Module org.apache.lucene.codecs

Package org.apache.lucene.codecs.uniformsplit

Class UniformSplitPostingsFormat

java.lang.Object

org.apache.lucene.codecs.PostingsFormat

org.apache.lucene.codecs.uniformsplit.UniformSplitPostingsFormat

All Implemented Interfaces:

NamedSPILoader.NamedSPI

Direct Known Subclasses:

STUniformSplitPostingsFormat

public class UniformSplitPostingsFormat
extends PostingsFormat

PostingsFormat based on the Uniform Split technique.

See Also:

• UniformSplitTermsWriter

Field Summary

Fields

Modifier and Type	Field	Description
protected final BlockDecoder	blockDecoder
protected final BlockEncoder	blockEncoder
protected final int	deltaNumLines
protected final boolean	dictionaryOnHeap
static final String	NAME
protected final int	targetNumBlockLines
static final String	TERMS_BLOCKS_EXTENSION	Extension of the file containing the terms blocks for each field and the fields metadata.
static final String	TERMS_DICTIONARY_EXTENSION	Extension of the file containing the terms dictionary (the FST "trie").
static final int	VERSION_CURRENT
static final int	VERSION_ENCODABLE_FIELDS_METADATA
static final int	VERSION_START

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

EMPTY

Constructor Summary

Constructors

Modifier	Constructor	Description
	UniformSplitPostingsFormat()	Creates a UniformSplitPostingsFormat with default settings.
	UniformSplitPostingsFormat(int targetNumBlockLines, int deltaNumLines, BlockEncoder blockEncoder, BlockDecoder blockDecoder, boolean dictionaryOnHeap)
protected	UniformSplitPostingsFormat(String name, int targetNumBlockLines, int deltaNumLines, BlockEncoder blockEncoder, BlockDecoder blockDecoder, boolean dictionaryOnHeap)

Method Summary

Modifier and Type	Method	Description
protected FieldsProducer	createUniformSplitTermsReader(PostingsReaderBase postingsReader, SegmentReadState state, BlockDecoder blockDecoder)
protected FieldsConsumer	createUniformSplitTermsWriter(PostingsWriterBase postingsWriter, SegmentWriteState state, int targetNumBlockLines, int deltaNumLines, BlockEncoder blockEncoder)
FieldsConsumer	fieldsConsumer(SegmentWriteState state)	Writes a new segment
FieldsProducer	fieldsProducer(SegmentReadState state)	Reads a segment.
private static void	validateBlockEncoder(BlockEncoder blockEncoder, BlockDecoder blockDecoder)

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

availablePostingsFormats, forName, getName, reloadPostingsFormats, toString

Methods inherited from class java.lang.Object

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

Field Details

TERMS_DICTIONARY_EXTENSION

public static final String TERMS_DICTIONARY_EXTENSION

Extension of the file containing the terms dictionary (the FST "trie").

See Also:

• Constant Field Values

TERMS_BLOCKS_EXTENSION

public static final String TERMS_BLOCKS_EXTENSION

Extension of the file containing the terms blocks for each field and the fields metadata.

See Also:

• Constant Field Values

VERSION_START

public static final int VERSION_START

See Also:

• Constant Field Values

VERSION_ENCODABLE_FIELDS_METADATA

public static final int VERSION_ENCODABLE_FIELDS_METADATA

See Also:

• Constant Field Values

VERSION_CURRENT

public static final int VERSION_CURRENT

See Also:

• Constant Field Values

NAME

public static final String NAME

See Also:

• Constant Field Values

targetNumBlockLines

protected final int targetNumBlockLines

deltaNumLines

protected final int deltaNumLines

blockEncoder

protected final BlockEncoder blockEncoder

blockDecoder

protected final BlockDecoder blockDecoder

dictionaryOnHeap

protected final boolean dictionaryOnHeap

Constructor Details

UniformSplitPostingsFormat

public UniformSplitPostingsFormat()

Creates a UniformSplitPostingsFormat with default settings.

UniformSplitPostingsFormat

public UniformSplitPostingsFormat(int targetNumBlockLines,
 int deltaNumLines,
 BlockEncoder blockEncoder,
 BlockDecoder blockDecoder,
 boolean dictionaryOnHeap)

Parameters:

targetNumBlockLines - Target number of lines per block. Must be strictly greater than 0. The parameters can be pre-validated with UniformSplitTermsWriter.validateSettings(int, int). There is one term per block line, with its corresponding details (TermState).

deltaNumLines - Maximum allowed delta variation of the number of lines per block. Must be greater than or equal to 0 and strictly less than targetNumBlockLines. The block size will be targetNumBlockLines+-deltaNumLines. The block size must always be less than or equal to UniformSplitTermsWriter.MAX_NUM_BLOCK_LINES.

blockEncoder - Optional block encoder, may be null if none. If present, it is used to encode all terms blocks, as well as the FST dictionary and the fields metadata.

blockDecoder - Optional block decoder, may be null if none. If present, it is used to decode all terms blocks, as well as the FST dictionary and the fields metadata.

dictionaryOnHeap - Whether to force loading the terms dictionary on-heap. By default it is kept off-heap without impact on performance. If block encoding/decoding is used, then the dictionary is always loaded on-heap whatever this parameter value is.

UniformSplitPostingsFormat

protected UniformSplitPostingsFormat(String name,
 int targetNumBlockLines,
 int deltaNumLines,
 BlockEncoder blockEncoder,
 BlockDecoder blockDecoder,
 boolean dictionaryOnHeap)

See Also:

• UniformSplitPostingsFormat(int, int, BlockEncoder, BlockDecoder, boolean)

Method Details

fieldsConsumer

public FieldsConsumer fieldsConsumer(SegmentWriteState state)
                              throws IOException

Description copied from class: PostingsFormat

Writes a new segment

Specified by:

fieldsConsumer in class PostingsFormat

Throws:

IOException

fieldsProducer

public FieldsProducer fieldsProducer(SegmentReadState state)
                              throws IOException

Description copied from class: PostingsFormat

Reads a segment. NOTE: by the time this call returns, it must hold open any files it will need to use; else, those files may be deleted. Additionally, required files may be deleted during the execution of this call before there is a chance to open them. Under these circumstances an IOException should be thrown by the implementation. IOExceptions are expected and will automatically cause a retry of the segment opening logic with the newly revised segments.

Specified by:

fieldsProducer in class PostingsFormat

Throws:

IOException

createUniformSplitTermsWriter

protected FieldsConsumer createUniformSplitTermsWriter(PostingsWriterBase postingsWriter,
 SegmentWriteState state,
 int targetNumBlockLines,
 int deltaNumLines,
 BlockEncoder blockEncoder)
                                                throws IOException

Throws:

IOException

createUniformSplitTermsReader

protected FieldsProducer createUniformSplitTermsReader(PostingsReaderBase postingsReader,
 SegmentReadState state,
 BlockDecoder blockDecoder)
                                                throws IOException

Throws:

IOException

validateBlockEncoder

private static void validateBlockEncoder(BlockEncoder blockEncoder,
 BlockDecoder blockDecoder)