Package org.apache.datasketches.tuple

Class UpdatableSketch<U,​S extends UpdatableSummary<U>>

java.lang.Object
org.apache.datasketches.tuple.Sketch<S>
org.apache.datasketches.tuple.UpdatableSketch<U,​S>
Type Parameters:
U - Type of the value, which is passed to update method of a Summary
S - Type of the UpdatableSummary<U>
Direct Known Subclasses:
ArrayOfStringsSketch, DoubleSketch, IntegerSketch
public class UpdatableSketch<U,​S extends UpdatableSummary<U>>
extends Sketch<S>
An extension of QuickSelectSketch<S>, which can be updated with many types of keys. Summary objects are created using a user-defined SummaryFactory class, which should allow very flexible parameterization if needed. Keys are presented to a sketch along with values of a user-defined update type U. When an entry is inserted into a sketch or a duplicate key is presented to a sketch then summary.update(U value) method will be called. So any kind of user-defined accumulation is possible. Summaries also must know how to copy themselves. Also union and intersection of summaries can be implemented in a sub-class of SummarySetOperations, which will be used in case Union or Intersection of two instances of Tuple Sketch is needed

  • Field Summary

    Fields inherited from class org.apache.datasketches.tuple.Sketch

    PREAMBLE_LONGS

  • Constructor Summary

    Constructors 
    Constructor Description
    UpdatableSketch​(int nomEntries, int lgResizeFactor, float samplingProbability, SummaryFactory<S> summaryFactory)
    This is to create a new instance of an UpdatableQuickSelectSketch.
    UpdatableSketch​(org.apache.datasketches.memory.Memory srcMem, SummaryDeserializer<S> deserializer, SummaryFactory<S> summaryFactory)
    This is to create an instance of a sketch given a serialized form

  • Method Summary

    Modifier and Type Method Description
    CompactSketch<S> compact()
    Converts the current state of the sketch into a compact sketch
    int getCountLessThanThetaLong​(long thetaLong)
    Gets the number of hash values less than the given theta expressed as a long.
    int getCurrentCapacity()
    Get current capacity
    int getLgK()
    Get log_base2 of Nominal Entries
    int getNominalEntries()
    Get configured nominal number of entries
    ResizeFactor getResizeFactor()
    Get configured resize factor
    int getRetainedEntries()  
    float getSamplingProbability()
    Get configured sampling probability
    protected void insertSummary​(int index, S summary)  
    SketchIterator<S> iterator()
    Returns a SketchIterator
    void reset()
    Resets this sketch an empty state.
    byte[] toByteArray()
    This is to serialize an instance to a byte array.
    void trim()
    Rebuilds reducing the actual number of entries to the nominal number of entries if needed
    void update​(byte[] key, U value)
    Updates this sketch with a byte[] key and U value.
    void update​(double key, U value)
    Updates this sketch with a double key and U value.
    void update​(int[] key, U value)
    Updates this sketch with a int[] key and U value.
    void update​(long[] key, U value)
    Updates this sketch with a long[] key and U value.
    void update​(long key, U value)
    Updates this sketch with a long key and U value.
    void update​(String key, U value)
    Updates this sketch with a String key and U value.

    Methods inherited from class org.apache.datasketches.tuple.Sketch

    getEstimate, getEstimate, getLowerBound, getLowerBound, getTheta, getThetaLong, getUpperBound, getUpperBound, isEmpty, isEstimationMode, toString

    Methods inherited from class java.lang.Object

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

  • Constructor Details

    • UpdatableSketch

      public UpdatableSketch​(int nomEntries, int lgResizeFactor, float samplingProbability, SummaryFactory<S> summaryFactory)
      This is to create a new instance of an UpdatableQuickSelectSketch.
      Parameters:
      nomEntries - Nominal number of entries. Forced to the nearest power of 2 greater than or equal to the given value.
      lgResizeFactor - log2(resizeFactor) - value from 0 to 3: 
       0 - no resizing (max size allocated),
 1 - double internal hash table each time it reaches a threshold
 2 - grow four times
 3 - grow eight times (default)
      samplingProbability - See Sampling Probability
      summaryFactory - An instance of a SummaryFactory.

    • UpdatableSketch

      public UpdatableSketch​(org.apache.datasketches.memory.Memory srcMem, SummaryDeserializer<S> deserializer, SummaryFactory<S> summaryFactory)
      This is to create an instance of a sketch given a serialized form
      Parameters:
      srcMem - Memory object with data of a serialized UpdatableSketch
      deserializer - instance of SummaryDeserializer
      summaryFactory - instance of SummaryFactory

  • Method Details

    • update

      public void update​(long key, U value)
      Updates this sketch with a long key and U value. The value is passed to update() method of the Summary object associated with the key
      Parameters:
      key - The given long key
      value - The given U value

    • update

      public void update​(double key, U value)
      Updates this sketch with a double key and U value. The value is passed to update() method of the Summary object associated with the key
      Parameters:
      key - The given double key
      value - The given U value

    • update

      public void update​(String key, U value)
      Updates this sketch with a String key and U value. The value is passed to update() method of the Summary object associated with the key
      Parameters:
      key - The given String key
      value - The given U value

    • update

      public void update​(byte[] key, U value)
      Updates this sketch with a byte[] key and U value. The value is passed to update() method of the Summary object associated with the key
      Parameters:
      key - The given byte[] key
      value - The given U value

    • update

      public void update​(int[] key, U value)
      Updates this sketch with a int[] key and U value. The value is passed to update() method of the Summary object associated with the key
      Parameters:
      key - The given int[] key
      value - The given U value

    • update

      public void update​(long[] key, U value)
      Updates this sketch with a long[] key and U value. The value is passed to update() method of the Summary object associated with the key
      Parameters:
      key - The given long[] key
      value - The given U value

    • getRetainedEntries

      public int getRetainedEntries()
      Specified by:
      getRetainedEntries in class Sketch<S extends Summary>
      Returns:
      number of retained entries

    • getCountLessThanThetaLong

      public int getCountLessThanThetaLong​(long thetaLong)
      Description copied from class: Sketch
      Gets the number of hash values less than the given theta expressed as a long.
      Specified by:
      getCountLessThanThetaLong in class Sketch<S extends Summary>
      Parameters:
      thetaLong - the given theta as a long between zero and Long.MAX_VALUE.
      Returns:
      the number of hash values less than the given thetaLong.

    • getNominalEntries

      public int getNominalEntries()
      Get configured nominal number of entries
      Returns:
      nominal number of entries

    • getLgK

      public int getLgK()
      Get log_base2 of Nominal Entries
      Returns:
      log_base2 of Nominal Entries

    • getSamplingProbability

      public float getSamplingProbability()
      Get configured sampling probability
      Returns:
      sampling probability

    • getCurrentCapacity

      public int getCurrentCapacity()
      Get current capacity
      Returns:
      current capacity

    • getResizeFactor

      public ResizeFactor getResizeFactor()
      Get configured resize factor
      Returns:
      resize factor

    • trim

      public void trim()
      Rebuilds reducing the actual number of entries to the nominal number of entries if needed

    • reset

      public void reset()
      Resets this sketch an empty state.

    • compact

      public CompactSketch<S> compact()
      Converts the current state of the sketch into a compact sketch
      Specified by:
      compact in class Sketch<S extends Summary>
      Returns:
      compact sketch

    • toByteArray

      public byte[] toByteArray()
      Description copied from class: Sketch
      This is to serialize an instance to a byte array.
      Specified by:
      toByteArray in class Sketch<S extends Summary>
      Returns:
      serialized representation of the sketch

    • insertSummary

      protected void insertSummary​(int index, S summary)

    • iterator

      public SketchIterator<S> iterator()
      Description copied from class: Sketch
      Returns a SketchIterator
      Specified by:
      iterator in class Sketch<S extends Summary>
      Returns:
      a SketchIterator