/// <summary>
/// Applies an internally generated contract funds transfer message to the current state.
/// </summary>
public StateTransitionResult Apply(IState state, ContractTransferMessage message)
{
bool enoughBalance = EnsureSenderHasEnoughBalance(state, message.From, message.Amount);
if (!enoughBalance)
{
return(StateTransitionResult.Fail((Gas)0, StateTransitionErrorKind.InsufficientBalance));
}
var gasMeter = new GasMeter(message.GasLimit);
// If it's not a contract, create a regular P2PKH tx
// If it is a contract, do a regular contract call
byte[] contractCode = state.ContractState.GetCode(message.To);
if (contractCode == null || contractCode.Length == 0)
{
gasMeter.Spend((Gas)GasPriceList.TransferCost);
// No contract at this address, create a regular P2PKH xfer
state.AddInternalTransfer(new TransferInfo(message.From, message.To, message.Amount));
return(StateTransitionResult.Ok(gasMeter.GasConsumed, message.To));
}
// For internal contract-contract transfers we need to add the value contained in the contract invocation transaction
// to the internal transfer list. This must occur before we apply the message to the state.
state.AddInternalTransfer(new TransferInfo(message.From, message.To, message.Amount));
gasMeter.Spend((Gas)GasPriceList.BaseCost);
StateTransitionResult result = ApplyCall(state, message, contractCode, gasMeter);
return(result);
}
///<inheritdoc />
public ITransferResult Transfer(ISmartContractState smartContractState, Address addressTo, ulong amountToTransfer)
{
Gas gasRemaining = this.gasMeter.GasAvailable;
if (gasRemaining < GasPriceList.TransferCost)
{
return(TransferResult.Failed());
}
ulong gasBudget = (gasRemaining < DefaultGasLimit)
? gasRemaining // have enough for at least a transfer but not for the DefaultGasLimit
: DefaultGasLimit; // have enough for anything
var message = new ContractTransferMessage(
addressTo.ToUint160(),
smartContractState.Message.ContractAddress.ToUint160(),
amountToTransfer,
(Gas)gasBudget
);
// Create a snapshot of the current state
IState newState = this.state.Snapshot();
// Apply the message to the snapshot
StateTransitionResult result = this.stateProcessor.Apply(newState, message);
// Transition the current state to the new state
if (result.IsSuccess)
{
this.state.TransitionTo(newState);
}
this.gasMeter.Spend(result.GasConsumed);
return(result.IsSuccess
? TransferResult.Empty()
: TransferResult.Failed());
}