventContext is a handle to a particular action to which additional subjects can be added.

Field Summary

Fields

Modifier and Type	Field and Description
static String	DEBUG_TYPE
static String	EVENT_LINK
static String	GLOBAL_EVENT_ROOT
static String	LINK_TYPE

Constructor Summary

Constructors

Constructor and Description
ActionManager(com.tinkerpop.frames.FramedGraph<?> graph) Constructor.
ActionManager(com.tinkerpop.frames.FramedGraph<?> graph, Entity scope) Constructor with scope.

Method Summary

Modifier and Type	Method and Description
static boolean	canAggregate(SystemEvent event1, SystemEvent event2, int timeDiffInSeconds) Determine if two events are the same according to the following definition:
SystemEventQueue	getEventRoot()
SystemEvent	getLatestGlobalEvent() Get the latest global event.
Iterable<SystemEvent>	getLatestGlobalEvents() Get an iterable of global events in most-recent-first order.
static String	getTimestamp() Get the current time as a timestamp.
ActionManager.EventContext	newEventContext(Accessible subject, Actioner user, EventTypes type) Create an action for the given subject, user, and type.
ActionManager.EventContext	newEventContext(Accessible subject, Actioner user, EventTypes type, Optional<String> logMessage) Create an action node that describes what user U has done with subject S via logMessage log.
ActionManager.EventContext	newEventContext(Actioner user, EventTypes type) Create an action node describing something that user U has done.
ActionManager.EventContext	newEventContext(Actioner user, EventTypes type, Optional<String> logMessage) Create an action node describing something that user U has done.
static boolean	sameAs(SystemEvent event1, SystemEvent event2)
static boolean	sequentialWithSameAccessor(SystemEvent first, SystemEvent second) Test if two events are sequential with the same actioner.
ActionManager	setScope(Entity frame) Set the scope of this action.

Methods inherited from class java.lang.Object

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

Field Detail

GLOBAL_EVENT_ROOT

public static final String GLOBAL_EVENT_ROOT

See Also:

Constant Field Values

DEBUG_TYPE

public static final String DEBUG_TYPE

See Also:

Constant Field Values

EVENT_LINK

public static final String EVENT_LINK

See Also:

Constant Field Values

LINK_TYPE

public static final String LINK_TYPE

See Also:

Constant Field Values

Constructor Detail

ActionManager

public ActionManager(com.tinkerpop.frames.FramedGraph<?> graph,
                     Entity scope)

Constructor with scope.

Parameters:

graph - The framed graph

ActionManager

public ActionManager(com.tinkerpop.frames.FramedGraph<?> graph)

Constructor.

Parameters:

graph - The framed graph

Method Detail

getEventRoot

public SystemEventQueue getEventRoot()

getLatestGlobalEvent

public SystemEvent getLatestGlobalEvent()

Get the latest global event.

Returns:

The latest event node

getLatestGlobalEvents

public Iterable<SystemEvent> getLatestGlobalEvents()

Get an iterable of global events in most-recent-first order.

Returns:

A iterable of event nodes

newEventContext

public ActionManager.EventContext newEventContext(Actioner user,
                                                  EventTypes type,
                                                  Optional<String> logMessage)

Create an action node describing something that user U has done.

Parameters:

user - The actioner

type - The event type

logMessage - An optional log message

Returns:

An EventContext object

newEventContext

public ActionManager.EventContext newEventContext(Actioner user,
                                                  EventTypes type)

Create an action node describing something that user U has done.

Parameters:

user - The actioner

type - The event type

Returns:

An EventContext object

newEventContext

public ActionManager.EventContext newEventContext(Accessible subject,
                                                  Actioner user,
                                                  EventTypes type)

Create an action for the given subject, user, and type.

Parameters:

subject - The subject node

user - The actioner

type - The event type

Returns:

An EventContext object

newEventContext

public ActionManager.EventContext newEventContext(Accessible subject,
                                                  Actioner user,
                                                  EventTypes type,
                                                  Optional<String> logMessage)

Create an action node that describes what user U has done with subject S via logMessage log.

Parameters:

subject - The subjject node

user - The actioner

logMessage - A log message

Returns:

An EventContext object

setScope

public ActionManager setScope(Entity frame)

Set the scope of this action.

Parameters:

frame - The current permission scope

Returns:

A new ActionManager instance.

canAggregate

public static boolean canAggregate(SystemEvent event1,
                                   SystemEvent event2,
                                   int timeDiffInSeconds)

Determine if two events are the same according to the following definition:

1. They have the same scope and subject
2. They have the same actioner
3. They are both of the same type
4. They have the same log message, if any

This function allows filtering an event stream for duplicates, like someone repeatedly updating the same item.

Parameters:

event1 - the first event

event2 - the second event

timeDiffInSeconds - the elapsed time between the events

Returns:

whether or not the events are effectively the same.

sequentialWithSameAccessor

public static boolean sequentialWithSameAccessor(SystemEvent first,
                                                 SystemEvent second)

Test if two events are sequential with the same actioner. This is used for aggregating repeated events.

Parameters:

first - the first temporal event

second - the second temporal event

Returns:

whether events can be aggregated by user

sameAs

public static boolean sameAs(SystemEvent event1,
                             SystemEvent event2)

getTimestamp

public static String getTimestamp()

Get the current time as a timestamp.

Returns:

The current time in ISO DateTime format.