ai.grakn.engine.backgroundtasks.taskstatestorage

Class TaskStateGraphStore

java.lang.Object

ai.grakn.engine.backgroundtasks.taskstatestorage.TaskStateGraphStore

All Implemented Interfaces:

TaskStateStorage

public class TaskStateGraphStore
extends Object
implements TaskStateStorage

Implementation of StateStorage that stores task state in the Grakn system graph.

Author:

Denis Lobanov, alexandraorth

Constructor Summary

Constructors

Constructor and Description
TaskStateGraphStore()

Method Summary

Modifier and Type	Method and Description
TaskState	getState(String id) This is a copy of the internal TaskState object.
Set<TaskState>	getTasks(TaskStatus taskStatus, String taskClassName, String createdBy, int limit, int offset) Return a Set of Pairs of tasks that match any of the criteria.
Set<TaskState>	getTasks(TaskStatus taskStatus, String taskClassName, String createdBy, int limit, int offset, Boolean recurring)
TaskState	instanceToState(GraknGraph graph, Instance instance) Given an instance concept, turn it into a TaskState object.
String	newState(TaskState task) Create a new task state and store it, returning an ID to later access this task state.
Boolean	updateState(TaskState task) Used to update task state.

Methods inherited from class java.lang.Object

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

Constructor Detail

TaskStateGraphStore

public TaskStateGraphStore()

Method Detail

newState

public String newState(TaskState task)
                throws EngineStorageException

Description copied from interface: TaskStateStorage

Create a new task state and store it, returning an ID to later access this task state.

Specified by:

newState in interface TaskStateStorage

Parameters:

task - State to insert.

Returns:

String form of the task id, which can be use later to update or retrieve the task state. Null if task could not be created of mandatory fields were omitted.

Throws:

EngineStorageException

updateState

public Boolean updateState(TaskState task)

Description copied from interface: TaskStateStorage

Used to update task state. With the exception of @id any other fields may individually be null, however all parameters cannot be null at the same time. Setting any of the parameters to null indicates that their values should not be changed.

Specified by:

updateState in interface TaskStateStorage

Parameters:

task - State to update.

Returns:

true if inserted successfully

getState

public TaskState getState(String id)
                   throws EngineStorageException

Description copied from interface: TaskStateStorage

This is a copy of the internal TaskState object. It is guaranteed to be correct at the time of call, however the actual internal state may change at any time after.

Specified by:

getState in interface TaskStateStorage

Parameters:

id - String id of task.

Returns:

TaskState object or null if no TaskState with this id could be found.

Throws:

EngineStorageException

instanceToState

public TaskState instanceToState(GraknGraph graph,
                                 Instance instance)

Given an instance concept, turn it into a TaskState object. This is done by retrieving the serialized TaskState from the given graph and deserialising it.

Parameters:

graph - Graph in which to fetch serialized state

instance - Task instance to turn into task state

Returns:

TaskState representing given instance

getTasks

public Set<TaskState> getTasks(TaskStatus taskStatus,
                               String taskClassName,
                               String createdBy,
                               int limit,
                               int offset)

Description copied from interface: TaskStateStorage

Return a Set of Pairs of tasks that match any of the criteria. The first value of the Pair is the task id, whilst the second is the TaskState. Parameters may be set to null to not match against then (rather than to match null values), if *all* parameters are null then all known tasks in the system are returned.

Specified by:

getTasks in interface TaskStateStorage

Parameters:

taskStatus - See TaskStatus enum.

taskClassName - String containing task class name. See TaskState.

createdBy - String containing created by. See TaskState.

limit - Limit the returned result set to @limit amount of entries.

offset - Use in conjunction with @limit for pagination.

Returns:

Set of TaskStates corresponding to search

getTasks

public Set<TaskState> getTasks(TaskStatus taskStatus,
                               String taskClassName,
                               String createdBy,
                               int limit,
                               int offset,
                               Boolean recurring)