com.googlecode.javaewah

Class IteratorAggregation

java.lang.Object

com.googlecode.javaewah.IteratorAggregation

public final class IteratorAggregation
extends Object

Set of helper functions to aggregate bitmaps.

Field Summary

Fields

Modifier and Type	Field and Description
static int	DEFAULT_MAX_BUF_SIZE An optimization option.

Method Summary

Modifier and Type	Method and Description
static IteratingRLW	bufferedand(int bufSize, IteratingRLW... al) Aggregate the iterators using a bitmap buffer.
static IteratingRLW	bufferedand(IteratingRLW... al) Aggregate the iterators using a bitmap buffer.
static IteratingRLW	bufferedor(int bufSize, IteratingRLW... al) Aggregate the iterators using a bitmap buffer.
static IteratingRLW	bufferedor(IteratingRLW... al) Aggregate the iterators using a bitmap buffer.
static IteratingRLW	bufferedxor(int bufSize, IteratingRLW... al) Aggregate the iterators using a bitmap buffer.
static IteratingRLW	bufferedxor(IteratingRLW... al) Aggregate the iterators using a bitmap buffer.
protected static long	discharge(BitmapStorage container, IteratingRLW i, long max) Write out up to max words, returns how many were written
protected static void	dischargeAsEmpty(BitmapStorage container, IteratingRLW i) Write out the content of the iterator, but as if it were all zeros.
protected static long	dischargeNegated(BitmapStorage container, IteratingRLW i, long max) Write out up to max negated words, returns how many were written
protected static int	inplaceand(long[] bitmap, IteratingRLW i)
protected static int	inplaceor(long[] bitmap, IteratingRLW i)
protected static int	inplacexor(long[] bitmap, IteratingRLW i)
static IteratingRLW	not(IteratingRLW x)
static void	xorToContainer(BitmapStorage container, int desiredrlwcount, IteratingRLW rlwi, IteratingRLW rlwj) Compute the first few words of the XOR aggregate between two iterators.

Methods inherited from class java.lang.Object

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

Field Detail

DEFAULT_MAX_BUF_SIZE

public static final int DEFAULT_MAX_BUF_SIZE

An optimization option. Larger values may improve speed, but at the expense of memory.

See Also:

Constant Field Values

Method Detail

not

public static IteratingRLW not(IteratingRLW x)

Parameters:

x - iterator to negate

Returns:

negated version of the iterator

bufferedand

public static IteratingRLW bufferedand(IteratingRLW... al)

Aggregate the iterators using a bitmap buffer.

Parameters:

al - set of iterators to aggregate

Returns:

and aggregate

bufferedand

public static IteratingRLW bufferedand(int bufSize,
                                       IteratingRLW... al)

Aggregate the iterators using a bitmap buffer.

Parameters:

al - set of iterators to aggregate

bufSize - size of the internal buffer used by the iterator in 64-bit words (per input iterator)

Returns:

and aggregate

bufferedor

public static IteratingRLW bufferedor(IteratingRLW... al)

Aggregate the iterators using a bitmap buffer.

Parameters:

al - set of iterators to aggregate

Returns:

or aggregate

bufferedor

public static IteratingRLW bufferedor(int bufSize,
                                      IteratingRLW... al)

Aggregate the iterators using a bitmap buffer.

Parameters:

al - iterators to aggregate

bufSize - size of the internal buffer used by the iterator in 64-bit words

Returns:

or aggregate

bufferedxor

public static IteratingRLW bufferedxor(IteratingRLW... al)

Aggregate the iterators using a bitmap buffer.

Parameters:

al - set of iterators to aggregate

Returns:

xor aggregate

bufferedxor

public static IteratingRLW bufferedxor(int bufSize,
                                       IteratingRLW... al)

Aggregate the iterators using a bitmap buffer.

Parameters:

al - iterators to aggregate

bufSize - size of the internal buffer used by the iterator in 64-bit words

Returns:

xor aggregate

dischargeAsEmpty

protected static void dischargeAsEmpty(BitmapStorage container,
                                       IteratingRLW i)

Write out the content of the iterator, but as if it were all zeros.

Parameters:

container - where we write

i - the iterator

discharge

protected static long discharge(BitmapStorage container,
                                IteratingRLW i,
                                long max)

Write out up to max words, returns how many were written

Parameters:

container - target for writes

i - source of data

max - maximal number of writes

Returns:

how many written

dischargeNegated

protected static long dischargeNegated(BitmapStorage container,
                                       IteratingRLW i,
                                       long max)

Write out up to max negated words, returns how many were written

Parameters:

container - target for writes

i - source of data

max - maximal number of writes

Returns:

how many written

xorToContainer

public static void xorToContainer(BitmapStorage container,
                                  int desiredrlwcount,
                                  IteratingRLW rlwi,
                                  IteratingRLW rlwj)

Compute the first few words of the XOR aggregate between two iterators.

Parameters:

container - where to write

desiredrlwcount - number of words to be written (max)

rlwi - first iterator to aggregate

rlwj - second iterator to aggregate

inplaceor

protected static int inplaceor(long[] bitmap,
                               IteratingRLW i)

inplacexor

protected static int inplacexor(long[] bitmap,
                                IteratingRLW i)

inplaceand

protected static int inplaceand(long[] bitmap,
                                IteratingRLW i)