Package org.apache.lucene.backward_codecs.lucene50.compressing

Class Lucene50CompressingTermVectorsFormat

java.lang.Object

org.apache.lucene.codecs.TermVectorsFormat

org.apache.lucene.backward_codecs.lucene50.compressing.Lucene50CompressingTermVectorsFormat

Direct Known Subclasses:

Lucene50TermVectorsFormat

public class Lucene50CompressingTermVectorsFormat
extends TermVectorsFormat

A TermVectorsFormat that compresses chunks of documents together in order to improve the compression ratio.

WARNING: This API is experimental and might change in incompatible ways in the next release.

Field Summary

Fields

Modifier and Type	Field	Description
protected int	blockSize	block size
protected int	chunkSize	chunk size
protected CompressionMode	compressionMode	compression mode
protected String	formatName	format name
protected int	maxDocsPerChunk	max docs per chunk
protected String	segmentSuffix	segment suffix

Constructor Summary

Constructors

Constructor	Description
Lucene50CompressingTermVectorsFormat(String formatName, String segmentSuffix, CompressionMode compressionMode, int chunkSize, int maxDocsPerChunk, int blockSize)	Create a new Lucene50CompressingTermVectorsFormat.

Method Summary

Modifier and Type	Method	Description
String	toString()
TermVectorsReader	vectorsReader(Directory directory, SegmentInfo segmentInfo, FieldInfos fieldInfos, IOContext context)
TermVectorsWriter	vectorsWriter(Directory directory, SegmentInfo segmentInfo, IOContext context)

Methods inherited from class java.lang.Object

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

Field Detail

formatName

protected final String formatName

format name

segmentSuffix

protected final String segmentSuffix

segment suffix

compressionMode

protected final CompressionMode compressionMode

compression mode

chunkSize

protected final int chunkSize

chunk size

blockSize

protected final int blockSize

block size

maxDocsPerChunk

protected final int maxDocsPerChunk

max docs per chunk

Constructor Detail

Lucene50CompressingTermVectorsFormat

public Lucene50CompressingTermVectorsFormat(String formatName,
                                            String segmentSuffix,
                                            CompressionMode compressionMode,
                                            int chunkSize,
                                            int maxDocsPerChunk,
                                            int blockSize)

Create a new Lucene50CompressingTermVectorsFormat.

formatName is the name of the format. This name will be used in the file formats to perform codec header checks.

The compressionMode parameter allows you to choose between compression algorithms that have various compression and decompression speeds so that you can pick the one that best fits your indexing and searching throughput. You should never instantiate two Lucene50CompressingTermVectorsFormats that have the same name but different CompressionModes.

chunkSize is the minimum byte size of a chunk of documents. Higher values of chunkSize should improve the compression ratio but will require more memory at indexing time and might make document loading a little slower (depending on the size of your OS cache compared to the size of your index).

Parameters:

formatName - the name of the StoredFieldsFormat

segmentSuffix - a suffix to append to files created by this format

compressionMode - the CompressionMode to use

chunkSize - the minimum number of bytes of a single chunk of stored documents

maxDocsPerChunk - the maximum number of documents in a single chunk

blockSize - the number of chunks to store in an index block.

See Also:

CompressionMode

Method Detail

vectorsReader

public final TermVectorsReader vectorsReader(Directory directory,
                                             SegmentInfo segmentInfo,
                                             FieldInfos fieldInfos,
                                             IOContext context)
                                      throws IOException

Specified by:

vectorsReader in class TermVectorsFormat

Throws:

IOException

vectorsWriter

public TermVectorsWriter vectorsWriter(Directory directory,
                                       SegmentInfo segmentInfo,
                                       IOContext context)
                                throws IOException

Specified by:

vectorsWriter in class TermVectorsFormat

Throws:

IOException

toString

public String toString()

Overrides:

toString in class Object