Package org.rrd4j.core

Interface Robin

  • All Superinterfaces:
    RrdUpdater<Robin>
    All Known Implementing Classes:
    RobinArray, RobinMatrix
    public interface Robin
extends RrdUpdater<Robin>
    Class to represent archive values for a single datasource. Robin class is the heart of the so-called "round robin database" concept. Basically, each Robin object is a fixed length array of double values. Each double value represents consolidated, archived value for the specific timestamp. When the underlying array of double values gets completely filled, new values will replace the oldest ones.

    Robin object does not hold values in memory - such object could be quite large. Instead of it, Robin reads them from the backend I/O only when necessary.

    Author:
    Sasa Markovic

    • Method Summary

      All Methods Instance Methods Abstract Methods 
      Modifier and Type Method Description
      void bulkStore​(double newValue, int bulkCount)
      bulkStore.
      void copyStateTo​(Robin other)
      copyStateTo.
      String dump()
      dump.
      void filterValues​(double minValue, double maxValue)
      Filters values stored in this archive based on the given boundary.
      Archive getParent()
      Returns the Archive object to which this Robin object belongs.
      RrdAllocator getRrdAllocator()
      Required to implement RrdUpdater interface.
      RrdBackend getRrdBackend()
      Returns the underlying storage (backend) object which actually performs all I/O operations.
      int getSize()
      Returns the size of the underlying array of archived values.
      double getValue​(int index)
      Returns the i-th value from the Robin archive.
      double[] getValues()
      Fetches all archived values.
      double[] getValues​(int index, int count)
      getValues.
      void setValue​(int index, double value)
      Sets the i-th value in the Robin archive.
      void setValues​(double newValue)
      (Re)sets all values in this archive to the same value.
      void setValues​(double... newValues)
      Updates archived values in bulk.
      void store​(double newValue)
      store.
      void update​(double[] newValues)
      update.

    • Method Detail

      • getValues

        double[] getValues()
            throws IOException
        Fetches all archived values.
        Returns:
        Array of double archive values, starting from the oldest one.
        Throws:
        IOException - Thrown in case of I/O specific error.

      • setValues

        void setValues​(double... newValues)
        throws IOException
        Updates archived values in bulk.
        Parameters:
        newValues - Array of double values to be stored in the archive
        Throws:
        IOException - Thrown in case of I/O error
        IllegalArgumentException - Thrown if the length of the input array is different from the length of this archive

      • setValues

        void setValues​(double newValue)
        throws IOException
        (Re)sets all values in this archive to the same value.
        Parameters:
        newValue - New value
        Throws:
        IOException - Thrown in case of I/O error

      • getValue

        double getValue​(int index)
         throws IOException
        Returns the i-th value from the Robin archive.
        Parameters:
        index - Value index
        Returns:
        Value stored in the i-th position (the oldest value has zero index)
        Throws:
        IOException - Thrown in case of I/O specific error.

      • setValue

        void setValue​(int index,
              double value)
       throws IOException
        Sets the i-th value in the Robin archive.
        Parameters:
        index - index in the archive (the oldest value has zero index)
        value - value to be stored
        Throws:
        IOException - Thrown in case of I/O specific error.

      • getParent

        Archive getParent()
        Returns the Archive object to which this Robin object belongs.
        Returns:
        Parent Archive object

      • getSize

        int getSize()
        Returns the size of the underlying array of archived values.
        Returns:
        Number of stored values

      • filterValues

        void filterValues​(double minValue,
                  double maxValue)
           throws IOException
        Filters values stored in this archive based on the given boundary. Archived values found to be outside of [minValue, maxValue] interval (inclusive) will be silently replaced with NaN.
        Parameters:
        minValue - lower boundary
        maxValue - upper boundary
        Throws:
        IOException - Thrown in case of I/O error

      • getRrdBackend

        RrdBackend getRrdBackend()
        Returns the underlying storage (backend) object which actually performs all I/O operations.
        Specified by:
        getRrdBackend in interface RrdUpdater<Robin>
        Returns:
        I/O backend object

      • getRrdAllocator

        RrdAllocator getRrdAllocator()
        Required to implement RrdUpdater interface. You should never call this method directly.
        Specified by:
        getRrdAllocator in interface RrdUpdater<Robin>
        Returns:
        Allocator object

      • update

        void update​(double[] newValues)
     throws IOException

        update.

        Parameters:
        newValues - an array of double.
        Throws:
        IOException - if any.

      • store

        void store​(double newValue)
    throws IOException

        store.

        Parameters:
        newValue - a double.
        Throws:
        IOException - if any.

      • bulkStore

        void bulkStore​(double newValue,
               int bulkCount)
        throws IOException

        bulkStore.

        Parameters:
        newValue - a double.
        bulkCount - a int.
        Throws:
        IOException - if any.

      • getValues

        double[] getValues​(int index,
                   int count)
            throws IOException

        getValues.

        Parameters:
        index - a int.
        count - a int.
        Returns:
        an array of double.
        Throws:
        IOException - if any.