org.terrier.realtime.multi

Class MultiIndex

java.lang.Object

org.terrier.structures.Index

org.terrier.realtime.multi.MultiIndex

All Implemented Interfaces:

Closeable, Flushable, AutoCloseable

Direct Known Subclasses:

IncrementalIndex

public class MultiIndex
extends Index

The central MultiIndex structure. MultiIndex is a wrapper around multiple indices such that they appear as one single index. Matching over a MultiIndex can either be performed by a normal matching across all index shards or using a special selective matching class that only uses a subset of the shards this contains.

Properties

• multiindex.selectivematching - What policy should be used to perform matching. Two options are supported: all (default), mostrecent

Since:

4.0

Author:

Richard McCreadie, Stuart Mackie

Nested Class Summary

Nested classes/interfaces inherited from class org.terrier.structures.Index

Index.UpdatingCollectionStatistics

Field Summary

Fields

Modifier and Type	Field and Description
protected List<Index>	indices
protected IncrementalSelectiveMatching	selectiveMatchingPolicy Selective Matching policy, a policy for accessing only subsets of the indices within this multi-index.

Fields inherited from class org.terrier.structures.Index

dirtyProperties, EMPTY_CLASS_ARRAY, lastLoadError, MINIMUM_INDEX_TERRIER_VERSION, properties, PROPERTIES_SUFFIX, RETRIEVAL_LOADING_PROFILE

Constructor Summary

Constructors

Constructor and Description
MultiIndex(Index[] indices) Constructor.

Method Summary

Modifier and Type	Method and Description
void	close() Closes the data structures of the index.
void	flush() Write any dirty data structures down to disk
CollectionStatistics	getCollectionStatistics() Get the collection statistics
PostingIndex<?>	getDirectIndex() Return the DirectIndex associated with this index
DocumentIndex	getDocumentIndex() Return the DocumentIndex associated with this index
Object	getIndexStructure(String structureName) Obtains the named index structure, using an already loaded one if possible.
Object	getIndexStructureInputStream(String structureName) Not implemented.
PostingIndex<?>	getInvertedIndex() Returns the InvertedIndex to use for this index
Index	getIthShard(int i)
Lexicon<String>	getLexicon() Return the Lexicon associated with this index
MetaIndex	getMetaIndex() Get the Meta Index structure
int	getNumberOfShards() Returns the number of index shards that this incremental index contains
String	toString() Returns a String representation of this index

Methods inherited from class org.terrier.structures.Index

addIndexStructure, addIndexStructure, addIndexStructure, addIndexStructure, addIndexStructureInputStream, addIndexStructureInputStream, addIndexStructureInputStream, addIndexStructureInputStream, allExists, createIndex, createIndex, createNewIndex, existsIndex, getEnd, getIndexLoadingProfileAsRetrieval, getIndexProperty, getIndexRef, getIntIndexProperty, getLastIndexLoadError, getProperties, getStart, hasIndexStructure, hasIndexStructureInputStream, join, main, setIndexLoadingProfileAsRetrieval, setIndexProperty

Methods inherited from class java.lang.Object

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

Field Detail

indices

protected List<Index> indices

selectiveMatchingPolicy

protected IncrementalSelectiveMatching selectiveMatchingPolicy

Selective Matching policy, a policy for accessing only subsets of the indices within this multi-index.

Constructor Detail

MultiIndex

public MultiIndex(Index[] indices)

Constructor.

Method Detail

toString

public String toString()

Returns a String representation of this index

Specified by:

toString in class Index

getIndexStructure

public Object getIndexStructure(String structureName)

Obtains the named index structure, using an already loaded one if possible.

Specified by:

getIndexStructure in class Index

Parameters:

structureName - name of the required structure

Returns:

desired object or null if not found

getLexicon

public Lexicon<String> getLexicon()

Return the Lexicon associated with this index

Specified by:

getLexicon in class Index

getInvertedIndex

public PostingIndex<?> getInvertedIndex()

Returns the InvertedIndex to use for this index

Specified by:

getInvertedIndex in class Index

getMetaIndex

public MetaIndex getMetaIndex()

Get the Meta Index structure

Specified by:

getMetaIndex in class Index

getDocumentIndex

public DocumentIndex getDocumentIndex()

Return the DocumentIndex associated with this index

Specified by:

getDocumentIndex in class Index

getCollectionStatistics

public CollectionStatistics getCollectionStatistics()

Get the collection statistics

Specified by:

getCollectionStatistics in class Index

getDirectIndex

public PostingIndex<?> getDirectIndex()

Description copied from class: Index

Return the DirectIndex associated with this index

Specified by:

getDirectIndex in class Index

getIndexStructureInputStream

public Object getIndexStructureInputStream(String structureName)

Not implemented.

Specified by:

getIndexStructureInputStream in class Index

Parameters:

structureName - The name of the structure of which you want the inputstream. Eg "lexicon"

Returns:

Required structure, or null if not found

close

public void close()
           throws IOException

Closes the data structures of the index.

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

Specified by:

close in class Index

Throws:

IOException

flush

public void flush()
           throws IOException

Write any dirty data structures down to disk

Specified by:

flush in interface Flushable

Specified by:

flush in class Index

Throws:

IOException

getIthShard

public Index getIthShard(int i)

getNumberOfShards

public int getNumberOfShards()

Returns the number of index shards that this incremental index contains

Returns:

integer number of shards