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org.apache.xerces.impl.dtd.models

public Class CMStateSet

extends Object
Class Inheritance
This class is a very simple bitset class. The DFA content model code needs to support a bit set, but the java BitSet class is way, way overkill. Our bitset never needs to be expanded after creation, hash itself, etc... Since the vast majority of content models will never require more than 64 bits, and since allocation of anything in Java is expensive, this class provides a hybrid implementation that uses two ints for instances that use 64 bits or fewer. It has a byte array reference member which will only be used if more than 64 bits are required. Note that the code that uses this class will never perform operations on sets of different sizes, so that check does not have to be made here.
Version
$Id: CMStateSet.java 446752 2006-09-15 21:55:19Z mrglavas $

Field Summary

Modifier and TypeField and Description
pack-priv int
fBitCount

pack-priv int
fBits1

pack-priv int
fBits2

pack-priv byte[]
fByteArray

pack-priv int
fByteCount

Constructor Summary

AccessConstructor and Description
public
CMStateSet(int bitCount)

Method Summary

Modifier and TypeMethod and Description
public boolean
equals(Object
the reference object with which to compare.
o)

Overrides java.lang.Object.equals.

Indicates whether some other object is "equal to" this one.
public final boolean
getBit(int bitToGet)

public int
hashCode()

Overrides java.lang.Object.hashCode.

Returns a hash code value for the object.
public final void
intersection(CMStateSet setToAnd)

public final boolean
isEmpty()

pack-priv final boolean
isSameSet(CMStateSet setToCompare)

public final void
setBit(int bitToSet)

public final void
setTo(CMStateSet srcSet)

public String
toString()

Overrides java.lang.Object.toString.

Returns a string representation of the object.
public final void
union(CMStateSet setToOr)

public final void
zeroBits()

Inherited from java.lang.Object:
clonefinalizegetClassnotifynotifyAllwaitwaitwait

Field Detail

fBitCountback to summary
pack-priv int fBitCount
fBits1back to summary
pack-priv int fBits1
fBits2back to summary
pack-priv int fBits2
fByteArrayback to summary
pack-priv byte[] fByteArray
fByteCountback to summary
pack-priv int fByteCount

Constructor Detail

CMStateSetback to summary
public CMStateSet(int bitCount)

Method Detail

equalsback to summary
public boolean equals(Object o)

Overrides java.lang.Object.equals.

Doc from java.lang.Object.equals.

Indicates whether some other object is "equal to" this one.

The equals method implements an equivalence relation on non-null object references:

  • It is reflexive: for any non-null reference value x, x.equals(x) should return true.
  • It is symmetric: for any non-null reference values x and y, x.equals(y) should return true if and only if y.equals(x) returns true.
  • It is transitive: for any non-null reference values x, y, and z, if x.equals(y) returns true and y.equals(z) returns true, then x.equals(z) should return true.
  • It is consistent: for any non-null reference values x and y, multiple invocations of x.equals(y) consistently return true or consistently return false, provided no information used in equals comparisons on the objects is modified.
  • For any non-null reference value x, x.equals(null) should return false.

An equivalence relation partitions the elements it operates on into equivalence classes; all the members of an equivalence class are equal to each other. Members of an equivalence class are substitutable for each other, at least for some purposes.

Parameters
o:Object

the reference object with which to compare.

Returns:boolean

true if this object is the same as the obj argument; false otherwise.

getBitback to summary
public final boolean getBit(int bitToGet)
hashCodeback to summary
public int hashCode()

Overrides java.lang.Object.hashCode.

Doc from java.lang.Object.hashCode.

Returns a hash code value for the object. This method is supported for the benefit of hash tables such as those provided by java.util.HashMap.

The general contract of hashCode is:

  • Whenever it is invoked on the same object more than once during an execution of a Java application, the hashCode method must consistently return the same integer, provided no information used in equals comparisons on the object is modified. This integer need not remain consistent from one execution of an application to another execution of the same application.
  • If two objects are equal according to the equals method, then calling the hashCode method on each of the two objects must produce the same integer result.
  • It is not required that if two objects are unequal according to the equals method, then calling the hashCode method on each of the two objects must produce distinct integer results. However, the programmer should be aware that producing distinct integer results for unequal objects may improve the performance of hash tables.
Returns:int

a hash code value for this object.

intersectionback to summary
public final void intersection(CMStateSet setToAnd)
isEmptyback to summary
public final boolean isEmpty()
isSameSetback to summary
pack-priv final boolean isSameSet(CMStateSet setToCompare)
setBitback to summary
public final void setBit(int bitToSet)
setToback to summary
public final void setTo(CMStateSet srcSet)
toStringback to summary
public String toString()

Overrides java.lang.Object.toString.

Doc from java.lang.Object.toString.

Returns a string representation of the object.

Returns:String

a string representation of the object.

unionback to summary
public final void union(CMStateSet setToOr)
zeroBitsback to summary
public final void zeroBits()