Package com.cognite.client.statestore

Class MemoryStateStore

java.lang.Object

com.cognite.client.statestore.AbstractStateStore

com.cognite.client.statestore.MemoryStateStore

All Implemented Interfaces:

StateStore, Closeable, AutoCloseable

public abstract class MemoryStateStore
extends AbstractStateStore

A state store in-memory only. Not backed by any persisted storage. Abstract parent class for all state store implementations.

Field Summary

Fields inherited from class com.cognite.client.statestore.AbstractStateStore

COLUMN_KEY_HIGH, COLUMN_KEY_LOW, DEFAULT_MAX_COMMIT_INTERVAL, deletedEntries, executor, LOG, MAX_MAX_COMMIT_INTERVAL, MIN_MAX_COMMIT_INTERVAL, modifiedEntries, recurringTask, stateMap

Constructor Summary

Constructors

Constructor	Description
MemoryStateStore()

Method Summary

Modifier and Type	Method	Description
void	commit()	Commit the current states to the persistent store.
static MemoryStateStore	create()	Initialize an in-memory state store.
void	load()	Load the states from the persistent store.
boolean	start()	Start a background thread to perform a commit every maxUploadInterval.
boolean	stop()	Stops the background thread if it is running and ensures the upload queue is empty by calling upload() one last time after shutting down the thread.

Methods inherited from class com.cognite.client.statestore.AbstractStateStore

close, deleteState, expandHigh, expandLow, getHigh, getLow, getState, isOutsideState, keySet, setHigh, setLow, verifyStateMap

Methods inherited from class java.lang.Object

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

Constructor Details

MemoryStateStore

public MemoryStateStore()

Method Details

create

public static MemoryStateStore create()

Initialize an in-memory state store.

Returns:

the state store.

load

public void load()
          throws Exception

Load the states from the persistent store.

Specified by:

load in interface StateStore

Specified by:

load in class AbstractStateStore

Throws:

Exception

commit

public void commit()
            throws Exception

Commit the current states to the persistent store. Will overwrite/replace previously persisted states.

Specified by:

commit in interface StateStore

Specified by:

commit in class AbstractStateStore

Throws:

Exception

start

public boolean start()

Start a background thread to perform a commit every maxUploadInterval. The default upload interval is every 20 seconds. If the background thread has already been started (for example by an earlier call to start() then this method does nothing and returns false.

Specified by:

start in interface StateStore

Overrides:

start in class AbstractStateStore

Returns:

true if the upload thread started successfully, false if the background thread has already been started.

stop

public boolean stop()

Stops the background thread if it is running and ensures the upload queue is empty by calling upload() one last time after shutting down the thread.

Specified by:

stop in interface StateStore

Overrides:

stop in class AbstractStateStore

Returns:

true if the upload thread stopped successfully, false if the upload thread was not started in the first place.