refactor: consensus peer gossip mechanism

[shotonoff]

Issue being fixed or feature implemented

The gossip logic implemented as a part of the consensus reactor, that isn't easy to read, support and understand.
The objective of this refactoring is to decouple gossip logic from the consensus reactor into separate components, to address implementation flaws (mentioned above) and more detailed coverage of the gossip protocol.

What was done?

1. Decouple gossip handlers from the consensus reactor into 3 handler functions

• queryMaj23GossipHandler
• votesAndCommitGossipHandler
• dataGossipHandler

These handlers are responsible for checking the conditions for gossip of a particular data type, similar to the initial implementation of the protocol.

If the condition is satisfied then a handler calls one of the method of Gossiper interface

The idea of this refactoring is to separate the hander logic and the logic of creation and sending data to a peer. It allows us to cover with a test of each use case.

2. Each handler (mentioned above) must be registered with peerGossipWorker, similar to adding http handler to builtin web server. This component is responsible for starting all registered handlers and can gracefully stop them.

3. For the sending message is responsible for p2pMsgSender. Instead of using certain p2p channel, this component has all possible p2p channels (channelBundle) and route the message when we send it to a peer

4. Added a new GO dependency github.com/benbjohnson/clock.
   This package helps to mock time using a mock of clock.Clock interface

How Has This Been Tested?

Added a new unit tests for

1. msgGossiper is the implementation of Gossiper interface

• TestGossipVoteSetMaj23 is the test for msgGossiper.GossipVoteSetMaj23
• TestGossipProposalBlockParts is the test for msgGossiper.GossipProposalBlockParts
• TestGossipProposal is the test for msgGossiper.GossipProposal

not covered methods yet:

• msgGossiper.GossipBlockPartsAndCommitForCatchup
• msgGossiper.GossipCommit
• msgGossiper.GossipVote

2. peerGossipWorker is fully covered
3. p2pMsgSender is fully covered
4. gossip handlers:

• queryMaj23GossipHandler is covered

not covered handlers yet:

• votesAndCommitGossipHandler
• dataGossipHandler

Breaking Changes

The gossip protocol in almost not modified (removed only redundant sleep calls)

Checklist:

• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have added or updated relevant unit/integration/functional/e2e tests
• I have made corresponding changes to the documentation

For repository code-owners and collaborators only

• I have assigned this pull request to a milestone

[github-actions]

This pull request has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[lklimek]

Reviewed. I didn't check the logic in details, assuming it's ported correctly.

[shotonoff]

please have a look at the applied changes

[shotonoff]

As requested in the comments, peerGossipWorker implements service.Service interface

[lklimek]

I don't see any assertions here. Please fix or add a comment explaining expected result.

[shotonoff]

since the method doesn't return a value that we can check on correctness, the assertions/expectations are defined in mockFn as mocking methods.

[lklimek]

I don't see any assertions here. Please fix or add a comment explaining expected result.

[shotonoff]

answered