speed up epoch processing 6x+

beacon_chain/spec/datatypes/altair.nim

@@ -83,6 +83,10 @@ type
     sync_committee_bits*: BitArray[SYNC_COMMITTEE_SIZE]
     sync_committee_signature*: ValidatorSig
 
+  TrustedSyncAggregate* = object
+    sync_committee_bits*: BitArray[SYNC_COMMITTEE_SIZE]
+    sync_committee_signature*: TrustedSig
+
   # https://github.com/ethereum/consensus-specs/blob/v1.1.5/specs/altair/beacon-chain.md#synccommittee
   SyncCommittee* = object
     pubkeys*: HashArray[Limit SYNC_COMMITTEE_SIZE, ValidatorPubKey]
@@ -369,7 +373,7 @@ type
     voluntary_exits*: List[TrustedSignedVoluntaryExit, Limit MAX_VOLUNTARY_EXITS]
 
     # [New in Altair]
-    sync_aggregate*: SyncAggregate
+    sync_aggregate*: SyncAggregate # TODO TrustedSyncAggregate after batching
 
   SyncnetBits* = BitArray[SYNC_COMMITTEE_SUBNET_COUNT]
 
@@ -393,7 +397,7 @@ type
     voluntary_exits*: List[TrustedSignedVoluntaryExit, Limit MAX_VOLUNTARY_EXITS]
 
     # [New in Altair]
-    sync_aggregate*: SyncAggregate
+    sync_aggregate*: TrustedSyncAggregate
 
   # https://github.com/ethereum/consensus-specs/blob/v1.1.5/specs/phase0/beacon-chain.md#signedbeaconblock
   SignedBeaconBlock* = object
@@ -431,6 +435,8 @@ type
   SomeBeaconBlock* = BeaconBlock | SigVerifiedBeaconBlock | TrustedBeaconBlock
   SomeBeaconBlockBody* = BeaconBlockBody | SigVerifiedBeaconBlockBody | TrustedBeaconBlockBody
 
+  SomeSyncAggregate* = SyncAggregate | TrustedSyncAggregate
+
   SyncSubcommitteeIndex* = distinct uint8
   IndexInSyncCommittee* = distinct uint16
 

beacon_chain/spec/datatypes/base.nim

@@ -623,13 +623,10 @@ proc readValue*(reader: var JsonReader, value: var ForkDigest)
 static: doAssert high(int) >= high(int32)
 
 # `ValidatorIndex` seq handling.
-func `[]`*[T](a: var seq[T], b: ValidatorIndex): var T =
-  a[b.int]
-
-func `[]=`*[T](a: var seq[T], b: ValidatorIndex, c: T) =
+template `[]=`*[T](a: var seq[T], b: ValidatorIndex, c: T) =
   a[b.int] = c
 
-func `[]`*[T](a: seq[T], b: ValidatorIndex): auto =
+template `[]`*[T](a: seq[T], b: ValidatorIndex): auto = # Also var seq (!)
   a[b.int]
 
 # `ValidatorIndex` Nim integration

beacon_chain/spec/datatypes/merge.nim

@@ -263,7 +263,7 @@ type
     attestations*: List[Attestation, Limit MAX_ATTESTATIONS]
     deposits*: List[Deposit, Limit MAX_DEPOSITS]
     voluntary_exits*: List[SignedVoluntaryExit, Limit MAX_VOLUNTARY_EXITS]
-    sync_aggregate*: SyncAggregate
+    sync_aggregate*: SyncAggregate # TODO TrustedSyncAggregate after batching
 
     # Execution
     execution_payload*: ExecutionPayload  # [New in Merge]
@@ -283,7 +283,7 @@ type
     attestations*: List[TrustedAttestation, Limit MAX_ATTESTATIONS]
     deposits*: List[Deposit, Limit MAX_DEPOSITS]
     voluntary_exits*: List[TrustedSignedVoluntaryExit, Limit MAX_VOLUNTARY_EXITS]
-    sync_aggregate*: SyncAggregate
+    sync_aggregate*: TrustedSyncAggregate
 
     # Execution
     execution_payload*: ExecutionPayload  # [New in Merge]

beacon_chain/spec/state_transition_block.nim

@@ -429,7 +429,7 @@ proc process_operations(cfg: RuntimeConfig,
 # https://github.com/ethereum/consensus-specs/blob/v1.1.0-alpha.6/specs/altair/beacon-chain.md#sync-committee-processing
 proc process_sync_aggregate*(
     state: var (altair.BeaconState | merge.BeaconState),
-    aggregate: SyncAggregate, total_active_balance: Gwei, cache: var StateCache):
+    aggregate: SomeSyncAggregate, total_active_balance: Gwei, cache: var StateCache):
     Result[void, cstring] {.nbench.} =
   # Verify sync committee aggregate signature signing over the previous slot
   # block root
@@ -439,21 +439,22 @@ proc process_sync_aggregate*(
     domain = get_domain(state, DOMAIN_SYNC_COMMITTEE, compute_epoch_at_slot(previous_slot))
     signing_root = compute_signing_root(get_block_root_at_slot(state, previous_slot), domain)
 
-  var participant_pubkeys: seq[ValidatorPubKey]
-  for i in 0 ..< committee_pubkeys.len:
-    if aggregate.sync_committee_bits[i]:
-      participant_pubkeys.add committee_pubkeys[i]
+  when aggregate.sync_committee_signature isnot TrustedSig:
+    var participant_pubkeys: seq[ValidatorPubKey]
+    for i in 0 ..< committee_pubkeys.len:
+      if aggregate.sync_committee_bits[i]:
+        participant_pubkeys.add committee_pubkeys[i]
 
   # p2p-interface message validators check for empty sync committees, so it
   # shouldn't run except as part of test suite.
-  if  participant_pubkeys.len == 0 and
-      aggregate.sync_committee_signature != default(CookedSig).toValidatorSig():
-    return err("process_sync_aggregate: empty sync aggregates need signature of point at infinity")
-
-  # Empty participants allowed
-  if participant_pubkeys.len > 0 and not blsFastAggregateVerify(
-      participant_pubkeys, signing_root.data, aggregate.sync_committee_signature):
-    return err("process_sync_aggregate: invalid signature")
+    if participant_pubkeys.len == 0 and
+        aggregate.sync_committee_signature != default(CookedSig).toValidatorSig():
+      return err("process_sync_aggregate: empty sync aggregates need signature of point at infinity")
+
+    # Empty participants allowed
+    if participant_pubkeys.len > 0 and not blsFastAggregateVerify(
+        participant_pubkeys, signing_root.data, aggregate.sync_committee_signature):
+      return err("process_sync_aggregate: invalid signature")
 
   # Compute participant and proposer rewards
   let

beacon_chain/spec/state_transition_epoch.nim

@@ -870,10 +870,13 @@ func process_effective_balance_updates*(state: var ForkyBeaconState) {.nbench.}
     let effective_balance = state.validators.asSeq()[index].effective_balance
     if balance + DOWNWARD_THRESHOLD < effective_balance or
         effective_balance + UPWARD_THRESHOLD < balance:
-      state.validators[index].effective_balance =
+      let new_effective_balance =
         min(
           balance - balance mod EFFECTIVE_BALANCE_INCREMENT,
           MAX_EFFECTIVE_BALANCE)
+      # Protect against unnecessary cache invalidation
+      if new_effective_balance != effective_balance:
+        state.validators[index].effective_balance = new_effective_balance
 
 # https://github.com/ethereum/consensus-specs/blob/v1.1.5/specs/phase0/beacon-chain.md#slashings-balances-updates
 func process_slashings_reset*(state: var ForkyBeaconState) {.nbench.} =
@@ -946,13 +949,13 @@ func process_inactivity_updates*(
     previous_epoch = get_previous_epoch(state)  # get_eligible_validator_indices()
     not_in_inactivity_leak = not is_in_inactivity_leak(state)
 
-  state.inactivity_scores.clearCache()
   for index in 0'u64 ..< state.validators.lenu64:
     if not is_eligible_validator(info.validators[index]):
       continue
 
     # Increase the inactivity score of inactive validators
-    var inactivity_score = state.inactivity_scores.asSeq()[index]
+    let pre_inactivity_score = state.inactivity_scores.asSeq()[index]
+    var inactivity_score = pre_inactivity_score
     # TODO activeness already checked; remove redundant checks between
     # is_active_validator and is_unslashed_participating_index
     if is_unslashed_participating_index(
@@ -964,7 +967,9 @@ func process_inactivity_updates*(
     # leak-free epoch
     if not_in_inactivity_leak:
       inactivity_score -= min(INACTIVITY_SCORE_RECOVERY_RATE.uint64, inactivity_score)
-    state.inactivity_scores.asSeq()[index] = inactivity_score
+    # Most inactivity scores remain at 0 - avoid invalidating cache
+    if pre_inactivity_score != inactivity_score:
+      state.inactivity_scores[index] = inactivity_score
 
 # https://github.com/ethereum/consensus-specs/blob/v1.1.5/specs/phase0/beacon-chain.md#epoch-processing
 proc process_epoch*(