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

    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 Details

    • 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

    • copyStateTo

      void copyStateTo​(Robin other) throws IOException

      copyStateTo.

      Copies object's internal state to another Robin object.
      Specified by:
      copyStateTo in interface RrdUpdater<Robin>
      Parameters:
      other - a RrdUpdater object.
      Throws:
      IOException - if any.

    • 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.

    • dump

      String dump() throws IOException

      dump.

      Returns:
      a String object.
      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.