org.terrier.structures.integer

Class IntegerCodingPostingIndex

java.lang.Object

org.terrier.structures.integer.IntegerCodingPostingIndex

All Implemented Interfaces:

Closeable, AutoCloseable, PostingIndex<BitIndexPointer>

public class IntegerCodingPostingIndex
extends Object
implements PostingIndex<BitIndexPointer>

This implementation of PostingIndex provides access to an index of BasicIntegerCodingIterablePosting (or one of it subclasses). This expects in the data.properties file some information, such as index.structureName.fields.count=the number of fields in the postings, if any index.structureName.blocks=0 (no blocks) or 1 (positions) or >1 (blocks of any size) index.structureName.compression.integer.chunk-size=the maximum number of posting in a chunk index.structureName.compression.integer.ids.codec=the IntegerCodec implementation to use for docIds index.structureName.compression.integer.tfs.codec=the IntegerCodec implementation to use for tfs index.structureName.compression.integer.fields.codec=the IntegerCodec implementation to use for fields (optional) index.structureName.compression.integer.blocks.codec=the IntegerCodec implementation to use for blocks (optional)

Since:

4.0

Author:

Matteo Catena, Craig Macdonald

Nested Class Summary

Nested classes/interfaces inherited from interface org.terrier.structures.PostingIndex

PostingIndex.DocidSpecificDocumentIndex

Field Summary

Fields

Modifier and Type	Field and Description
protected IntegerCodec	blocksCodec
protected int	chunkSize
protected DocumentIndex	documentIndex
protected IntegerCodec	fieldsCodec
protected int	fieldsCount
protected ByteInSeekable[]	file
protected int	hasBlocks
protected IntegerCodec	idsCodec
protected IndexOnDisk	index
protected IntegerCodec	tfsCodec

Constructor Summary

Constructors

Constructor and Description
IntegerCodingPostingIndex(IndexOnDisk index, String structureName)

Method Summary

Methods

Modifier and Type	Method and Description
void	close()
IterablePosting	getPostings(Pointer _pointer) Get the posting given a pointer
protected void	openFile(String structureName)

Methods inherited from class java.lang.Object

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

Field Detail

index

protected IndexOnDisk index

file

protected ByteInSeekable[] file

documentIndex

protected DocumentIndex documentIndex

fieldsCount

protected int fieldsCount

hasBlocks

protected int hasBlocks

chunkSize

protected int chunkSize

idsCodec

protected IntegerCodec idsCodec

tfsCodec

protected IntegerCodec tfsCodec

fieldsCodec

protected IntegerCodec fieldsCodec

blocksCodec

protected IntegerCodec blocksCodec

Constructor Detail

IntegerCodingPostingIndex

public IntegerCodingPostingIndex(IndexOnDisk index,
                         String structureName)
                          throws IOException

Throws:

IOException

Method Detail

openFile

protected void openFile(String structureName)
                 throws IOException

Throws:

IOException

close

public void close()
           throws IOException

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

Throws:

IOException

getPostings

public IterablePosting getPostings(Pointer _pointer)
                            throws IOException

Description copied from interface: PostingIndex

Get the posting given a pointer

Specified by:

getPostings in interface PostingIndex<BitIndexPointer>

Throws:

IOException