Package org.terrier.realtime.memory

Class MemoryIterablePosting

java.lang.Object

org.terrier.structures.postings.IterablePostingImpl

org.terrier.realtime.memory.MemoryIterablePosting

All Implemented Interfaces:

java.io.Closeable, java.lang.AutoCloseable, IterablePosting, Posting

Direct Known Subclasses:

MemoryFieldsIterablePosting

public class MemoryIterablePosting
extends IterablePostingImpl

A postings list implementation held fully in memory.

Since:

4.0

Author:

Richard McCreadie, Stuart Mackie

Field Summary

Fields

Modifier and Type	Field	Description
protected DocumentIndex	doi
protected int	id
protected int	index
protected gnu.trove.TIntArrayList	pl_doc

Fields inherited from interface org.terrier.structures.postings.IterablePosting

END_OF_LIST, EOL

Constructor Summary

Constructors

Constructor	Description
MemoryIterablePosting(DocumentIndex doi, gnu.trove.TIntArrayList pl_doc, gnu.trove.TIntArrayList pl_freq)	Constructor.

Method Summary

Modifier and Type	Method	Description
WritablePosting	asWritablePosting()	Copy this posting to one free of an iterator.
void	close()
boolean	endOfPostings()	Status method to see if this posting list iterator has been finished.
int	getDocumentLength()	Return the length of the document of the current posting in tokens.
int	getFrequency()	Return the frequency of the term in the current document, in tokens.
int	getId()	Return the id of the current posting.
int	next()	Move this iterator to the next posting.

Methods inherited from class org.terrier.structures.postings.IterablePostingImpl

next

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.terrier.structures.postings.Posting

setId

Field Detail

index

protected int index

id

protected int id

doi

protected DocumentIndex doi

pl_doc

protected gnu.trove.TIntArrayList pl_doc

Constructor Detail

MemoryIterablePosting

public MemoryIterablePosting(DocumentIndex doi,
                             gnu.trove.TIntArrayList pl_doc,
                             gnu.trove.TIntArrayList pl_freq)

Constructor.

Method Detail

getFrequency

public int getFrequency()

Return the frequency of the term in the current document, in tokens.

Returns:

frequency of the term in the current document, in tokens.

getDocumentLength

public int getDocumentLength()

Return the length of the document of the current posting in tokens. Usually uses the DocumentIndex, may do otherwise if document length statistics are in posting list.

Returns:

length of the document of the current posting in tokens.

getId

public int getId()

Return the id of the current posting. For the inverted index, this is the current docid; for the direct index it corresponds to the current term id.

Returns:

id of the posting.

next

public int next()
         throws java.io.IOException

Move this iterator to the next posting.

Returns:

id of next posting, or EOL if end of posting list.

Throws:

java.io.IOException

endOfPostings

public boolean endOfPostings()

Status method to see if this posting list iterator has been finished.

Returns:

true if IterablePosting.next() or IterablePosting.next(int) would return EOL or have returned EOL.

close

public void close()
           throws java.io.IOException

Throws:

java.io.IOException

asWritablePosting

public WritablePosting asWritablePosting()

Copy this posting to one free of an iterator. Kind of like a clone.

Returns:

an identical posting, but which can be manipulated free of this iterator