Cardano Updates

With the currently selected generation sizes, we hit the different
voting rules in a somewhat decent proportion, even against randomly
generated functions as part of the PerasVotingView interface.

ouroboros-consensus
  Peras
    Peras voting rules
      isPerasVotingAllowed: OK (1.55s)
        +++ OK, passed 10000 tests.

        Actual result (10000 in total):
        60.29% NoVoteReason(VR-1A or VR-2A)
        20.90% NoVoteReason(VR-1A or VR-2B)
         9.60% VoteReason(VR-2A and VR-2B)
         4.93% VoteReason(VR-1A and VR-1B)
         2.67% NoVoteReason(VR-1B or VR-2A)
         1.61% NoVoteReason(VR-1B or VR-2B)

        Should vote according to model (10000 in total):
        85.47% False
        14.53% True

        VR-(1A|1B|2A|2B) (10000 in total):
        21.30% (False,True,False,False)
        21.24% (False,False,False,False)
        10.63% (False,False,True,False)
        10.27% (False,True,True,False)
         8.99% (False,False,False,True)
         8.76% (False,True,False,True)
         4.67% (False,True,True,True)
         4.26% (False,False,True,True)
         1.93% (True,False,False,False)
         1.77% (True,True,False,False)
         1.71% (True,True,True,False)
         1.61% (True,False,True,False)
         0.75% (True,True,True,True)
         0.74% (True,False,False,True)
         0.70% (True,True,False,True)
         0.67% (True,False,True,True)

        VR-1A (10000 in total):
        90.12% False
         9.88% True

        VR-1B (10000 in total):
        50.07% False
        49.93% True

        VR-2A (10000 in total):
        65.43% False
        34.57% True

        VR-2B (10000 in total):
        70.46% False
        29.54% True

Co-authored-by: Agustin Mista <[email protected]>
Co-authored-by: Alexander Esgen <[email protected]>
Co-authored-by: Georgy Lukyanov <[email protected]>
Co-authored-by: Thomas BAGREL <[email protected]>
Co-authored-by: Nicolas BACQUEY <[email protected]>

This commit introduces a couple of new types to represent Peras votes
and their corresponding certificate forging API. Notably, this requires
an initial representation of notions like vote targets, vote stakes and stake
distributions over multiple stake pools.

Co-authored-by: Agustin Mista <[email protected]>
Co-authored-by: Alexander Esgen <[email protected]>
Co-authored-by: Georgy Lukyanov <[email protected]>
Co-authored-by: Thomas BAGREL <[email protected]>
Co-authored-by: Nicolas BACQUEY <[email protected]>

This commit simplifies the interface of the HasPerasCertX typeclasses,
removing the StandardHash superclass constraint, and splitting them into
several smaller typeclasses.

Co-authored-by: Agustin Mista <[email protected]>
Co-authored-by: Alexander Esgen <[email protected]>
Co-authored-by: Georgy Lukyanov <[email protected]>
Co-authored-by: Thomas BAGREL <[email protected]>
Co-authored-by: Nicolas BACQUEY <[email protected]>

This commits introduces the module:

Ouroboros.Consensus.Peras.Params

To consolidate all the protocol parameters related to Peras in one
place. Until we defined concrete BlockSupportsPeras for the different
block types + HFC, all blocks satisfy:

type PerasCfg blk = PerasParams

Co-authored-by: Agustin Mista <[email protected]>
Co-authored-by: Alexander Esgen <[email protected]>
Co-authored-by: Georgy Lukyanov <[email protected]>
Co-authored-by: Thomas BAGREL <[email protected]>
Co-authored-by: Nicolas BACQUEY <[email protected]>

This commit adds a method to the PerasCertDB API to retrieve the latest
certificate seen. This is certificate needed to implement the Peras voting
and must be kept around even after garbage collection. Because of this,
we extend the internal state of the PerasCertDB to store this special
certificate on the side, and (potentially) update it after new
certificates are added to the database.

Co-authored-by: Agustin Mista <[email protected]>
Co-authored-by: Alexander Esgen <[email protected]>
Co-authored-by: Georgy Lukyanov <[email protected]>
Co-authored-by: Thomas BAGREL <[email protected]>
Co-authored-by: Nicolas BACQUEY <[email protected]>

This commit defines a generic WithArrivalTime combinator to wrap a value
with its arrival time (as a Relative time). This is needed by Peras in
several places, e.g., to evaluate the voting rules.

Notably, we store a raw Relative time instead of a (arguably more apt)
SlotNo or PerasRoundNo to defer as much as possible having to deal with
the case where making this translation (timestamp -> slot/round) is not
possible due to the HFC time translation horizon. Instead, the client
will need to perform this translation in a context where such a failure
cannot occur or can be more easily dealt with.

Co-authored-by: Agustin Mista <[email protected]>
Co-authored-by: Alexander Esgen <[email protected]>
Co-authored-by: Georgy Lukyanov <[email protected]>
Co-authored-by: Thomas BAGREL <[email protected]>
Co-authored-by: Nicolas BACQUEY <[email protected]>

This commit wraps the existing ValidatedPerasCerts stored in the
PerasCertDB with their corresponding arrival time. In addition, it
adapts tests to use either a randomly generated arrival time, or (when
appropriate) one generated by a monotonically increasing SystemTime.

Co-authored-by: Agustin Mista <[email protected]>
Co-authored-by: Alexander Esgen <[email protected]>
Co-authored-by: Georgy Lukyanov <[email protected]>
Co-authored-by: Thomas BAGREL <[email protected]>
Co-authored-by: Nicolas BACQUEY <[email protected]>

This commit adds a small helper to compute over Peras round numbers.
Will be needed later on to implement the Peras voting rules.

Co-authored-by: Agustin Mista <[email protected]>
Co-authored-by: Alexander Esgen <[email protected]>
Co-authored-by: Georgy Lukyanov <[email protected]>
Co-authored-by: Thomas BAGREL <[email protected]>
Co-authored-by: Nicolas BACQUEY <[email protected]>

Co-authored-by: Agustin Mista <[email protected]>
Co-authored-by: Alexander Esgen <[email protected]>
Co-authored-by: Georgy Lukyanov <[email protected]>
Co-authored-by: Thomas BAGREL <[email protected]>
Co-authored-by: Nicolas BACQUEY <[email protected]>