Now that the 1.2.0-rc.2 spec contains the same `LightClientUpdate`
definition that Nimbus was already using before, the corresponding
SSZ test vectors can be re-enabled.
Merkle proofs tend to have long underlying type definitions, e.g.,
`array[log2trunc(NEXT_SYNC_COMMITTEE_INDEX), Eth2Digest]`. For the
ones used in the LC sync protocol, dedicated types are introduced
to improve readability. Furthermore, the `CachedLightClientBootstrap`
wrapper that solely wrapped a merkle branch is eliminated.
This updates `nim-ssz-serialization` to
`3db6cc0f282708aca6c290914488edd832971d61`.
Notable changes:
- Use `uint64` for `GeneralizedIndex`
- Add support for building merkle multiproofs
Incorporates the latest changes to the light client sync protocol based
on Devconnect AMS feedback. Note that this breaks compatibility with the
previous prototype, due to changes to data structures and endpoints.
See https://github.com/ethereum/consensus-specs/pull/2802
One more step on the journey to reduce `BlockRef` usage across the
codebase - this one gets rid of `StateData` whose job was to keep track
of which block was last assigned to a state - these duties have now been
taken over by `latest_block_root`, a fairly recent addition that
computes this block root from state data (at a small cost that should be
insignificant)
99% mechanical change.
When syncing as a light client, different behaviour is needed to handle
the various ways how errors may occur. The existing logic for blocks can
also be applied to light client objects:
- `Invalid`: Malformed object that is clearly an error by its producer.
- `MissingParent`: More data is needed to decide applicability.
- `UnviableFork`: Object may be valid but will never apply on this fork.
- `Duplicate`: No errors were encountered but the object was not useful.
This adopts the spec sections of the pre-release proposal of the libp2p
based light client sync protocol, and also adds a test runner for the
new accompanying tests. While the release version of the light client
sync protocol contains conflicting definitions, it is currently unused,
and the code specific to the pre-release proposal is marked as such.
See https://github.com/ethereum/consensus-specs/pull/2802
The spec does not provide code for validating the `fork_version` field
of `LightClientUpdate`. However, we can use our own logic for additional
validation of that field. The spec's python test suite sets up states
that do not follow the fork schedule (e.g., that use Altair fork version
before Altair fork epoch), which complicates upstreaming this as code.
In practice, the sync committee signs `LightClientUpdate` instances at
the next slot following the block. This is not correctly reflected in
the tests, where it is signed one slot early. This patch updates the
tests to use the correct slot for the computation.
Time in the beacon chain is expressed relative to the genesis time -
this PR creates a `beacon_time` module that collects helpers and
utilities for dealing the time units - the new module does not deal with
actual wall time (that's remains in `beacon_clock`).
Collecting the time related stuff in one place makes it easier to find,
avoids some circular imports and allows more easily identifying the code
actually needs wall time to operate.
* move genesis-time-related functionality into `spec/beacon_time`
* avoid using `chronos.Duration` for time differences - it does not
support negative values (such as when something happens earlier than it
should)
* saturate conversions between `FAR_FUTURE_XXX`, so as to avoid
overflows
* fix delay reporting in validator client so it uses the expected
deadline of the slot, not "closest wall slot"
* simplify looping over the slots of an epoch
* `compute_start_slot_at_epoch` -> `start_slot`
* `compute_epoch_at_slot` -> `epoch`
A follow-up PR will (likely) introduce saturating arithmetic for the
time units - this is merely code moves, renames and fixing of small
bugs.
* batch-verify sync messages for a small perf boost
Generally reuses the same structure as attestation and aggregate
verification
* normalize `signatures` and `signature_batch` to use the same pattern
of verification
* normalize parameter names, order etc for signature stuff in general
* avoid calling `blsSign` directly - instead, go through `signatures`
consistently
* ncli_db: add putState, putBlock
These tools allow modifying an existing nimbus database for the purpose
of recovery or reorg, moving the head, tail and genesis to arbitrary
points.
* remove potentially expensive `putState` in `BeaconStateDB`
* introduce `latest_block_root` which computes the root of the latest
applied block from the `latest_block_header` field (instead of passing
it in separately)
* avoid some unnecessary BeaconState copies during init
* discover https://github.com/nim-lang/Nim/issues/19094
* prefer `HashedBeaconState` in a few places to avoid recomputing state
root
* fetch latest block root from state when creating blocks
* harden `get_beacon_proposer_index` against invalid slots and document
* move random spec function tests to `test_spec.nim`
* avoid unnecessary state root computation before block proposal
The sync committee period used to be a plain `uint64`. With the light
client sync relying more heavily on them, it makes sense to introduce
a proper type for them, similar to how they are already used for `Slot`
and `Epoch`. This introduces such a `SyncCommitteePeriod` type.
Furthermore, some usage code dealing with those periods is cleaned up.
tersec
Etan Kissling
Jacek Sieka
Zahary Karadjov