org.apache.derby.iapi.util
Class JBitSet

java.lang.Object
  extended by org.apache.derby.iapi.util.JBitSet

public final class JBitSet
extends java.lang.Object

JBitSet is a wrapper class for BitSet. It is a fixed length implementation which can be extended via the grow() method. It provides additional methods to manipulate BitSets. NOTE: JBitSet was driven by the (current and perceived) needs of the optimizer, but placed in the util package since it is not specific to query trees.. NOTE: java.util.BitSet is final, so we must provide a wrapper class which includes a BitSet member in order to extend the functionality. We want to make it look like JBitSet extends BitSet, so we need to provide wrapper methods for all of BitSet's methods.


Field Summary
private  java.util.BitSet bitSet
           
private  int size
           
 
Constructor Summary
private JBitSet(java.util.BitSet bitSet, int size)
          Construct a JBitSet with the specified bitSet.
  JBitSet(int size)
          Construct a JBitSet of the specified size.
 
Method Summary
 void and(JBitSet set)
           
 void clear(int bitIndex)
           
 void clearAll()
          Clear all of the bits in this JBitSet
 java.lang.Object clone()
           
 boolean contains(JBitSet jBitSet)
          Test to see if one JBitSet contains another one of the same size.
 boolean equals(java.lang.Object obj)
           
 boolean get(int bitIndex)
           
 int getFirstSetBit()
          Get the first set bit (starting at index 0) from a JBitSet.
 void grow(int newSize)
          Grow an existing JBitSet to the specified size.
 int hashCode()
           
 boolean hasSingleBitSet()
          See of a JBitSet has exactly 1 bit set.
 void or(JBitSet set)
           
 void set(int bitIndex)
           
 void setTo(JBitSet sourceBitSet)
          Set the BitSet to have the exact same bits set as the parameter's BitSet.
 int size()
          Return the size of bitSet
 java.lang.String toString()
           
 void xor(JBitSet set)
           
 
Methods inherited from class java.lang.Object
finalize, getClass, notify, notifyAll, wait, wait, wait
 

Field Detail

bitSet

private final java.util.BitSet bitSet

size

private int size
Constructor Detail

JBitSet

public JBitSet(int size)
Construct a JBitSet of the specified size.

Parameters:
size - The number of bits in the JBitSet.

JBitSet

private JBitSet(java.util.BitSet bitSet,
                int size)
Construct a JBitSet with the specified bitSet.

Parameters:
bitSet - The BitSet.
size - The size of bitSet. NOTE: We need to specify the size since the size of a BitSet is not guaranteed to be the same as JBitSet.size().
Method Detail

setTo

public void setTo(JBitSet sourceBitSet)
Set the BitSet to have the exact same bits set as the parameter's BitSet.

Parameters:
sourceBitSet - The JBitSet to copy.

contains

public boolean contains(JBitSet jBitSet)
Test to see if one JBitSet contains another one of the same size.

Parameters:
jBitSet - JBitSet that we want to know if it is a subset of current JBitSet
Returns:
boolean Whether or not jBitSet is a subset.

hasSingleBitSet

public boolean hasSingleBitSet()
See of a JBitSet has exactly 1 bit set.

Returns:
boolean Whether or not JBitSet has a single bit set.

getFirstSetBit

public int getFirstSetBit()
Get the first set bit (starting at index 0) from a JBitSet.

Returns:
int Index of first set bit, -1 if none set.

grow

public void grow(int newSize)
Grow an existing JBitSet to the specified size.

Parameters:
newSize - The new size

clearAll

public void clearAll()
Clear all of the bits in this JBitSet


toString

public java.lang.String toString()
Overrides:
toString in class java.lang.Object

equals

public boolean equals(java.lang.Object obj)
Overrides:
equals in class java.lang.Object

hashCode

public int hashCode()
Overrides:
hashCode in class java.lang.Object

clone

public java.lang.Object clone()
Overrides:
clone in class java.lang.Object

get

public boolean get(int bitIndex)

set

public void set(int bitIndex)

clear

public void clear(int bitIndex)

and

public void and(JBitSet set)

or

public void or(JBitSet set)

xor

public void xor(JBitSet set)

size

public int size()
Return the size of bitSet

Returns:
int Size of bitSet

Built on Thu 2010-12-23 20:49:13+0000, from revision ???

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