CONSENSUS: dBFT 3.0 with double speakers model

[vncoelho]

Migrated from neo-project/neo-modules#680

close #2029

dBFT 3.0 - Part I of NeoResearch's researching on consensus improvements. @igormcoelho

Part II will later involve changes in governance and decentralization, in particular, considering the ability to always have a fallback Speaker/Primary.

[vncoelho]

Built, tested and working perfect again!

Here is an alternative client for anyway interested in testing dBFT 3.0 with double speakers model
https://github.com/NeoResearch/neo-tests/blob/master/releases/neo-release-3.8.0-all-plugins-preview1-monorepo-dbft3.0.zip

[cschuchardt88]

I think you should add some kind of error TryCatch to catch if KeyNotFound or InvalidIndex on pId

[vncoelho]

Can you create a PR trying to improve that? Pointing to this branch?

[cschuchardt88]

I can, will be later though.

[vncoelho]

ping @ZhangTao1596

[cschuchardt88]

What should the value be when it errors?

[vncoelho]

Transactions is initialized here

https://github.com/neo-project/neo/blob/20d0b49cedb85c6d61b4a0db691d8e4be52ee0ed/src/Plugins/DBFTPlugin/Consensus/ConsensusContext.cs

[vncoelho]

neo/src/Plugins/DBFTPlugin/Consensus/ConsensusContext.cs

Line 303 in 20d0b49

Transactions[1] = null;

[cschuchardt88]

Lets say this method crashes cause of IndexOutOfRangeException than what?

[vncoelho]

Transactions[pID] = transactions.Length == 0 && !RequestSentOrReceived ? null : transactions.ToDictionary(p => p.Hash);

[vncoelho]

This loop here

neo/src/Plugins/DBFTPlugin/Consensus/ConsensusContext.cs

Lines 320 to 347 in 20d0b49

	for (uint pID = 0; pID <= 1; pID++)
	{
	if (ViewNumber > 0 && pID > 0) break;
	if (reader.ReadUInt32() != Block[pID].Version) throw new FormatException();
	if (reader.ReadUInt32() != Block[pID].Index) throw new InvalidOperationException();
	Block[pID].Header.Timestamp = reader.ReadUInt64();
	Block[pID].Header.Nonce = reader.ReadUInt64();
	Block[pID].Header.PrimaryIndex = reader.ReadByte();
	Block[pID].Header.NextConsensus = reader.ReadSerializable<UInt160>();
	if (Block[pID].NextConsensus.Equals(UInt160.Zero))
	Block[pID].Header.NextConsensus = null;
	TransactionHashes[pID] = reader.ReadSerializableArray<UInt256>(ushort.MaxValue);
	Transaction[] transactions = reader.ReadSerializableArray<Transaction>(ushort.MaxValue);
	PreparationPayloads[pID] = reader.ReadNullableArray<ExtensiblePayload>(neoSystem.Settings.ValidatorsCount);
	PreCommitPayloads[pID] = reader.ReadNullableArray<ExtensiblePayload>(neoSystem.Settings.ValidatorsCount);
	CommitPayloads[pID] = reader.ReadNullableArray<ExtensiblePayload>(neoSystem.Settings.ValidatorsCount);
	if (TransactionHashes[pID].Length == 0 && !RequestSentOrReceived)
	TransactionHashes[pID] = null;
	Transactions[pID] = transactions.Length == 0 && !RequestSentOrReceived ? null : transactions.ToDictionary(p => p.Hash);
	VerificationContext[pID] = new TransactionVerificationContext();
	if (Transactions[pID] != null)
	{
	foreach (Transaction tx in Transactions[pID].Values)
	VerificationContext[pID].AddTransaction(tx);
	}
	}