FixedSizeBitSet

java.lang.Object
- org.jgroups.util.FixedSizeBitSet

Direct Known Subclasses:

SeqnoList
```
public class FixedSizeBitSet
extends java.lang.Object
```
Class copied from BitSet. Changes are that the FixedSizeBitSet doesn't expand, so access to it doesn't need to be synchronized, plus we only need a few methods so most methods of the old class have been removed.

Author:

Bela Ban

Field Summary

Fields
Modifier and Type	Field and Description
`protected static int`	`ADDRESS_BITS_PER_WORD`
`protected static int`	`BITS_PER_WORD`
`protected int`	`size`
`protected static long`	`WORD_MASK`
`protected long[]`	`words`

Constructor Summary

Constructors
Constructor and Description

FixedSizeBitSet()

FixedSizeBitSet(int size)
Creates a bit set whose initial size is the range 0 through size-1.

Constructors
Constructor and Description
`FixedSizeBitSet()`
`FixedSizeBitSet(int size)` Creates a bit set whose initial size is the range `0` through `size-1`.

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`int`	`cardinality()` Returns the number of bits set to `true` in this bit set
`void`	`clear(int index)` Sets the bit specified by the index to `false`.
`void`	`clear(int from, int to)` Sets the bits from the specified `from` (inclusive) to the specified `to` (inclusive) to `false`.
`void`	`flip()` Flips all bits: 1 --> 0 and 0 --> 1
`boolean`	`get(int index)` Returns the value of the bit with the specified index.
`int`	`nextClearBit(int fromIndex)` Returns the index of the first bit that is set to `false` that occurs on or after the specified starting index.
`int`	`nextSetBit(int fromIndex)` Returns the index of the first bit that is set to `true` that occurs on or after the specified starting index.
`int`	`previousSetBit(int from)` Returns the index of the nearest bit that is set to `true` that occurs on or before the specified starting index.
`boolean`	`set(int index)` Sets the bit at the specified index to `true`.
`void`	`set(int from, int to)` Sets the bits from the specified `from` (inclusive) to the specified `to` (inclusive) to `true`.
`int`	`size()`
`java.lang.String`	`toString()` Returns a string representation of this bit set.
`protected static int`	`wordIndex(int bitIndex)`

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

- Field Detail
  - ADDRESS_BITS_PER_WORD
```
protected static final int ADDRESS_BITS_PER_WORD
```
    See Also:
    
    Constant Field Values
  - BITS_PER_WORD
```
protected static final int BITS_PER_WORD
```
    See Also:
    
    Constant Field Values
  - WORD_MASK
```
protected static final long WORD_MASK
```
    See Also:
    
    Constant Field Values
  - words
```
protected long[] words
```
  - size
```
protected int size
```
- Constructor Detail
  - FixedSizeBitSet
```
public FixedSizeBitSet()
```
  - FixedSizeBitSet
```
public FixedSizeBitSet(int size)
```
    Creates a bit set whose initial size is the range 0 through size-1. All bits are initially false.
    
    Parameters:
    
    size - the initial size of the bit set (in bits).
    
    Throws:
    
    java.lang.NegativeArraySizeException - if the specified initial size is negative
- Method Detail
  - set
```
public boolean set(int index)
```
    Sets the bit at the specified index to true.
    
    Parameters:
    
    index - a bit index.
    
    Returns:
    
    true if the bit was 0 before, false otherwise
    
    Throws:
    
    java.lang.IndexOutOfBoundsException - if the specified index is negative.
  - set
```
public void set(int from,
                int to)
```
    Sets the bits from the specified from (inclusive) to the specified to (inclusive) to true.
    
    Parameters:
    
    from - index of the first bit to be set
    
    to - index of the last bit to be set
    
    Throws:
    
    java.lang.IndexOutOfBoundsException - if from is negative, or to is negative, or from is larger than to
  - clear
```
public void clear(int index)
```
    Sets the bit specified by the index to false.
    
    Parameters:
    
    index - the index of the bit to be cleared.
    
    Throws:
    
    java.lang.IndexOutOfBoundsException - if the specified index is negative.
  - clear
```
public void clear(int from,
                  int to)
```
    Sets the bits from the specified from (inclusive) to the specified to (inclusive) to false.
    
    Parameters:
    
    from - index of the first bit to be cleared
    
    to - index of the last bit to be cleared
    
    Throws:
    
    java.lang.IndexOutOfBoundsException - if from is negative, or to is negative, or from is larger than to
  - get
```
public boolean get(int index)
```
    Returns the value of the bit with the specified index. The value is true if the bit with the index index is currently set in this bit set; otherwise, the result is false.
    
    Parameters:
    
    index - the bit index.
    
    Returns:
    
    the value of the bit with the specified index.
    
    Throws:
    
    java.lang.IndexOutOfBoundsException - if the specified index is negative.
  - nextSetBit
```
public int nextSetBit(int fromIndex)
```
    Returns the index of the first bit that is set to true that occurs on or after the specified starting index. If no such bit exists then -1 is returned.
    To iterate over the true bits in a BitSet, use the following loop:
```
 for (int i = bs.nextSetBit(0); i >= 0; i = bs.nextSetBit(i+1)) {
     // operate on index i here
 }
```
    Parameters:
    
    fromIndex - the index to start checking from (inclusive).
    
    Returns:
    
    the index of the next set bit.
    
    Throws:
    
    java.lang.IndexOutOfBoundsException - if the specified index is negative.
  - nextClearBit
```
public int nextClearBit(int fromIndex)
```
    Returns the index of the first bit that is set to false that occurs on or after the specified starting index.
    
    Parameters:
    
    fromIndex - the index to start checking from (inclusive).
    
    Returns:
    
    the index of the next clear bit.
    
    Throws:
    
    java.lang.IndexOutOfBoundsException - if the specified index is negative.
  - previousSetBit
```
public int previousSetBit(int from)
```
    Returns the index of the nearest bit that is set to true that occurs on or before the specified starting index. If no such bit exists, or if -1 is given as the starting index, then -1 is returned.
    
    Parameters:
    
    from - the index to start checking from (inclusive)
    
    Returns:
    
    the index of the previous set bit, or -1 if there is no such bit
    
    Throws:
    
    java.lang.IndexOutOfBoundsException - if the specified index is less than -1
  - cardinality
```
public int cardinality()
```
    Returns the number of bits set to true in this bit set
    
    Returns:
    
    the number of bits set to true in this bit set
  - size
```
public int size()
```
  - flip
```
public void flip()
```
    Flips all bits: 1 --> 0 and 0 --> 1
  - toString
```
public java.lang.String toString()
```
    Returns a string representation of this bit set. For every index for which this BitSet contains a bit in the set state, the decimal representation of that index is included in the result. Such indices are listed in order from lowest to highest, separated by ", " (a comma and a space) and surrounded by braces, resulting in the usual mathematical notation for a set of integers.
    Overrides the toString method of Object.
    Example:
```
 BitSet drPepper = new BitSet();
```
    Now drPepper.toString() returns "{}".
```
 drPepper.set(2);
```
    Now drPepper.toString() returns "{2}".
```
 drPepper.set(4);
 drPepper.set(10);
```
    Now drPepper.toString() returns "{2, 4, 10}".
    Overrides:
    
    toString in class java.lang.Object
    
    Returns:
    
    a string representation of this bit set.
  - wordIndex
```
protected static int wordIndex(int bitIndex)
```

Class FixedSizeBitSet

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

ADDRESS_BITS_PER_WORD

BITS_PER_WORD

WORD_MASK

words

size

Constructor Detail

FixedSizeBitSet

FixedSizeBitSet

Method Detail

set

set

clear

clear

get

nextSetBit

nextClearBit

previousSetBit

cardinality

size

flip

toString

wordIndex