Package bftsmart.tom.leaderchange

Class LCManager

java.lang.Object

bftsmart.tom.leaderchange.LCManager

public class LCManager
extends java.lang.Object

This class implements a manager of information related to the leader change protocol It also implements some predicates and methods necessary for the protocol in accordance to Cachin's 'Yet Another Visit to Paxos' (April 2011).

Constructor Summary

Constructors

Constructor	Description
LCManager(TOMLayer tomLayer, ServerViewController SVController, java.security.MessageDigest md)	Constructor

Method Summary

Modifier and Type	Method	Description
void	addCollect(int regency, java.security.SignedObject signedCollect)	Keep collect from an incoming SYNC message
void	addLastCID(int regency, CertifiedDecision lastCID)	Keep last CID from an incoming SYNC message
void	addRequestsFromSTOP(TOMMessage[] requestsFromSTOP)	This is meant to keep track of requests received in STOP messages
void	addStop(int regency, int pid)	Keep information about an incoming STOP message
boolean	binds(int timestamp, byte[] value, java.util.HashSet<CollectData> collects)	The predicate "binds".
boolean	certifiedValue(int timestamp, byte[] value, java.util.HashSet<CollectData> collects)	The predicate "certifiedValue".
void	clearCurrentRequestTimedOut()	Discard timed out requests in this replica
void	clearRequestsFromSTOP()	Discard requests received in STOP messages
byte[]	getBindValue(java.util.HashSet<CollectData> collects)	Return a value that is "bind", that is different from null, and with a timestamp greater or equal to zero
java.util.HashSet<java.security.SignedObject>	getCollects(int regency)	Get the set of collects related to a regency
int	getCollectsSize(int regency)	Get the quantity of stored collect information
java.util.List<TOMMessage>	getCurrentRequestTimedOut()	Get the timed out requests in this replica
int	getETS(int cid, java.util.Set<CollectData> collects)	Gets the highest ETS associated with a consensus ID from the given collects
CertifiedDecision	getHighestLastCID(int ts)	Gets the highest valid last CID related to the given timestamp
java.util.HashSet<CertifiedDecision>	getLastCIDs(int regency)	Get the set of last CIDs related to a regency
int	getLastCIDsSize(int regency)	Get the quantity of stored last CID information
byte[]	getLastCIDValue(int regency, int cid)	Returns the value of the specified last CID for a given regency
int	getLastReg()	The current regency
int	getNewLeader()	Deterministically elects a new leader, based current leader and membership
int	getNextReg()	The next regency
java.util.List<TOMMessage>	getRequestsFromSTOP()	Get the requests received in STOP messages
int	getStopsSize(int regency)	Get the quantity of stored STOP information
boolean	hasValidProof(CertifiedDecision cDec)
boolean	quorumHighest(int timestamp, byte[] value, java.util.HashSet<CollectData> collects)	The predicate "quorumHighest".
void	removeCollects(int regency)	Discard collect information up to the given regency
void	removeLastCIDs(int regency)	Discard last CID information up to the specified regency
void	removeStops(int regency)	Discard information about STOP messages up to specified regency
java.util.HashSet<CollectData>	selectCollects(int regency, int cid)	Fetchs a set of correctly signed and normalized collect data structures
java.util.HashSet<CollectData>	selectCollects(java.util.HashSet<java.security.SignedObject> signedObjects, int cid, int regency)	Fetchs a set of correctly signed and normalized collect data structures from the specified original set of collects
void	setCollects(int regency, java.util.HashSet<java.security.SignedObject> colls)	Defines the set of collects related to a regency
void	setCurrentRequestTimedOut(java.util.List<TOMMessage> currentRequestTimedOut)	This is meant to keep track of timed out requests in this replica
void	setLastCIDs(int regency, java.util.HashSet<CertifiedDecision> lasts)	Defines the set of last CIDs related to a regency
void	setLastReg(int lastreg)	Set the previous regency
void	setNewLeader(int leader)	Informs the object of who is the current leader
void	setNextReg(int nextreg)	Set the next regency
boolean	sound(java.util.HashSet<CollectData> collects)	The all-important predicate "sound".
boolean	unbound(java.util.HashSet<CollectData> collects)	The predicate "unbound".

Methods inherited from class java.lang.Object

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

Constructor Detail

LCManager

public LCManager(TOMLayer tomLayer,
                 ServerViewController SVController,
                 java.security.MessageDigest md)

Constructor

Parameters:

reconfManager - The reconfiguration manager from TOM layer

md - The message digest engine from TOM layer

Method Detail

getNewLeader

public int getNewLeader()

Deterministically elects a new leader, based current leader and membership

Returns:

The new leader

setNewLeader

public void setNewLeader(int leader)

Informs the object of who is the current leader

Parameters:

leader - The current leader

setCurrentRequestTimedOut

public void setCurrentRequestTimedOut(java.util.List<TOMMessage> currentRequestTimedOut)

This is meant to keep track of timed out requests in this replica

Parameters:

currentRequestTimedOut - Timed out requests in this replica

getCurrentRequestTimedOut

public java.util.List<TOMMessage> getCurrentRequestTimedOut()

Get the timed out requests in this replica

Returns:

timed out requests in this replica

clearCurrentRequestTimedOut

public void clearCurrentRequestTimedOut()

Discard timed out requests in this replica

addRequestsFromSTOP

public void addRequestsFromSTOP(TOMMessage[] requestsFromSTOP)

This is meant to keep track of requests received in STOP messages

Parameters:

requestsFromSTOP - Requests received in a STOP message

getRequestsFromSTOP

public java.util.List<TOMMessage> getRequestsFromSTOP()

Get the requests received in STOP messages

Returns:

requests received in STOP messages

clearRequestsFromSTOP

public void clearRequestsFromSTOP()

Discard requests received in STOP messages

setLastReg

public void setLastReg(int lastreg)

Set the previous regency

Parameters:

lastreg - current regency

getLastReg

public int getLastReg()

The current regency

Returns:

current regency

setNextReg

public void setNextReg(int nextreg)

Set the next regency

Parameters:

nextts - next regency

getNextReg

public int getNextReg()

The next regency

Returns:

next regency

addStop

public void addStop(int regency,
                    int pid)

Keep information about an incoming STOP message

Parameters:

regency - the next regency

pid - the process that sent the message

removeStops

public void removeStops(int regency)

Discard information about STOP messages up to specified regency

Parameters:

ts - timestamp up to which to discard messages

getStopsSize

public int getStopsSize(int regency)

Get the quantity of stored STOP information

Parameters:

regency - Regency to be considered

Returns:

quantity of stored STOP information for given timestamp

addLastCID

public void addLastCID(int regency,
                       CertifiedDecision lastCID)

Keep last CID from an incoming SYNC message

Parameters:

regency - the current regency

lastCID - the last CID data

removeLastCIDs

public void removeLastCIDs(int regency)

Discard last CID information up to the specified regency

Parameters:

regency - Regency up to which to discard information

getLastCIDsSize

public int getLastCIDsSize(int regency)

Get the quantity of stored last CID information

Parameters:

regency - regency to be considered

Returns:

quantity of stored last CID information for given regency

getLastCIDs

public java.util.HashSet<CertifiedDecision> getLastCIDs(int regency)

Get the set of last CIDs related to a regency

Parameters:

regency - Regency for the last CID info

Returns:

a set of last CID data

setLastCIDs

public void setLastCIDs(int regency,
                        java.util.HashSet<CertifiedDecision> lasts)

Defines the set of last CIDs related to a regency

Parameters:

regency - Regency for the last CID info

lasts - a set of last CID data

addCollect

public void addCollect(int regency,
                       java.security.SignedObject signedCollect)

Keep collect from an incoming SYNC message

Parameters:

ts - the current regency

signedCollect - the signed collect data

removeCollects

public void removeCollects(int regency)

Discard collect information up to the given regency

Parameters:

regency - Regency up to which to discard information

getCollectsSize

public int getCollectsSize(int regency)

Get the quantity of stored collect information

Parameters:

regency - Regency to be considered

Returns:

quantity of stored collect information for given regency

getCollects

public java.util.HashSet<java.security.SignedObject> getCollects(int regency)

Get the set of collects related to a regency

Parameters:

regency - Regency for collects

Returns:

a set of collect data

setCollects

public void setCollects(int regency,
                        java.util.HashSet<java.security.SignedObject> colls)

Defines the set of collects related to a regency

Parameters:

regency - Regency for the last CID info

colls - a set of collect data

sound

public boolean sound(java.util.HashSet<CollectData> collects)

The all-important predicate "sound". This method must received a set of collects that were filtered using the method selectCollects()

Parameters:

collects - the collect data to which to apply the predicate.

Returns:

See Cachin's 'Yet Another Visit to Paxos' (April 2011), page 11 In addition, see pages 252 and 253 from "Introduction to Reliable and Secure Distributed Programming"

binds

public boolean binds(int timestamp,
                     byte[] value,
                     java.util.HashSet<CollectData> collects)

The predicate "binds". This method must received a set of collects that were filtered using the method selectCollects()

Parameters:

timestamp - the timestamp to search for

value - the value to search for

collects - the collect data to which to apply the predicate.

Returns:

See Cachin's 'Yet Another Visit to Paxos' (April 2011), page 11 In addition, see pages 252 and 253 from "Introduction to Reliable and Secure Distributed Programming"

getBindValue

public byte[] getBindValue(java.util.HashSet<CollectData> collects)

Return a value that is "bind", that is different from null, and with a timestamp greater or equal to zero

Parameters:

collects - Set of collects from which to determine the value

Returns:

The bind value See Cachin's 'Yet Another Visit to Paxos' (April 2011), page 11 Also, see pages 252 and 253 from "Introduction to Reliable and Secure Distributed Programming"

unbound

public boolean unbound(java.util.HashSet<CollectData> collects)

The predicate "unbound". This method must received a set of collects that were filtered using the method selectCollects()

Parameters:

collects - the collect data to which to apply the predicate.

Returns:

See Cachin's 'Yet Another Visit to Paxos' (April 2011), page 11 In addition, see page 253 from "Introduction to Reliable and Secure Distributed Programming"

quorumHighest

public boolean quorumHighest(int timestamp,
                             byte[] value,
                             java.util.HashSet<CollectData> collects)

The predicate "quorumHighest". This method must received a set of collects that were filtered using the method selectCollects()

Parameters:

timestamp - the timestamp to search for

value - the value to search for

collects - the collect data to which to apply the predicate.

Returns:

See Cachin's 'Yet Another Visit to Paxos' (April 2011), pages 10-11 In addition, see pages 252 and 253 from "Introduction to Reliable and Secure Distributed Programming"

certifiedValue

public boolean certifiedValue(int timestamp,
                              byte[] value,
                              java.util.HashSet<CollectData> collects)

The predicate "certifiedValue". This method must received a set of collects that were filtered using the method selectCollects()

Parameters:

timestamp - the timestamp to search for

value - the value to search for

collects - the collect data to which to apply the predicate.

Returns:

See Cachin's 'Yet Another Visit to Paxos' (April 2011), page 11 In addition, see page 253 from "Introduction to Reliable and Secure Distributed Programming"

selectCollects

public java.util.HashSet<CollectData> selectCollects(int regency,
                                                     int cid)

Fetchs a set of correctly signed and normalized collect data structures

Parameters:

regency - the regency from which the collects were stored

cid - the CID to which to normalize the collects

Returns:

a set of correctly signed and normalized collect data structures

selectCollects

public java.util.HashSet<CollectData> selectCollects(java.util.HashSet<java.security.SignedObject> signedObjects,
                                                     int cid,
                                                     int regency)

Fetchs a set of correctly signed and normalized collect data structures from the specified original set of collects

Parameters:

signedObjects - original set of signed collects

cid - the CID to which to normalize the collects

Returns:

a set of correctly signed and normalized collect data structures

getHighestLastCID

public CertifiedDecision getHighestLastCID(int ts)

Gets the highest valid last CID related to the given timestamp

Parameters:

ts - the timestamp

Returns:

-1 if there is no such CID, otherwise returns the highest valid last CID

hasValidProof

public boolean hasValidProof(CertifiedDecision cDec)

getLastCIDValue

public byte[] getLastCIDValue(int regency,
                              int cid)

Returns the value of the specified last CID for a given regency

Parameters:

regency - the related regency

cid - the last CID

Returns:

null if there is no such CID or is invalid, otherwise returns the value

getETS

public int getETS(int cid,
                  java.util.Set<CollectData> collects)

Gets the highest ETS associated with a consensus ID from the given collects

Parameters:

cid - The consensus ID

collects - The collects from the other replicas

Returns:

The highest ETS