Package com.googlecode.javaewah32

Class FastAggregation32

java.lang.Object

com.googlecode.javaewah32.FastAggregation32

public final class FastAggregation32
extends Object

Fast algorithms to aggregate many bitmaps. These algorithms are just given as reference. They may not be faster than the corresponding methods in the EWAHCompressedBitmap class.

Author:

Daniel Lemire

Method Summary

Modifier and Type	Method	Description
static EWAHCompressedBitmap32	bufferedand(int bufSize, EWAHCompressedBitmap32... bitmaps)	Compute the and aggregate using a temporary uncompressed bitmap.
static void	bufferedandWithContainer(BitmapStorage32 container, int bufSize, EWAHCompressedBitmap32... bitmaps)	Compute the and aggregate using a temporary uncompressed bitmap.
static EWAHCompressedBitmap32	bufferedor(int bufSize, EWAHCompressedBitmap32... bitmaps)	Compute the or aggregate using a temporary uncompressed bitmap.
static void	bufferedorWithContainer(BitmapStorage32 container, int bufSize, EWAHCompressedBitmap32... bitmaps)	Compute the or aggregate using a temporary uncompressed bitmap.
static EWAHCompressedBitmap32	bufferedxor(int bufSize, EWAHCompressedBitmap32... bitmaps)	Compute the xor aggregate using a temporary uncompressed bitmap.
static void	bufferedxorWithContainer(BitmapStorage32 container, int bufSize, EWAHCompressedBitmap32... bitmaps)	Compute the xor aggregate using a temporary uncompressed bitmap.
static EWAHCompressedBitmap32	or(EWAHCompressedBitmap32... bitmaps)	Simple algorithm that computes the OR aggregate.
static EWAHCompressedBitmap32	or(Iterator<EWAHCompressedBitmap32> bitmaps)	Simple algorithm that computes the OR aggregate.
static void	orToContainer(BitmapStorage32 container, EWAHCompressedBitmap32... bitmaps)	Uses a priority queue to compute the or aggregate.
static EWAHCompressedBitmap32	xor(EWAHCompressedBitmap32... bitmaps)	Simple algorithm that computes the XOR aggregate.
static EWAHCompressedBitmap32	xor(Iterator<EWAHCompressedBitmap32> bitmaps)	Simple algorithm that computes the XOR aggregate.
static void	xorToContainer(BitmapStorage32 container, EWAHCompressedBitmap32... bitmaps)	Uses a priority queue to compute the xor aggregate.

Methods inherited from class java.lang.Object

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

Method Detail

bufferedand

public static EWAHCompressedBitmap32 bufferedand(int bufSize,
                                                 EWAHCompressedBitmap32... bitmaps)

Compute the and aggregate using a temporary uncompressed bitmap. This function does not seek to match the "sizeinbits" attributes of the input bitmaps.

Parameters:

bitmaps - the source bitmaps

bufSize - buffer size used during the computation in 64-bit words (per input bitmap)

Returns:

the or aggregate.

bufferedandWithContainer

public static void bufferedandWithContainer(BitmapStorage32 container,
                                            int bufSize,
                                            EWAHCompressedBitmap32... bitmaps)

Compute the and aggregate using a temporary uncompressed bitmap. This function does not seek to match the "sizeinbits" attributes of the input bitmaps.

Parameters:

container - where the aggregate is written

bufSize - buffer size used during the computation in 64-bit words (per input bitmap)

bitmaps - the source bitmaps

bufferedor

public static EWAHCompressedBitmap32 bufferedor(int bufSize,
                                                EWAHCompressedBitmap32... bitmaps)

Compute the or aggregate using a temporary uncompressed bitmap.

Parameters:

bitmaps - the source bitmaps

bufSize - buffer size used during the computation in 64-bit words

Returns:

the or aggregate.

bufferedorWithContainer

public static void bufferedorWithContainer(BitmapStorage32 container,
                                           int bufSize,
                                           EWAHCompressedBitmap32... bitmaps)

Compute the or aggregate using a temporary uncompressed bitmap.

Parameters:

container - where the aggregate is written

bufSize - buffer size used during the computation in 64-bit words

bitmaps - the source bitmaps

bufferedxor

public static EWAHCompressedBitmap32 bufferedxor(int bufSize,
                                                 EWAHCompressedBitmap32... bitmaps)

Compute the xor aggregate using a temporary uncompressed bitmap.

Parameters:

bitmaps - the source bitmaps

bufSize - buffer size used during the computation in 64-bit words

Returns:

the xor aggregate.

bufferedxorWithContainer

public static void bufferedxorWithContainer(BitmapStorage32 container,
                                            int bufSize,
                                            EWAHCompressedBitmap32... bitmaps)

Compute the xor aggregate using a temporary uncompressed bitmap.

Parameters:

container - where the aggregate is written

bufSize - buffer size used during the computation in 64-bit words

bitmaps - the source bitmaps

orToContainer

public static void orToContainer(BitmapStorage32 container,
                                 EWAHCompressedBitmap32... bitmaps)

Uses a priority queue to compute the or aggregate. The content of the container is overwritten. This algorithm runs in linearithmic time (O(n log n)) with respect to the number of bitmaps.

Parameters:

container - where we write the result

bitmaps - to be aggregated

or

public static EWAHCompressedBitmap32 or(EWAHCompressedBitmap32... bitmaps)

Simple algorithm that computes the OR aggregate.

Parameters:

bitmaps - input bitmaps

Returns:

new bitmap containing the aggregate

xor

public static EWAHCompressedBitmap32 xor(EWAHCompressedBitmap32... bitmaps)

Simple algorithm that computes the XOR aggregate.

Parameters:

bitmaps - input bitmaps

Returns:

new bitmap containing the aggregate

or

public static EWAHCompressedBitmap32 or(Iterator<EWAHCompressedBitmap32> bitmaps)

Simple algorithm that computes the OR aggregate.

Parameters:

bitmaps - input bitmaps

Returns:

new bitmap containing the aggregate

xor

public static EWAHCompressedBitmap32 xor(Iterator<EWAHCompressedBitmap32> bitmaps)

Simple algorithm that computes the XOR aggregate.

Parameters:

bitmaps - input bitmaps

Returns:

new bitmap containing the aggregate

xorToContainer

public static void xorToContainer(BitmapStorage32 container,
                                  EWAHCompressedBitmap32... bitmaps)

Uses a priority queue to compute the xor aggregate. The content of the container is overwritten. This algorithm runs in linearithmic time (O(n log n)) with respect to the number of bitmaps.

Parameters:

container - where we write the result

bitmaps - to be aggregated