Package org.apache.lucene.search.grouping

Class AllGroupHeadsCollector.GroupHead<T>

java.lang.Object

org.apache.lucene.search.grouping.AllGroupHeadsCollector.GroupHead<T>

Enclosing class:

AllGroupHeadsCollector<T>

public abstract static class AllGroupHeadsCollector.GroupHead<T>
extends Object

Represents a group head. A group head is the most relevant document for a particular group. The relevancy is based is usually based on the sort.

The group head contains a group value with its associated most relevant document id.

Field Summary

Fields

Modifier and Type	Field	Description
int	doc
protected int	docBase
T	groupValue

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	GroupHead(T groupValue, int doc, int docBase)	Create a new GroupHead for the given value

Method Summary

Modifier and Type	Method	Description
protected abstract int	compare(int compIDX, int doc)	Compares the specified document for a specified comparator against the current most relevant document.
protected void	setNextReader(LeafReaderContext ctx)	Called for each segment
protected abstract void	setScorer(Scorable scorer)	Called for each segment
protected abstract void	updateDocHead(int doc)	Updates the current most relevant document with the specified document.

Methods inherited from class java.lang.Object

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

Field Detail

groupValue

public final T groupValue

doc

public int doc

docBase

protected int docBase

Constructor Detail

GroupHead

protected GroupHead(T groupValue,
                    int doc,
                    int docBase)

Create a new GroupHead for the given value

Method Detail

setNextReader

protected void setNextReader(LeafReaderContext ctx)
                      throws IOException

Called for each segment

Throws:

IOException

setScorer

protected abstract void setScorer(Scorable scorer)
                           throws IOException

Called for each segment

Throws:

IOException

compare

protected abstract int compare(int compIDX,
                               int doc)
                        throws IOException

Compares the specified document for a specified comparator against the current most relevant document.

Parameters:

compIDX - The comparator index of the specified comparator.

doc - The specified document.

Returns:

-1 if the specified document wasn't competitive against the current most relevant document, 1 if the specified document was competitive against the current most relevant document. Otherwise 0.

Throws:

IOException - If I/O related errors occur

updateDocHead

protected abstract void updateDocHead(int doc)
                               throws IOException

Updates the current most relevant document with the specified document.

Parameters:

doc - The specified document

Throws:

IOException - If I/O related errors occur