Package org.apache.lucene.backward_codecs.lucene99

Class Lucene99SkipWriter

java.lang.Object

org.apache.lucene.codecs.MultiLevelSkipListWriter

org.apache.lucene.backward_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)	Sole constructor.

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()
void	setField(boolean fieldHasPositions, boolean fieldHasOffsets, boolean fieldHasPayloads)	Reset state for the given index options.
static void	writeImpacts(CompetitiveImpactAccumulator acc, DataOutput out)	Write impacts to the given output.
protected void	writeSkipData(int level, DataOutput skipBuffer)

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 Detail

Lucene99SkipWriter

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

Sole constructor.

Method Detail

setField

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

Reset state for the given index options.

resetSkip

public void resetSkip()

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

Specified by:

writeSkipData in class MultiLevelSkipListWriter

Throws:

IOException

writeImpacts

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

Write impacts to the given output.

Throws:

IOException