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

Class MemoryMappedHPIndex

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.MemoryMappedHPIndex

All Implemented Interfaces:

Serializable

public class MemoryMappedHPIndex
extends BitStreamHPIndex

A memory-mapped BitStreamHPIndex. See the discussion in MemoryMappedIndex (and consider that since a high-performance index is actually split in two files, memory mapping is actually easier).

Since:

1.2

Author:

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
protected ByteBufferInputStream	index	The byte buffer containing the index.
protected ByteBufferInputStream	positions	The byte buffer 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

MemoryMappedHPIndex(ByteBufferInputStream index, ByteBufferInputStream positions, 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, 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 bufferSizeUnused)	Returns an input bit stream over the index.
ByteBufferInputStream	getInputStream()	Returns an input stream over the index.
InputBitStream	getPositionsInputBitStream(int bufferSizeUnused)	Returns an input bit stream over the index.
InputStream	getPositionsInputStream()	Returns an input stream over the index.

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, toString

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

index

protected final ByteBufferInputStream index

The byte buffer containing the index.

positions

protected final ByteBufferInputStream positions

The byte buffer containing the positions.

Constructor Detail

MemoryMappedHPIndex

public MemoryMappedHPIndex(ByteBufferInputStream index,
                           ByteBufferInputStream positions,
                           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,
                           TermProcessor termProcessor,
                           String field,
                           Properties properties,
                           StringMap<? extends CharSequence> termMap,
                           PrefixMap<? extends CharSequence> prefixMap,
                           IntBigList sizes,
                           LongBigList offsets)

Method Detail

getInputBitStream

public InputBitStream getInputBitStream(int bufferSizeUnused)

Description copied from class: BitStreamIndex

Returns an input bit stream over the index.

Specified by:

getInputBitStream in class BitStreamIndex

Parameters:

bufferSizeUnused - a suggested buffer size.

Returns:

an input bit stream over the index.

getInputStream

public ByteBufferInputStream getInputStream()

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.

getPositionsInputBitStream

public InputBitStream getPositionsInputBitStream(int bufferSizeUnused)
                                          throws IOException

Description copied from class: BitStreamHPIndex

Returns an input bit stream over the index.

Specified by:

getPositionsInputBitStream in class BitStreamHPIndex

Parameters:

bufferSizeUnused - a suggested buffer size.

Returns:

an input bit stream over the index.

Throws:

IOException

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