com.atlassian.jira.issue.search.parameters.lucene.sort

Class MappedSortComparator

java.lang.Object

org.apache.lucene.search.FieldComparatorSource

com.atlassian.jira.issue.search.parameters.lucene.sort.MappedSortComparator

All Implemented Interfaces:

Serializable

public class MappedSortComparator
extends org.apache.lucene.search.FieldComparatorSource

This Sort Comparator uses a mixed strategy to retrieve the term values. If we are retrieving less than 1% of the documents in the index, we get each document value individually. Once passed the 1% threshold however we switch to reading through the terms dictionary in lucene, and builds up a list of ordered terms. It then sorts the documents according to the order that they appear in the terms list. This latter approach, whilst very fast, does load the entire term dictionary into memory, and allocates a slot for every document value, which is why we do not use it all the time.

We believe that most searches in very large JIRA installations will return a very small portion of the document index, either because they are over only one of many projects or they return only open issues, especially on dashboards and in GreenHopper and similar plugins as well as in general navigator searches.

See Also:

Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
class	MappedSortComparator.InternalFieldComparator

Constructor Summary

Constructors

Constructor and Description
MappedSortComparator(LuceneFieldSorter sorter)

Method Summary

Modifier and Type	Method and Description
boolean	equals(Object o)
Object	getComparable(String termtext) Returns an object which, when sorted according by the comparator returned from LuceneFieldSorter.getComparator() , will order the Term values in the correct order.
Comparator	getComparator()
int	hashCode()
org.apache.lucene.search.FieldComparator	newComparator(String fieldname, int numHits, int sortPos, boolean reversed)

Methods inherited from class java.lang.Object

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

Constructor Detail

MappedSortComparator

public MappedSortComparator(LuceneFieldSorter sorter)

Method Detail

newComparator

public org.apache.lucene.search.FieldComparator newComparator(String fieldname,
                                                              int numHits,
                                                              int sortPos,
                                                              boolean reversed)
                                                       throws IOException

Specified by:

newComparator in class org.apache.lucene.search.FieldComparatorSource

Throws:

IOException

getComparable

public Object getComparable(String termtext)

Returns an object which, when sorted according by the comparator returned from LuceneFieldSorter.getComparator() , will order the Term values in the correct order.

For example, if the Terms contained integer values, this method would return new Integer(termtext). Note that this might not always be the most efficient implementation - for this particular example, a better implementation might be to make a ScoreDocLookupComparator that uses an internal lookup table of int.

Parameters:

termtext - The textual value of the term.

Returns:

An object representing termtext that can be sorted by LuceneFieldSorter.getComparator()

See Also:

Comparable, FieldComparator

getComparator

public Comparator getComparator()

equals

public boolean equals(Object o)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object