Package com.inductiveautomation.ignition.gateway.history

Interface DataStore

All Superinterfaces:

DataSink, HistoryStorer

public interface DataStore
extends DataSink

A DataStore is an intermediate data sink - ie, the "store" part of "store and forward". Therefore, it takes data in as HistoricalData (through the DataSink interface), and then produces ForwardTransactions, which can be forwarded along.

Field Summary

Fields inherited from interface com.inductiveautomation.ignition.gateway.history.DataSink

LOG_NAME_TEMPLATE

Method Summary

Modifier and Type	Method	Description
void	addDataCountChangeListener(PropertyChangeListener listener)	Listener will be notified when new data is available for storage.
int	getDataCount()	Amount of data in the cache available to be forwarded.
long	getOldestTimestamp()	Gets the timestamp of the oldest data, in order to calculate how long data has been present.
void	removeDataCountChangeListener(PropertyChangeListener listener)
TransactionSet	takeNext(boolean wait, int desiredTransactionSize, Date olderThan)	Gets the next set of transactions to run.

Methods inherited from interface com.inductiveautomation.ignition.gateway.history.DataSink

getInfo, getLogName, getPipelineName, getQuarantineManager, isAccepting, shutdown, startup

Methods inherited from interface com.inductiveautomation.ignition.gateway.history.HistoryStorer

acceptsData, isLicensedFor, storeData

Method Details

addDataCountChangeListener

void addDataCountChangeListener(PropertyChangeListener listener)

Listener will be notified when new data is available for storage.

removeDataCountChangeListener

void removeDataCountChangeListener(PropertyChangeListener listener)

getDataCount

int getDataCount()

Amount of data in the cache available to be forwarded. This value cannot be trusted to be 100% accurate, it could be an estimation, and could return negative values if the cache thinks nothing is available or does not yet know how many points are available.

getOldestTimestamp

long getOldestTimestamp()

Gets the timestamp of the oldest data, in order to calculate how long data has been present. Does not look at quarantined data. Returns Long.MaxValue if there is no value available (because that will be in the future, and thus not old).

takeNext

@Nullable
TransactionSet takeNext(boolean wait,
 int desiredTransactionSize,
 @Nullable
 Date olderThan)
                 throws InterruptedException

Gets the next set of transactions to run.

Parameters:

wait - whether to block until data is available. If false, or if an olderThan parameter is provided, will return null if no data is present.

desiredTransactionSize - the desired size of data in the transactions. ONLY A HINT! Stores are free to return whatever they think is best. If -1, it's left to the store's discretion (usually will return 1 at a time)

olderThan - If null, not used. Otherwise only returns data older than the given value. Returns null if there is no old data available.

Throws:

InterruptedException