| Safe Haskell | Safe-Inferred |
|---|---|
| Language | Haskell2010 |
Ouroboros.Consensus.Ledger.Basics
Description
Definition is IsLedger
Normally this is imported from Ouroboros.Consensus.Ledger.Abstract. We pull this out to avoid circular module dependencies.
Synopsis
- class GetTip l where
- getTipHash ∷ GetTip l ⇒ l → ChainHash l
- getTipSlot ∷ GetTip l ⇒ l → WithOrigin SlotNo
- data LedgerResult l a = LedgerResult {
- lrEvents ∷ [AuxLedgerEvent l]
- lrResult ∷ !a
- data VoidLedgerEvent l
- castLedgerResult ∷ AuxLedgerEvent l ~ AuxLedgerEvent l' ⇒ LedgerResult l a → LedgerResult l' a
- embedLedgerResult ∷ (AuxLedgerEvent l → AuxLedgerEvent l') → LedgerResult l a → LedgerResult l' a
- pureLedgerResult ∷ a → LedgerResult l a
- class (Show l, Eq l, NoThunks l, NoThunks (LedgerCfg l), Show (LedgerErr l), Eq (LedgerErr l), NoThunks (LedgerErr l), GetTip l, GetTip (Ticked l)) ⇒ IsLedger l where
- type LedgerErr l ∷ Type
- type AuxLedgerEvent l ∷ Type
- applyChainTickLedgerResult ∷ LedgerCfg l → SlotNo → l → LedgerResult l (Ticked l)
- type family LedgerCfg l ∷ Type
- applyChainTick ∷ IsLedger l ⇒ LedgerCfg l → SlotNo → l → Ticked l
- type LedgerConfig blk = LedgerCfg (LedgerState blk)
- type LedgerError blk = LedgerErr (LedgerState blk)
- data family LedgerState blk ∷ Type
- type TickedLedgerState blk = Ticked (LedgerState blk)
GetTip
Methods
Point of the most recently applied block
Should be GenesisPoint when no blocks have been applied yet
Instances
getTipHash ∷ GetTip l ⇒ l → ChainHash l Source #
getTipSlot ∷ GetTip l ⇒ l → WithOrigin SlotNo Source #
Ledger Events
data LedgerResult l a Source #
The result of invoke a ledger function that does validation
Note: we do not instantiate Applicative or Monad for this type because
those interfaces would typically incur space leaks. We encourage you to
process the events each time you invoke a ledger function.
Constructors
| LedgerResult | |
Fields
| |
Instances
data VoidLedgerEvent l Source #
A Void isomorph for explicitly declaring that some ledger has
no events
castLedgerResult ∷ AuxLedgerEvent l ~ AuxLedgerEvent l' ⇒ LedgerResult l a → LedgerResult l' a Source #
embedLedgerResult ∷ (AuxLedgerEvent l → AuxLedgerEvent l') → LedgerResult l a → LedgerResult l' a Source #
pureLedgerResult ∷ a → LedgerResult l a Source #
Definition of a ledger independent of a choice of block
class (Show l, Eq l, NoThunks l, NoThunks (LedgerCfg l), Show (LedgerErr l), Eq (LedgerErr l), NoThunks (LedgerErr l), GetTip l, GetTip (Ticked l)) ⇒ IsLedger l where Source #
Associated Types
type LedgerErr l ∷ Type Source #
Errors that can arise when updating the ledger
This is defined here rather than in ApplyBlock, since the type of
these errors does not depend on the type of the block.
type AuxLedgerEvent l ∷ Type Source #
Event emitted by the ledger
TODO we call this AuxLedgerEvent to differentiate from LedgerEvent in
InspectLedger. When that module is rewritten to make use of ledger
derived events, we may rename this type.
Methods
applyChainTickLedgerResult ∷ LedgerCfg l → SlotNo → l → LedgerResult l (Ticked l) Source #
Apply "slot based" state transformations
When a block is applied to the ledger state, a number of things happen purely based on the slot number of that block. For example:
- In Byron, scheduled updates are applied, and the update system state is updated.
- In Shelley, delegation state is updated (on epoch boundaries).
The consensus layer must be able to apply such a "chain tick" function, primarily when validating transactions in the mempool (which, conceptually, live in "some block in the future") or when extracting valid transactions from the mempool to insert into a new block to be produced.
This is not allowed to throw any errors. After all, if this could fail, it would mean a previous block set up the ledger state in such a way that as soon as a certain slot was reached, any block would be invalid.
PRECONDITION: The slot number must be strictly greater than the slot at the tip of the ledger (except for EBBs, obviously..).
NOTE: applyChainTickLedgerResult should not change the tip of the
underlying ledger state, which should still refer to the most recent
applied block. In other words, we should have
ledgerTipPoint (applyChainTick cfg slot st) == ledgerTipPoint st
Instances
type family LedgerCfg l ∷ Type Source #
Static environment required for the ledger
Types that inhabit this family will come from the Ledger code.
Instances
| type LedgerCfg (LedgerState (HardForkBlock xs)) Source # | |
| type LedgerCfg (LedgerState (DualBlock m a)) Source # | |
Defined in Ouroboros.Consensus.Ledger.Dual | |
| type LedgerCfg (ExtLedgerState blk) Source # | |
Defined in Ouroboros.Consensus.Ledger.Extended | |
Link block to its ledger
type LedgerConfig blk = LedgerCfg (LedgerState blk) Source #
type LedgerError blk = LedgerErr (LedgerState blk) Source #
data family LedgerState blk ∷ Type Source #
Ledger state associated with a block
This is the Consensus notion of a ledger state. Each block type is
associated with one of the Ledger types for the ledger state. Virtually
every concept in this codebase revolves around this type, or the referenced
blk. Whenever we use the type variable l, we intend to denote that the
expected instantiation is either a LedgerState or some wrapper over it
(like the ExtLedgerState).
The main operations we can do with a LedgerState are ticking (defined in
IsLedger), and applying a block (defined in
ApplyBlock).
Instances
type TickedLedgerState blk = Ticked (LedgerState blk) Source #