Package com.yahoo.search.predicate.index

Class ZstarCompressedPostingList

java.lang.Object

com.yahoo.search.predicate.index.MultiIntervalPostingList

com.yahoo.search.predicate.index.ZstarCompressedPostingList

All Implemented Interfaces:

PostingList

public class ZstarCompressedPostingList
extends MultiIntervalPostingList

Wraps a posting list of compressed NOT-features. The compression works by implying an interval of size 1 after each stored interval, unless the next interval starts with 16 bits of 0, in which case the current interval is extended to the next.

Author:

Magnar Nedland, bjorncs

Constructor Summary

Constructors

Constructor	Description
ZstarCompressedPostingList(PredicateIntervalStore store, int[] docIds, int[] dataRefs)

Method Summary

Modifier and Type	Method	Description
int	getInterval()
boolean	nextInterval()	Fetches the next interval for the current document.
protected boolean	prepareIntervals(int dataRef)

Methods inherited from class com.yahoo.search.predicate.index.MultiIntervalPostingList

getDocId, getDocIds, getSubquery, nextDocument, prepareIntervals, size

Methods inherited from class java.lang.Object

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

Constructor Details

ZstarCompressedPostingList

public ZstarCompressedPostingList(PredicateIntervalStore store,
 int[] docIds,
 int[] dataRefs)

Parameters:

docIds - Posting list as a stream.

Method Details

prepareIntervals

protected boolean prepareIntervals(int dataRef)

Specified by:

prepareIntervals in class MultiIntervalPostingList

nextInterval

public boolean nextInterval()

Description copied from interface: PostingList

Fetches the next interval for the current document.

Returns:

True if there was a next interval

getInterval

public int getInterval()

Returns:

The current interval for the current document