ch.epfl.dedis.lib.omniledger.contracts

Class ValueInstance

java.lang.Object

ch.epfl.dedis.lib.omniledger.contracts.ValueInstance

public class ValueInstance
extends Object

ValueInstance represents a simple value store on omniledger.

Constructor Summary

Constructors

Constructor and Description
ValueInstance(OmniledgerRPC ol, InstanceId id) Instantiates a new ValueInstance given a working omniledger instance and an instanceId.
ValueInstance(OmniledgerRPC ol, Proof p)

Method Summary

Modifier and Type	Method and Description
TransactionId	evolveValue(byte[] newValue, Signer owner)
void	evolveValueAndWait(byte[] newValue, Signer owner) Asks omniledger to update the value and waits until the new value has been stored in the global state.
Instruction	evolveValueInstruction(byte[] newValue, Signer owner, int pos, int len) Creates an instruction to evolve the value in omniledger.
InstanceId	getId()
Instance	getInstance()
byte[]	getValue()
void	update()

Methods inherited from class java.lang.Object

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

Constructor Detail

ValueInstance

public ValueInstance(OmniledgerRPC ol,
                     InstanceId id)
              throws CothorityException

Instantiates a new ValueInstance given a working omniledger instance and an instanceId. This instantiator will contact omniledger and try to get the current valueInstance. If the instance is not found, or is not of contractId "Value", an exception will be thrown.

Parameters:

ol - is a link to an omniledger instance that is running

id - of the value-instance to connect to

Throws:

CothorityException

ValueInstance

public ValueInstance(OmniledgerRPC ol,
                     Proof p)
              throws CothorityException

Throws:

CothorityException

Method Detail

update

public void update()
            throws CothorityException

Throws:

CothorityException

evolveValueInstruction

public Instruction evolveValueInstruction(byte[] newValue,
                                          Signer owner,
                                          int pos,
                                          int len)
                                   throws CothorityCryptoException

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

TODO: allow for evolution if the expression has more than one identity.

Parameters:

newValue - the value to replace the old value.

owner - 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 omniledger

Throws:

CothorityCryptoException

evolveValue

public TransactionId evolveValue(byte[] newValue,
                                 Signer owner)
                          throws CothorityException

Throws:

CothorityException

evolveValueAndWait

public void evolveValueAndWait(byte[] newValue,
                               Signer owner)
                        throws CothorityException

Asks omniledger to update the value and waits until the new value has been stored in the global state. TODO: check if there has been an error in the transaction!

Parameters:

newValue - the value to replace the old value.

owner - is the owner that can sign to evolve the darc

Throws:

CothorityException

getId

public InstanceId getId()

Returns:

the id of the instance

getValue

public byte[] getValue()
                throws CothorityCryptoException

Returns:

a copy of the value stored in this instance.

Throws:

CothorityCryptoException

getInstance

public Instance getInstance()

Returns:

the instance used.