org.terrier.structures.indexing.singlepass

Class SimplePostingInRun

java.lang.Object

org.terrier.structures.indexing.singlepass.PostingInRun

org.terrier.structures.indexing.singlepass.SimplePostingInRun

Direct Known Subclasses:

BlockPostingInRun, FieldPostingInRun

public class SimplePostingInRun
extends PostingInRun

Class holding the information for a posting list read from a previously written run at disk. Used in the merging phase of the Single pass inversion method. This class knows how to append itself to a BitOut and it represents the simpler class of posting (TF, df, maxtf, [docid, tf])

Author:

Roi Blanco

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
protected class	SimplePostingInRun.PIRPostingIterator

Field Summary

Fields inherited from class org.terrier.structures.indexing.singlepass.PostingInRun

maxtf, postingSource, term, termDf, termTF

Constructor Summary

Constructors

Constructor and Description
SimplePostingInRun() Constructor for the class.

Method Summary

Modifier and Type	Method and Description
int	append(BitOut bos, int last, int runShift) Writes the document data of this posting to a BitOut It encodes the data with the right compression methods.
IterablePosting	getPostingIterator(int runShift) Returns an IterablePosting object for the postings in this run

Methods inherited from class org.terrier.structures.indexing.singlepass.PostingInRun

addToLexiconEntry, append, getDf, getLexiconEntry, getTerm, getTF, setDf, setMaxtf, setPostingSource, setTerm, setTF

Methods inherited from class java.lang.Object

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

Constructor Detail

SimplePostingInRun

public SimplePostingInRun()

Constructor for the class.

Method Detail

append

public int append(BitOut bos,
                  int last,
                  int runShift)
           throws IOException

Writes the document data of this posting to a BitOut It encodes the data with the right compression methods. The stream is written as d1, idf(d1), d2 - d1, idf(d2) etc.

Specified by:

append in class PostingInRun

Parameters:

bos - BitOut to be written.

last - int representing the last document written in this posting.

runShift - int representing the last document read document read in this posting stream.

Returns:

The last posting written.

Throws:

IOException

getPostingIterator

public IterablePosting getPostingIterator(int runShift)
                                   throws IOException

Description copied from class: PostingInRun

Returns an IterablePosting object for the postings in this run

Specified by:

getPostingIterator in class PostingInRun

Throws:

IOException