ch.epfl.dedis.byzcoin.transaction

Class Instruction

java.lang.Object

ch.epfl.dedis.byzcoin.transaction.Instruction

public class Instruction
extends Object

An instruction is sent and executed by ByzCoin.

Constructor Summary

Constructors

Constructor and Description
Instruction(ByzCoinProto.Instruction inst) Construct Instruction from its protobuf representation.
Instruction(InstanceId instId, List<Identity> ids, List<Long> ctrs, Delete delete) Use this constructor if it is a delete instruction, i.e.
Instruction(InstanceId instId, List<Identity> ids, List<Long> ctrs, Invoke invoke) Use this constructor if it is an invoke instruction, i.e.
Instruction(InstanceId instId, List<Identity> ids, List<Long> ctrs, Spawn spawn) Use this constructor if it is a spawn instruction, i.e.

Method Summary

Modifier and Type	Method and Description
String	action() Outputs the action of the instruction, this action be the same as an action in the corresponding darc.
InstanceId	deriveId(String what) This function derives a contract ID from the instruction with the given string.
Delete	getDelete() Getter for the delete argument.
InstanceId	getInstanceId() Getter for the instance ID.
Invoke	getInvoke() Getter for the invoke argument.
List<byte[]>	getSignatures() Getter for the signatures.
List<Long>	getSignerCounters() Getter for signer counters.
List<Identity>	getSignerIdentities() Getter for signer identities.
Spawn	getSpawn() Getter for the spawn argument.
byte[]	hash() This method computes the sha256 hash of the instruction.
void	setSignatures(List<byte[]> signatures) Setter for the signatures.
void	setSignerCounters(List<Long> signerCounters) Setter for the signer counters, they must map to the signers in the signature.
void	setSignerIdentities(List<Identity> signerIdentities)
void	signWith(byte[] ctxHash, List<Signer> signers) Have a list of signers sign the instruction.
ByzCoinProto.Instruction	toProto() Converts this object to the protobuf representation.
String	toString()

Methods inherited from class java.lang.Object

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

Constructor Detail

Instruction

public Instruction(InstanceId instId,
                   List<Identity> ids,
                   List<Long> ctrs,
                   Spawn spawn)

Use this constructor if it is a spawn instruction, i.e. you want to create a new object.

Parameters:

instId - The instance ID.

ids - The identities of all the signers.

ctrs - The list of monotonically increasing counter for those that will eventually sign the instruction.

spawn - The spawn object, which contains the value and the argument.

Instruction

public Instruction(InstanceId instId,
                   List<Identity> ids,
                   List<Long> ctrs,
                   Invoke invoke)

Use this constructor if it is an invoke instruction, i.e. you want to mutate an object.

Parameters:

instId - The ID of the object, which must be unique.

ids - The identities of all the signers.

ctrs - The list of monotonically increasing counter for those that will eventually sign the instruction.

invoke - The invoke object.

Instruction

public Instruction(InstanceId instId,
                   List<Identity> ids,
                   List<Long> ctrs,
                   Delete delete)

Use this constructor if it is a delete instruction, i.e. you want to delete an object.

Parameters:

instId - The ID of the object, which must be unique.

ids - The identities of all the signers.

ctrs - The list of monotonically increasing counter for those that will eventually sign the instruction.

delete - The delete object.

Instruction

public Instruction(ByzCoinProto.Instruction inst)

Construct Instruction from its protobuf representation.

Parameters:

inst - the protobuf representation of the instruction

Method Detail

getSignerIdentities

public List<Identity> getSignerIdentities()

Getter for signer identities.

getSignerCounters

public List<Long> getSignerCounters()

Getter for signer counters.

getSignatures

public List<byte[]> getSignatures()

Getter for the signatures.

Returns:

the signatures in this instruction.

getInstanceId

public InstanceId getInstanceId()

Getter for the instance ID.

Returns:

the InstanceID

getSpawn

public Spawn getSpawn()

Getter for the spawn argument.

Returns:

the spawn-argument of the instruction - only one of spawn, invoke, and delete should be present.

getInvoke

public Invoke getInvoke()

Getter for the invoke argument.

Returns:

the invoke-argument of the instruction - only one of spawn, invoke, and delete should be present.

getDelete

public Delete getDelete()

Getter for the delete argument.

Returns:

the delete-argument of the instruction - only one of spawn, invoke, and delete should be present.

setSignerCounters

public void setSignerCounters(List<Long> signerCounters)

Setter for the signer counters, they must map to the signers in the signature.

Parameters:

signerCounters - the list of counters

setSignatures

public void setSignatures(List<byte[]> signatures)

Setter for the signatures.

Parameters:

signatures - the signatures to set

setSignerIdentities

public void setSignerIdentities(List<Identity> signerIdentities)

hash

public byte[] hash()

This method computes the sha256 hash of the instruction.

Returns:

The digest.

toProto

public ByzCoinProto.Instruction toProto()

Converts this object to the protobuf representation.

Returns:

The protobuf representation.

action

public String action()

Outputs the action of the instruction, this action be the same as an action in the corresponding darc. Otherwise this instruction may not be accepted.

Returns:

The action.

signWith

public void signWith(byte[] ctxHash,
                     List<Signer> signers)
              throws CothorityCryptoException

Have a list of signers sign the instruction. The instruction will *not* be accepted by byzcoin if it is not signed. The signature will not be valid if the instruction is modified after signing.

Parameters:

ctxHash - - the hash of all instruction in the client transaction

signers - - the list of signers.

Throws:

CothorityCryptoException - if there's a problem with the cryptography

deriveId

public InstanceId deriveId(String what)

This function derives a contract ID from the instruction with the given string. The derived instance ID if useful as a key to this instruction.

Parameters:

what - - the string that gets mixed into the derived instance ID

Returns:

the instance ID

toString

public String toString()

Overrides:

toString in class Object