Package org.epics.archiverappliance.engine.model

Class DeltaArchiveChannel

java.lang.Object

org.epics.archiverappliance.engine.model.ArchiveChannel

org.epics.archiverappliance.engine.model.DeltaArchiveChannel

public class DeltaArchiveChannel
extends ArchiveChannel

An ArchiveChannel that stores each incoming value that differs from the previous sample by some 'delta'.

Author:

Kay Kasemir

Field Summary

Fields inherited from class org.epics.archiverappliance.engine.model.ArchiveChannel

lastDBRTimeEvent, latestDBRTimeEvent, pvMetrics, SAVE_META_DATA_PERIOD_SECS

Constructor Summary

Constructors

Constructor	Description
DeltaArchiveChannel(String name, Writer writer, int buffer_capacity, Instant last_timeestamp, double period_estimate, double delta, ConfigService configservice, ArchDBRTypes archdbrtype, String controlPVname, int commandThreadID, boolean usePVAccess)

Method Summary

Modifier and Type	Method	Description
String	getMechanism()
protected boolean	handleNewValue(DBRTimeEvent timeevent)	Attempt to add each new value to the buffer.

Methods inherited from class org.epics.archiverappliance.engine.model.ArchiveChannel

aboutToWriteBuffer, addValueToBuffer, getConnectedMetaChannelCount, getControlPVname, getCurrentCopyOfMetaFields, getHostName, getJCACommandThreadID, getLastArchivedValue, getLatestMetadata, getLowLevelChannelStateInfo, getMetaChannelCount, getMetaPVNames, getName, getPVData, getPVMetrics, getSampleBuffer, getSecondsElapsedSinceSearchRequest, getWriter, handleDisconnected, initializeMetaFieldPVS, isConnected, isMetaPVConnected, isPaused, metaChannelsNeedStartingUp, reset, setlastRotateLogsEpochSeconds, setPaused, shutdownMetaChannels, start, startUpMetaChannels, stop, toString, updateMetadataOnceADay

Methods inherited from class java.lang.Object

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

Constructor Details

DeltaArchiveChannel

public DeltaArchiveChannel(String name,
 Writer writer,
 int buffer_capacity,
 Instant last_timeestamp,
 double period_estimate,
 double delta,
 ConfigService configservice,
 ArchDBRTypes archdbrtype,
 String controlPVname,
 int commandThreadID,
 boolean usePVAccess)
                    throws Exception

Parameters:

name - Name of the channel (PV)

writer -  

buffer_capacity - Size of sample buffer

last_timeestamp -  

period_estimate - Estimated change period [seconds]

delta - Value changes ≥ this value will be stored

configservice - ConfigService

archdbrtype - ArchDBRTypeS

controlPVname -  

commandThreadID -  

usePVAccess -  

Throws:

Exception - On error in PV setup

Method Details

getMechanism

public String getMechanism()

Specified by:

getMechanism in class ArchiveChannel

Returns:

Short description of sample mechanism

handleNewValue

protected boolean handleNewValue(DBRTimeEvent timeevent)

Attempt to add each new value to the buffer.

Overrides:

handleNewValue in class ArchiveChannel

Parameters:

timeevent - DBRTimeEvent

Returns:

true if the value was already written because it's the first value after startup or error, so there's no need to write that sample again.