org.galagosearch.core.index
Class PositionIndexReader

java.lang.Object
  org.galagosearch.core.index.PositionIndexReader

All Implemented Interfaces:

StructuredIndexPartReader

public class PositionIndexReader
extends java.lang.Object
implements StructuredIndexPartReader

Reads a simple positions-based index, where each inverted list in the index contains both term count information and term position information. The term counts data is stored separately from term position information for faster query processing when no positions are needed. For now, the iterator loads everything into memory before starting query processing, which is not a workable solution for larger collections.

Author:

trevor

Nested Class Summary

class

PositionIndexReader.Iterator

Constructor Summary

PositionIndexReader(IndexReader reader)

PositionIndexReader(java.lang.String pathname)

Method Summary

void	close()
PositionIndexReader.Iterator	getIterator() Returns an iterator pointing at the first term in the index.
IndexIterator	getIterator(Node node)
java.util.Map<java.lang.String,NodeType>	getNodeTypes()
PositionIndexReader.Iterator	getTermExtents(java.lang.String term) Returns an iterator pointing at the specified term, or null if the term doesn't exist in the inverted file.

Methods inherited from class java.lang.Object

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

Constructor Detail

PositionIndexReader

public PositionIndexReader(IndexReader reader)
                    throws java.io.IOException

Throws:

java.io.IOException

PositionIndexReader

public PositionIndexReader(java.lang.String pathname)
                    throws java.io.FileNotFoundException,
                           java.io.IOException

Throws:

java.io.FileNotFoundException

java.io.IOException

Method Detail

getIterator

public PositionIndexReader.Iterator getIterator()
                                         throws java.io.IOException

Returns an iterator pointing at the first term in the index.

Specified by:

getIterator in interface StructuredIndexPartReader

Throws:

java.io.IOException

getTermExtents

public PositionIndexReader.Iterator getTermExtents(java.lang.String term)
                                            throws java.io.IOException

Returns an iterator pointing at the specified term, or null if the term doesn't exist in the inverted file.

Throws:

java.io.IOException

close

public void close()
           throws java.io.IOException

Specified by:

close in interface StructuredIndexPartReader

Throws:

java.io.IOException

getNodeTypes

public java.util.Map<java.lang.String,NodeType> getNodeTypes()

Specified by:

getNodeTypes in interface StructuredIndexPartReader

getIterator

public IndexIterator getIterator(Node node)
                          throws java.io.IOException

Specified by:

getIterator in interface StructuredIndexPartReader

Throws:

java.io.IOException