EPIC: Block Production Lottery

[nistanimirov]

Implement the block production lottery algorithm as well as the underlying required functions and Runtime calls.

• Consensus message is provided in the header of each produced block.

  • The first block of each epoch contains the following epoch’s authority list and randomness seed
  • Contains the index of an authority that has to be disabled in the current authority list
  • On config change or first block provides a change in the BABE constant (C) and the secondary slot type in the next epoch

• We’ll need a next epoch config that stores data from these messages.

• At the start of every epoch we’ll need to update the current epoch with data from the next epoch config and then update it as well.

• The block production lottery gives us 2 results:

  • The slots in the epoch that the node is chosen to produce a block (VRF output < Winning threshold for the epoch)
  • The secondary slots in the epoch that the node is chosen to produce a block (if the calculated Id (index in the list of authorities) matches the producers public session key)

• Initialize BABE constant #545

• Implement Winning threshold algorithm #546

• Implement Block-Production-Lottery algorithm #547

• Implement Secondary slots #548