public async Task <ByteString> PostTransaction(ByteString rawMutation, IReadOnlyList <SignatureEvidence> authentication)
{
Mutation mutation;
try
{
// Verify that the mutation can be deserialized
mutation = MessageSerializer.DeserializeMutation(rawMutation);
}
catch (InvalidProtocolBufferException)
{
throw new TransactionInvalidException("InvalidMutation");
}
ParsedMutation parsedMutation = ParsedMutation.Parse(mutation);
IReadOnlyDictionary <AccountKey, AccountStatus> accounts = await ValidateMutation(mutation, parsedMutation);
ValidateAuthentication(authentication, MessageSerializer.ComputeHash(rawMutation.ToByteArray()));
DateTime date = DateTime.UtcNow;
IList <Mutation> generatedMutations = await this.validator.Validate(parsedMutation, authentication, accounts);
TransactionMetadata metadata = new TransactionMetadata(authentication);
byte[] rawMetadata = SerializeMetadata(metadata);
Transaction transaction = new Transaction(rawMutation, date, new ByteString(rawMetadata));
byte[] serializedTransaction = MessageSerializer.SerializeTransaction(transaction);
List <ByteString> transactions = new List <ByteString>()
{
new ByteString(serializedTransaction)
};
transactions.AddRange(await Task.WhenAll(generatedMutations.Select(async generatedMutation =>
{
await ValidateMutation(generatedMutation, ParsedMutation.Parse(generatedMutation));
Transaction generatedTransaction = new Transaction(new ByteString(MessageSerializer.SerializeMutation(generatedMutation)), date, ByteString.Empty);
return(new ByteString(MessageSerializer.SerializeTransaction(generatedTransaction)));
})));
try
{
await this.store.AddTransactions(transactions);
}
catch (ConcurrentMutationException)
{
throw new TransactionInvalidException("OptimisticConcurrency");
}
return(new ByteString(MessageSerializer.ComputeHash(serializedTransaction)));
}
private async Task <IReadOnlyDictionary <AccountKey, AccountStatus> > ValidateMutation(Mutation mutation, ParsedMutation parsedMutation)
{
if (!mutation.Namespace.Equals(this.Namespace))
{
throw new TransactionInvalidException("InvalidNamespace");
}
if (mutation.Records.Count == 0)
{
throw new TransactionInvalidException("InvalidMutation");
}
if (mutation.Records.Any(record => record.Key.Value.Count > MaxKeySize))
{
throw new TransactionInvalidException("InvalidMutation");
}
// All assets must have an overall zero balance
IReadOnlyDictionary <AccountKey, AccountStatus> accounts =
await this.store.GetAccounts(parsedMutation.AccountMutations.Select(entry => entry.AccountKey));
var groups = parsedMutation.AccountMutations
.GroupBy(account => account.AccountKey.Asset.FullPath)
.Select(group => group.Sum(entry => entry.Balance - accounts[entry.AccountKey].Balance));
if (groups.Any(group => group != 0))
{
throw new TransactionInvalidException("UnbalancedTransaction");
}
return(accounts);
}
