iglu.ir
Class InvertedIndex

java.lang.Object
  |
  +--iglu.ir.InvertedIndex

public class InvertedIndex

extends java.lang.Object

Computes and stores an inverted index, which can be used by a search engine.

Author:

Ryan Scherle

Field Summary

private boolean	dataChanged
private java.util.HashMap	forwardVectors
private java.util.HashMap	invertedVectors
private java.io.File	storedIn

Constructor Summary

InvertedIndex(java.io.File storedIn)
Creates a new index, or opens an existing index.

Method Summary

void	close() Closes the index.
boolean	containsKey(java.io.Serializable docId) Indicates whether a document is contained in the index.
void	flush() Forces the index to be written to file.
ValueSortedMap	getDocuments(java.lang.String term) Returns all documents containing term.
TermVector	getVector(java.lang.Object docId) Returns the term vector assocated with a document ID.
private void	initializeFromFile() Initializes the index from a saved file.
java.util.Set	keySet() Returns a set of all document ID's contained in the index.
static void	main(java.lang.String[] args) Runs some tests on this class.
void	put(java.io.Serializable docId, TermVector docVector) Adds a document to the index.
int	size() Returns the number of documents in this index.
static void	test() Runs some tests on this class.

Methods inherited from class java.lang.Object

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

Field Detail

invertedVectors

private java.util.HashMap invertedVectors

forwardVectors

private java.util.HashMap forwardVectors

storedIn

private java.io.File storedIn

dataChanged

private boolean dataChanged

Constructor Detail

InvertedIndex

public InvertedIndex(java.io.File storedIn)

Creates a new index, or opens an existing index. The index will be saved in the single file storedIn. If storedIn is a directory, the index will be stored in a file named "invertedIndex.dat" in this directory.

Method Detail

initializeFromFile

private void initializeFromFile()

Initializes the index from a saved file.

put

public void put(java.io.Serializable docId,
                TermVector docVector)

Adds a document to the index.

getVector

public TermVector getVector(java.lang.Object docId)

Returns the term vector assocated with a document ID.

getDocuments

public ValueSortedMap getDocuments(java.lang.String term)

Returns all documents containing term.

Returns:

a ValueSortedMap that maps each document to its score for the term.

containsKey

public boolean containsKey(java.io.Serializable docId)

Indicates whether a document is contained in the index.

keySet

public java.util.Set keySet()

Returns a set of all document ID's contained in the index.

size

public int size()

Returns the number of documents in this index.

flush

public void flush()

Forces the index to be written to file.

close

public void close()

Closes the index.

test

public static void test()

Runs some tests on this class.

main

public static void main(java.lang.String[] args)

Runs some tests on this class.