ai.grakn.engine.backgroundtasks.taskstatestorage

Class TaskStateInMemoryStore

java.lang.Object

ai.grakn.engine.backgroundtasks.taskstatestorage.TaskStateInMemoryStore

All Implemented Interfaces:

TaskStateStorage

public class TaskStateInMemoryStore
extends Object
implements TaskStateStorage

Implementation of StateStorage that stores task state in memory. If engine fails, task state recovery is not possible.

Author:

Denis Lobanov, alexandraorth

Constructor Summary

Constructors

Constructor and Description
TaskStateInMemoryStore()

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.
String	newState(TaskState state) Create a new task state and store it, returning an ID to later access this task state.
Boolean	updateState(TaskState state) 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

TaskStateInMemoryStore

public TaskStateInMemoryStore()

Method Detail

newState

public String newState(TaskState state)

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:

state - 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.

updateState

public Boolean updateState(TaskState state)

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:

state - State to update.

Returns:

true if inserted successfully

getState

public TaskState getState(String id)

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.

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