A utility class that implements a number list that keeps track of which tokens have arrived by storing their token numbers in the list. It helps detect old tokens, out of sequence tokens, and duplicate tokens. Each element of the list is an interval [a, b]. Its existence in the list implies that all token numbers in the range a, a+1, ..., b-1, b have arrived. Gaps in arrived token numbers are represented by the numbers that fall in between two elements of the list. e.g. {[a,b], [c,d]} indicates that the token numbers b+1, ..., c-1 have not arrived yet. The maximum number of intervals that we keep track of is MAX_INTERVALS. Thus, if there are too many gaps, then some older sequence numbers are deleted from the list. The earliest sequence number that exists in the list is the windowStart. The next expected sequence number, or expectedNumber, is one greater than the latest sequence number in the list. The list keeps track the first token number that should have arrived (initNumber) so that it is able to detect if certain numbers occur after the first valid token number but before windowStart. That would happen if the number of elements (intervals) exceeds MAX_INTERVALS and some initial elements had to be deleted. The working of the list is optimized for the normal case where the tokens arrive in sequence.

Nested and Inner Type Summary

Modifier and Type	Class and Description
pack-priv static class	TokenTracker.Entry An entry in the list that represents the sequence of received tokens.

Field Summary

Modifier and Type	Field and Description
private int	expectedNumber
private final int	initNumber
private final LinkedList<TokenTracker.Entry>	list
pack-priv static final int	MAX_INTERVALS
private int	windowStart
private int	windowStartIndex

Access	Constructor and Description
public	TokenTracker(int initNumber)

Method Summary

Modifier and Type	Method and Description
private void	add(int number, int prevEntryPos) Adds the number to the list just after the entry that is currently at position prevEntryPos.
private int	getIntervalIndex(int number) Returns the index for the entry into which this number will fit.
public final synchronized void	getProps(int number, MessageProp prop) Sets the sequencing and replay information for the given token number.
public String	toString() Overrides java.lang.Object.toString. Returns a string representation of the object.

Inherited from java.lang.Object:: clone equals finalize getClass hashCode notify notifyAll wait wait wait

Field Detail

expectedNumber	back to summary
private int expectedNumber

initNumber	back to summary
private final int initNumber

list	back to summary
private final LinkedList<TokenTracker.Entry> list

MAX_INTERVALS	back to summary
pack-priv static final int MAX_INTERVALS

windowStart	back to summary
private int windowStart

windowStartIndex	back to summary
private int windowStartIndex

TokenTracker	back to summary
public TokenTracker(int initNumber)

Method Detail

add	back to summary
private void add(int number, int prevEntryPos) Adds the number to the list just after the entry that is currently at position prevEntryPos. If prevEntryPos is -1, then the number will begin a new interval at the front of the list.

getIntervalIndex	back to summary
private int getIntervalIndex(int number) Returns the index for the entry into which this number will fit. If there is none, it returns the index of the last interval which precedes this number. It returns -1 if the number needs to be a in a new interval ahead of the whole list.

getProps	back to summary
public final synchronized void getProps(int number, MessageProp prop) Sets the sequencing and replay information for the given token number. The following represents the number line with positions of initNumber, windowStart, expectedNumber marked on it. Regions in between them show the different sequencing and replay state possibilities for tokens that fall in there. (1) windowStart initNumber expectedNumber \| \| ---\|---------------------------\|--- GAP \| DUP/UNSEQ \| GAP (2) initNumber windowStart expectedNumber \| \| \| ---\|---------------\|--------------\|--- GAP \| OLD \| DUP/UNSEQ \| GAP (3) windowStart expectedNumber initNumber \| \| ---\|---------------------------\|--- DUP/UNSEQ \| GAP \| DUP/UNSEQ (4) expectedNumber initNumber windowStart \| \| \| ---\|---------------\|--------------\|--- DUP/UNSEQ \| GAP \| OLD \| DUP/UNSEQ (5) windowStart expectedNumber initNumber \| \| \| ---\|---------------\|--------------\|--- OLD \| DUP/UNSEQ \| GAP \| OLD (This analysis leaves out the possibility that expectedNumber passes initNumber after wrapping around. That may be added later.)

getProps

back to summary

public final synchronized void getProps(int number, MessageProp prop)

Sets the sequencing and replay information for the given token number. The following represents the number line with positions of initNumber, windowStart, expectedNumber marked on it. Regions in between them show the different sequencing and replay state possibilities for tokens that fall in there. (1) windowStart initNumber expectedNumber | | ---|---------------------------|--- GAP | DUP/UNSEQ | GAP (2) initNumber windowStart expectedNumber | | | ---|---------------|--------------|--- GAP | OLD | DUP/UNSEQ | GAP (3) windowStart expectedNumber initNumber | | ---|---------------------------|--- DUP/UNSEQ | GAP | DUP/UNSEQ (4) expectedNumber initNumber windowStart | | | ---|---------------|--------------|--- DUP/UNSEQ | GAP | OLD | DUP/UNSEQ (5) windowStart expectedNumber initNumber | | | ---|---------------|--------------|--- OLD | DUP/UNSEQ | GAP | OLD (This analysis leaves out the possibility that expectedNumber passes initNumber after wrapping around. That may be added later.)

toString back to summary

toString	back to summary
public String toString() Overrides java.lang.Object.toString. Doc from java.lang.Object.toString. Returns a string representation of the object. Satisfying this method's contract implies a non-`null` result must be returned.

public String toString()

Overrides java.lang.Object.toString.

Doc from java.lang.Object.toString.

Returns a string representation of the object. Satisfying this method's contract implies a non-null result must be returned.

sun.security.jgss back to summary

pack-priv Class TokenTracker.Entry

Class Inheritance

extends Object

java.lang.Object
sun.security.jgss.TokenTracker.Entry

An entry in the list that represents the sequence of received tokens. Each entry is actually an interval of numbers, all of which have been received.

Field Summary

Modifier and Type	Field and Description
private int	end
private int	start

Constructor Summary

Access	Constructor and Description
pack-priv	Entry(int number)

Method Summary

Modifier and Type	Method and Description
pack-priv final void	append(int number)
pack-priv final int	compareTo(int number) Returns -1 if this interval represented by this entry precedes the number, 0 if the number is contained in the interval, and -1 if the interval occurs after the number.
pack-priv final boolean	contains(int number)
pack-priv final int	getEnd()
pack-priv final int	getStart()
pack-priv final void	setEnd(int end)
pack-priv final void	setInterval(int start, int end)
pack-priv final void	setStart(int start)
public String	toString() Overrides java.lang.Object.toString. Returns a string representation of the object.

Inherited from java.lang.Object:: clone equals finalize getClass hashCode notify notifyAll wait wait wait

Field Detail

end	back to summary
private int end

start	back to summary
private int start

Constructor Detail

Entry	back to summary
pack-priv Entry(int number)

Method Detail

append	back to summary
pack-priv final void append(int number)

compareTo	back to summary
pack-priv final int compareTo(int number) Returns -1 if this interval represented by this entry precedes the number, 0 if the number is contained in the interval, and -1 if the interval occurs after the number.

contains	back to summary
pack-priv final boolean contains(int number)

getEnd	back to summary
pack-priv final int getEnd()

getStart	back to summary
pack-priv final int getStart()

setEnd	back to summary
pack-priv final void setEnd(int end)

setInterval	back to summary
pack-priv final void setInterval(int start, int end)

setStart	back to summary
pack-priv final void setStart(int start)

toString back to summary

toString	back to summary
public String toString() Overrides java.lang.Object.toString. Doc from java.lang.Object.toString. Returns a string representation of the object. Satisfying this method's contract implies a non-`null` result must be returned.

public String toString()

Overrides java.lang.Object.toString.

Doc from java.lang.Object.toString.

Returns a string representation of the object. Satisfying this method's contract implies a non-null result must be returned.

public Class TokenTracker

Nested and Inner Type Summary

Field Summary

Constructor Summary

Method Summary

Field Detail

Constructor Detail

Method Detail

pack-priv Class TokenTracker.Entry

Field Summary

Constructor Summary

Method Summary

Field Detail

Constructor Detail

Method Detail