org.apache.giraph.utils

Class IncreasingBitSet

java.lang.Object

org.apache.giraph.utils.IncreasingBitSet

public class IncreasingBitSet
extends Object

Bit set optimized for increasing longs to save storage space. The general idea is that even though some keys will be added out-of-order, there is a base key that keeps increasing so that the bit set doesn't get very big. When there are enough set bits, the bit set gets compacted. Thread-safe.

Field Summary

Fields

Modifier and Type	Field and Description
static int	MIN_BITS_TO_SHIFT Minimum number of bits to shift

Constructor Summary

Constructors

Constructor and Description
IncreasingBitSet()

Method Summary

Modifier and Type	Method and Description
boolean	add(long key) Add a key if it is possible.
long	cardinality() Get the number of set bits
long	getLastBaseKey() Get the last base key (mainly for debugging).
boolean	has(long key) Check for existence of a key
int	size() Get the size of the bit set

Methods inherited from class java.lang.Object

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

Field Detail

MIN_BITS_TO_SHIFT

public static final int MIN_BITS_TO_SHIFT

Minimum number of bits to shift

See Also:

Constant Field Values

Constructor Detail

IncreasingBitSet

public IncreasingBitSet()

Method Detail

add

public boolean add(long key)

Add a key if it is possible.

Parameters:

key - Key to add

Returns:

True if the key was added, false otherwise

cardinality

public long cardinality()

Get the number of set bits

Returns:

Number of set bits

size

public int size()

Get the size of the bit set

Returns:

Size of the bit set

has

public boolean has(long key)

Check for existence of a key

Parameters:

key - Key to check for

Returns:

True if the key exists, false otherwise

getLastBaseKey

public long getLastBaseKey()

Get the last base key (mainly for debugging).

Returns:

Last base key