com.tangosol.util.filter
Class ComparisonFilter

java.lang.Object
  com.tangosol.util.Base
      com.tangosol.util.BitHelper
          com.tangosol.util.ExternalizableHelper
              com.tangosol.util.filter.ExtractorFilter
                  com.tangosol.util.filter.ComparisonFilter

All Implemented Interfaces:

ExternalizableLite, PortableObject, Filter, EntryFilter, java.io.Serializable

Direct Known Subclasses:

ContainsAllFilter, ContainsAnyFilter, ContainsFilter, EqualsFilter, GreaterEqualsFilter, GreaterFilter, InFilter, LessEqualsFilter, LessFilter, LikeFilter, NotEqualsFilter

public abstract class ComparisonFilter
extends ExtractorFilter

Filter which compares the result of a method invocation with a value.

Author:

cp/gg 2002.10.27

Field Summary

protected java.lang.Object

m_oValue The value to compare to.

Fields inherited from class com.tangosol.util.filter.ExtractorFilter

EVAL_COST, m_extractor

Constructor Summary

ComparisonFilter()
Default constructor (necessary for the ExternalizableLite interface).

ComparisonFilter(java.lang.String sMethod, java.lang.Object oValue)
Construct a ComparisonFilter.

ComparisonFilter(ValueExtractor extractor, java.lang.Object oValue)
Construct a ComparisonFilter.

Method Summary

static int	calculateIteratorEffectiveness(int cKeys) Helper method to calculate effectiveness (or rather ineffectiveness) of a simple iteration against a key set that has to be performed due to an absence of corresponding index.
protected int	calculateMatchEffectiveness(java.util.Map mapIndexes, java.util.Set setKeys) Helper method to calculate effectiveness for ComparisonFilters that need no more than a single index match in order to retrieve all necessary keys to perform the applyIndex() operation.
protected int	calculateRangeEffectiveness(java.util.Map mapIndexes, java.util.Set setKeys) Helper method to calculate effectiveness for ComparisonFilters that need a range of values from an index in order to retrieve all necessary keys to perform the applyIndex() operation.
boolean	equals(java.lang.Object o) Compare the ComparisonFilter with another object to determine equality.
java.lang.Object	getValue() Get the object to compare the reflection result with.
int	hashCode() Determine a hash value for the ComparisonFilter object according to the general Object.hashCode() contract.
void	readExternal(java.io.DataInput in) Restore the contents of this object by loading the object's state from the passed DataInput object.
void	readExternal(PofReader in) Restore the contents of a user type instance by reading its state using the specified PofReader object.
java.lang.String	toString() Return a human-readable description for this Filter.
void	writeExternal(java.io.DataOutput out) Save the contents of this object by storing the object's state into the passed DataOutput object.
void	writeExternal(PofWriter out) Save the contents of a POF user type instance by writing its state using the specified PofWriter object.

Methods inherited from class com.tangosol.util.filter.ExtractorFilter

evaluate, evaluateEntry, evaluateExtracted, extract, getValueExtractor

Methods inherited from class com.tangosol.util.BitHelper

countBits, countBits, countBits, indexOfLSB, indexOfLSB, indexOfLSB, indexOfMSB, indexOfMSB, indexOfMSB, toBitString, toBitString, toBitString

Field Detail

m_oValue

protected java.lang.Object m_oValue

The value to compare to.

Constructor Detail

ComparisonFilter

public ComparisonFilter()

Default constructor (necessary for the ExternalizableLite interface).

ComparisonFilter

public ComparisonFilter(ValueExtractor extractor,
                        java.lang.Object oValue)

Construct a ComparisonFilter.

Parameters:

extractor - the ComparisonFilter to use by this filter

oValue - the object to compare the result with

ComparisonFilter

public ComparisonFilter(java.lang.String sMethod,
                        java.lang.Object oValue)

Construct a ComparisonFilter.

Parameters:

sMethod - the name of the method to invoke via reflection

oValue - the object to compare the result with

Method Detail

getValue

public java.lang.Object getValue()

Get the object to compare the reflection result with.

Returns:

the object to compare the reflection result with

calculateMatchEffectiveness

protected int calculateMatchEffectiveness(java.util.Map mapIndexes,
                                          java.util.Set setKeys)

Helper method to calculate effectiveness for ComparisonFilters that need no more than a single index match in order to retrieve all necessary keys to perform the applyIndex() operation. Such filters are: Contains, Equals, NotEquals.

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

calculateRangeEffectiveness

protected int calculateRangeEffectiveness(java.util.Map mapIndexes,
                                          java.util.Set setKeys)

Helper method to calculate effectiveness for ComparisonFilters that need a range of values from an index in order to retrieve all necessary keys to perform the applyIndex() operation. Such filters are: Less, LessEquals, Greater, GreaterEquals.

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

calculateIteratorEffectiveness

public static int calculateIteratorEffectiveness(int cKeys)

Helper method to calculate effectiveness (or rather ineffectiveness) of a simple iteration against a key set that has to be performed due to an absence of corresponding index.

Parameters:

cKeys - the number of keys to iterate through

equals

public boolean equals(java.lang.Object o)

Compare the ComparisonFilter with another object to determine equality. Two ComparisonFilter objects are considered equal iff they belong to exactly the same class and their extractor and value are equal.

Returns:

true iff this ComparisonFilter and the passed object are equivalent ComparisonFilters

hashCode

public int hashCode()

Determine a hash value for the ComparisonFilter object according to the general Object.hashCode() contract.

Returns:

an integer hash value for this ComparisonFilter object

toString

public java.lang.String toString()

Return a human-readable description for this Filter.

Returns:

a String description of the Filter

readExternal

public void readExternal(java.io.DataInput in)
                  throws java.io.IOException

Restore the contents of this object by loading the object's state from the passed DataInput object.

Specified by:

readExternal in interface ExternalizableLite

Overrides:

readExternal in class ExtractorFilter

Parameters:

in - the DataInput stream to read data from in order to restore the state of this object

Throws:

java.io.IOException - if an I/O exception occurs

java.io.NotActiveException - if the object is not in its initial state, and therefore cannot be deserialized into

writeExternal

public void writeExternal(java.io.DataOutput out)
                   throws java.io.IOException

Save the contents of this object by storing the object's state into the passed DataOutput object.

Specified by:

writeExternal in interface ExternalizableLite

Overrides:

writeExternal in class ExtractorFilter

Parameters:

out - the DataOutput stream to write the state of this object to

Throws:

java.io.IOException - if an I/O exception occurs

readExternal

public void readExternal(PofReader in)
                  throws java.io.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 ExtractorFilter

Parameters:

in - the PofReader from which to read the object's state

Throws:

java.io.IOException - if an I/O error occurs

writeExternal

public void writeExternal(PofWriter out)
                   throws java.io.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 ExtractorFilter

Parameters:

out - the PofWriter to which to write the object's state

Throws:

java.io.IOException - if an I/O error occurs