ouroboros-consensus-0.1.0.1: Consensus layer for the Ouroboros blockchain protocol
Safe Haskell None
Language Haskell2010

Ouroboros.Consensus.HeaderStateHistory

Description

HeaderState history

Intended for qualified import

import           Ouroboros.Consensus.HeaderStateHistory (HeaderStateHistory)
import qualified Ouroboros.Consensus.HeaderStateHistory as HeaderStateHistory
Synopsis

Documentation

newtype HeaderStateHistory blk Source #

Maintain a history of HeaderState s.

Instances

Instances details
( BlockSupportsProtocol blk, HasAnnTip blk) => Eq ( HeaderStateHistory blk) Source #
Instance details

Defined in Ouroboros.Consensus.HeaderStateHistory

( BlockSupportsProtocol blk, HasAnnTip blk) => Show ( HeaderStateHistory blk) Source #
Instance details

Defined in Ouroboros.Consensus.HeaderStateHistory

Generic ( HeaderStateHistory blk) Source #
Instance details

Defined in Ouroboros.Consensus.HeaderStateHistory

( BlockSupportsProtocol blk, HasAnnTip blk) => NoThunks ( HeaderStateHistory blk) Source #
Instance details

Defined in Ouroboros.Consensus.HeaderStateHistory

type Rep ( HeaderStateHistory blk) Source #
Instance details

Defined in Ouroboros.Consensus.HeaderStateHistory

type Rep ( HeaderStateHistory blk) = D1 (' MetaData "HeaderStateHistory" "Ouroboros.Consensus.HeaderStateHistory" "ouroboros-consensus-0.1.0.1-DT4Cvwf63DZKctsEvaJqCU" ' True ) ( C1 (' MetaCons "HeaderStateHistory" ' PrefixI ' True ) ( S1 (' MetaSel (' Just "unHeaderStateHistory") ' NoSourceUnpackedness ' NoSourceStrictness ' DecidedLazy ) ( Rec0 ( AnchoredSeq ( WithOrigin SlotNo ) ( HeaderState blk) ( HeaderState blk)))))

rewind :: forall blk. ( BlockSupportsProtocol blk, HasAnnTip blk) => Point blk -> HeaderStateHistory blk -> Maybe ( HeaderStateHistory blk) Source #

\( O\(n\) ). Rewind the header state history

NOTE: we don't distinguish headers of regular blocks from headers of EBBs. Whenever we use "header" it can be either. In practice, EBB headers do not affect the ChainDepState , but they do affect the AnnTip .

PRECONDITION: the point to rewind to must correspond to a header (or GenesisPoint ) that was previously applied to the header state history.

Rewinding the header state history is intended to be used when switching to a fork, longer or equally long to the chain to which the current header state corresponds. So each rewinding should be followed by rolling forward (using headerStateHistoryPush ) at least as many blocks that we have rewound.

Note that repeatedly rewinding a header state history does not make it possible to rewind it all the way to genesis (this would mean that the whole historical header state is accumulated or derivable from the current header state history). For example, rewinding a header state by i blocks and then rewinding that header state again by j where i + j > k is not possible and will yield Nothing .

trim :: Int -> HeaderStateHistory blk -> HeaderStateHistory blk Source #

Trim the HeaderStateHistory to the given size, dropping the oldest snapshots. The anchor will be shifted accordingly.

Note that we do not include the anchor in the size. For example, trimming to 0 results in no snapshots but still an anchor. Trimming to 1 results in 1 snapshot and an anchor.

Validation

validateHeader :: forall blk. ( BlockSupportsProtocol blk, ValidateEnvelope blk) => TopLevelConfig blk -> Ticked ( LedgerView ( BlockProtocol blk)) -> Header blk -> HeaderStateHistory blk -> Except ( HeaderError blk) ( HeaderStateHistory blk) Source #

Variation on validateHeader that maintains a HeaderStateHistory .

This is used only in the chain sync client for header-only validation.

Note: this function does not trim the HeaderStateHistory .

Support for tests

fromChain Source #

Arguments

:: ApplyBlock ( ExtLedgerState blk) blk
=> TopLevelConfig blk
-> ExtLedgerState blk

Initial ledger state

-> Chain blk
-> HeaderStateHistory blk

Create a HeaderStateHistory corresponding to the blocks in the given Chain .

PRECONDITION: the blocks in the chain are valid.