org.bitcoinj.protocols.channels

Class PaymentChannelV1ServerState

java.lang.Object

org.bitcoinj.protocols.channels.PaymentChannelServerState

org.bitcoinj.protocols.channels.PaymentChannelV1ServerState

public class PaymentChannelV1ServerState
extends PaymentChannelServerState

Version 1 of the payment channel server state object. Common functionality is present in the parent class.

Nested Class Summary

Nested classes/interfaces inherited from class org.bitcoinj.protocols.channels.PaymentChannelServerState

PaymentChannelServerState.State

Field Summary

Fields

Modifier and Type	Field and Description
protected ECKey	clientKey

Fields inherited from class org.bitcoinj.protocols.channels.PaymentChannelServerState

bestValueSignature, bestValueToMe, broadcaster, contract, minExpireTime, serverKey, stateMachine, storedServerChannel

Constructor Summary

Constructors

Constructor and Description
PaymentChannelV1ServerState(TransactionBroadcaster broadcaster, Wallet wallet, ECKey serverKey, long minExpireTime) Creates a new state object to track the server side of a payment channel.

Method Summary

Modifier and Type	Method and Description
com.google.common.util.concurrent.ListenableFuture<Transaction>	close(org.bouncycastle.crypto.params.KeyParameter userKey) Closes this channel and broadcasts the highest value payment transaction on the network.
protected Script	createOutputScript()
protected ECKey	getClientKey()
TransactionOutput	getClientOutput()
Coin	getFeePaid() Gets the fee paid in the final payment transaction (only available if settle() did not throw an exception)
int	getMajorVersion()
long	getRefundTransactionUnlockTime() Gets the client's refund transaction which they can spend to get the entire channel value back if it reaches its lock time.
protected Script	getSignedScript() Gets the script that signatures should sign against.
com.google.common.collect.Multimap<PaymentChannelServerState.State,PaymentChannelServerState.State>	getStateTransitions()
byte[]	provideRefundTransaction(Transaction refundTx, byte[] clientMultiSigPubKey) Called when the client provides the refund transaction.

Methods inherited from class org.bitcoinj.protocols.channels.PaymentChannelServerState

close, getBestValueToMe, getContract, getContractScript, getExpiryTime, getState, getTotalValue, incrementPayment, makeUnsignedChannelContract, provideContract, storeChannelInWallet, updateChannelInWallet, verifyContract

Methods inherited from class java.lang.Object

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

Field Detail

clientKey

protected ECKey clientKey

Constructor Detail

PaymentChannelV1ServerState

public PaymentChannelV1ServerState(TransactionBroadcaster broadcaster,
                                   Wallet wallet,
                                   ECKey serverKey,
                                   long minExpireTime)

Creates a new state object to track the server side of a payment channel.

Parameters:

broadcaster - The peer group which we will broadcast transactions to, this should have multiple peers

wallet - The wallet which will be used to complete transactions

serverKey - The private key which we use for our part of the multi-sig contract (this MUST be fresh and CANNOT be used elsewhere)

minExpireTime - The earliest time at which the client can claim the refund transaction (UNIX timestamp of block)

Method Detail

getStateTransitions

public com.google.common.collect.Multimap<PaymentChannelServerState.State,PaymentChannelServerState.State> getStateTransitions()

Specified by:

getStateTransitions in class PaymentChannelServerState

getMajorVersion

public int getMajorVersion()

Specified by:

getMajorVersion in class PaymentChannelServerState

getClientOutput

public TransactionOutput getClientOutput()

Specified by:

getClientOutput in class PaymentChannelServerState

getSignedScript

protected Script getSignedScript()

Description copied from class: PaymentChannelServerState

Gets the script that signatures should sign against. This is never a P2SH script, rather the script that would be inside a P2SH script.

Specified by:

getSignedScript in class PaymentChannelServerState

Returns:

the script that signatures should sign against.

provideRefundTransaction

public byte[] provideRefundTransaction(Transaction refundTx,
                                       byte[] clientMultiSigPubKey)
                                throws VerificationException

Called when the client provides the refund transaction. The refund transaction must have one input from the multisig contract (that we don't have yet) and one output that the client creates to themselves. This object will later be modified when we start getting paid.

Parameters:

refundTx - The refund transaction, this object will be mutated when payment is incremented.

clientMultiSigPubKey - The client's pubkey which is required for the multisig output

Returns:

Our signature that makes the refund transaction valid

Throws:

VerificationException - If the transaction isnt valid or did not meet the requirements of a refund transaction.

createOutputScript

protected Script createOutputScript()

Specified by:

createOutputScript in class PaymentChannelServerState

getClientKey

protected ECKey getClientKey()

Specified by:

getClientKey in class PaymentChannelServerState

close

public com.google.common.util.concurrent.ListenableFuture<Transaction> close(@Nullable
                                                                             org.bouncycastle.crypto.params.KeyParameter userKey)
                                                                      throws InsufficientMoneyException

Closes this channel and broadcasts the highest value payment transaction on the network.

This will set the state to PaymentChannelServerState.State.CLOSED if the transaction is successfully broadcast on the network. If we fail to broadcast for some reason, the state is set to PaymentChannelServerState.State.ERROR.

If the current state is before PaymentChannelServerState.State.READY (ie we have not finished initializing the channel), we simply set the state to PaymentChannelServerState.State.CLOSED and let the client handle getting its refund transaction confirmed.

Specified by:

close in class PaymentChannelServerState

Parameters:

userKey - The AES key to use for decryption of the private key. If null then no decryption is required.

Returns:

a future which completes when the provided multisig contract successfully broadcasts, or throws if the broadcast fails for some reason. Note that if the network simply rejects the transaction, this future will never complete, a timeout should be used.

Throws:

InsufficientMoneyException - If the payment tx would have cost more in fees to spend than it is worth.

getFeePaid

public Coin getFeePaid()

Gets the fee paid in the final payment transaction (only available if settle() did not throw an exception)

Specified by:

getFeePaid in class PaymentChannelServerState

getRefundTransactionUnlockTime

public long getRefundTransactionUnlockTime()

Gets the client's refund transaction which they can spend to get the entire channel value back if it reaches its lock time.