protected NativeContract()
{
using (ScriptBuilder sb = new ScriptBuilder())
{
sb.EmitPush(Name);
sb.EmitSysCall(ApplicationEngine.Neo_Native_Call);
this.Script = sb.ToArray();
}
this.Hash = Script.ToScriptHash();
List <ContractMethodDescriptor> descriptors = new List <ContractMethodDescriptor>();
List <string> safeMethods = new List <string>();
foreach (MemberInfo member in GetType().GetMembers(BindingFlags.Instance | BindingFlags.NonPublic | BindingFlags.Public))
{
ContractMethodAttribute attribute = member.GetCustomAttribute <ContractMethodAttribute>();
if (attribute is null)
{
continue;
}
ContractMethodMetadata metadata = new ContractMethodMetadata(member, attribute);
descriptors.Add(new ContractMethodDescriptor
{
Name = metadata.Name,
ReturnType = ToParameterType(metadata.Handler.ReturnType),
Parameters = metadata.Parameters.Select(p => new ContractParameterDefinition {
Type = ToParameterType(p.Type), Name = p.Name
}).ToArray()
});
if (!attribute.RequiredCallFlags.HasFlag(CallFlags.AllowModifyStates))
{
safeMethods.Add(metadata.Name);
}
methods.Add(metadata.Name, metadata);
}
this.Manifest = new ContractManifest
{
Groups = System.Array.Empty <ContractGroup>(),
Features = ContractFeatures.NoProperty,
SupportedStandards = new string[0],
Abi = new ContractAbi()
{
Hash = Hash,
Events = System.Array.Empty <ContractEventDescriptor>(),
Methods = descriptors.ToArray()
},
Permissions = new[] { ContractPermission.DefaultPermission },
Trusts = WildcardContainer <UInt160> .Create(),
SafeMethods = WildcardContainer <string> .Create(safeMethods.ToArray()),
Extra = null
};
contractsList.Add(this);
contractsNameDictionary.Add(Name, this);
contractsHashDictionary.Add(Hash, this);
}
internal async void Invoke(ApplicationEngine engine, byte version)
{
try
{
if (version != 0)
{
throw new InvalidOperationException($"The native contract of version {version} is not active.");
}
ExecutionContext context = engine.CurrentContext;
ContractMethodMetadata method = methods[context.InstructionPointer];
ExecutionContextState state = context.GetState <ExecutionContextState>();
if (!state.CallFlags.HasFlag(method.RequiredCallFlags))
{
throw new InvalidOperationException($"Cannot call this method with the flag {state.CallFlags}.");
}
engine.AddGas(method.CpuFee * Policy.GetExecFeeFactor(engine.Snapshot) + method.StorageFee * Policy.GetStoragePrice(engine.Snapshot));
List <object> parameters = new List <object>();
if (method.NeedApplicationEngine)
{
parameters.Add(engine);
}
if (method.NeedSnapshot)
{
parameters.Add(engine.Snapshot);
}
for (int i = 0; i < method.Parameters.Length; i++)
{
parameters.Add(engine.Convert(context.EvaluationStack.Pop(), method.Parameters[i]));
}
object returnValue = method.Handler.Invoke(this, parameters.ToArray());
if (returnValue is ContractTask task)
{
await task;
returnValue = task.GetResult();
}
if (method.Handler.ReturnType != typeof(void) && method.Handler.ReturnType != typeof(ContractTask))
{
context.EvaluationStack.Push(engine.Convert(returnValue));
}
}
catch (Exception ex)
{
engine.Throw(ex);
}
}
internal void Invoke(ApplicationEngine engine, byte version)
{
if (ActiveBlockIndex > Ledger.CurrentIndex(engine.Snapshot))
{
throw new InvalidOperationException($"The native contract {Name} is not active.");
}
if (version != 0)
{
throw new InvalidOperationException($"The native contract of version {version} is not active.");
}
ExecutionContext context = engine.CurrentContext;
ContractMethodMetadata method = methods[context.InstructionPointer];
ExecutionContextState state = context.GetState <ExecutionContextState>();
if (!state.CallFlags.HasFlag(method.RequiredCallFlags))
{
throw new InvalidOperationException($"Cannot call this method with the flag {state.CallFlags}.");
}
engine.AddGas(method.Price);
List <object> parameters = new List <object>();
if (method.NeedApplicationEngine)
{
parameters.Add(engine);
}
if (method.NeedSnapshot)
{
parameters.Add(engine.Snapshot);
}
for (int i = 0; i < method.Parameters.Length; i++)
{
parameters.Add(engine.Convert(context.EvaluationStack.Pop(), method.Parameters[i]));
}
object returnValue = method.Handler.Invoke(this, parameters.ToArray());
if (method.Handler.ReturnType != typeof(void))
{
context.EvaluationStack.Push(engine.Convert(returnValue));
}
}
internal void Invoke(ApplicationEngine engine)
{
if (!engine.CurrentScriptHash.Equals(Hash))
{
throw new InvalidOperationException("It is not allowed to use Neo.Native.Call directly to call native contracts. System.Contract.Call should be used.");
}
ExecutionContext context = engine.CurrentContext;
string operation = context.EvaluationStack.Pop().GetString();
Array args = context.EvaluationStack.Pop <Array>();
ContractMethodMetadata method = methods[operation];
ExecutionContextState state = context.GetState <ExecutionContextState>();
if (!state.CallFlags.HasFlag(method.RequiredCallFlags))
{
throw new InvalidOperationException($"Cannot call this method with the flag {state.CallFlags}.");
}
engine.AddGas(method.Price);
List <object> parameters = new List <object>();
if (method.NeedApplicationEngine)
{
parameters.Add(engine);
}
if (method.NeedSnapshot)
{
parameters.Add(engine.Snapshot);
}
for (int i = 0; i < method.Parameters.Length; i++)
{
StackItem item = i < args.Count ? args[i] : StackItem.Null;
parameters.Add(engine.Convert(item, method.Parameters[i]));
}
object returnValue = method.Handler.Invoke(this, parameters.ToArray());
if (method.Handler.ReturnType != typeof(void))
{
context.EvaluationStack.Push(engine.Convert(returnValue));
}
}
protected NativeContract()
{
this.Id = --id_counter;
byte[] script;
using (ScriptBuilder sb = new ScriptBuilder())
{
sb.EmitPush(Id);
sb.EmitSysCall(ApplicationEngine.System_Contract_CallNative);
script = sb.ToArray();
}
this.Nef = new NefFile
{
Compiler = nameof(ScriptBuilder),
Version = "3.0",
Tokens = System.Array.Empty <MethodToken>(),
Script = script
};
this.Nef.CheckSum = NefFile.ComputeChecksum(Nef);
this.Hash = Helper.GetContractHash(UInt160.Zero, script);
List <ContractMethodDescriptor> descriptors = new List <ContractMethodDescriptor>();
foreach (MemberInfo member in GetType().GetMembers(BindingFlags.Instance | BindingFlags.NonPublic | BindingFlags.Public))
{
ContractMethodAttribute attribute = member.GetCustomAttribute <ContractMethodAttribute>();
if (attribute is null)
{
continue;
}
ContractMethodMetadata metadata = new ContractMethodMetadata(member, attribute);
descriptors.Add(new ContractMethodDescriptor
{
Name = metadata.Name,
ReturnType = ToParameterType(metadata.Handler.ReturnType),
Parameters = metadata.Parameters.Select(p => new ContractParameterDefinition {
Type = ToParameterType(p.Type), Name = p.Name
}).ToArray(),
Safe = (attribute.RequiredCallFlags & ~CallFlags.ReadOnly) == 0
});
methods.Add(metadata.Name, metadata);
}
this.Manifest = new ContractManifest
{
Name = Name,
Groups = System.Array.Empty <ContractGroup>(),
SupportedStandards = new string[0],
Abi = new ContractAbi()
{
Events = System.Array.Empty <ContractEventDescriptor>(),
Methods = descriptors.ToArray()
},
Permissions = new[] { ContractPermission.DefaultPermission },
Trusts = WildcardContainer <UInt160> .Create(),
Extra = null
};
if (ProtocolSettings.Default.NativeActivations.TryGetValue(Name, out uint activationIndex))
{
this.ActiveBlockIndex = activationIndex;
}
contractsList.Add(this);
contractsIdDictionary.Add(Id, this);
contractsHashDictionary.Add(Hash, this);
}