When the EL/Builder fails to produce an execution payload, we fall back
to an empty `ExecutionPayload`. Even though it contains no transactions
it should refer to the configured fee recipient. This is useful for
privacy reasons (do not reveal the reason for the empty payload) and for
compliance with additional fee recipient rules by staking pools.
Implements the latest proposal for providing LC data via REST, as of
https://github.com/ethereum/beacon-APIs/pull/247 with a v0 suffix.
Requests:
- `/eth/v0/beacon/light_client/bootstrap/{block_root}`
- `/eth/v0/beacon/light_client/updates?start_period={start_period}&count={count}`
- `/eth/v0/beacon/light_client/finality_update`
- `/eth/v0/beacon/light_client/optimistic_update`
HTTP Server-Sent Events (SSE):
- `light_client_finality_update_v0`
- `light_client_optimistic_update_v0`
Removes a few extra-ambitious templates to make `self` updates explicit,
and moves the `FinalityCheckpoints` type from `base` to `helpers` as it
is an additional Nimbus specific type not defined by spec.
The justified and finalized `Checkpoint` are frequently passed around
together. This introduces a new `FinalityCheckpoint` data structure that
combines them into one.
Due to the large usage of this structure in fork choice, also took this
opportunity to update fork choice tests to the latest v1.2.0-rc.1 spec.
Many additional tests enabled, some need more work, e.g. EL mock blocks.
Also implemented `discard_equivocations` which was skipped in #3661,
and improved code reuse across fork choice logic while at it.
* optimistic sync
* flag that initially loaded blocks from database might need execution block root filled in
* return optimistic status in REST calls
* refactor blockslot pruning
* ensure beacon_blocks_by_{root,range} do not provide optimistic blocks
* handle forkchoice head being pre-merge with block being postmerge
* re-enable blocking head updates on validator duties
* fix is_optimistic_candidate_block per spec; don't crash with nil future
* fix is_optimistic_candidate_block per spec; don't crash with nil future
* mark blocks sans execution payloads valid during head update
This updates `nim-ssz-serialization` to
`3db6cc0f282708aca6c290914488edd832971d61`.
Notable changes:
- Use `uint64` for `GeneralizedIndex`
- Add support for building merkle multiproofs
When launched with `--light-client-enable` the latest blocks are fetched
and optimistic candidate blocks are passed to a callback (log for now).
This helps accelerate syncing in the future (optimistic sync).
* SSZ `[]` -> `mitem`
* `[]` -> `item`
immutable access via mutable instance cannot rely on template
overloading, and `[]` cannot be a `func` because of special seq handling
in compiler.
* document static vs dynamic range checking requirements
* add `vindices` iterator to iterate over valid validator indices in a
state
* clean up spec comments in general
* fixup
Co-authored-by: tersec <tersec@users.noreply.github.com>
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
