org.terrier.structures.postings

Class FieldOnlyIterablePosting

java.lang.Object

org.terrier.structures.postings.IterablePostingImpl

org.terrier.structures.postings.FieldOnlyIterablePosting

All Implemented Interfaces:

Closeable, AutoCloseable, IterablePosting, Posting

public class FieldOnlyIterablePosting
extends IterablePostingImpl

This class takes an IterablePosting list that has fields, and makes it appear as a single basic posting list.

Since:

4.2

Author:

Craig Macdonald

Field Summary

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

END_OF_LIST, EOL

Constructor Summary

Constructors

Constructor and Description
FieldOnlyIterablePosting(IterablePosting _ip, int _fieldId)

Method Summary

Modifier and Type	Method and Description
WritablePosting	asWritablePosting() Copies 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 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	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

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

Constructor Detail

FieldOnlyIterablePosting

public FieldOnlyIterablePosting(IterablePosting _ip,
                                int _fieldId)

Method Detail

next

public int next()
         throws IOException

Description copied from interface: IterablePosting

Move this iterator to the next posting.

Returns:

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

Throws:

IOException

endOfPostings

public boolean endOfPostings()

Description copied from interface: IterablePosting

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

Returns:

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

getId

public int getId()

Description copied from interface: Posting

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

Returns:

id of the posting

getFrequency

public int getFrequency()

Description copied from interface: Posting

Return the frequency of the term in the current document

Returns:

frequency of posting, in tokens

getDocumentLength

public int getDocumentLength()

Description copied from interface: Posting

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:

length of the document of the current posting in tokens.

setId

public void setId(int id)

Description copied from interface: Posting

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.

asWritablePosting

public WritablePosting asWritablePosting()

Description copied from interface: Posting

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

Returns:

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

close

public void close()
           throws IOException

Throws:

IOException