org.terrier.structures.postings

Class ArrayOfIdsIterablePosting

java.lang.Object

org.terrier.structures.postings.IterablePostingImpl

org.terrier.structures.postings.ArrayOfIdsIterablePosting

All Implemented Interfaces:

Closeable, AutoCloseable, Cloneable, IterablePosting, Posting

Direct Known Subclasses:

ArrayOfBasicIterablePosting

public class ArrayOfIdsIterablePosting
extends IterablePostingImpl
implements Cloneable

An instance of IterablePostings that works with a passed array of ids

Author:

Craig Macdonald

Field Summary

Fields

Modifier and Type	Field and Description
protected int[]	ids ids of each of the entries in this posting list
protected int	indice where we are in the current posting list

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

END_OF_LIST, EOL

Constructor Summary

Constructors

Constructor and Description
ArrayOfIdsIterablePosting(int[] _ids) Make a new IterablePosting using these ids

Method Summary

Modifier and Type	Method and Description
WritablePosting	asWritablePosting() Copies this posting to one free of an iterator.
ArrayOfIdsIterablePosting	clone()
void	close()
boolean	endOfPostings() Status method to see if this posting list iterator has been finished
int	getDocumentLength() Return the length of the document for this posting.
int	getFrequency() Return the frequency of the term in the current document
int	getId() Return the id of the current posting.
int	next() Move this iterator to the next posting.
void	reset()
void	setId(int id) It may be of benefit to update the frequency of the id in some applications.

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

next

Methods inherited from class java.lang.Object

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

Field Detail

ids

protected int[] ids

ids of each of the entries in this posting list

indice

protected int indice

where we are in the current posting list

Constructor Detail

ArrayOfIdsIterablePosting

public ArrayOfIdsIterablePosting(int[] _ids)

Make a new IterablePosting using these ids

Method Detail

next

public int next()
         throws IOException

Move this iterator to the next posting.

Specified by:

next in interface IterablePosting

Returns:

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

Throws:

IOException

endOfPostings

public boolean endOfPostings()

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

Specified by:

endOfPostings in interface IterablePosting

Returns:

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

asWritablePosting

public WritablePosting asWritablePosting()

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

Specified by:

asWritablePosting in interface Posting

Returns:

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

getId

public int getId()

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

Specified by:

getId in interface Posting

Returns:

id of the posting

getDocumentLength

public int getDocumentLength()

Return the length of the document for this posting. Usually uses the DocumentIndex, may do otherwise if document length statistics are in posting list Returns 0.

Specified by:

getDocumentLength in interface Posting

Returns:

length of the document of the current posting in tokens.

getFrequency

public int getFrequency()

Return the frequency of the term in the current document

Specified by:

getFrequency in interface Posting

Returns:

frequency of posting, in tokens

setId

public void setId(int id)

It may be of benefit to update the frequency of the id in some applications. This should not be used lightly, as it may break the decompression of other postings in iterators.

Specified by:

setId in interface Posting

close

public void close()
           throws IOException

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

Throws:

IOException

reset

public void reset()

clone

public ArrayOfIdsIterablePosting clone()

Overrides:

clone in class Object