org.apache.lucene.search.function

Class ValueSource

java.lang.Object

org.apache.lucene.search.function.ValueSource

All Implemented Interfaces:

java.io.Serializable

Direct Known Subclasses:

FieldCacheSource, OrdFieldSource, ReverseOrdFieldSource

public abstract class ValueSource
extends java.lang.Object
implements java.io.Serializable

Expert: source of values for basic function queries.

At its default/simplest form, values - one per doc - are used as the score of that doc.

Values are instantiated as DocValues for a particular reader.

ValueSource implementations differ in RAM requirements: it would always be a factor of the number of documents, but for each document the number of bytes can be 1, 2, 4, or 8.

WARNING: The status of the search.function package is experimental. The APIs introduced here might change in the future and will not be supported anymore in such a case.

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
ValueSource()

Method Summary

Modifier and Type	Method and Description
abstract java.lang.String	description() description of field, used in explain()
abstract boolean	equals(java.lang.Object o) Needed for possible caching of query results - used by ValueSourceQuery.equals(Object).
abstract DocValues	getValues(IndexReader reader) Return the DocValues used by the function query.
abstract int	hashCode() Needed for possible caching of query results - used by ValueSourceQuery.hashCode().
java.lang.String	toString()

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

ValueSource

public ValueSource()

Method Detail

getValues

public abstract DocValues getValues(IndexReader reader)
                             throws java.io.IOException

Return the DocValues used by the function query.

Parameters:

reader - the IndexReader used to read these values. If any caching is involved, that caching would also be IndexReader based.

Throws:

java.io.IOException - for any error.

description

public abstract java.lang.String description()

description of field, used in explain()

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

equals

public abstract boolean equals(java.lang.Object o)

Needed for possible caching of query results - used by ValueSourceQuery.equals(Object).

Overrides:

equals in class java.lang.Object

See Also:

Object.equals(Object)

hashCode

public abstract int hashCode()

Needed for possible caching of query results - used by ValueSourceQuery.hashCode().

Overrides:

hashCode in class java.lang.Object

See Also:

Object.hashCode()