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

Class LexicalClusterIndexReader

java.lang.Object

it.unimi.di.big.mg4j.index.AbstractIndexReader

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

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

All Implemented Interfaces:

IndexReader, SafelyCloseable, Closeable, AutoCloseable

public class LexicalClusterIndexReader
extends AbstractIndexClusterIndexReader

An index reader for a lexical cluster. It diverts a call for the documents of a given term or prefix to the suitable local index (or set of indices).

Author:

Alessandro Arrabito, Sebastiano Vigna

Field Summary

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

indexReader

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

closed

Constructor Summary

Constructors

Constructor	Description
LexicalClusterIndexReader(LexicalCluster index, int bufferSize)

Method Summary

Modifier and Type	Method	Description
IndexIterator	documents(long term)	Returns a document iterator over the documents containing a term.
IndexIterator	documents(CharSequence term)	Returns an index iterator over the documents containing a term; the term is given explicitly.

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

close

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

finalize, nextIterator

Methods inherited from class java.lang.Object

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

Constructor Detail

LexicalClusterIndexReader

public LexicalClusterIndexReader(LexicalCluster index,
                                 int bufferSize)
                          throws IOException

Throws:

IOException

Method Detail

documents

public IndexIterator documents(long term)
                        throws IOException

Description copied from interface: IndexReader

Returns a document iterator over the documents containing a term.

Note that the index iterator returned by this method will return null on a call to term().

Note that it is always possible to call this method with argument 0, even if the underlying index does not provide random access.

Parameters:

term - the number of a term.

Throws:

IOException

documents

public IndexIterator documents(CharSequence term)
                        throws IOException

Description copied from interface: IndexReader

Returns an index iterator over the documents containing a term; the term is given explicitly.

Unless the term processor of the associated index is null, words coming from a query will have to be processed before being used with this method.

Note that the index iterator returned by this method will return term on a call to term().

Parameters:

term - a term (the term will be downcased if the index is case insensitive).

Throws:

IOException