org.terrier.structures.postings
Class BasicIterablePostingDocidOnly

java.lang.Object
  org.terrier.structures.postings.BasicPostingImpl
      org.terrier.structures.postings.BasicIterablePosting
          org.terrier.structures.postings.BasicIterablePostingDocidOnly

All Implemented Interfaces:

java.io.Closeable, org.apache.hadoop.io.Writable, IterablePosting, Posting, WritablePosting

public class BasicIterablePostingDocidOnly
extends BasicIterablePosting

Posting iterator class that only returns identifiers, not frequencies. This differs from BasicIterablePosting in that only ids are recorded.

Since:

3.0

Author:

Craig Macdonald

Field Summary

Fields inherited from class org.terrier.structures.postings.BasicIterablePosting

bitFileReader, doi, numEntries

Fields inherited from class org.terrier.structures.postings.BasicPostingImpl

id, tf

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

EOL

Constructor Summary

BasicIterablePostingDocidOnly()
Create a new posting iterator

BasicIterablePostingDocidOnly(BitIn _bitFileReader, int _numEntries, DocumentIndex _doi)
Create a new posting iterator

Method Summary

int	getFrequency() Returns 0.
int	next() Move this iterator to the next posting.

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

asWritablePosting, close, endOfPostings, getDocumentLength, next

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

getId, readFields, setId, toString, write

Methods inherited from class java.lang.Object

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

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

getId, setId

Constructor Detail

BasicIterablePostingDocidOnly

public BasicIterablePostingDocidOnly()

Create a new posting iterator

BasicIterablePostingDocidOnly

public BasicIterablePostingDocidOnly(BitIn _bitFileReader,
                                     int _numEntries,
                                     DocumentIndex _doi)
                              throws java.io.IOException

Create a new posting iterator

Parameters:

_bitFileReader - BitIn to read the postings from

_numEntries - number of postings in the list

_doi - document index to use to satisfy getDocumentLength()

Throws:

java.io.IOException - thrown in an IO exception occurs

Method Detail

next

public int next()
         throws java.io.IOException

Move this iterator to the next posting.

Specified by:

next in interface IterablePosting

Overrides:

next in class BasicIterablePosting

Returns:

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

Throws:

java.io.IOException

getFrequency

public int getFrequency()

Returns 0.

Specified by:

getFrequency in interface Posting

Overrides:

getFrequency in class BasicPostingImpl

Returns:

frequency of posting, in tokens