org.terrier.structures.indexing.singlepass
Class FieldPostingInRun

java.lang.Object
  org.terrier.structures.indexing.singlepass.PostingInRun
      org.terrier.structures.indexing.singlepass.SimplePostingInRun
          org.terrier.structures.indexing.singlepass.FieldPostingInRun

public class FieldPostingInRun
extends SimplePostingInRun

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 a posting with field information (tf, df, [docid, tf, [tff]])

Author:

Roi Blanco

Nested Class Summary

protected class

FieldPostingInRun.fPIRPostingIterator

Nested classes/interfaces inherited from class org.terrier.structures.indexing.singlepass.SimplePostingInRun

SimplePostingInRun.PIRPostingIterator

Field Summary

protected int	fieldTags The number of different fields that are used for indexing field information.
protected int[]	fieldTFs

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

postingSource, term, termDf, termTF

Constructor Summary

FieldPostingInRun(int _fieldTags)
Constructor for the class.

Method Summary

protected static void	addTo(int[] target, int[] additions)
void	addToLexiconEntry(LexiconEntry _le) Add statistics for this posting onto the given LexiconEntry
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.
LexiconEntry	getLexiconEntry() Return the LexiconEntry for this Posting
IterablePosting	getPostingIterator(int runShift) Returns an IterablePosting object for the postings in this run
void	setTerm(java.lang.String term) Setter for the term.

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

append, getDf, getTerm, getTF, setDf, setPostingSource, setTF

Methods inherited from class java.lang.Object

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

Field Detail

fieldTFs

protected final int[] fieldTFs

fieldTags

protected final int fieldTags

The number of different fields that are used for indexing field information.

Constructor Detail

FieldPostingInRun

public FieldPostingInRun(int _fieldTags)

Constructor for the class.

Method Detail

append

public int append(BitOut bos,
                  int last,
                  int runShift)
           throws java.io.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), fieldScore(d1) , d2 - d1, idf(d2), fieldScore(d2) etc.

Overrides:

append in class SimplePostingInRun

Parameters:

bos - BitOut to be written.

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

runShift - amount of delta to apply to the first posting read.

Returns:

The docid of the last posting written.

Throws:

java.io.IOException

getLexiconEntry

public LexiconEntry getLexiconEntry()

Description copied from class: PostingInRun

Return the LexiconEntry for this Posting

Overrides:

getLexiconEntry in class PostingInRun

addToLexiconEntry

public void addToLexiconEntry(LexiconEntry _le)

Description copied from class: PostingInRun

Add statistics for this posting onto the given LexiconEntry

Overrides:

addToLexiconEntry in class PostingInRun

addTo

protected static void addTo(int[] target,
                            int[] additions)

getPostingIterator

public IterablePosting getPostingIterator(int runShift)
                                   throws java.io.IOException

Description copied from class: PostingInRun

Returns an IterablePosting object for the postings in this run

Overrides:

getPostingIterator in class SimplePostingInRun

Throws:

java.io.IOException

setTerm

public void setTerm(java.lang.String term)

Description copied from class: PostingInRun

Setter for the term.

Overrides:

setTerm in class PostingInRun

Parameters:

term - String containing the term for this posting list.