Package com.inductiveautomation.historian.gateway.interop

Class HistorianPointQueryExecutor<P extends DataPoint<?>,K extends DataPointQueryKey>

java.lang.Object

com.inductiveautomation.historian.gateway.interop.HistorianPointQueryExecutor<P,K>

All Implemented Interfaces:

QueriedPointProcessor<P,K,DataPointType>, HistoryQueryExecutor

Direct Known Subclasses:

HistorianAggregatedQueryExecutor, HistorianRawQueryExecutor

public abstract class HistorianPointQueryExecutor<P extends DataPoint<?>,K extends DataPointQueryKey>
extends Object
implements HistoryQueryExecutor, QueriedPointProcessor<P,K,DataPointType>

Field Summary

Fields

Modifier and Type	Field	Description
protected final com.google.common.collect.Multimap<K,HistorianDataColumn<K>>	columnMap
protected final List<HistorianDataColumn<K>>	columns
protected final QueryController	controller
protected static final LoggerEx	log
protected final QueryEngine	queryEngine

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	HistorianPointQueryExecutor(QueryEngine queryEngine, Collection<HistorianDataColumn<K>> columns, QueryController controller)

Method Summary

Modifier and Type	Method	Description
void	endReading()	If startReading was called, this function must be called (that is, it should be in a finally block).
protected abstract void	executeQuery()
List<? extends ResultNode>	getColumnNodes()	Returns the HistoryNodes of this executor.
boolean	hasMore()	Returns TRUE if there is more data available to be written on call to processData()
void	initialize()	Initializes the query, performing any actions necessary to get the information required to run the query.
protected boolean	isFinished()
protected boolean	isOperationTimedOut(long startMS)
long	nextTime()	The timestamp of the next value.
protected void	notifyValueBuffer()
void	onComplete()	Called when all processing is complete.
void	onError(QualityCode error)	Handles a terminal error condition with a quality code.
void	onError(Exception error)	Handles a terminal error condition with an exception.
boolean	onInitialize(ProcessingContext<K,DataPointType> context)	Initializes the processor with context information before processing begins.
void	onKeyFailure(K queryKey, QualityCode failureCode)	Handles a failure specific to a query key.
boolean	onPointAvailable(K queryKey, P point)	Processes a single temporal point.
long	processData()	Puts the next value(s) into the appropriate column, returning the latest timestamp loaded, or -1 if no data was loaded.
void	startReading()	Begins reading data.
protected void	waitForColumnInit()
protected void	waitForData()

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.inductiveautomation.ignition.gateway.sqltags.history.query.HistoryQueryExecutor

getEffectiveWindowSizeMS

Field Details

log

protected static final LoggerEx log

columnMap

protected final com.google.common.collect.Multimap<K extends DataPointQueryKey,HistorianDataColumn<K extends DataPointQueryKey>> columnMap

columns

protected final List<HistorianDataColumn<K extends DataPointQueryKey>> columns

queryEngine

protected final QueryEngine queryEngine

controller

protected final QueryController controller

Constructor Details

HistorianPointQueryExecutor

protected HistorianPointQueryExecutor(QueryEngine queryEngine,
 Collection<HistorianDataColumn<K>> columns,
 QueryController controller)

Method Details

initialize

public void initialize()

Description copied from interface: HistoryQueryExecutor

Initializes the query, performing any actions necessary to get the information required to run the query.

Specified by:

initialize in interface HistoryQueryExecutor

getColumnNodes

public List<? extends ResultNode> getColumnNodes()

Description copied from interface: HistoryQueryExecutor

Returns the HistoryNodes of this executor. There MUST be one for every tag path, and they must be in the same order as the paths provided to the executor when it was created. Also, these values must be available as soon as the executor is created. However, they won't be consulted for their data type until after initialize is called, so the normal procedure is to create and return DelegatingResultNodes, which get filled in later.

Specified by:

getColumnNodes in interface HistoryQueryExecutor

startReading

public void startReading()

Description copied from interface: HistoryQueryExecutor

Begins reading data. IMPORTANT: endReading should always be called at some point after calling startReading.

Specified by:

startReading in interface HistoryQueryExecutor

waitForColumnInit

protected void waitForColumnInit()

endReading

public void endReading()

Description copied from interface: HistoryQueryExecutor

If startReading was called, this function must be called (that is, it should be in a finally block).

Specified by:

endReading in interface HistoryQueryExecutor

isOperationTimedOut

protected boolean isOperationTimedOut(long startMS)

waitForData

protected void waitForData()

isFinished

protected boolean isFinished()

hasMore

public boolean hasMore()

Description copied from interface: HistoryQueryExecutor

Returns TRUE if there is more data available to be written on call to processData()

Specified by:

hasMore in interface HistoryQueryExecutor

nextTime

public long nextTime()

Description copied from interface: HistoryQueryExecutor

The timestamp of the next value. -1 if no value is available.

Specified by:

nextTime in interface HistoryQueryExecutor

processData

public long processData()

Description copied from interface: HistoryQueryExecutor

Puts the next value(s) into the appropriate column, returning the latest timestamp loaded, or -1 if no data was loaded.

Specified by:

processData in interface HistoryQueryExecutor

onInitialize

public boolean onInitialize(ProcessingContext<K,DataPointType> context)

Description copied from interface: QueriedPointProcessor

Initializes the processor with context information before processing begins. This method is called once before any points are processed.

Specified by:

onInitialize in interface QueriedPointProcessor<P extends DataPoint<?>,K extends DataPointQueryKey,DataPointType>

Parameters:

context - The processing context containing initialization properties.

Returns:

True if initialization was successful and processing should continue, false to stop.

onPointAvailable

public boolean onPointAvailable(K queryKey,
 P point)

Description copied from interface: QueriedPointProcessor

Processes a single temporal point. Called repeatedly for each point in the result set.

Specified by:

onPointAvailable in interface QueriedPointProcessor<P extends DataPoint<?>,K extends DataPointQueryKey,DataPointType>

Parameters:

queryKey - The query key associated with the point.

point - The temporal point to process.

Returns:

True to continue processing additional points, false to stop.

onKeyFailure

public void onKeyFailure(K queryKey,
 QualityCode failureCode)

Description copied from interface: QueriedPointProcessor

Handles a failure specific to a query key. Processing continues for other query keys after this is called. This method can be called prior to QueriedPointProcessor.onInitialize(ProcessingContext) as needed.

Specified by:

onKeyFailure in interface QueriedPointProcessor<P extends DataPoint<?>,K extends DataPointQueryKey,DataPointType>

Parameters:

queryKey - The query key that failed.

failureCode - The quality code indicating the reason for failure.

onError

public void onError(QualityCode error)

Description copied from interface: QueriedPointProcessor

Handles a terminal error condition with a quality code. Processing stops after this method is called.

Specified by:

onError in interface QueriedPointProcessor<P extends DataPoint<?>,K extends DataPointQueryKey,DataPointType>

Parameters:

error - The quality code representing the error condition.

onError

public void onError(Exception error)

Description copied from interface: QueriedPointProcessor

Handles a terminal error condition with an exception. Processing stops after this method is called.

Specified by:

onError in interface QueriedPointProcessor<P extends DataPoint<?>,K extends DataPointQueryKey,DataPointType>

Parameters:

error - The exception that caused the error.

onComplete

public void onComplete()

Description copied from interface: QueriedPointProcessor

Called when all processing is complete. This method is called exactly once after all points have been processed or processing has been stopped.

Specified by:

onComplete in interface QueriedPointProcessor<P extends DataPoint<?>,K extends DataPointQueryKey,DataPointType>

notifyValueBuffer

protected void notifyValueBuffer()

executeQuery

protected abstract void executeQuery()