[WIP] Peras/HFC support by agustinmista · Pull Request #1829 · IntersectMBO/ouroboros-consensus

agustinmista · 2026-01-14T15:26:07Z

Description

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New code should be properly tested (even if it does not add new features).
The fix for a regression should include a test that reproduces said regression.

…(instance of ObjectDiffusion) (#1679)" This reverts commit 474bfff.

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 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]>

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 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 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]>

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]>

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 the vote aggregation routine used to turn sufficiently many Peras votes for the same block into a Peras certificate. Co-authored-by: Nicolas BACQUEY <[email protected]> Co-authored-by: Thomas BAGREL <[email protected]> Co-authored-by: Agustin Mista <[email protected]>

This commit defined the API and implements an initial in-memory version of the PerasVoteDB, used to keep track of Peras votes received through object diffusion. Co-authored-by: Nicolas BACQUEY <[email protected]> Co-authored-by: Thomas BAGREL <[email protected]> Co-authored-by: Agustin Mista <[email protected]>

This commit defines ObjectDiffusion instances for Peras votes using the PerasVoteDB as a storage backend. Co-authored-by: Nicolas BACQUEY <[email protected]> Co-authored-by: Thomas BAGREL <[email protected]> Co-authored-by: Agustin Mista <[email protected]>

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

This commit splits the PerasCert and PerasVote types defined as part of the degenerate global BlockSupportsPeras instance into separate modules. This is the first step of a series of changes needed to define a proper BlockSupportsPeras instance for individual block types and the HFC.

jasagredo · 2026-03-03T11:09:45Z

+    -- Ledger state is forecast into ledger view for the target 'PerasRoundNo'.
+    (OneEraLedgerView nsLedgerView) <- forecastToViewAtRound hfpcLedgerConfig ledgerState roundNo
+    nsVoteAndLedgerView <- ensureSameEraPair (nsVote, nsLedgerView)
+    -- Dispatch to the per-era forgePerasVote.


Suggested change

-- Dispatch to the per-era forgePerasVote.

-- Dispatch to the per-era validatePerasVote.

jasagredo · 2026-03-03T11:12:40Z

+  let summary = State.reconstructSummaryLedger ledgerConfig unwrappedLedgerState
+  -- Query the hard fork history to determine what is the start slot of this
+  -- PerasRound. Thanks to 'runQueryNS', the result is wrapped in an 'NS' which
+  -- \*also* gives us the era the round falls in by its position.


Suggested change

-- \*also* gives us the era the round falls in by its position.

-- __also__ gives us the era the round falls in by its position.

This is the haddock markup for bold

jasagredo · 2026-03-03T11:13:15Z

+  -- Ledger state is forecast into ledger view for the target slot.
+  nsLedgerView <- forcastToViewAtSlot ledgerConfig slot ledgerState
+  -- Ensure the query era and the forecasted view era agree.
+  nsQueryResAndLedgerView <- ensureSameEraPair (nsQueryRes, getOneEraLedgerView nsLedgerView)


Isn't this trivially true always?

jasagredo · 2026-03-03T11:14:56Z

+downcastHardForkPoint ::
+  forall blk xs.
+  SingleEraBlock blk =>
+  Point (HardForkBlock xs) ->
+  Point blk
+downcastHardForkPoint = \case
+  GenesisPoint ->
+    GenesisPoint
+  BlockPoint s (OneEraHash h) ->
+    BlockPoint s (fromShortRawHash (Proxy @blk) h)


This feels weird. I think you should be able to do castPoint directly no?

jasagredo · 2026-03-03T11:15:09Z

+-- | Upcast a 'Point' from a single era into a 'Point' of the hard fork block
+-- by encoding the raw hash via 'toShortRawHash'. Used by accessor instances
+-- to return 'Point (HardForkBlock xs)' from single-era point values.
+upcastToHardForkPoint ::
+  forall blk xs.
+  SingleEraBlock blk =>
+  Point blk ->
+  Point (HardForkBlock xs)
+upcastToHardForkPoint = \case
+  GenesisPoint ->
+    GenesisPoint
+  BlockPoint s h ->
+    BlockPoint s (OneEraHash (toShortRawHash (Proxy @blk) h))


agustinmista and others added 16 commits December 16, 2025 10:00

Reintroduce "[Peras 4] Add ObjectDiffusion and PerasCert diffusion …

2fd1498

…(instance of ObjectDiffusion) (#1679)" This reverts commit 474bfff.

Add changelog entries

ecff70d

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]>

Add changelog entry

4b0c1af

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]>

Break stake above threshold comparison into separate function

28ce323

Add changelog entry

f937cb5

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

agustinmista assigned agustinmista and tbagrel1 Jan 14, 2026

agustinmista changed the base branch from main to peras/vote-db January 14, 2026 15:34

tbagrel1 mentioned this pull request Jan 16, 2026

[Peras 13] Introduce votes and certificate forging API #1801

Merged

tbagrel1 force-pushed the peras/hfc-supports-peras branch 2 times, most recently from e141a8b to 57602e0 Compare January 22, 2026 16:21

agustinmista force-pushed the peras/vote-db branch 4 times, most recently from 77d474b to 1860284 Compare February 2, 2026 16:05

agustinmista force-pushed the peras/vote-db branch 4 times, most recently from 1a3a058 to 109a836 Compare February 17, 2026 09:46

tbagrel1 force-pushed the peras/hfc-supports-peras branch from 57602e0 to 86e4177 Compare February 17, 2026 14:11

agustinmista force-pushed the peras/vote-db branch 8 times, most recently from bc855a0 to 023456f Compare February 23, 2026 10:22

tbagrel1 force-pushed the peras/hfc-supports-peras branch from 86e4177 to d15e94b Compare February 23, 2026 17:18

agustinmista force-pushed the peras/vote-db branch from 023456f to cc3b2fd Compare February 23, 2026 17:50

Base automatically changed from peras/vote-db to main February 23, 2026 20:46

WIP: refactor BlockSupportPeras and HFC plumbing

15c4cf0

tbagrel1 force-pushed the peras/hfc-supports-peras branch from d15e94b to 15c4cf0 Compare February 24, 2026 10:28

[WIP] Use forecast instead of ticking

62ca030

tbagrel1 force-pushed the peras/hfc-supports-peras branch from 7fdc36b to 62ca030 Compare February 26, 2026 09:11

Cleanup imports

5611fa1

tbagrel1 force-pushed the peras/hfc-supports-peras branch from c679fad to 5611fa1 Compare February 26, 2026 09:21

tbagrel1 added 2 commits February 26, 2026 11:48

Extract forecastViewToRound and Improve documentation

6e63379

Modify validatePerasCert to take a LedgerStateOrView

ba1ee92

jasagredo reviewed Mar 3, 2026

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qnikst linked an issue Mar 24, 2026 that may be closed by this pull request

Interface design & HFC plumbing for Peras tweag/cardano-peras#213

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[WIP] Peras/HFC support#1829

[WIP] Peras/HFC support#1829
agustinmista wants to merge 21 commits intomainfrom
peras/hfc-supports-peras

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	-- Dispatch to the per-era forgePerasVote.
	-- Dispatch to the per-era validatePerasVote.

	-- \also gives us the era the round falls in by its position.
	-- __also__ gives us the era the round falls in by its position.

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agustinmista commented Jan 14, 2026

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