Package org.epics.archiverappliance.retrieval.postprocessors

Class DeadBand

java.lang.Object
org.epics.archiverappliance.retrieval.postprocessors.DeadBand
All Implemented Interfaces:
PostProcessor
public class DeadBand extends Object implements PostProcessor
The intent is to mimic ADEL; this is principally targeted at decimation Like ADEL, it applies only to scalar numbers. We have some notion of a "last" value that was written out. The very first sample we get we write out and that becomes the "last" value. 
 Diff = Math.abs(current value - last value)
 If Diff ≥ ADEL
     Write out value
     Update last known value
  1. If either current value or previous value is NAN/INF, unconditionally write out current value and update last known value
  2. Also need to to write out when alarm severity changes (MD)
  3. Also need to to write out when connection state changes (connect/disconnect) (MD)
Author:
mshankar

  • Constructor Details

    • DeadBand

      public DeadBand()

  • 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, javax.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: