Package com.cognite.client.statestore

Class AbstractStateStore

java.lang.Object

com.cognite.client.statestore.AbstractStateStore

All Implemented Interfaces:

StateStore, Closeable, AutoCloseable

Direct Known Subclasses:

LocalStateStore, MemoryStateStore, RawStateStore

public abstract class AbstractStateStore
extends Object
implements StateStore, Closeable

Abstract parent class for all state store implementations.

Field Summary

Fields

Modifier and Type	Field	Description
protected static String	COLUMN_KEY_HIGH
protected static String	COLUMN_KEY_LOW
protected static Duration	DEFAULT_MAX_COMMIT_INTERVAL
protected Set<String>	deletedEntries
protected ScheduledThreadPoolExecutor	executor
protected org.slf4j.Logger	LOG
protected static Duration	MAX_MAX_COMMIT_INTERVAL
protected static Duration	MIN_MAX_COMMIT_INTERVAL
protected Set<String>	modifiedEntries
protected ScheduledFuture<?>	recurringTask
protected ConcurrentMap<String,com.google.protobuf.Struct>	stateMap

Constructor Summary

Constructors

Constructor	Description
AbstractStateStore()

Method Summary

Modifier and Type	Method	Description
void	close()	A mirror of the stop() method to support auto close in a try-with-resources statement.
abstract void	commit()	Commit the current states to the persistent store.
void	deleteState(String key)	Delete the state(s) for a given id.
void	expandHigh(String key, long value)	Like StateStore.setHigh(String, long), but only sets the state if the proposed state is higher than the current state.
void	expandLow(String key, long value)	Like StateStore.setLow(String, long), but only sets the state if the proposed state is lower than the current state.
OptionalLong	getHigh(String key)	Get the high watermark state for a single id.
OptionalLong	getLow(String key)	Get the low watermark state for a single id.
Optional<com.google.protobuf.Struct>	getState(String key)	Get the set of states for a single id.
boolean	isOutsideState(String key, long value)	Check if a state is outside the stored state interval.
Set<String>	keySet()	Returns a read-only set of all state keys.
abstract void	load()	Load the states from the persistent store.
void	setHigh(String key, long value)	Set/update the high watermark for a single id.
void	setLow(String key, long value)	Set/update the low watermark for a single id.
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.
protected boolean	verifyStateMap()

Methods inherited from class java.lang.Object

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

Field Detail

COLUMN_KEY_LOW

protected static final String COLUMN_KEY_LOW

See Also:

Constant Field Values

COLUMN_KEY_HIGH

protected static final String COLUMN_KEY_HIGH

See Also:

Constant Field Values

MIN_MAX_COMMIT_INTERVAL

protected static final Duration MIN_MAX_COMMIT_INTERVAL

DEFAULT_MAX_COMMIT_INTERVAL

protected static final Duration DEFAULT_MAX_COMMIT_INTERVAL

MAX_MAX_COMMIT_INTERVAL

protected static final Duration MAX_MAX_COMMIT_INTERVAL

LOG

protected final org.slf4j.Logger LOG

stateMap

protected ConcurrentMap<String,com.google.protobuf.Struct> stateMap

modifiedEntries

protected Set<String> modifiedEntries

deletedEntries

protected Set<String> deletedEntries

executor

protected final ScheduledThreadPoolExecutor executor

recurringTask

protected ScheduledFuture<?> recurringTask

Constructor Detail

AbstractStateStore

public AbstractStateStore()

Method Detail

setHigh

public void setHigh(String key,
                    long value)

Set/update the high watermark for a single id.

Specified by:

setHigh in interface StateStore

Parameters:

key - The id to store the state of.

value - The value of the high watermark.

expandHigh

public void expandHigh(String key,
                       long value)

Like StateStore.setHigh(String, long), but only sets the state if the proposed state is higher than the current state.

Specified by:

expandHigh in interface StateStore

Parameters:

key - key The id to store the state of.

value - The value of the high watermark.

getHigh

public OptionalLong getHigh(String key)

Get the high watermark state for a single id.

Specified by:

getHigh in interface StateStore

Parameters:

key - The id to get the state of.

Returns:

The value of the high watermark. An empty optional in case the state does not exist.

setLow

public void setLow(String key,
                   long value)

Set/update the low watermark for a single id.

Specified by:

setLow in interface StateStore

Parameters:

key - The id to store the state of.

value - The value of the low watermark.

expandLow

public void expandLow(String key,
                      long value)

Like StateStore.setLow(String, long), but only sets the state if the proposed state is lower than the current state.

Specified by:

expandLow in interface StateStore

Parameters:

key - key The id to store the state of.

value - The value of the low watermark.

getLow

public OptionalLong getLow(String key)

Get the low watermark state for a single id.

Specified by:

getLow in interface StateStore

Parameters:

key - The id to get the state of.

Returns:

The value of the low watermark. An empty optional in case the state does not exist.

isOutsideState

public boolean isOutsideState(String key,
                              long value)

Check if a state is outside the stored state interval. I.e. if a state is higher than the current high watermark or lower than the current low watermark. The method can be used for determining if a data object should be processed or not.

Specified by:

isOutsideState in interface StateStore

Parameters:

key - the id to test.

value - the state to test.

Returns:

True if the state is outside of stored state or if the key is previously unseen.

getState

public Optional<com.google.protobuf.Struct> getState(String key)

Get the set of states for a single id. This will give you both the low and high watermark (if set) as a Struct. The returned Struct is a read-only view of the state values.

Specified by:

getState in interface StateStore

Parameters:

key - The id to get the state of.

Returns:

All the states in a Struct.

deleteState

public void deleteState(String key)

Delete the state(s) for a given id.

Specified by:

deleteState in interface StateStore

Parameters:

key - The id to delete the state(s) of.

keySet

public Set<String> keySet()

Returns a read-only set of all state keys.

Specified by:

keySet in interface StateStore

Returns:

An immutable Set of all state keys.

load

public abstract void load()
                   throws Exception

Load the states from the persistent store.

Specified by:

load in interface StateStore

Throws:

Exception

commit

public abstract void commit()
                     throws Exception

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

Specified by:

commit in interface StateStore

Throws:

Exception

verifyStateMap

protected boolean verifyStateMap()

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

Returns:

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

close

public void close()

A mirror of the stop() method to support auto close in a try-with-resources statement.

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable

See Also:

stop()

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

Returns:

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