Lots of big changes in this commit:
* Introduction of "network map" and "legally identifiable node" concepts to the networking abstraction.
* State machines framework now lets you send messages to multiple different destinations in the same protocol.
* Timestamping service that can run inside a node is now implemented and unit tested.
* Starting to benefit from the improvements in Quasar (the initialArgs concept can mostly be got rid of now, etc)
Quasar is a more modern, better maintained and more powerful framework. The main improvement is that this lets us avoid the ClassLoader tricks that JavaFlow was requiring, by using an agent. This introduces a requirement to mark methods that might be on a suspended stack as @Suspendable, but means that code interops cleanly. In Java 9 it is hoped that the marking requirement may even go away entirely.
As a result, TimestampedWireTransaction is gone. Timestamp fields are gone. Timestamp commands contain before/after fields. The notion of time tolerance is now a part of the timestamping interface and timestamp data.
TODO:
- Unit tests to verify the notBefore/notAfter logic
- Documentation update
1. Rename Command -> CommandData, WireCommand -> Command, PartialTransaction.addArg -> addCommand
2. Add some helper functions to PartialTransaction to make creation of transactions simpler.
- Now supports simulated restart of nodes
- Messages sent to non-running nodes are queued for delivery
- Messages received by a node that don't match any topics are queued until handlers are registered
These improvements help us unit test various robustness features and ensure things work in truly concurrent context where there can be race conditions like receiving a message before the node had a chance to register the right handlers.
This is/was an attempt to be secure against malicious streams, but as Kryo is just a temporary bit of scaffolding and isn't intended to be actually used in any real product, it was just a waste of time and the registration requirement was getting increasingly awkward.
- Use the OpaqueBytes wrapper (a box for byte[]) inside TimestampedWireTransaction to avoid array comparison issues.
- Introduce a few utility functions to make OpaqueBytes less painful.
- Make StateAndRef serialisable
- Introduce the notion of an OwnedState which abstracts out the owner field.
