File Doc Category Size Date Package
ValueSource.java API Doc Apache Lucene 2.2.0 2733 Sat Jun 16 22:20:34 BST 2007 org.apache.lucene.search.function

ValueSource

java.lang.Object

public abstract class ValueSource extends Object implements 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 {@link org.apache.lucene.search.function.DocValues 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.

author: yonik

Fields Summary
Constructors Summary
Methods Summary
public abstract java.lang.String description()
description of field, used in explain()
public abstract boolean equals(java.lang.Object o)
Needed for possible caching of query results - used by {@link ValueSourceQuery#equals(Object)}.
see
Object#equals(Object)
public abstract org.apache.lucene.search.function.DocValues getValues(org.apache.lucene.index.IndexReader reader)
Return the DocValues used by the function query.
param
reader the IndexReader used to read these values. If any caching is involved, that caching would also be IndexReader based.
throws
IOException for any error.
public abstract int hashCode()
Needed for possible caching of query results - used by {@link ValueSourceQuery#hashCode()}.
see
Object#hashCode()
public java.lang.String toString()
return description();