org.terrier.structures
Class DirectIndexInputStream

java.lang.Object
  org.terrier.structures.BitPostingIndexInputStream
      org.terrier.structures.DirectIndexInputStream

All Implemented Interfaces:

java.io.Closeable, java.util.Iterator<IterablePosting>, PostingIndexInputStream, Skipable

Direct Known Subclasses:

BlockDirectIndexInputStream

public class DirectIndexInputStream
extends BitPostingIndexInputStream

This class reads the direct index structure, sequentially, as an input stream.

Author:

Douglas Johnson, Vassilis Plachouras, Craig Macdonald

See Also:

DirectIndex

Field Summary

Fields inherited from class org.terrier.structures.BitPostingIndexInputStream

currentEntryCount, currentFile, currentPointer, doi, entriesSkipped, fieldCount, file, fileCount, index, logger, pointerList, postingConstructor, postingIteratorClass, structureName

Constructor Summary

	DirectIndexInputStream(Index index, java.lang.String structureName) Constructs an instance of the class with
	DirectIndexInputStream(Index index, java.lang.String structureName, java.lang.Class<? extends IterablePosting> postingIterator) Constructs an instance of the class with
protected	DirectIndexInputStream(Index _index, java.lang.String structureName, java.util.Iterator<? extends BitIndexPointer> _pointerList, java.lang.Class<? extends IterablePosting> _postingIteratorClass)

Method Summary

protected DocumentIndex	getDocumentIndex(BitIndexPointer pointer)
int[][]	getNextTerms() One call returns all the data for one document - [0][] is term ids, [1][] is frequency, [2][] is fields.
int[][]	getNextTerms(BitIndexPointer pointer) Get the terms for the next document at the pointer specified

Methods inherited from class org.terrier.structures.BitPostingIndexInputStream

_next, close, getCurrentPointer, getEntriesSkipped, getFilename, getFilename, getNextPostings, getNumberOfCurrentPostings, getPos, hasNext, loadPostingIterator, next, print, remove, skip

Methods inherited from class java.lang.Object

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

Constructor Detail

DirectIndexInputStream

protected DirectIndexInputStream(Index _index,
                                 java.lang.String structureName,
                                 java.util.Iterator<? extends BitIndexPointer> _pointerList,
                                 java.lang.Class<? extends IterablePosting> _postingIteratorClass)
                          throws java.io.IOException

Throws:

java.io.IOException

DirectIndexInputStream

public DirectIndexInputStream(Index index,
                              java.lang.String structureName,
                              java.lang.Class<? extends IterablePosting> postingIterator)
                       throws java.io.IOException

Constructs an instance of the class with

Parameters:

index -

structureName -

postingIterator -

Throws:

java.io.IOException

DirectIndexInputStream

public DirectIndexInputStream(Index index,
                              java.lang.String structureName)
                       throws java.io.IOException

Constructs an instance of the class with

Parameters:

index -

structureName -

Throws:

java.io.IOException

Method Detail

getNextTerms

public int[][] getNextTerms()
                     throws java.io.IOException

One call returns all the data for one document - [0][] is term ids, [1][] is frequency, [2][] is fields. The size of [0,1,2][] is how many unique terms occur in each document. Between calls, use getDocumentsSkipped() to keep track of what docid you're currently processing.

Returns:

int[][] the two dimensional array containing the term ids, fields

Throws:

java.io.IOException - if an I/O error occurs

getNextTerms

public int[][] getNextTerms(BitIndexPointer pointer)
                     throws java.io.IOException

Get the terms for the next document at the pointer specified

Throws:

java.io.IOException

getDocumentIndex

protected DocumentIndex getDocumentIndex(BitIndexPointer pointer)

Overrides:

getDocumentIndex in class BitPostingIndexInputStream