Merge pull request #516 from ethereum/get_ancestor
Fix ToC and #189: `get_ancestor()` can fail to terminate
This commit is contained in:
Danny Ryan
GitHub
commit
56c6322054
|
|
@ -104,33 +104,33 @@
|
|||
- [Beacon chain processing](#beacon-chain-processing)
|
||||
- [Beacon chain fork choice rule](#beacon-chain-fork-choice-rule)
|
||||
- [Beacon chain state transition function](#beacon-chain-state-transition-function)
|
||||
- [Per-slot processing](#per-slot-processing)
|
||||
- [Slot](#slot)
|
||||
- [Block roots](#block-roots)
|
||||
- [Per-block processing](#per-block-processing)
|
||||
- [Slot](#slot-1)
|
||||
- [Proposer signature](#proposer-signature)
|
||||
- [RANDAO](#randao)
|
||||
- [Eth1 data](#eth1-data)
|
||||
- [Operations](#operations)
|
||||
- [Proposer slashings](#proposer-slashings-1)
|
||||
- [Attester slashings](#attester-slashings-1)
|
||||
- [Attestations](#attestations-1)
|
||||
- [Deposits](#deposits-1)
|
||||
- [Exits](#exits-1)
|
||||
- [Per-epoch processing](#per-epoch-processing)
|
||||
- [Helpers](#helpers)
|
||||
- [Eth1 data](#eth1-data-1)
|
||||
- [Justification](#justification)
|
||||
- [Crosslinks](#crosslinks)
|
||||
- [Rewards and penalties](#rewards-and-penalties)
|
||||
- [Justification and finalization](#justification-and-finalization)
|
||||
- [Attestation inclusion](#attestation-inclusion)
|
||||
- [Crosslinks](#crosslinks-1)
|
||||
- [Ejections](#ejections)
|
||||
- [Validator registry and shuffling seed data](#validator-registry-and-shuffling-seed-data)
|
||||
- [Final updates](#final-updates)
|
||||
- [State root verification](#state-root-verification)
|
||||
- [Per-slot processing](#per-slot-processing)
|
||||
- [Slot](#slot)
|
||||
- [Block roots](#block-roots)
|
||||
- [Per-block processing](#per-block-processing)
|
||||
- [Slot](#slot-1)
|
||||
- [Proposer signature](#proposer-signature)
|
||||
- [RANDAO](#randao)
|
||||
- [Eth1 data](#eth1-data)
|
||||
- [Operations](#operations)
|
||||
- [Proposer slashings](#proposer-slashings-1)
|
||||
- [Attester slashings](#attester-slashings-1)
|
||||
- [Attestations](#attestations-1)
|
||||
- [Deposits](#deposits-1)
|
||||
- [Exits](#exits-1)
|
||||
- [Per-epoch processing](#per-epoch-processing)
|
||||
- [Helpers](#helpers)
|
||||
- [Eth1 data](#eth1-data-1)
|
||||
- [Justification](#justification)
|
||||
- [Crosslinks](#crosslinks)
|
||||
- [Rewards and penalties](#rewards-and-penalties)
|
||||
- [Justification and finalization](#justification-and-finalization)
|
||||
- [Attestation inclusion](#attestation-inclusion)
|
||||
- [Crosslinks](#crosslinks-1)
|
||||
- [Ejections](#ejections)
|
||||
- [Validator registry and shuffling seed data](#validator-registry-and-shuffling-seed-data)
|
||||
- [Final updates](#final-updates)
|
||||
- [State root verification](#state-root-verification)
|
||||
- [References](#references)
|
||||
- [Normative](#normative)
|
||||
- [Informative](#informative)
|
||||
|
|
@ -778,7 +778,7 @@ def get_shuffling(seed: Bytes32,
|
|||
|
||||
**Note**: this definition and the next few definitions make heavy use of repetitive computing. Production implementations are expected to appropriately use caching/memoization to avoid redoing work.
|
||||
|
||||
#### `get_previous_epoch_committee_count`
|
||||
### `get_previous_epoch_committee_count`
|
||||
|
||||
```python
|
||||
def get_previous_epoch_committee_count(state: BeaconState) -> int:
|
||||
|
|
@ -1491,7 +1491,18 @@ The beacon chain fork choice rule is a hybrid that combines justification and fi
|
|||
* Abstractly define `Store` as the type of storage object for the chain data and `store` be the set of attestations and blocks that the [validator](#dfn-validator) `v` has observed and verified (in particular, block ancestors must be recursively verified). Attestations not yet included in any chain are still included in `store`.
|
||||
* Let `finalized_head` be the finalized block with the highest epoch. (A block `B` is finalized if there is a descendant of `B` in `store` the processing of which sets `B` as finalized.)
|
||||
* Let `justified_head` be the descendant of `finalized_head` with the highest epoch that has been justified for at least 1 epoch. (A block `B` is justified if there is a descendant of `B` in `store` the processing of which sets `B` as justified.) If no such descendant exists set `justified_head` to `finalized_head`.
|
||||
* Let `get_ancestor(store: Store, block: BeaconBlock, slot: SlotNumber) -> BeaconBlock` be the ancestor of `block` with slot number `slot`. The `get_ancestor` function can be defined recursively as `def get_ancestor(store: Store, block: BeaconBlock, slot: SlotNumber) -> BeaconBlock: return block if block.slot == slot else get_ancestor(store, store.get_parent(block), slot)`.
|
||||
* Let `get_ancestor(store: Store, block: BeaconBlock, slot: SlotNumber) -> BeaconBlock` be the ancestor of `block` with slot number `slot`. The `get_ancestor` function can be defined recursively as:
|
||||
|
||||
```python
|
||||
def get_ancestor(store: Store, block: BeaconBlock, slot: SlotNumber) -> BeaconBlock:
|
||||
if block.slot == slot:
|
||||
return block
|
||||
elif block.slot < slot:
|
||||
return None
|
||||
else:
|
||||
return get_ancestor(store, store.get_parent(block), slot)
|
||||
```
|
||||
|
||||
* Let `get_latest_attestation(store: Store, validator: Validator) -> Attestation` be the attestation with the highest slot number in `store` from `validator`. If several such attestations exist, use the one the [validator](#dfn-validator) `v` observed first.
|
||||
* Let `get_latest_attestation_target(store: Store, validator: Validator) -> BeaconBlock` be the target block in the attestation `get_latest_attestation(store, validator)`.
|
||||
* Let `get_children(store: Store, block: BeaconBlock) -> List[BeaconBlock]` returns the child blocks of the given `block`.
|
||||
|
|
|
|||
Loading…
Reference in New Issue