Package com.tangosol.util.filter

Class InFilter<T,E>

java.lang.Object
com.tangosol.util.Base
com.tangosol.util.BitHelper
com.tangosol.util.ExternalizableHelper
com.tangosol.util.filter.AbstractQueryRecorderFilter<T>
com.tangosol.util.filter.ExtractorFilter<T,E>
com.tangosol.util.filter.ComparisonFilter<T,E,Set<? extends E>>
com.tangosol.util.filter.InFilter<T,E>
All Implemented Interfaces:
ExternalizableLite, PortableObject, Filter<T>, EntryFilter<Object,T>, IndexAwareFilter<Object,T>, QueryRecorderFilter<T>, Serializable
public class InFilter<T,E> extends ComparisonFilter<T,E,Set<? extends E>> implements IndexAwareFilter<Object,T>
Filter which checks whether the result of a method invocation belongs to a predefined set of values.
Author:
cp/gg/hr 2002.11.08
See Also:

  • Constructor Details

    • InFilter

      public InFilter()
      Default constructor (necessary for the ExternalizableLite interface).

    • InFilter

      public InFilter(ValueExtractor<? super T,? extends E> extractor, Set<? extends E> setValues)
      Construct an InFilter for testing "In" condition.
      Parameters:
      extractor - the ValueExtractor to use by this filter
      setValues - the set of values to compare the result with

    • InFilter

      public InFilter(String sMethod, Set<? extends E> setValues)
      Construct an InFilter for testing "In" condition.
      Parameters:
      sMethod - the name of the method to invoke via reflection
      setValues - the set of values to compare the result with

  • Method Details

    • evaluateExtracted

      protected boolean evaluateExtracted(E extracted)
      Evaluate the specified extracted value.
      Specified by:
      evaluateExtracted in class ExtractorFilter<T,E>
      Parameters:
      extracted - an extracted value to evaluate
      Returns:
      true iff the test passes

    • toStringValue

      public String toStringValue()
      Return the string representation of the value.
      Overrides:
      toStringValue in class ComparisonFilter<T,E,Set<? extends E>>
      Returns:
      the string representation of the value

    • calculateEffectiveness

      public int calculateEffectiveness(Map mapIndexes, Set setKeys)
      Given a Map of available indexes, determine if this IndexAwareFilter can use any of the indexes to assist in its processing, and if so, determine how effective the use of that index would be.

      The returned value is an effectiveness estimate of how well this filter can use the specified indexes to filter the specified keys. An operation that requires no more than a single access to the index content (i.e. Equals, NotEquals) has an effectiveness of one. Evaluation of a single entry is assumed to have an effectiveness that depends on the index implementation and is usually measured as a constant number of the single operations. This number is referred to as evaluation cost.

      If the effectiveness of a filter evaluates to a number larger than the keySet.size() * <evaluation cost> then a user could avoid using the index and iterate through the keySet calling evaluate rather then applyIndex.

      Specified by:
      calculateEffectiveness in interface IndexAwareFilter<T,E>
      Overrides:
      calculateEffectiveness in class ExtractorFilter<T,E>
      Parameters:
      mapIndexes - the available MapIndex objects keyed by the related ValueExtractor; read-only
      setKeys - the set of keys that will be filtered; read-only
      Returns:
      an effectiveness estimate of how well this filter can use the specified indexes to filter the specified keys

    • applyIndex

      public Filter applyIndex(Map mapIndexes, Set setKeys)
      Filter remaining keys using a Map of available indexes.

      The filter is responsible for removing all keys from the passed set of keys that the applicable indexes can prove should be filtered. If the filter does not fully evaluate the remaining keys using just the index information, it must return a filter (which may be an EntryFilter) that can complete the task using an iterating implementation. If, on the other hand, the filter does fully evaluate the remaining keys using just the index information, then it should return null to indicate that no further filtering is necessary.

      Specified by:
      applyIndex in interface IndexAwareFilter<T,E>
      Overrides:
      applyIndex in class ExtractorFilter<T,E>
      Parameters:
      mapIndexes - the available MapIndex objects keyed by the related ValueExtractor; read-only
      setKeys - the mutable set of keys that remain to be filtered
      Returns:
      a Filter object (which may be an EntryFilter) that can be used to process the remaining keys, or null if no additional filter processing is necessary

    • readExternal

      public void readExternal(PofReader in) throws IOException
      Restore the contents of a user type instance by reading its state using the specified PofReader object.
      Specified by:
      readExternal in interface PortableObject
      Overrides:
      readExternal in class ComparisonFilter<T,E,Set<? extends E>>
      Parameters:
      in - the PofReader from which to read the object's state
      Throws:
      IOException - if an I/O error occurs

    • writeExternal

      public void writeExternal(PofWriter out) throws IOException
      Save the contents of a POF user type instance by writing its state using the specified PofWriter object.
      Specified by:
      writeExternal in interface PortableObject
      Overrides:
      writeExternal in class ComparisonFilter<T,E,Set<? extends E>>
      Parameters:
      out - the PofWriter to which to write the object's state
      Throws:
      IOException - if an I/O error occurs