org.apache.lucene.codecs.compressing

Class CompressingTermVectorsFormat

java.lang.Object

org.apache.lucene.codecs.TermVectorsFormat

org.apache.lucene.codecs.compressing.CompressingTermVectorsFormat

Direct Known Subclasses:

Lucene50TermVectorsFormat

public class CompressingTermVectorsFormat
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.

Constructor Summary

Constructors

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

Method Summary

Modifier and Type	Method and Description
String	toString()
TermVectorsReader	vectorsReader(Directory directory, SegmentInfo segmentInfo, FieldInfos fieldInfos, IOContext context) Returns a TermVectorsReader to read term vectors.
TermVectorsWriter	vectorsWriter(Directory directory, SegmentInfo segmentInfo, IOContext context) Returns a TermVectorsWriter to write term vectors.

Methods inherited from class java.lang.Object

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

Constructor Detail

CompressingTermVectorsFormat

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

Create a new CompressingTermVectorsFormat.

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 CompressingTermVectorsFormats 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

Description copied from class: TermVectorsFormat

Returns a TermVectorsReader to read term vectors.

Specified by:

vectorsReader in class TermVectorsFormat

Throws:

IOException

vectorsWriter

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

Description copied from class: TermVectorsFormat

Returns a TermVectorsWriter to write term vectors.

Specified by:

vectorsWriter in class TermVectorsFormat

Throws:

IOException

toString

public String toString()

Overrides:

toString in class Object