/// <summary>
/// Creates an InvocationTransactions. Serves to invoke a contract on the blockchain.
/// It need the contract script hash, operation and operation arguments.
/// This can be used for the "mintTokens" NEP5 method for example.
/// </summary>
/// <param name="contractScriptHash"></param>
/// <param name="operation"></param>
/// <param name="args"></param>
/// <param name="outputs"></param>
/// <param name="fee"></param>
/// <param name="attributes"></param>
/// <returns></returns>
public override async Task <Transaction> CallContract(string contractScriptHash, string operation,
object[] args, IEnumerable <TransferOutput> outputs = null,
decimal fee = 0, List <TransactionAttribute> attributes = null)
{
if (string.IsNullOrEmpty(contractScriptHash))
{
throw new ArgumentNullException(nameof(contractScriptHash));
}
if (string.IsNullOrEmpty(operation))
{
throw new ArgumentNullException(nameof(operation));
}
var script = Utils.GenerateScript(contractScriptHash, operation, args);
if (attributes == null)
{
attributes = new List <TransactionAttribute>();
}
attributes.Add(new TransactionAttribute
{
Usage = TransactionAttributeUsage.Script,
Data = AddressScriptHash.ToArray()
});
var tx = new InvocationTransaction
{
Version = 1,
Script = script,
Attributes = attributes.ToArray(),
Inputs = new CoinReference[0],
Outputs = outputs == null ? new TransactionOutput[0] : outputs.Where(p => p.IsGlobalAsset).Select(p => p.ToTxOutput()).ToArray(),
Witnesses = new Witness[0]
};
var gasConsumed = await EstimateGasAsync(tx.Script.ToHexString());
tx.Gas = InvocationTransaction.GetGas(Fixed8.FromDecimal(gasConsumed));
tx = MakeTransaction(tx, AddressScriptHash, null, Fixed8.FromDecimal(fee));
var success = await SignAndSendTransaction(tx);
return(success ? tx : null);
}
public Transaction MakeTransaction(List <TransactionAttribute> attributes, IEnumerable <TransferOutput> outputs, UInt160 from = null, UInt160 change_address = null, Fixed8 fee = default(Fixed8))
{
var cOutputs = outputs.Where(p => !p.IsGlobalAsset).GroupBy(p => new
{
AssetId = (UInt160)p.AssetId,
Account = p.ScriptHash
}, (k, g) => new
{
k.AssetId,
Value = g.Aggregate(BigInteger.Zero, (x, y) => x + y.Value.Value),
k.Account
}).ToArray();
Transaction tx;
if (attributes == null)
{
attributes = new List <TransactionAttribute>();
}
if (cOutputs.Length == 0)
{
tx = new ContractTransaction();
}
else
{
UInt160[] accounts = from == null?GetAccounts().Where(p => !p.Lock && !p.WatchOnly).Select(p => p.ScriptHash).ToArray() : new[] { from };
HashSet <UInt160> sAttributes = new HashSet <UInt160>();
using (ScriptBuilder sb = new ScriptBuilder())
{
foreach (var output in cOutputs)
{
byte[] script;
using (ScriptBuilder sb2 = new ScriptBuilder())
{
foreach (UInt160 account in accounts)
{
sb2.EmitAppCall(output.AssetId, "balanceOf", account);
}
sb2.Emit(OpCode.DEPTH, OpCode.PACK);
script = sb2.ToArray();
}
ApplicationEngine engine = ApplicationEngine.Run(script);
if (engine.State.HasFlag(VMState.FAULT))
{
return(null);
}
var balances = ((IEnumerable <StackItem>)(VMArray) engine.ResultStack.Pop()).Reverse().Zip(accounts, (i, a) => new
{
Account = a,
Value = i.GetBigInteger()
}).ToArray();
BigInteger sum = balances.Aggregate(BigInteger.Zero, (x, y) => x + y.Value);
if (sum < output.Value)
{
return(null);
}
if (sum != output.Value)
{
balances = balances.OrderByDescending(p => p.Value).ToArray();
BigInteger amount = output.Value;
int i = 0;
while (balances[i].Value <= amount)
{
amount -= balances[i++].Value;
}
if (amount == BigInteger.Zero)
{
balances = balances.Take(i).ToArray();
}
else
{
balances = balances.Take(i).Concat(new[] { balances.Last(p => p.Value >= amount) }).ToArray();
}
sum = balances.Aggregate(BigInteger.Zero, (x, y) => x + y.Value);
}
sAttributes.UnionWith(balances.Select(p => p.Account));
for (int i = 0; i < balances.Length; i++)
{
BigInteger value = balances[i].Value;
if (i == 0)
{
BigInteger change = sum - output.Value;
if (change > 0)
{
value -= change;
}
}
sb.EmitAppCall(output.AssetId, "transfer", balances[i].Account, output.Account, value);
sb.Emit(OpCode.THROWIFNOT);
}
}
byte[] nonce = new byte[8];
rand.NextBytes(nonce);
sb.Emit(OpCode.RET, nonce);
tx = new InvocationTransaction
{
Version = 1,
Script = sb.ToArray()
};
}
attributes.AddRange(sAttributes.Select(p => new TransactionAttribute
{
Usage = TransactionAttributeUsage.Script,
Data = p.ToArray()
}));
}
tx.Attributes = attributes.ToArray();
tx.Inputs = new CoinReference[0];
tx.Outputs = outputs.Where(p => p.IsGlobalAsset).Select(p => p.ToTxOutput()).ToArray();
tx.Witnesses = new Witness[0];
if (tx is InvocationTransaction itx)
{
ApplicationEngine engine = ApplicationEngine.Run(itx.Script, itx);
if (engine.State.HasFlag(VMState.FAULT))
{
return(null);
}
tx = new InvocationTransaction
{
Version = itx.Version,
Script = itx.Script,
Gas = InvocationTransaction.GetGas(engine.GasConsumed),
Attributes = itx.Attributes,
Inputs = itx.Inputs,
Outputs = itx.Outputs
};
}
tx = MakeTransaction(tx, from, change_address, fee);
return(tx);
}
/// <summary>
/// 发送invoke交易
/// </summary>
/// <param name="script">合约执行脚本</param>
/// <param name="gas_consumed">手续费</param>
/// <param name="check_witness_address">见证者地址并作为输入地址，可选参数</param>
/// <returns></returns>
private JObject SendInvokeScript(JArray _params)
{
if (wallet == null || walletTimeLock.IsLocked())
{
throw new RpcException(-400, "Access denied");
}
else
{
byte[] script = _params[0].AsString().HexToBytes();
Fixed8 gas_consumed = Fixed8.Parse(_params[1].AsString());
if (gas_consumed < Fixed8.Zero)
{
throw new RpcException(-32602, "Invalid params");
}
UInt160 check_witness_address = _params.Count >= 3 ? _params[2].AsString().ToScriptHash() : null;
InvocationTransaction tx = null;
gas_consumed = InvocationTransaction.GetGas(gas_consumed);
tx = new InvocationTransaction
{
Version = 1,
Script = script,
Gas = gas_consumed
};
List <TransactionAttribute> attributes = new List <TransactionAttribute>();
byte[] timeStamp = System.Text.ASCIIEncoding.ASCII.GetBytes(DateTime.UtcNow.ToString("yyyyMMddHHmmssfff"));
byte[] nonce = new byte[8];
rand.NextBytes(nonce);
attributes.Add(
new TransactionAttribute()
{
Usage = TransactionAttributeUsage.Remark,
Data = timeStamp.Concat(nonce).ToArray()
});
if (check_witness_address != null)
{
attributes.Add(
new TransactionAttribute()
{
Usage = TransactionAttributeUsage.Script,
Data = check_witness_address.ToArray()
});
}
tx.Attributes = attributes.ToArray();
tx = wallet.MakeTransaction(tx, from: check_witness_address);
if (tx == null)
{
throw new RpcException(-300, "Insufficient funds");
}
ContractParametersContext context = new ContractParametersContext(tx);
wallet.Sign(context);
if (context.Completed)
{
tx.Witnesses = context.GetWitnesses();
if (tx.Size > Transaction.MaxTransactionSize)
{
throw new RpcException(-301, "The size of the free transaction must be less than 102400 bytes");
}
wallet.ApplyTransaction(tx);
system.LocalNode.Tell(new LocalNode.Relay {
Inventory = tx
});
return(tx.ToJson());
}
else
{
return(context.ToJson());
}
}
}
/// <summary>
/// Transfer NEP5 tokens.
/// </summary>
/// <param name="attributes"></param>
/// <param name="outputs"></param>
/// <param name="changeAddress"></param>
/// <param name="fee"></param>
/// <returns></returns>
public override async Task <Transaction> TransferNep5(List <TransactionAttribute> attributes,
IEnumerable <TransferOutput> outputs,
UInt160 changeAddress = null, decimal fee = 0)
{
InvocationTransaction tx;
var cOutputs = outputs.Where(p => !p.IsGlobalAsset).GroupBy(p => new
{
AssetId = (UInt160)p.AssetId,
Account = p.ScriptHash
}, (k, g) => new
{
k.AssetId,
Value = g.Aggregate(BigInteger.Zero, (x, y) => x + y.Value.Value),
k.Account
}).ToArray();
if (cOutputs.Length == 0)
{
return(null);
}
var nep5Balances = await TransactionBuilderHelper.GetNep5Balances(AddressScriptHash.ToAddress(), _restService);
using (ScriptBuilder sb = new ScriptBuilder())
{
foreach (var output in cOutputs)
{
var nep5Balance = nep5Balances.SingleOrDefault(x => x.AssetHash == output.AssetId.ToString().Remove(0, 2));
if (nep5Balance == null)
{
throw new WalletException($"Not enough balance of: {output.AssetId} ");
}
sb.EmitAppCall(output.AssetId, Nep5Methods.transfer.ToString(), AddressScriptHash, output.Account, output.Value);
sb.Emit(OpCode.THROWIFNOT);
}
byte[] nonce = GenerateNonce(8);
sb.Emit(OpCode.RET, nonce);
tx = new InvocationTransaction
{
Version = 1,
Script = sb.ToArray()
};
}
if (attributes == null)
{
attributes = new List <TransactionAttribute>();
}
attributes.Add(new TransactionAttribute
{
Usage = TransactionAttributeUsage.Script,
Data = AddressScriptHash.ToArray()
});
tx.Attributes = attributes.ToArray();
tx.Inputs = new CoinReference[0];
tx.Outputs = outputs.Where(p => p.IsGlobalAsset).Select(p => p.ToTxOutput()).ToArray();
tx.Witnesses = new Witness[0];
var gasConsumed = await EstimateGasAsync(tx.Script.ToHexString()); //todo add gas limit
tx.Gas = InvocationTransaction.GetGas(Fixed8.FromDecimal(gasConsumed));
tx = MakeTransaction(tx, AddressScriptHash, changeAddress, Fixed8.FromDecimal(fee));
var success = await SignAndSendTransaction(tx);
return(success ? tx : null);
}