don't used sorted() in get_indexed_attestation()

beacon_chain/spec/beaconstate.nim

@@ -8,7 +8,7 @@
 {.push raises: [Defect].}
 
 import
-  std/[algorithm, intsets, math, options, sequtils, tables],
+  std/[algorithm, collections/heapqueue, math, options, sequtils, tables],
   stew/assign2,
   json_serialization/std/sets,
   chronicles,
@@ -475,35 +475,12 @@ proc is_valid_indexed_attestation*(
 
   ok()
 
-# https://github.com/ethereum/eth2.0-specs/blob/v1.0.0/specs/phase0/beacon-chain.md#get_attesting_indices
-iterator get_attesting_indices*(bits: CommitteeValidatorsBits,
-                                committee: openArray[ValidatorIndex]):
-                                  ValidatorIndex =
-  if bits.len == committee.len:
-    for i, index in committee:
-      if bits[i]:
-        yield index
-  else:
-    # This shouldn't happen if one begins with a valid BeaconState and applies
-    # valid updates, but one can construct a BeaconState where it does. Do not
-    # do anything here since the PendingAttestation wouldn't have made it past
-    # https://github.com/ethereum/eth2.0-specs/blob/v1.0.0/specs/phase0/beacon-chain.md#attestations
-    # which checks len(attestation.aggregation_bits) == len(committee) that in
-    # nimbus-eth2 lives in check_attestation(...).
-    # Addresses https://github.com/status-im/nimbus-eth2/issues/922
-
-    trace "get_attesting_indices: inconsistent aggregation and committee length"
-
-func get_attesting_indices*(bits: CommitteeValidatorsBits,
-                            committee: openArray[ValidatorIndex]): IntSet =
-  for idx in get_attesting_indices(bits, committee):
-    result.incl idx.int
-
 # https://github.com/ethereum/eth2.0-specs/blob/v1.0.0/specs/phase0/beacon-chain.md#get_attesting_indices
 iterator get_attesting_indices*(state: BeaconState,
                                 data: AttestationData,
                                 bits: CommitteeValidatorsBits,
                                 cache: var StateCache): ValidatorIndex =
+  ## Return the set of attesting indices corresponding to ``data`` and ``bits``.
   if bits.lenu64 != get_beacon_committee_len(state, data.slot, data.index.CommitteeIndex, cache):
     trace "get_attesting_indices: inconsistent aggregation and committee length"
   else:
@@ -513,28 +490,30 @@ iterator get_attesting_indices*(state: BeaconState,
         yield index
       inc i
 
-# https://github.com/ethereum/eth2.0-specs/blob/v1.0.0/specs/phase0/beacon-chain.md#get_attesting_indices
-func get_attesting_indices*(state: BeaconState,
-                            data: AttestationData,
-                            bits: CommitteeValidatorsBits,
-                            cache: var StateCache): IntSet =
-  # Return the set of attesting indices corresponding to ``data`` and ``bits``.
+iterator get_sorted_attesting_indices*(state: BeaconState,
+                                       data: AttestationData,
+                                       bits: CommitteeValidatorsBits,
+                                       cache: var StateCache): ValidatorIndex =
+  var heap = initHeapQueue[ValidatorIndex]()
   for index in get_attesting_indices(state, data, bits, cache):
-    result.incl index.int
+    heap.push(index)
+
+  while heap.len > 0:
+    yield heap.pop()
+
+func get_sorted_attesting_indices_list*(
+    state: BeaconState, data: AttestationData, bits: CommitteeValidatorsBits,
+    cache: var StateCache): List[uint64, Limit MAX_VALIDATORS_PER_COMMITTEE] =
+  for index in get_sorted_attesting_indices(state, data, bits, cache):
+    result.add index.uint64
 
 # https://github.com/ethereum/eth2.0-specs/blob/v1.0.0/specs/phase0/beacon-chain.md#get_indexed_attestation
 func get_indexed_attestation(state: BeaconState, attestation: Attestation,
     cache: var StateCache): IndexedAttestation =
   ## Return the indexed attestation corresponding to ``attestation``.
-  let
-    attesting_indices =
-      get_attesting_indices(
-        state, attestation.data, attestation.aggregation_bits, cache)
-
   IndexedAttestation(
-    attesting_indices:
-      List[uint64, Limit MAX_VALIDATORS_PER_COMMITTEE].init(
-        sorted(mapIt(attesting_indices.toSeq, it.uint64), system.cmp)),
+    attesting_indices: get_sorted_attesting_indices_list(
+      state, attestation.data, attestation.aggregation_bits, cache),
     data: attestation.data,
     signature: attestation.signature
   )
@@ -542,15 +521,9 @@ func get_indexed_attestation(state: BeaconState, attestation: Attestation,
 func get_indexed_attestation(state: BeaconState, attestation: TrustedAttestation,
     cache: var StateCache): TrustedIndexedAttestation =
   ## Return the indexed attestation corresponding to ``attestation``.
-  let
-    attesting_indices =
-      get_attesting_indices(
-        state, attestation.data, attestation.aggregation_bits, cache)
-
   TrustedIndexedAttestation(
-    attesting_indices:
-      List[uint64, Limit MAX_VALIDATORS_PER_COMMITTEE].init(
-        sorted(mapIt(attesting_indices.toSeq, it.uint64), system.cmp)),
+    attesting_indices: get_sorted_attesting_indices_list(
+      state, attestation.data, attestation.aggregation_bits, cache),
     data: attestation.data,
     signature: attestation.signature
   )

beacon_chain/spec/network.nim

@@ -86,6 +86,7 @@ func getAttestationTopic*(forkDigest: ForkDigest, subnetIndex: uint64):
   except ValueError as e:
     raiseAssert e.msg
 
+# https://github.com/ethereum/eth2.0-specs/blob/v1.0.0/specs/phase0/validator.md#validator-assignments
 iterator get_committee_assignments*(
     state: BeaconState, epoch: Epoch,
     validator_indices: IntSet,

beacon_chain/spec/validator.nim

@@ -369,31 +369,3 @@ func get_beacon_proposer_index*(state: BeaconState, cache: var StateCache, slot:
 func get_beacon_proposer_index*(state: BeaconState, cache: var StateCache):
     Option[ValidatorIndex] =
   get_beacon_proposer_index(state, cache, state.slot)
-
-# https://github.com/ethereum/eth2.0-specs/blob/v1.0.0/specs/phase0/validator.md#validator-assignments
-func get_committee_assignment*(
-    state: BeaconState, epoch: Epoch,
-    validator_index: ValidatorIndex):
-    Option[tuple[a: seq[ValidatorIndex], b: CommitteeIndex, c: Slot]] =
-  ## Return the committee assignment in the ``epoch`` for ``validator_index``.
-  ## ``assignment`` returned is a tuple of the following form:
-  ##     * ``assignment[0]`` is the list of validators in the committee
-  ##     * ``assignment[1]`` is the index to which the committee is assigned
-  ##     * ``assignment[2]`` is the slot at which the committee is assigned
-  ## Return None if no assignment.
-  let next_epoch = get_current_epoch(state) + 1
-  doAssert epoch <= next_epoch
-
-  var cache = StateCache()
-
-  let
-    start_slot = compute_start_slot_at_epoch(epoch)
-    committee_count_per_slot =
-      get_committee_count_per_slot(state, epoch, cache)
-  for slot in start_slot ..< start_slot + SLOTS_PER_EPOCH:
-    for index in 0'u64 ..< committee_count_per_slot:
-      let idx = index.CommitteeIndex
-      let committee = get_beacon_committee(state, slot, idx, cache)
-      if validator_index in committee:
-        return some((committee, idx, slot))
-  none(tuple[a: seq[ValidatorIndex], b: CommitteeIndex, c: Slot])

tests/mocking/mock_attestations.nim

@@ -58,16 +58,15 @@ proc mockAttestationData(
 
 proc signMockAttestation*(state: BeaconState, attestation: var Attestation) =
   var cache = StateCache()
-  let participants = get_attesting_indices(
-    state,
-    attestation.data,
-    attestation.aggregation_bits,
-    cache
-  )
 
   var agg {.noInit.}: AggregateSignature
   var first_iter = true # Can't do while loop on hashset
-  for validator_index in participants:
+  for validator_index in get_attesting_indices(
+        state,
+        attestation.data,
+        attestation.aggregation_bits,
+        cache
+      ):
     let sig = get_attestation_signature(
       state.fork, state.genesis_validators_root, attestation.data,
       MockPrivKeys[validator_index]