ch.epfl.dedis.lib.omniledger

Class OmniledgerRPC

java.lang.Object

ch.epfl.dedis.lib.omniledger.OmniledgerRPC

public class OmniledgerRPC
extends Object

Class OmniledgerRPC interacts with the omniledger service of a conode. It can either start a new omniledger service (this needs to be secured somehow) or link to an existing omniledger instance.

OmniledgerRPC is the new skipchain service of the cothority that allows batching of transactions and simplified proofs. It is a permissioned blockchain with high throughput (100-1000 transactions) and a byzantine-tolerant consensus algorithm.

Field Summary

Fields

Modifier and Type	Field and Description
static int	currentVersion

Constructor Summary

Constructors

Constructor and Description
OmniledgerRPC(byte[] buf) Instantiates an omniledger object given the byte representation.
OmniledgerRPC(Roster r, Darc d, java.time.Duration blockInterval) This instantiates a new omniledger object by asking the cothority to set up a new omniledger.
OmniledgerRPC(Roster roster, SkipblockId skipchainId) Constructs an OmniLedgerRPC from known configuration.

Method Summary

Modifier and Type	Method and Description
boolean	checkLiveness() Verifies if the nodes representing the cothority are alive and reply to a ping.
Config	getConfig()
SkipBlock	getGenesis()
Darc	getGenesisDarc()
SkipBlock	getLatest()
Proof	getProof(InstanceId id) Gets a proof from omniledger to show that a given instance is in the global state.
Roster	getRoster()
void	sendTransaction(ClientTransaction t) Sends a transaction to omniledger, but doesn't wait for the inclusion of this transaction in a block.
void	sendTransactionAndWait(ClientTransaction t, int wait) Sends a transaction to omniledger and waits for up to 'wait' blocks for the transaction to be included in the global state.
byte[]	toBytes()
void	update() Fetches the latest configuration and genesis darc from omniledger.

Methods inherited from class java.lang.Object

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

Field Detail

currentVersion

public static final int currentVersion

See Also:

Constant Field Values

Constructor Detail

OmniledgerRPC

public OmniledgerRPC(Roster r,
                     Darc d,
                     java.time.Duration blockInterval)
              throws CothorityException

This instantiates a new omniledger object by asking the cothority to set up a new omniledger.

Parameters:

r - is the roster to be used

d - is the genesis darc

blockInterval - is the block interval between two blocks

Throws:

CothorityException

OmniledgerRPC

public OmniledgerRPC(Roster roster,
                     SkipblockId skipchainId)
              throws CothorityException

Constructs an OmniLedgerRPC from known configuration. The constructor will communicate with the service to populate other fields and perform verification.

Parameters:

roster - the roster to talk to

skipchainId - the ID of the genesis skipblock, aka skipchain ID

Throws:

CothorityException

OmniledgerRPC

public OmniledgerRPC(byte[] buf)

Instantiates an omniledger object given the byte representation. The omniledger must already have been initialized on the cothority.

Parameters:

buf - is the representation of the basic omniledger parameters, it should have a Roster and a skipchain ID.

Method Detail

sendTransaction

public void sendTransaction(ClientTransaction t)
                     throws CothorityException

Sends a transaction to omniledger, but doesn't wait for the inclusion of this transaction in a block. Once the transaction has been sent, you need to poll to verify if it has been included or not.

Parameters:

t - is the client transaction holding one or more instructions to be sent to omniledger.

Throws:

CothorityException

sendTransactionAndWait

public void sendTransactionAndWait(ClientTransaction t,
                                   int wait)
                            throws CothorityException

Sends a transaction to omniledger and waits for up to 'wait' blocks for the transaction to be included in the global state. If more than 'wait' blocks are created and the transaction is not included, an exception will be raised.

Parameters:

t - is the client transaction holding one or more instructions to be sent to omniledger.

wait - indicates the number of blocks to wait for the transaction to be included.

Throws:

CothorityException - if the transaction has not been included within 'wait' blocks.

getProof

public Proof getProof(InstanceId id)
               throws CothorityException

Gets a proof from omniledger to show that a given instance is in the global state.

Parameters:

id - is the id of the instance to be fetched

Throws:

CothorityException

update

public void update()
            throws CothorityException

Fetches the latest configuration and genesis darc from omniledger.

Throws:

CothorityException

checkLiveness

public boolean checkLiveness()
                      throws CothorityException

Verifies if the nodes representing the cothority are alive and reply to a ping.

Returns:

true if all nodes are live, false if one or more are not responding.

Throws:

CothorityException - if something failed.

toBytes

public byte[] toBytes()

Returns:

a byte representation of this omniledger object.

getConfig

public Config getConfig()

Returns:

current configuration

getGenesisDarc

public Darc getGenesisDarc()

Returns:

current genesis darc

getLatest

public SkipBlock getLatest()

Returns:

latest skipblock - might be null if omniledger has been instantiated from a buffer and didn't 'update' yet.

getGenesis

public SkipBlock getGenesis()

getRoster

public Roster getRoster()