Module roaringbitmap

Package org.roaringbitmap

Class RoaringBitmapWriter.Wizard<C extends WordStorage<C>,T extends BitmapDataProvider & AppendableStorage<C>>

java.lang.Object

org.roaringbitmap.RoaringBitmapWriter.Wizard<C,T>

All Implemented Interfaces:

Supplier<RoaringBitmapWriter<T>>

Direct Known Subclasses:

RoaringBitmapWriter.BufferWizard, RoaringBitmapWriter.RoaringWizard

Enclosing interface:

RoaringBitmapWriter<T extends BitmapDataProvider>

public abstract static class RoaringBitmapWriter.Wizard<C extends WordStorage<C>,T extends BitmapDataProvider & AppendableStorage<C>>
extends Object
implements Supplier<RoaringBitmapWriter<T>>

Field Summary

Fields

Modifier and Type	Field	Description
protected boolean	constantMemory
protected Supplier<C>	containerSupplier
protected int	expectedContainerSize
protected int	initialCapacity
protected boolean	partiallySortValues
protected boolean	runCompress

Method Summary

Modifier and Type	Method	Description
protected abstract Supplier<C>	arraySupplier()
RoaringBitmapWriter.Wizard<C,T>	constantMemory()	All writes are buffered into the same buffer of 8kB, before converting to the best container representation and appending to the bitmap.
protected abstract T	createUnderlying(int initialCapacity)
RoaringBitmapWriter.Wizard<C,T>	doPartialRadixSort()	Will partially sort values, which can allocate O(n) temporary memory but can significantly speed up adding unsorted values to a bitmap.
RoaringBitmapWriter.Wizard<C,T>	expectedDensity(double density)	Influence default container choice by how dense the bitmap is expected to be.
RoaringBitmapWriter.Wizard<C,T>	expectedRange(long min, long max)	Guesses the number of prefices required based on an estimate of the range the bitmap will contain, assumes that all prefices in the range will be required.
RoaringBitmapWriter.Wizard<C,T>	expectedValuesPerContainer(int count)
RoaringBitmapWriter.Wizard<Container,FastRankRoaringBitmap>	fastRank()
RoaringBitmapWriter<T>	get()	Builds a bitmap writer based on the supplied options.
RoaringBitmapWriter.Wizard<C,T>	initialCapacity(int count)	Takes control of the size of the prefix array, in case it can be precalculated or estimated.
RoaringBitmapWriter.Wizard<C,T>	optimiseForArrays()	Choose this option if it is known that most containers will be sparse.
RoaringBitmapWriter.Wizard<C,T>	optimiseForRuns()	Choose this option if the bitmap is expected to be RLE compressible.
RoaringBitmapWriter.Wizard<C,T>	runCompress(boolean runCompress)	By default the bitmap will be run-compressed on the fly, but it can be disabled (and run compressed at the end).
protected abstract Supplier<C>	runSupplier()

Methods inherited from class java.lang.Object

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

Field Details

initialCapacity

protected int initialCapacity

constantMemory

protected boolean constantMemory

partiallySortValues

protected boolean partiallySortValues

runCompress

protected boolean runCompress

containerSupplier

protected Supplier<C extends WordStorage<C>> containerSupplier

expectedContainerSize

protected int expectedContainerSize

Method Details

optimiseForArrays

public RoaringBitmapWriter.Wizard<C,T> optimiseForArrays()

Choose this option if it is known that most containers will be sparse.

Returns:

this

optimiseForRuns

public RoaringBitmapWriter.Wizard<C,T> optimiseForRuns()

Choose this option if the bitmap is expected to be RLE compressible. Will buffer additions into a RunContainer.

Returns:

this

runCompress

public RoaringBitmapWriter.Wizard<C,T> runCompress(boolean runCompress)

By default the bitmap will be run-compressed on the fly, but it can be disabled (and run compressed at the end).

Parameters:

runCompress - whether to apply run compression on the fly.

Returns:

this

expectedValuesPerContainer

public RoaringBitmapWriter.Wizard<C,T> expectedValuesPerContainer(int count)

Parameters:

count - how many values are expected to fall within any 65536 bit range.

Returns:

this

fastRank

public RoaringBitmapWriter.Wizard<Container,FastRankRoaringBitmap> fastRank()

constantMemory

public RoaringBitmapWriter.Wizard<C,T> constantMemory()

All writes are buffered into the same buffer of 8kB, before converting to the best container representation and appending to the bitmap. This option overrides any optimiseForArrays, optimiseForRuns and optimiseForBitmaps settings.

Returns:

this

expectedDensity

public RoaringBitmapWriter.Wizard<C,T> expectedDensity(double density)

Influence default container choice by how dense the bitmap is expected to be.

Parameters:

density - value in [0.0, 1.0], density of the bitmap

Returns:

this

expectedRange

public RoaringBitmapWriter.Wizard<C,T> expectedRange(long min,
 long max)

Guesses the number of prefices required based on an estimate of the range the bitmap will contain, assumes that all prefices in the range will be required. This is a good heuristic for a contiguous bitmap, and, for instance, a very bad heuristic for a bitmap with just two values far apart.

Parameters:

min - the inclusive min value

max - the exclusive max value

Returns:

this

initialCapacity

public RoaringBitmapWriter.Wizard<C,T> initialCapacity(int count)

Takes control of the size of the prefix array, in case it can be precalculated or estimated. This can potentially save many array allocations during building the bitmap.

Parameters:

count - an estimate of the number of prefix keys required.

Returns:

this

doPartialRadixSort

public RoaringBitmapWriter.Wizard<C,T> doPartialRadixSort()

Will partially sort values, which can allocate O(n) temporary memory but can significantly speed up adding unsorted values to a bitmap.

Returns:

this

arraySupplier

protected abstract Supplier<C> arraySupplier()

runSupplier

protected abstract Supplier<C> runSupplier()

createUnderlying

protected abstract T createUnderlying(int initialCapacity)

get

public RoaringBitmapWriter<T> get()

Builds a bitmap writer based on the supplied options. A call to this method is repeatable, and will not fail because the wizard should already be in a valid state.

Specified by:

get in interface Supplier<C extends WordStorage<C>>

Returns:

a new RoaringBitmapWriter