Package org.apache.lucene.codecs.lucene99

Class Lucene99SkipWriter

java.lang.Object

org.apache.lucene.codecs.MultiLevelSkipListWriter

org.apache.lucene.codecs.lucene99.Lucene99SkipWriter

public final class Lucene99SkipWriter
extends MultiLevelSkipListWriter

Write skip lists with multiple levels, and support skip within block ints.

Assume that docFreq = 28, skipInterval = blockSize = 12

  |       block#0       | |      block#1        | |vInts|
  d d d d d d d d d d d d d d d d d d d d d d d d d d d d (posting list)
                          ^                       ^       (level 0 skip point)
 

Note that skipWriter will ignore first document in block#0, since it is useless as a skip point. Also, we'll never skip into the vInts block, only record skip data at the start its start point(if it exist).

For each skip point, we will record: 1. docID in former position, i.e. for position 12, record docID[11], etc. 2. its related file points(position, payload), 3. related numbers or uptos(position, payload). 4. start offset.

Field Summary

Fields inherited from class org.apache.lucene.codecs.MultiLevelSkipListWriter

numberOfSkipLevels

Constructor Summary

Constructors

Constructor	Description
Lucene99SkipWriter(int maxSkipLevels, int blockSize, int docCount, IndexOutput docOut, IndexOutput posOut, IndexOutput payOut)

Method Summary

Modifier and Type	Method	Description
void	bufferSkip(int doc, CompetitiveImpactAccumulator competitiveFreqNorms, int numDocs, long posFP, long payFP, int posBufferUpto, int payloadByteUpto)	Sets the values for the current skip data.
void	resetSkip()	Creates new buffers or empties the existing ones
void	setField(boolean fieldHasPositions, boolean fieldHasOffsets, boolean fieldHasPayloads)
static void	writeImpacts(CompetitiveImpactAccumulator acc, DataOutput out)
protected void	writeSkipData(int level, DataOutput skipBuffer)	Subclasses must implement the actual skip data encoding in this method.

Methods inherited from class org.apache.lucene.codecs.MultiLevelSkipListWriter

bufferSkip, init, writeChildPointer, writeLevelLength, writeSkip

Methods inherited from class java.lang.Object

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

Constructor Details

Lucene99SkipWriter

public Lucene99SkipWriter(int maxSkipLevels,
 int blockSize,
 int docCount,
 IndexOutput docOut,
 IndexOutput posOut,
 IndexOutput payOut)

Method Details

setField

public void setField(boolean fieldHasPositions,
 boolean fieldHasOffsets,
 boolean fieldHasPayloads)

resetSkip

public void resetSkip()

Description copied from class: MultiLevelSkipListWriter

Creates new buffers or empties the existing ones

Overrides:

resetSkip in class MultiLevelSkipListWriter

bufferSkip

public void bufferSkip(int doc,
 CompetitiveImpactAccumulator competitiveFreqNorms,
 int numDocs,
 long posFP,
 long payFP,
 int posBufferUpto,
 int payloadByteUpto)
                throws IOException

Sets the values for the current skip data.

Throws:

IOException

writeSkipData

protected void writeSkipData(int level,
 DataOutput skipBuffer)
                      throws IOException

Description copied from class: MultiLevelSkipListWriter

Subclasses must implement the actual skip data encoding in this method.

Specified by:

writeSkipData in class MultiLevelSkipListWriter

Parameters:

level - the level skip data shall be writing for

skipBuffer - the skip buffer to write to

Throws:

IOException

writeImpacts

public static void writeImpacts(CompetitiveImpactAccumulator acc,
 DataOutput out)
                         throws IOException

Throws:

IOException