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

Class FileHPIndex

java.lang.Object

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

it.unimi.di.big.mg4j.index.BitStreamIndex

it.unimi.di.big.mg4j.index.BitStreamHPIndex

it.unimi.di.big.mg4j.index.FileHPIndex

All Implemented Interfaces:

Serializable

public class FileHPIndex
extends BitStreamHPIndex

A file-based high-performance index.

An instance of this class stores additional index data for indices based on files: for instance, basename, compression flags, etc.

Since:

0.9

Author:

Paolo Boldi, Sebastiano Vigna

See Also:

Serialized Form

Nested Class Summary

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

BitStreamIndex.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
String	basename	The basename of this index.
File	indexFile	The file containing the index.
File	positionsFile	The file containing the positions.

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

bufferSize, countCoding, DEFAULT_BUFFER_SIZE, DEFAULT_FIXED_QUANTUM, DEFAULT_HEIGHT, DEFAULT_QUANTUM, FIXED_POINT_BITS, FIXED_POINT_MULTIPLIER, frequencyCoding, height, offsets, pointerCoding, positionCoding, quantum, readerConstructor

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

FileHPIndex(String basename, long numberOfDocuments, long numberOfTerms, long numberOfPostings, long numberOfOccurrences, int maxCount, Payload payload, CompressionFlags.Coding frequencyCoding, CompressionFlags.Coding pointerCoding, CompressionFlags.Coding countCoding, CompressionFlags.Coding positionCoding, int quantum, int height, int bufferSize, TermProcessor termProcessor, String field, Properties properties, StringMap<? extends CharSequence> termMap, PrefixMap<? extends CharSequence> prefixMap, IntBigList sizes, LongBigList offsets)

Method Summary

Modifier and Type	Method	Description
InputBitStream	getInputBitStream(int bufferSize)	Returns an input bit stream over the index.
FileInputStream	getInputStream()	Returns an input stream over the index.
InputBitStream	getPositionsInputBitStream(int bufferSize)	Returns an input bit stream over the index.
InputStream	getPositionsInputStream()	Returns an input stream over the index.
String	toString()

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

getConstructor, getReader

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

featureName, gaussianGolombModulus, golombModulus, quantumSigma

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

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

Methods inherited from class java.lang.Object

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

Field Detail

basename

public final String basename

The basename of this index. All file names will be stemmed from the basename. It may be null.

indexFile

public final File indexFile

The file containing the index. It may be null.

positionsFile

public final File positionsFile

The file containing the positions. It may be null. // TODO: Why ?

Constructor Detail

FileHPIndex

public FileHPIndex(String basename,
                   long numberOfDocuments,
                   long numberOfTerms,
                   long numberOfPostings,
                   long numberOfOccurrences,
                   int maxCount,
                   Payload payload,
                   CompressionFlags.Coding frequencyCoding,
                   CompressionFlags.Coding pointerCoding,
                   CompressionFlags.Coding countCoding,
                   CompressionFlags.Coding positionCoding,
                   int quantum,
                   int height,
                   int bufferSize,
                   TermProcessor termProcessor,
                   String field,
                   Properties properties,
                   StringMap<? extends CharSequence> termMap,
                   PrefixMap<? extends CharSequence> prefixMap,
                   IntBigList sizes,
                   LongBigList offsets)

Method Detail

toString

public String toString()

Overrides:

toString in class BitStreamIndex

getInputStream

public FileInputStream getInputStream()
                               throws FileNotFoundException

Description copied from class: BitStreamIndex

Returns an input stream over the index.

Specified by:

getInputStream in class BitStreamIndex

Returns:

an input stream over the index.

Throws:

FileNotFoundException

getInputBitStream

public InputBitStream getInputBitStream(int bufferSize)
                                 throws FileNotFoundException

Description copied from class: BitStreamIndex

Returns an input bit stream over the index.

Specified by:

getInputBitStream in class BitStreamIndex

Parameters:

bufferSize - a suggested buffer size.

Returns:

an input bit stream over the index.

Throws:

FileNotFoundException

getPositionsInputStream

public InputStream getPositionsInputStream()
                                    throws IOException

Description copied from class: BitStreamHPIndex

Returns an input stream over the index.

Specified by:

getPositionsInputStream in class BitStreamHPIndex

Returns:

an input stream over the index.

Throws:

IOException

getPositionsInputBitStream

public InputBitStream getPositionsInputBitStream(int bufferSize)
                                          throws IOException

Description copied from class: BitStreamHPIndex

Returns an input bit stream over the index.

Specified by:

getPositionsInputBitStream in class BitStreamHPIndex

Parameters:

bufferSize - a suggested buffer size.

Returns:

an input bit stream over the index.

Throws:

IOException