Package org.epics.archiverappliance.retrieval.postprocessors

Class LastSample

java.lang.Object

org.epics.archiverappliance.retrieval.postprocessors.LastSample

All Implemented Interfaces:

PostProcessor, PostProcessorWithConsolidatedEventStream

public class LastSample
extends Object
implements PostProcessor, PostProcessorWithConsolidatedEventStream

Similar to the firstSample operator with the exception that we use the last sample in the bin.\

Author:

mshankar

Constructor Summary

Constructors

Constructor	Description
LastSample()

Method Summary

Modifier and Type	Method	Description
long	estimateMemoryConsumption(String pvName, PVTypeInfo typeInfo, Instant start, Instant end, jakarta.servlet.http.HttpServletRequest req)	Estimate the amount of memory required for the data generated by the post processors.
LinkedList<TimeSpan>	getBinTimestamps()
EventStream	getConsolidatedEventStream()
long	getEndBinEpochSeconds()
String	getExtension()	This is the full form of the identity for the post processor and includes any parameters for the post processor.
String	getIdentity()	The string used by clients to identify this post processor when making retrieval requests.
long	getStartBinEpochSeconds()
void	initialize(String userarg, String pvName)	Initialize this post processor for the given PV and request parameters.
Callable<EventStream>	wrap(Callable<EventStream> callable)	Primary data generation method.

Methods inherited from class java.lang.Object

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

Constructor Details

LastSample

public LastSample()

Method Details

initialize

public void initialize(String userarg,
 String pvName)
                throws IOException

Description copied from interface: PostProcessor

Initialize this post processor for the given PV and request parameters.

Specified by:

initialize in interface PostProcessor

Parameters:

userarg - This is the full form (extension) of the identity for the post processor.

pvName - The name of PV

Throws:

IOException -  

estimateMemoryConsumption

public long estimateMemoryConsumption(String pvName,
 PVTypeInfo typeInfo,
 Instant start,
 Instant end,
 jakarta.servlet.http.HttpServletRequest req)

Description copied from interface: PostProcessor

Estimate the amount of memory required for the data generated by the post processors.

Specified by:

estimateMemoryConsumption in interface PostProcessor

Parameters:

pvName - The name of PV

typeInfo - PVTypeInfo

start - Instant

end - Instant

req - HttpServletRequest

Returns:

Estimated Memory comsumption

wrap

public Callable<EventStream> wrap(Callable<EventStream> callable)

Description copied from interface: PostProcessor

Primary data generation method. Using the event stream provided, do your magic and generate processed data

Specified by:

wrap in interface PostProcessor

Parameters:

callable -  

Returns:

EventStream  

getIdentity

public String getIdentity()

Description copied from interface: PostProcessor

The string used by clients to identify this post processor when making retrieval requests. For example to identify the FirstSamplePP postprocessor, users would add a pp=firstSample to the request for data. The situation is a little more complex; if a post processor has parameters then it needs to combine these into a string and offer that as an extension. The identity is just the starting part of this.

1. For example, pp=firstSample_600 asks the server to sparsify with an interval of 600 seconds.
2. identity is firstSample.
3. extension is firstSample_600.
4. User specifies firstSample_600.
5. ETL caches the data as firstSample_600 if asked to.

Specified by:

getIdentity in interface PostProcessor

Returns:

identify  

getExtension

public String getExtension()

Description copied from interface: PostProcessor

This is the full form of the identity for the post processor and includes any parameters for the post processor. The exact format and interpretation of this is left to the post processor; however the convention is to use underscores to separate the params and have them in a specific order.

Specified by:

getExtension in interface PostProcessor

Returns:

extension  

See Also:

• PostProcessor.getIdentity()

getConsolidatedEventStream

public EventStream getConsolidatedEventStream()

Specified by:

getConsolidatedEventStream in interface PostProcessorWithConsolidatedEventStream

getStartBinEpochSeconds

public long getStartBinEpochSeconds()

Specified by:

getStartBinEpochSeconds in interface PostProcessorWithConsolidatedEventStream

getEndBinEpochSeconds

public long getEndBinEpochSeconds()

Specified by:

getEndBinEpochSeconds in interface PostProcessorWithConsolidatedEventStream

getBinTimestamps

public LinkedList<TimeSpan> getBinTimestamps()

Specified by:

getBinTimestamps in interface PostProcessorWithConsolidatedEventStream