com.googlecode.javaewah

Class IteratorUtil

java.lang.Object

com.googlecode.javaewah.IteratorUtil

public final class IteratorUtil
extends Object

Convenience functions for working over iterators

Method Summary

Modifier and Type	Method and Description
static int	cardinality(IteratingRLW i)
static EWAHCompressedBitmap	materialize(IteratingRLW i) Turn an iterator into a bitmap.
static void	materialize(IteratingRLW i, BitmapStorage c) Generate a bitmap from an iterator.
static long	materialize(IteratingRLW i, BitmapStorage c, long max) Turn an iterator into a bitmap.
static IteratingRLW[]	toIterators(EWAHCompressedBitmap... x)
static IntIterator	toSetBitsIntIterator(IteratingRLW i)
static Iterator<Integer>	toSetBitsIterator(IteratingRLW i)

Methods inherited from class java.lang.Object

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

Method Detail

toSetBitsIntIterator

public static IntIterator toSetBitsIntIterator(IteratingRLW i)

Parameters:

i - iterator we wish to iterate over

Returns:

an iterator over the set bits corresponding to the iterator

toSetBitsIterator

public static Iterator<Integer> toSetBitsIterator(IteratingRLW i)

Parameters:

i - iterator we wish to iterate over

Returns:

an iterator over the set bits corresponding to the iterator

materialize

public static void materialize(IteratingRLW i,
                               BitmapStorage c)

Generate a bitmap from an iterator.

Parameters:

i - iterator we wish to materialize

c - where we write

cardinality

public static int cardinality(IteratingRLW i)

Parameters:

i - iterator we wish to iterate over

Returns:

the cardinality (number of set bits) corresponding to the iterator

toIterators

public static IteratingRLW[] toIterators(EWAHCompressedBitmap... x)

Parameters:

x - set of bitmaps

Returns:

an array of iterators corresponding to the array of bitmaps

materialize

public static long materialize(IteratingRLW i,
                               BitmapStorage c,
                               long max)

Turn an iterator into a bitmap.

Parameters:

i - iterator we wish to materialize

c - where we write

max - maximum number of words we wish to materialize

Returns:

how many words were actually materialized

materialize

public static EWAHCompressedBitmap materialize(IteratingRLW i)

Turn an iterator into a bitmap. This can be used to effectively clone a bitmap in the following manner: EWAHCompressedBitmap n = IteratorUtil.materialize(bitmap.getIteratingRLW())); n.setSizeInBitsWithinLastWord(bitmap.sizeInBits());

Parameters:

i - iterator we wish to materialize

Returns:

materialized version of the iterator