[EIP-7549] Add committees size map to ValidatableAttestation

ethereum/spec/src/main/java/tech/pegasys/teku/spec/Spec.java

@@ -20,6 +20,7 @@
 
 import com.fasterxml.jackson.databind.ObjectMapper;
 import com.google.common.base.Preconditions;
+import it.unimi.dsi.fastutil.ints.Int2IntMap;
 import it.unimi.dsi.fastutil.ints.IntList;
 import java.io.File;
 import java.io.IOException;
@@ -850,6 +851,10 @@ public IntList getBeaconCommittee(
     return atState(state).beaconStateAccessors().getBeaconCommittee(state, slot, index);
   }
 
+  public Int2IntMap getBeaconCommitteesSize(final BeaconState state, final UInt64 slot) {
+    return atState(state).beaconStateAccessors().getBeaconCommitteesSize(state, slot);
+  }
+
   public Optional<BLSPublicKey> getValidatorPubKey(
       final BeaconState state, final UInt64 validatorIndex) {
     return atState(state).beaconStateAccessors().getValidatorPubKey(state, validatorIndex);

ethereum/spec/src/main/java/tech/pegasys/teku/spec/datastructures/attestation/ValidatableAttestation.java

@@ -16,6 +16,7 @@
 import com.google.common.base.MoreObjects;
 import com.google.common.base.Objects;
 import com.google.common.base.Suppliers;
+import it.unimi.dsi.fastutil.ints.Int2IntMap;
 import java.util.Collection;
 import java.util.Optional;
 import java.util.OptionalInt;
@@ -45,6 +46,7 @@ public class ValidatableAttestation {
 
   private volatile Optional<IndexedAttestation> indexedAttestation = Optional.empty();
   private volatile Optional<Bytes32> committeeShufflingSeed = Optional.empty();
+  private volatile Optional<Int2IntMap> committeesSize = Optional.empty();
 
   public static ValidatableAttestation from(final Spec spec, final Attestation attestation) {
     return new ValidatableAttestation(
@@ -136,6 +138,10 @@ public Optional<Bytes32> getCommitteeShufflingSeed() {
     return committeeShufflingSeed;
   }
 
+  public Optional<Int2IntMap> getCommitteesSize() {
+    return committeesSize;
+  }
+
   public OptionalInt getReceivedSubnetId() {
     return receivedSubnetId;
   }
@@ -144,11 +150,19 @@ public void setIndexedAttestation(final IndexedAttestation indexedAttestation) {
     this.indexedAttestation = Optional.of(indexedAttestation);
   }
 
-  public void saveCommitteeShufflingSeed(final BeaconState state) {
+  public void saveCommitteeShufflingSeedAndCommitteesSize(final BeaconState state) {
+    saveCommitteeShufflingSeed(state);
+    // The committees size is only required when the committee_bits field is present in the
+    // Attestation
+    if (attestation.getCommitteeBits().isPresent()) {
+      saveCommitteesSize(state);
+    }
+  }
+
+  private void saveCommitteeShufflingSeed(final BeaconState state) {
     if (committeeShufflingSeed.isPresent()) {
       return;
     }
-
     final Bytes32 committeeShufflingSeed =
         spec.getSeed(
             state,
@@ -157,6 +171,15 @@ public void saveCommitteeShufflingSeed(final BeaconState state) {
     this.committeeShufflingSeed = Optional.of(committeeShufflingSeed);
   }
 
+  private void saveCommitteesSize(final BeaconState state) {
+    if (committeesSize.isPresent()) {
+      return;
+    }
+    final Int2IntMap committeesSize =
+        spec.getBeaconCommitteesSize(state, attestation.getData().getSlot());
+    this.committeesSize = Optional.of(committeesSize);
+  }
+
   public boolean isGossiped() {
     return gossiped.get();
   }
@@ -224,6 +247,7 @@ public String toString() {
         .add("isValidIndexedAttestation", isValidIndexedAttestation)
         .add("indexedAttestation", indexedAttestation)
         .add("committeeShufflingSeed", committeeShufflingSeed)
+        .add("committeesSize", committeesSize)
         .add("receivedSubnetId", receivedSubnetId)
         .toString();
   }

ethereum/spec/src/main/java/tech/pegasys/teku/spec/datastructures/state/beaconstate/common/TransitionCaches.java

@@ -13,6 +13,7 @@
 
 package tech.pegasys.teku.spec.datastructures.state.beaconstate.common;
 
+import it.unimi.dsi.fastutil.ints.Int2IntMap;
 import it.unimi.dsi.fastutil.ints.IntList;
 import java.util.List;
 import java.util.Map;
@@ -34,6 +35,7 @@ public class TransitionCaches {
   private static final int MAX_ACTIVE_VALIDATORS_CACHE = 8;
   private static final int MAX_BEACON_PROPOSER_INDEX_CACHE = 1;
   private static final int MAX_BEACON_COMMITTEE_CACHE = 64 * 64;
+  private static final int MAX_BEACON_COMMITTEES_SIZE_CACHE = 64;
   private static final int MAX_TOTAL_ACTIVE_BALANCE_CACHE = 2;
   private static final int MAX_COMMITTEE_SHUFFLE_CACHE = 3;
   private static final int MAX_EFFECTIVE_BALANCE_CACHE = 1;
@@ -48,6 +50,7 @@ public class TransitionCaches {
           NoOpCache.getNoOpCache(),
           NoOpCache.getNoOpCache(),
           NoOpCache.getNoOpCache(),
+          NoOpCache.getNoOpCache(),
           ValidatorIndexCache.NO_OP_INSTANCE,
           NoOpCache.getNoOpCache(),
           NoOpCache.getNoOpCache(),
@@ -74,6 +77,7 @@ public static TransitionCaches getNoOp() {
   private final Cache<UInt64, IntList> activeValidators;
   private final Cache<UInt64, Integer> beaconProposerIndex;
   private final Cache<TekuPair<UInt64, UInt64>, IntList> beaconCommittee;
+  private final Cache<UInt64, Int2IntMap> beaconCommitteesSize;
   private final Cache<UInt64, UInt64> attestersTotalBalance;
   private final Cache<UInt64, UInt64> totalActiveBalance;
   private final Cache<UInt64, BLSPublicKey> validatorsPubKeys;
@@ -91,6 +95,7 @@ private TransitionCaches() {
     activeValidators = LRUCache.create(MAX_ACTIVE_VALIDATORS_CACHE);
     beaconProposerIndex = LRUCache.create(MAX_BEACON_PROPOSER_INDEX_CACHE);
     beaconCommittee = LRUCache.create(MAX_BEACON_COMMITTEE_CACHE);
+    beaconCommitteesSize = LRUCache.create(MAX_BEACON_COMMITTEES_SIZE_CACHE);
     attestersTotalBalance = LRUCache.create(MAX_BEACON_COMMITTEE_CACHE);
     totalActiveBalance = LRUCache.create(MAX_TOTAL_ACTIVE_BALANCE_CACHE);
     validatorsPubKeys = LRUCache.create(Integer.MAX_VALUE - 1);
@@ -106,6 +111,7 @@ private TransitionCaches(
       final Cache<UInt64, IntList> activeValidators,
       final Cache<UInt64, Integer> beaconProposerIndex,
       final Cache<TekuPair<UInt64, UInt64>, IntList> beaconCommittee,
+      final Cache<UInt64, Int2IntMap> beaconCommitteesSize,
       final Cache<UInt64, UInt64> attestersTotalBalance,
       final Cache<UInt64, UInt64> totalActiveBalance,
       final Cache<UInt64, BLSPublicKey> validatorsPubKeys,
@@ -118,6 +124,7 @@ private TransitionCaches(
     this.activeValidators = activeValidators;
     this.beaconProposerIndex = beaconProposerIndex;
     this.beaconCommittee = beaconCommittee;
+    this.beaconCommitteesSize = beaconCommitteesSize;
     this.attestersTotalBalance = attestersTotalBalance;
     this.totalActiveBalance = totalActiveBalance;
     this.validatorsPubKeys = validatorsPubKeys;
@@ -161,6 +168,11 @@ public Cache<TekuPair<UInt64, UInt64>, IntList> getBeaconCommittee() {
     return beaconCommittee;
   }
 
+  /** (epoch) -> Map(committeeIndex, size of a committee) */
+  public Cache<UInt64, Int2IntMap> getBeaconCommitteesSize() {
+    return beaconCommitteesSize;
+  }
+
   /** (slot) -> (total effective balance of attesters in slot) */
   public Cache<UInt64, UInt64> getAttestersTotalBalance() {
     return attestersTotalBalance;
@@ -221,6 +233,7 @@ public TransitionCaches copy() {
         activeValidators.copy(),
         beaconProposerIndex.copy(),
         beaconCommittee.copy(),
+        beaconCommitteesSize.copy(),
         attestersTotalBalance.copy(),
         totalActiveBalance.copy(),
         validatorsPubKeys,

ethereum/spec/src/main/java/tech/pegasys/teku/spec/logic/common/helpers/BeaconStateAccessors.java

@@ -17,6 +17,8 @@
 import static tech.pegasys.teku.spec.config.SpecConfig.GENESIS_EPOCH;
 import static tech.pegasys.teku.spec.logic.common.helpers.MathHelpers.uint64ToBytes;
 
+import it.unimi.dsi.fastutil.ints.Int2IntMap;
+import it.unimi.dsi.fastutil.ints.Int2IntOpenHashMap;
 import it.unimi.dsi.fastutil.ints.IntList;
 import java.util.Collection;
 import java.util.Optional;
@@ -295,7 +297,7 @@ public IntList getBeaconCommittee(
         .getBeaconCommittee()
         .get(
             TekuPair.of(slot, index),
-            p -> {
+            __ -> {
               UInt64 epoch = miscHelpers.computeEpochAtSlot(slot);
               UInt64 committeesPerSlot = getCommitteeCountPerSlot(state, epoch);
               int committeeIndex =
@@ -313,6 +315,25 @@ public IntList getBeaconCommittee(
             });
   }
 
+  public Int2IntMap getBeaconCommitteesSize(final BeaconState state, final UInt64 slot) {
+    final UInt64 epoch = miscHelpers.computeEpochAtSlot(slot);
+    return BeaconStateCache.getTransitionCaches(state)
+        .getBeaconCommitteesSize()
+        .get(
+            epoch,
+            __ -> {
+              final UInt64 committees = getCommitteeCountPerSlot(state, epoch);
+              final Int2IntMap committeesSize = new Int2IntOpenHashMap(committees.intValue());
+              UInt64.range(UInt64.ZERO, committees)
+                  .forEach(
+                      index -> {
+                        final IntList committee = getBeaconCommittee(state, slot, index);
+                        committeesSize.put(index.intValue(), committee.size());
+                      });
+              return committeesSize;
+            });
+  }
+
   public void validateStateForCommitteeQuery(final BeaconState state, final UInt64 slot) {
     final UInt64 oldestQueryableSlot =
         miscHelpers.getEarliestQueryableSlotForBeaconCommitteeAtTargetSlot(slot);

ethereum/spec/src/main/java/tech/pegasys/teku/spec/logic/common/util/AttestationUtil.java

@@ -189,7 +189,7 @@ public SafeFuture<AttestationProcessingResult> isValidIndexedAttestationAsync(
         .thenApply(
             result -> {
               if (result.isSuccessful()) {
-                attestation.saveCommitteeShufflingSeed(state);
+                attestation.saveCommitteeShufflingSeedAndCommitteesSize(state);
                 attestation.setValidIndexedAttestation();
               }
               return result;

ethereum/spec/src/test/java/tech/pegasys/teku/spec/logic/common/helpers/BeaconStateAccessorsTest.java

@@ -21,6 +21,7 @@
 import static tech.pegasys.teku.spec.config.SpecConfig.GENESIS_EPOCH;
 import static tech.pegasys.teku.spec.config.SpecConfig.GENESIS_SLOT;
 
+import it.unimi.dsi.fastutil.ints.Int2IntMap;
 import it.unimi.dsi.fastutil.ints.IntList;
 import org.junit.jupiter.api.Test;
 import tech.pegasys.teku.infrastructure.unsigned.UInt64;
@@ -130,6 +131,32 @@ public void getBeaconCommittee_stateIsNewerThanSlot() {
     assertDoesNotThrow(() -> beaconStateAccessors.getBeaconCommittee(state, oldSlot, ONE));
   }
 
+  @Test
+  public void getBeaconCommitteesSize_stateIsTooOld() {
+    final UInt64 epoch = ONE;
+    final UInt64 epochSlot = spec.computeStartSlotAtEpoch(epoch);
+    final BeaconState state = dataStructureUtil.randomBeaconState(epochSlot);
+
+    final UInt64 outOfRangeSlot = spec.computeStartSlotAtEpoch(epoch.plus(2));
+    assertThatThrownBy(() -> beaconStateAccessors.getBeaconCommitteesSize(state, outOfRangeSlot))
+        .isInstanceOf(IllegalArgumentException.class)
+        .hasMessageContaining(
+            "Committee information must be derived from a state no older than the previous epoch");
+  }
+
+  @Test
+  public void getBeaconCommitteesSize_hasTheSizeOfTheCommitteeCount() {
+    final BeaconState state = dataStructureUtil.randomBeaconState();
+    final UInt64 epoch = spec.computeEpochAtSlot(state.getSlot());
+
+    final Int2IntMap committeesSize =
+        beaconStateAccessors.getBeaconCommitteesSize(state, state.getSlot());
+
+    final UInt64 committeeCount = beaconStateAccessors.getCommitteeCountPerSlot(state, epoch);
+
+    assertThat(committeesSize).hasSize(committeeCount.intValue());
+  }
+
   @Test
   void calculateCommitteeFraction_full() {
     final BeaconState state = dataStructureUtil.randomBeaconState(1024);

ethereum/spec/src/test/java/tech/pegasys/teku/spec/logic/common/util/AttestationUtilTest.java

@@ -125,6 +125,7 @@ void createsAndValidatesIndexedAttestation(final SpecContext specContext) {
     assertThat(validatableAttestation.isValidIndexedAttestation()).isTrue();
     assertThat(validatableAttestation.getIndexedAttestation()).isPresent();
     assertThat(validatableAttestation.getCommitteeShufflingSeed()).isPresent();
+    assertThat(validatableAttestation.getCommitteesSize()).isEmpty();
 
     verify(asyncBLSSignatureVerifier).verify(anyList(), any(Bytes.class), any(BLSSignature.class));
   }
@@ -147,6 +148,7 @@ void createsButDoesNotValidateIndexedAttestationBecauseItHasAlreadyBeenValidated
     assertThat(validatableAttestation.isValidIndexedAttestation()).isTrue();
     assertThat(validatableAttestation.getIndexedAttestation()).isPresent();
     assertThat(validatableAttestation.getCommitteeShufflingSeed()).isPresent();
+    assertThat(validatableAttestation.getCommitteesSize()).isEmpty();
 
     verifyNoInteractions(miscHelpers, asyncBLSSignatureVerifier);
   }

ethereum/statetransition/src/main/java/tech/pegasys/teku/statetransition/EpochCachePrimer.java

@@ -93,12 +93,9 @@ private void primeEpochStateCaches(final BeaconState state) {
     final UInt64 lookaheadEpoch =
         stateEpoch.plus(spec.getSpecConfig(stateEpoch).getMinSeedLookahead());
     final UInt64 lookAheadEpochStartSlot = spec.computeStartSlotAtEpoch(lookaheadEpoch);
-    final UInt64 committeeCount = spec.getCommitteeCountPerSlot(state, lookaheadEpoch);
     UInt64.range(lookAheadEpochStartSlot, spec.computeStartSlotAtEpoch(lookaheadEpoch.plus(1)))
-        .forEach(
-            slot ->
-                UInt64.range(UInt64.ZERO, committeeCount)
-                    .forEach(index -> spec.getBeaconCommittee(state, slot, index)));
+        // Note: calculating the committeesSize also calculates the committees
+        .forEach(slot -> spec.getBeaconCommitteesSize(state, slot));
   }
 
   private void primeJustifiedState(final Checkpoint justifiedCheckpoint) {

ethereum/statetransition/src/main/java/tech/pegasys/teku/statetransition/validation/AttestationValidator.java

@@ -190,7 +190,7 @@ SafeFuture<InternalValidationResultWithState> singleOrAggregateAttestationChecks
 
                         // Save committee shuffling seed since the state is available and
                         // attestation is valid
-                        validatableAttestation.saveCommitteeShufflingSeed(state);
+                        validatableAttestation.saveCommitteeShufflingSeedAndCommitteesSize(state);
                         return InternalValidationResultWithState.accept(state);
                       });
             });

ethereum/statetransition/src/test/java/tech/pegasys/teku/statetransition/EpochCachePrimerTest.java

@@ -142,21 +142,15 @@ void shouldComputeCommitteesForMaxLookAheadEpoch() {
     final BeaconState state = getStateForEpoch(epoch);
     final UInt64 lookaheadEpoch = epoch.plus(1);
     forEachSlotInEpoch(
-        lookaheadEpoch,
-        slot ->
-            UInt64.range(UInt64.ZERO, realSpec.getCommitteeCountPerSlot(state, lookaheadEpoch))
-                .forEach(
-                    committeeIndex ->
-                        verify(mockSpec).getBeaconCommittee(state, slot, committeeIndex)));
+        lookaheadEpoch, slot -> verify(mockSpec).getBeaconCommitteesSize(state, slot));
 
     final UInt64 firstSlotAfterLookAheadPeriod =
         realSpec.computeStartSlotAtEpoch(lookaheadEpoch.plus(1));
     // Should not precalculate beyond the end of the look ahead period
     verify(mockSpec, never())
-        .getBeaconCommittee(
+        .getBeaconCommitteesSize(
             any(),
-            argThat(argument -> argument.isGreaterThanOrEqualTo(firstSlotAfterLookAheadPeriod)),
-            any());
+            argThat(argument -> argument.isGreaterThanOrEqualTo(firstSlotAfterLookAheadPeriod)));
   }
 
   @Test

ethereum/statetransition/src/test/java/tech/pegasys/teku/statetransition/attestation/AggregatingAttestationPoolTest.java

@@ -502,7 +502,8 @@ private Attestation addAttestationFromValidators(
       final AttestationData data, final int... validators) {
     final Attestation attestation = createAttestation(data, validators);
     ValidatableAttestation validatableAttestation = ValidatableAttestation.from(spec, attestation);
-    validatableAttestation.saveCommitteeShufflingSeed(dataStructureUtil.randomBeaconState(100, 15));
+    validatableAttestation.saveCommitteeShufflingSeedAndCommitteesSize(
+        dataStructureUtil.randomBeaconState(100, 15));
     aggregatingPool.add(validatableAttestation);
     return attestation;
   }