Safe Haskell | None |
---|---|
Language | Haskell2010 |
Ouroboros.Consensus.Fragment.InFuture
Contents
Description
Intended for qualified import
import Ouroboros.Consensus.Fragment.InFuture (CheckInFuture(..), ClockSkew(..)) import qualified Ouroboros.Consensus.Fragment.InFuture as InFuture
Synopsis
-
data
CheckInFuture
m blk =
CheckInFuture
{
- checkInFuture :: ValidatedFragment ( Header blk) ( LedgerState blk) -> m ( AnchoredFragment ( Header blk), [ InFuture m blk])
- data InFuture m blk = InFuture { }
- reference :: forall m blk. ( Monad m, UpdateLedger blk, HasHardForkHistory blk) => LedgerConfig blk -> ClockSkew -> SystemTime m -> CheckInFuture m blk
- clockSkewInSeconds :: Double -> ClockSkew
- defaultClockSkew :: ClockSkew
- data ClockSkew
- dontCheck :: Monad m => CheckInFuture m blk
- miracle :: forall m blk. ( MonadSTM m, HasHeader ( Header blk)) => STM m SlotNo -> Word64 -> CheckInFuture m blk
Documentation
data CheckInFuture m blk Source #
Constructors
CheckInFuture | |
Fields
|
Instances
NoThunks ( CheckInFuture m blk) Source # | |
Defined in Ouroboros.Consensus.Fragment.InFuture |
Header of block that we found to be in the future
Constructors
InFuture | |
Fields
|
reference :: forall m blk. ( Monad m, UpdateLedger blk, HasHardForkHistory blk) => LedgerConfig blk -> ClockSkew -> SystemTime m -> CheckInFuture m blk Source #
Clock skew
clockSkewInSeconds :: Double -> ClockSkew Source #
Specify maximum clock skew in seconds
defaultClockSkew :: ClockSkew Source #
Default maximum permissible clock skew
See
ClockSkew
for details. We allow for 5 seconds skew by default.
opaque
Maximum permissible clock skew
When running NTP, systems clocks will never be perfectly synchronized. The maximum clock skew records how much of a difference we consider acceptable.
For example. Suppose
- Two nodes A and B
- A's clock is 0.5 ahead of B's
- A produces a block and sends it to B
-
When B translates the
SlotNo
of that block to a time, it may find that it is 0.5 seconds ahead of its current clock (worst case).
The maximum permissible clock skew decides if B will consider this block to be valid (even if it will not yet consider it for chain seleciton) or as invalid (and disconnect from A, since A is sending it invalid blocks).
Use
defaultClockSkew
when unsure.
Instances
Eq ClockSkew Source # | |
Ord ClockSkew Source # | |
Defined in Ouroboros.Consensus.Fragment.InFuture Methods compare :: ClockSkew -> ClockSkew -> Ordering Source # (<) :: ClockSkew -> ClockSkew -> Bool Source # (<=) :: ClockSkew -> ClockSkew -> Bool Source # (>) :: ClockSkew -> ClockSkew -> Bool Source # (>=) :: ClockSkew -> ClockSkew -> Bool Source # |
|
Show ClockSkew Source # | |
Testing
dontCheck :: Monad m => CheckInFuture m blk Source #
Trivial
InFuture
check that doesn't do any check at all
This is useful for testing and tools such as the DB converter.
Arguments
:: forall m blk. ( MonadSTM m, HasHeader ( Header blk)) | |
=> STM m SlotNo |
Get current slot |
-> Word64 |
Maximum clock skew (in terms of slots) |
-> CheckInFuture m blk |
If by some miracle we have a function that can always tell us what the
correct slot is, implementing
CheckInFuture
is easy
NOTE: Use of
miracle
in tests means that none of the hard fork
infrastructure for converting slots to time is tested.