ch.epfl.dedis.byzcoin.contracts

Class ChainConfigInstance

java.lang.Object

ch.epfl.dedis.byzcoin.contracts.ChainConfigInstance

public class ChainConfigInstance
extends Object

ChainConfigInstance represents the only Configuration present in a ByzCoin ledger. This should not be used directly, as ruining your chain config might have bad consequences for the liveness of the ByzCoin ledger. Do use the corresponding methods in ByzCoinRPC.

Field Summary

Fields

Modifier and Type	Field and Description
static String	ContractId

Method Summary

Modifier and Type	Method and Description
void	evolveChainConfig(ChainConfigData newConfig, List<Signer> owners) Sends the instruction to change the Chain Config and returns immediately.
Instruction	evolveChainConfigInstruction(ChainConfigData newConfig, List<Signer> owners, int pos, int len) Creates an instruction to evolve the value in byzcoin.
void	evolveConfigAndWait(ChainConfigData newConfig, List<Signer> owners, int wait) Send the instruction to change the Chain Config and wait for it to be included.
static ChainConfigInstance	fromByzcoin(ByzCoinRPC bc) Instantiates a new ChainConfigInstance given a working byzcoin service.
static ChainConfigInstance	fromByzcoin(ByzCoinRPC bc, Proof p) Convenience function to connect to an existing ValueInstance.
ChainConfigData	getChainConfig()
InstanceId	getId()
Instance	getInstance()
void	update() Updates the value by getting the latest instance and updating it.

Methods inherited from class java.lang.Object

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

Field Detail

ContractId

public static String ContractId

Method Detail

update

public void update()
            throws CothorityCommunicationException,
                   CothorityNotFoundException

Updates the value by getting the latest instance and updating it.

Throws:

CothorityNotFoundException - if the chainConfiguration couldn't be found in ByzCoin

CothorityCommunicationException - if there was an communication error

evolveChainConfigInstruction

public Instruction evolveChainConfigInstruction(ChainConfigData newConfig,
                                                List<Signer> owners,
                                                int pos,
                                                int len)
                                         throws CothorityCryptoException

Creates an instruction to evolve the value in byzcoin. The signer must have its identity in the current darc as "invoke:update" rule.

Parameters:

newConfig - the new config to store in the ChainConfig

owners - must have its identity in the "invoke:update" rule

pos - position of the instruction in the ClientTransaction

len - total number of instructions in the ClientTransaction

Returns:

Instruction to be sent to byzcoin

Throws:

CothorityCryptoException - if there's a problem with the cryptography

evolveChainConfig

public void evolveChainConfig(ChainConfigData newConfig,
                              List<Signer> owners)
                       throws CothorityException

Sends the instruction to change the Chain Config and returns immediately.

Parameters:

newConfig - the new config to store

owners - a list of owners needed to evolve the configuration

Throws:

CothorityException - if something goes wrong

evolveConfigAndWait

public void evolveConfigAndWait(ChainConfigData newConfig,
                                List<Signer> owners,
                                int wait)
                         throws CothorityException

Send the instruction to change the Chain Config and wait for it to be included. If you udpate the roster, be sure to tell ByzCoinRPC that it has a new roster.

Parameters:

newConfig - the new config to sture

owners - a list of owners needed to evolve the configuration

wait - how many blocks to wait for inclusion of the instruction

Throws:

CothorityException - if something goes wrong

getId

public InstanceId getId()

Returns:

the id of the instance - should be the all null id.

getChainConfig

public ChainConfigData getChainConfig()

Returns:

a copy of the configuration stored in this instance

getInstance

public Instance getInstance()

Returns:

the instance used.

fromByzcoin

public static ChainConfigInstance fromByzcoin(ByzCoinRPC bc)
                                       throws CothorityNotFoundException,
                                              CothorityCommunicationException

Instantiates a new ChainConfigInstance given a working byzcoin service. As the ChainConfig is always at id 0x00, there is no need for an instanceId.

Parameters:

bc - is a running ByzCoin service

Returns:

the new ValueInstance

Throws:

CothorityNotFoundException - if the configuration is not where it is supposed to be

CothorityCommunicationException - if the communication throws an error

fromByzcoin

public static ChainConfigInstance fromByzcoin(ByzCoinRPC bc,
                                              Proof p)
                                       throws CothorityNotFoundException,
                                              CothorityCommunicationException

Convenience function to connect to an existing ValueInstance.

Parameters:

bc - a running ByzCoin service

p - the proof for the valueInstance

Returns:

the new ValueInstance

Throws:

CothorityNotFoundException - if the configuration is not where it is supposed to be

CothorityCommunicationException - if the communication throws an error