# beacon_chain # Copyright (c) 2018-2024 Status Research & Development GmbH # Licensed and distributed under either of # * MIT license (license terms in the root directory or at https://opensource.org/licenses/MIT). # * Apache v2 license (license terms in the root directory or at https://www.apache.org/licenses/LICENSE-2.0). # at your option. This file may not be copied, modified, or distributed except according to those terms. {.push raises: [].} import ./datatypes/base, ./beaconstate, ./forks, ./helpers # https://github.com/ethereum/consensus-specs/blob/v1.5.0-alpha.4/specs/phase0/weak-subjectivity.md#configuration const SAFETY_DECAY* = 10'u64 # https://github.com/ethereum/consensus-specs/blob/v1.5.0-alpha.4/specs/phase0/weak-subjectivity.md#compute_weak_subjectivity_period func compute_weak_subjectivity_period( cfg: RuntimeConfig, state: ForkyBeaconState): uint64 = ## Returns the weak subjectivity period for the current ``state``. ## This computation takes into account the effect of: ## - validator set churn ## (bounded by ``get_validator_churn_limit()`` per epoch), and ## - validator balance top-ups ## (bounded by ``MAX_DEPOSITS * SLOTS_PER_EPOCH`` per epoch). ## A detailed calculation can be found at: ## https://github.com/runtimeverification/beacon-chain-verification/blob/master/weak-subjectivity/weak-subjectivity-analysis.pdf var cache: StateCache ws_period = cfg.MIN_VALIDATOR_WITHDRAWABILITY_DELAY let N = get_active_validator_indices_len(state, get_current_epoch(state)) t = (get_total_active_balance(state, cache) div N).toEther() const T = MAX_EFFECTIVE_BALANCE.Gwei.toEther() let delta = cfg.get_validator_churn_limit(state, cache) const Delta = MAX_DEPOSITS * SLOTS_PER_EPOCH D = SAFETY_DECAY if T * (200 + 3 * D) < t * (200 + 12 * D): let epochs_for_validator_set_churn = N * (t * (200 + 12 * D) - T * (200 + 3 * D)) div (600 * delta * (2 * t + T)) epochs_for_balance_top_ups = N * (200 + 3 * D) div (600 * Delta) ws_period += max(epochs_for_validator_set_churn, epochs_for_balance_top_ups) else: ws_period += 3 * N * D * t div (200 * Delta * (T - t)) ws_period # https://github.com/ethereum/consensus-specs/blob/v1.5.0-alpha.4/specs/phase0/weak-subjectivity.md#is_within_weak_subjectivity_period func is_within_weak_subjectivity_period*(cfg: RuntimeConfig, current_slot: Slot, ws_state: ForkedHashedBeaconState, ws_checkpoint: Checkpoint): bool = ## Clients may choose to validate the input state against the input Weak Subjectivity Checkpoint doAssert getStateField(ws_state, latest_block_header).state_root == ws_checkpoint.root doAssert epoch(getStateField(ws_state, slot)) == ws_checkpoint.epoch let ws_period = withState(ws_state): cfg.compute_weak_subjectivity_period(forkyState.data) ws_state_epoch = epoch(getStateField(ws_state, slot)) current_epoch = epoch(current_slot) current_epoch <= ws_state_epoch + ws_period