Package it.unimi.di.big.mg4j.index.cluster

Class LexicalCluster

java.lang.Object

it.unimi.di.big.mg4j.index.Index

it.unimi.di.big.mg4j.index.cluster.IndexCluster

it.unimi.di.big.mg4j.index.cluster.LexicalCluster

All Implemented Interfaces:

Serializable

public class LexicalCluster
extends IndexCluster

A cluster exhibiting local indices referring to the same collection, but containing different set of terms, as a single index.

Author:

Alessandro Arrabito, Sebastiano Vigna

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class it.unimi.di.big.mg4j.index.cluster.IndexCluster

IndexCluster.PropertyKeys

Nested classes/interfaces inherited from class it.unimi.di.big.mg4j.index.Index

Index.EmptyIndexIterator, Index.UriKeys

Field Summary

Fields

Modifier and Type	Field	Description
protected LexicalPartitioningStrategy	partitioningStrategy	The strategy, cast to a partition strategy, or null.
protected LexicalClusteringStrategy	strategy	The strategy to be used.

Fields inherited from class it.unimi.di.big.mg4j.index.cluster.IndexCluster

BLOOM_EXTENSION, localIndex, STRATEGY_DEFAULT_EXTENSION, termFilter

Fields inherited from class it.unimi.di.big.mg4j.index.Index

field, hasCounts, hasPayloads, hasPositions, keyIndex, maxCount, numberOfDocuments, numberOfOccurrences, numberOfPostings, numberOfTerms, payload, prefixMap, properties, singletonSet, sizes, termMap, termProcessor

Constructor Summary

Constructors

Constructor	Description
LexicalCluster(Index[] localIndex, LexicalClusteringStrategy strategy, BloomFilter<Void>[] termFilter, int numberOfDocuments, int numberOfTerms, long numberOfPostings, long numberOfOccurrences, int maxCount, Payload payload, boolean hasCounts, boolean hasPositions, TermProcessor termProcessor, String field, IntBigList sizes, Properties properties)	Creates a new lexical index cluster.

Method Summary

Modifier and Type	Method	Description
IndexIterator	documents(CharSequence prefix, int limit)	Creates a number of instances of IndexReader for this index and uses them to return a MultiTermIndexIterator over the documents containing any term our of a set of terms defined by a prefix; the prefix is given explicitly, and unless the index has a prefix map, an UnsupportedOperationException will be thrown.
IndexReader	getReader(int bufferSize)	Creates and returns a new IndexReader based on this index.

Methods inherited from class it.unimi.di.big.mg4j.index.cluster.IndexCluster

getInstance, keyIndex

Methods inherited from class it.unimi.di.big.mg4j.index.Index

documents, documents, getEmptyIndexIterator, getEmptyIndexIterator, getEmptyIndexIterator, getEmptyIndexIterator, getInstance, getInstance, getInstance, getInstance, getInstance, getReader, getTermProcessor

Methods inherited from class java.lang.Object

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

Field Detail

strategy

protected final LexicalClusteringStrategy strategy

The strategy to be used.

partitioningStrategy

protected final LexicalPartitioningStrategy partitioningStrategy

The strategy, cast to a partition strategy, or null.

Constructor Detail

LexicalCluster

public LexicalCluster(Index[] localIndex,
                      LexicalClusteringStrategy strategy,
                      BloomFilter<Void>[] termFilter,
                      int numberOfDocuments,
                      int numberOfTerms,
                      long numberOfPostings,
                      long numberOfOccurrences,
                      int maxCount,
                      Payload payload,
                      boolean hasCounts,
                      boolean hasPositions,
                      TermProcessor termProcessor,
                      String field,
                      IntBigList sizes,
                      Properties properties)

Creates a new lexical index cluster.

Method Detail

getReader

public IndexReader getReader(int bufferSize)
                      throws IOException

Description copied from class: Index

Creates and returns a new IndexReader based on this index. After that, you can use the reader to read this index.

Specified by:

getReader in class Index

Parameters:

bufferSize - the size of the buffer to be used accessing the reader, or -1 for a default buffer size.

Returns:

a new IndexReader to read this index.

Throws:

IOException

documents

public IndexIterator documents(CharSequence prefix,
                               int limit)
                        throws IOException,
                               TooManyTermsException

Description copied from class: Index

Creates a number of instances of IndexReader for this index and uses them to return a MultiTermIndexIterator over the documents containing any term our of a set of terms defined by a prefix; the prefix is given explicitly, and unless the index has a prefix map, an UnsupportedOperationException will be thrown.

Overrides:

documents in class Index

Parameters:

prefix - a prefix.

limit - a limit on the number of terms that will be used to resolve the prefix query; if the terms starting with prefix are more than limit, a TooManyTermsException will be thrown.

Throws:

TooManyTermsException - if there are more than limit terms starting with prefix.

IOException