Package org.terrier.realtime.memory

Class MemoryInvertedIndex

java.lang.Object

org.terrier.realtime.memory.MemoryInvertedIndex

All Implemented Interfaces:

java.io.Closeable, java.io.Serializable, java.lang.AutoCloseable, PostingIndex<MemoryPointer>

Direct Known Subclasses:

MemoryFieldsInvertedIndex

public class MemoryInvertedIndex
extends java.lang.Object
implements PostingIndex<MemoryPointer>, java.io.Serializable

A basic inverted file implementation for use with MemoryIndex structures. This version does not support fields or blocks. Since it is a memory-based structure, access is via a MemoryPointer rather than BitIndexPointer.

Since:

4.0

Author:

Richard McCreadie, Stuart Mackie

See Also:

Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
class	MemoryInvertedIndex.BasicMemoryPostingList
class	MemoryInvertedIndex.InvertedIterator	Inverted index iterator.

Field Summary

Fields

Modifier and Type	Field	Description
protected DocumentIndex	doi
protected Lexicon<java.lang.String>	lex
protected gnu.trove.TIntObjectHashMap<MemoryPostingList>	postings

Constructor Summary

Constructors

Constructor	Description
MemoryInvertedIndex(Lexicon<java.lang.String> lex, DocumentIndex doi)	Constructor.

Method Summary

Modifier and Type	Method	Description
void	add(int ptr, int docid, int freq)	Add posting to inverted file.
boolean	addOrUpdate(int ptr, int docid, int freq)	Adds or updates the frequency of the term denoted by ptr by freq.
void	close()
DocumentIndex	getDoi()
IterablePosting	getPostings(Pointer pointer)	Returns the posting iterator given a pointer.
PostingIndexInputStream	iterator()	Return an iterator over the inverted file.
void	remove(int ptr)	Remove a term posting list from the index, e.g.
void	setDoi(DocumentIndex doi)

Methods inherited from class java.lang.Object

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

Field Detail

doi

protected DocumentIndex doi

lex

protected Lexicon<java.lang.String> lex

postings

protected gnu.trove.TIntObjectHashMap<MemoryPostingList> postings

Constructor Detail

MemoryInvertedIndex

public MemoryInvertedIndex(Lexicon<java.lang.String> lex,
                           DocumentIndex doi)

Constructor.

Method Detail

add

public void add(int ptr,
                int docid,
                int freq)

Add posting to inverted file.

addOrUpdate

public boolean addOrUpdate(int ptr,
                           int docid,
                           int freq)

Adds or updates the frequency of the term denoted by ptr by freq.

Returns:

true if a new posting was created, false if the document already contained the term

remove

public void remove(int ptr)

Remove a term posting list from the index, e.g. remove a stopword

Parameters:

ptr -

getPostings

public IterablePosting getPostings(Pointer pointer)
                            throws java.io.IOException

Returns the posting iterator given a pointer.

Specified by:

getPostings in interface PostingIndex<MemoryPointer>

Returns:

the posting iterator given a pointer.

Throws:

java.io.IOException

close

public void close()
           throws java.io.IOException

Specified by:

close in interface java.lang.AutoCloseable

Specified by:

close in interface java.io.Closeable

Throws:

java.io.IOException

iterator

public PostingIndexInputStream iterator()

Return an iterator over the inverted file.

getDoi

public DocumentIndex getDoi()

setDoi

public void setDoi(DocumentIndex doi)