From 7705ecf89cd240152576527bf290b5a3daeea0d9 Mon Sep 17 00:00:00 2001 From: Justin Date: Sun, 14 Apr 2019 17:28:45 +1000 Subject: [PATCH] Update 0_beacon-chain.md --- specs/core/0_beacon-chain.md | 27 ++++++++++++--------------- 1 file changed, 12 insertions(+), 15 deletions(-) diff --git a/specs/core/0_beacon-chain.md b/specs/core/0_beacon-chain.md index 78aade7cb..6ec3ca739 100644 --- a/specs/core/0_beacon-chain.md +++ b/specs/core/0_beacon-chain.md @@ -184,6 +184,7 @@ These configurations are updated for releases, but may be out of sync during `de | `TARGET_COMMITTEE_SIZE` | `2**7` (= 128) | | `MAX_ATTESTATION_PARTICIPANTS` | `2**12` (= 4,096) | | `MIN_PER_EPOCH_CHURN_LIMIT` | `2**2` (= 4) | +| `CHURN_LIMIT_QUOTIENT` | `2**16` (= 65,536) | | `SHUFFLE_ROUND_COUNT` | 90 | * For the safety of crosslinks `TARGET_COMMITTEE_SIZE` exceeds [the recommended minimum committee size of 111](https://vitalik.ca/files/Ithaca201807_Sharding.pdf); with sufficient active validators (at least `SLOTS_PER_EPOCH * TARGET_COMMITTEE_SIZE`), the shuffling algorithm ensures committee sizes of at least `TARGET_COMMITTEE_SIZE`. (Unbiasable randomness with a Verifiable Delay Function (VDF) will improve committee robustness and lower the safe minimum committee size.) @@ -237,7 +238,6 @@ These configurations are updated for releases, but may be out of sync during `de * `MAX_CROSSLINK_EPOCHS` should be a small constant times `SHARD_COUNT // SLOTS_PER_EPOCH` - ### State list lengths | Name | Value | Unit | Duration | @@ -746,11 +746,11 @@ def is_slashable_validator(validator: Validator, epoch: Epoch) -> bool: ### `get_active_validator_indices` ```python -def get_active_validator_indices(validators: List[Validator], epoch: Epoch) -> List[ValidatorIndex]: +def get_active_validator_indices(state: BeaconState, epoch: Epoch) -> List[ValidatorIndex]: """ - Get indices of active validators from ``validators``. + Get active validator indices at ``epoch``. """ - return [i for i, v in enumerate(validators) if is_active_validator(v, epoch)] + return [i for i, v in enumerate(state.validator_registry) if is_active_validator(v, epoch)] ``` ### `get_balance` @@ -844,7 +844,7 @@ def get_epoch_committee_count(state: BeaconState, epoch: Epoch) -> int: """ Return the number of committees in one epoch. """ - active_validators = get_active_validator_indices(state.validator_registry, epoch) + active_validators = get_active_validator_indices(state, epoch) return max( 1, min( @@ -896,10 +896,7 @@ def get_crosslink_committees_at_slot(state: BeaconState, next_epoch = current_epoch + 1 assert previous_epoch <= epoch <= next_epoch - indices = get_active_validator_indices( - state.validator_registry, - epoch, - ) + indices = get_active_validator_indices(state, epoch) if epoch == current_epoch: start_shard = state.latest_start_shard @@ -1276,7 +1273,7 @@ def get_delayed_activation_exit_epoch(epoch: Epoch) -> Epoch: def get_churn_limit(state: BeaconState) -> int: return max( MIN_PER_EPOCH_CHURN_LIMIT, - MAX_FULL_CHURN_EPOCHS // len(get_active_validator_indices(state, get_current_epoch(state))) + len(get_active_validator_indices(state, get_current_epoch(state))) // CHURN_LIMIT_QUOTIENT ) ``` @@ -1517,7 +1514,7 @@ def get_genesis_beacon_state(genesis_validator_deposits: List[Deposit], if get_effective_balance(state, validator_index) >= MAX_DEPOSIT_AMOUNT: activate_validator(state, validator_index, is_genesis=True) - genesis_active_index_root = hash_tree_root(get_active_validator_indices(state.validator_registry, GENESIS_EPOCH)) + genesis_active_index_root = hash_tree_root(get_active_validator_indices(state, GENESIS_EPOCH)) for index in range(LATEST_ACTIVE_INDEX_ROOTS_LENGTH): state.latest_active_index_roots[index] = genesis_active_index_root @@ -1651,12 +1648,12 @@ We define some helper functions utilized when processing an epoch transition: ```python def get_current_total_balance(state: BeaconState) -> Gwei: - return get_total_balance(state, get_active_validator_indices(state.validator_registry, get_current_epoch(state))) + return get_total_balance(state, get_active_validator_indices(state, get_current_epoch(state))) ``` ```python def get_previous_total_balance(state: BeaconState) -> Gwei: - return get_total_balance(state, get_active_validator_indices(state.validator_registry, get_previous_epoch(state))) + return get_total_balance(state, get_active_validator_indices(state, get_previous_epoch(state))) ``` ```python @@ -1994,7 +1991,7 @@ def process_slashings(state: BeaconState) -> None: Note that this function mutates ``state``. """ current_epoch = get_current_epoch(state) - active_validator_indices = get_active_validator_indices(state.validator_registry, current_epoch) + active_validator_indices = get_active_validator_indices(state, current_epoch) total_balance = get_total_balance(state, active_validator_indices) # Compute `total_penalties` @@ -2022,7 +2019,7 @@ def finish_epoch_update(state: BeaconState) -> None: # Set active index root index_root_position = (next_epoch + ACTIVATION_EXIT_DELAY) % LATEST_ACTIVE_INDEX_ROOTS_LENGTH state.latest_active_index_roots[index_root_position] = hash_tree_root( - get_active_validator_indices(state.validator_registry, next_epoch + ACTIVATION_EXIT_DELAY) + get_active_validator_indices(state, next_epoch + ACTIVATION_EXIT_DELAY) ) # Set total slashed balances state.latest_slashed_balances[next_epoch % LATEST_SLASHED_EXIT_LENGTH] = (