test: add fork-choice benchmark for updateHead (#5577)

* Add fork-choice benchmark for updateHead

* Add more benchmarks

packages/fork-choice/src/protoArray/computeDeltas.ts

@@ -35,16 +35,16 @@ export function computeDeltas(
 
     // IF the validator was not included in the _old_ balances (i.e. it did not exist yet)
     // then say its balance was 0
-    const oldBalance = oldBalances[vIndex] || 0;
+    const oldBalance = oldBalances[vIndex] ?? 0;
 
     // If the validator's vote is not known in the _new_ balances, then use a balance of zero.
     //
     // It is possible that there was a vote for an unknown validator if we change our justified
     // state to a new state with a higher epoch that is on a different fork because that fork may have
     // on-boarded fewer validators than the prior fork.
-    const newBalance = newBalances[vIndex] || 0;
+    const newBalance = newBalances[vIndex] ?? 0;
 
-    if (equivocatingIndices.has(vIndex)) {
+    if (equivocatingIndices.size > 0 && equivocatingIndices.has(vIndex)) {
       // this function could be called multiple times but we only want to process slashing validator for 1 time
       if (currentRoot !== zeroHash) {
         const currentDeltaIndex = indices.get(currentRoot);

packages/fork-choice/src/protoArray/protoArray.ts

@@ -216,24 +216,19 @@ export class ProtoArray {
       bestDescendant: undefined,
     };
 
-    let nodeIndex = this.nodes.length;
+    const nodeIndex = this.nodes.length;
 
     this.indices.set(node.blockRoot, nodeIndex);
     this.nodes.push(node);
 
-    let parentIndex = node.parent;
     // If this node is valid, lets propagate the valid status up the chain
     // and throw error if we counter invalid, as this breaks consensus
-    if (node.executionStatus === ExecutionStatus.Valid && parentIndex !== undefined) {
-      this.propagateValidExecutionStatusByIndex(parentIndex);
-    }
+    if (node.parent !== undefined) {
+      this.maybeUpdateBestChildAndDescendant(node.parent, nodeIndex, currentSlot);
 
-    let n: ProtoNode | undefined = node;
-    while (parentIndex !== undefined) {
-      this.maybeUpdateBestChildAndDescendant(parentIndex, nodeIndex, currentSlot);
-      nodeIndex = parentIndex;
-      n = this.getNodeByIndex(nodeIndex);
-      parentIndex = n?.parent;
+      if (node.executionStatus === ExecutionStatus.Valid) {
+        this.propagateValidExecutionStatusByIndex(node.parent);
+      }
     }
   }
 

packages/fork-choice/test/perf/forkChoice/onAttestation.test.ts

@@ -0,0 +1,94 @@
+import {itBench} from "@dapplion/benchmark";
+import {AttestationData, IndexedAttestation} from "@lodestar/types/phase0";
+import {ATTESTATION_SUBNET_COUNT} from "@lodestar/params";
+import {ssz} from "@lodestar/types";
+import {computeEpochAtSlot} from "@lodestar/state-transition";
+import {fromHexString, toHexString} from "@chainsafe/ssz";
+import {initializeForkChoice} from "./util.js";
+
+describe("ForkChoice onAttestation", () => {
+  /**
+   * Committee:       | ----------- 0 --------------| ... | ----------------------- i --------------------- | ------------------------63 -------------------------|
+   * Validator index: | 0 1 2 ... committeeLength-1 | ... | (i*committeeLengh + ) 0 1 2 ... committeeLengh-1| (63*committeeLengh +) 0 1 2 ... committeeLength - 1 |
+   */
+  itBench({
+    id: "pass gossip attestations to forkchoice per slot",
+    beforeEach: () => {
+      const initialBlockCount = 64;
+      const forkchoice = initializeForkChoice({
+        initialBlockCount,
+        initialValidatorCount: 600_000,
+        initialEquivocatedCount: 0,
+      });
+      const head = forkchoice.updateHead();
+
+      // at slot 64, forkchoice receives attestations of slot 63
+      forkchoice.updateTime(initialBlockCount);
+      // there are 700 aggregate and proof max per slot
+      // as of Jan 2022
+      const committeeLength = 135;
+      // considering TARGET_AGGREGATORS_PER_COMMITTEE=16, it's not likely we have more than this number of aggregators
+      // connect to node per slot
+      const numAggregatorsConnectedToNode = 3;
+      const attestationDataOmitIndex: Omit<AttestationData, "index"> = {
+        beaconBlockRoot: fromHexString(head.blockRoot),
+        slot: initialBlockCount - 1,
+        source: {
+          epoch: head.justifiedEpoch,
+          root: fromHexString(head.justifiedRoot),
+        },
+        target: {
+          epoch: computeEpochAtSlot(head.slot),
+          root: fromHexString(head.targetRoot),
+        },
+      };
+
+      // unaggregatedAttestations: aggregator {i} for committee index {i}
+      const unaggregatedAttestations: IndexedAttestation[] = [];
+      for (let committeeIndex = 0; committeeIndex < numAggregatorsConnectedToNode; committeeIndex++) {
+        const attestationData: AttestationData = {
+          ...attestationDataOmitIndex,
+          index: committeeIndex,
+        };
+        for (let i = 0; i < committeeLength; i++) {
+          const validatorIndex = committeeIndex * committeeLength + i;
+          unaggregatedAttestations.push({
+            attestingIndices: [validatorIndex],
+            data: attestationData,
+            signature: Buffer.alloc(96),
+          });
+        }
+      }
+
+      // aggregated attestations: each committee index has 11 aggregators in average
+      // 64 committee indices map to 704 aggregated attestations per slot
+      const aggregatedAttestations: IndexedAttestation[] = [];
+      const averageAggregatorsPerSlot = 11;
+      for (let committeeIndex = 0; committeeIndex < ATTESTATION_SUBNET_COUNT; committeeIndex++) {
+        const tbAttestationData = {
+          ...attestationDataOmitIndex,
+          index: committeeIndex,
+        };
+
+        // cache the root
+        ssz.phase0.AttestationData.hashTreeRoot(tbAttestationData);
+
+        for (let aggregator = 0; aggregator < averageAggregatorsPerSlot; aggregator++) {
+          // same data, different signatures
+          aggregatedAttestations.push({
+            attestingIndices: Array.from({length: committeeLength}, (_, i) => committeeIndex * committeeLength + i),
+            data: tbAttestationData,
+            signature: Buffer.alloc(96, aggregator),
+          });
+        }
+      }
+
+      return {forkchoice, allAttestationsPerSlot: [...unaggregatedAttestations, ...aggregatedAttestations]};
+    },
+    fn: ({forkchoice, allAttestationsPerSlot}) => {
+      for (const attestation of allAttestationsPerSlot) {
+        forkchoice.onAttestation(attestation, toHexString(ssz.phase0.AttestationData.hashTreeRoot(attestation.data)));
+      }
+    },
+  });
+});

packages/fork-choice/test/perf/forkChoice/updateHead.test.ts

@@ -0,0 +1,66 @@
+import {itBench} from "@dapplion/benchmark";
+import {computeEpochAtSlot} from "@lodestar/state-transition";
+import {ForkChoice, ProtoBlock} from "../../../src/index.js";
+import {initializeForkChoice, Opts} from "./util.js";
+
+describe("forkchoice updateHead", () => {
+  for (const initialValidatorCount of [100_000, 600_000, 1_000_000]) {
+    runUpdateHeadBenchmark({initialValidatorCount, initialBlockCount: 64, initialEquivocatedCount: 0});
+  }
+
+  for (const initialBlockCount of [
+    // 10 epochs of blocks ~ 1 hour
+    10 * 32,
+    // 4 hours of blocks
+    (4 * 60 * 60) / 12,
+    // // 1 day of blocks
+    // (24 * 60 * 60) / 12,
+    // // 20 days of blocks
+    // (20 * 24 * 60 * 60) / 12,
+  ]) {
+    runUpdateHeadBenchmark({initialValidatorCount: 600_000, initialBlockCount, initialEquivocatedCount: 0});
+  }
+
+  for (const initialEquivocatedCount of [1_000, 10_000, 300_000]) {
+    runUpdateHeadBenchmark({initialValidatorCount: 600_000, initialBlockCount: 64, initialEquivocatedCount});
+  }
+
+  function runUpdateHeadBenchmark(opts: Opts): void {
+    itBench({
+      id: `forkChoice updateHead vc ${opts.initialValidatorCount} bc ${opts.initialBlockCount} eq ${opts.initialEquivocatedCount}`,
+      before: () => {
+        const forkChoice = initializeForkChoice(opts);
+
+        const vote1 = forkChoice.updateHead();
+        const vote2 = forkChoice.getBlockHex(vote1.parentRoot);
+        if (!vote2) throw Error("no vote2");
+        if (vote1.blockRoot === vote2.blockRoot) throw Error("blockRoot vote1 == vote2");
+        if (vote1.slot === vote2.slot) throw Error("slot vote1 == vote2");
+
+        return {
+          forkChoice,
+          vote1,
+          vote2,
+          currentVoteIs1: true,
+        };
+      },
+      beforeEach: (data) => {
+        // Flip all votes every run
+        everyoneVotes(data.currentVoteIs1 ? data.vote2 : data.vote1, data.forkChoice);
+        data.currentVoteIs1 = !data.currentVoteIs1;
+        return data;
+      },
+      fn: ({forkChoice}) => {
+        forkChoice.updateHead();
+      },
+    });
+  }
+});
+
+function everyoneVotes(vote: ProtoBlock, forkChoice: ForkChoice): void {
+  const nextEpoch = computeEpochAtSlot(vote.slot);
+  const nextRoot = vote.blockRoot;
+  for (let i = 0; i < forkChoice["balances"].length; i++) {
+    forkChoice["addLatestMessage"](i, nextEpoch, nextRoot);
+  }
+}