refactor: update the block production race

packages/beacon-node/src/api/impl/validator/utils.ts

@@ -1,6 +1,8 @@
 import {BeaconStateAllForks, computeSlotsSinceEpochStart} from "@lodestar/state-transition";
 import {ATTESTATION_SUBNET_COUNT} from "@lodestar/params";
-import {BLSPubkey, CommitteeIndex, Slot, ValidatorIndex} from "@lodestar/types";
+import {routes} from "@lodestar/api";
+import {BLSPubkey, CommitteeIndex, ProducedBlockSource, Slot, ValidatorIndex} from "@lodestar/types";
+import {MAX_BUILDER_BOOST_FACTOR} from "@lodestar/validator";
 
 export function computeSubnetForCommitteesAtSlot(
   slot: Slot,
@@ -41,3 +43,30 @@ export function getPubkeysForIndices(
 
   return pubkeys;
 }
+
+export function selectBlockProductionSource({
+  builderSelection,
+  engineBlockValue,
+  builderBlockValue,
+  builderBoostFactor,
+}: {
+  builderSelection: routes.validator.BuilderSelection;
+  engineBlockValue: bigint;
+  builderBlockValue: bigint;
+  builderBoostFactor: bigint;
+}): ProducedBlockSource {
+  switch (builderSelection) {
+    case routes.validator.BuilderSelection.ExecutionOnly:
+      return ProducedBlockSource.engine;
+
+    case routes.validator.BuilderSelection.MaxProfit:
+      return builderBoostFactor !== MAX_BUILDER_BOOST_FACTOR &&
+        (builderBoostFactor === BigInt(0) || engineBlockValue >= (builderBlockValue * builderBoostFactor) / BigInt(100))
+        ? ProducedBlockSource.engine
+        : ProducedBlockSource.builder;
+
+    default:
+      // For everything else just select the builder
+      return ProducedBlockSource.builder;
+  }
+}

packages/utils/src/format.ts

@@ -27,3 +27,15 @@ export function truncBytes(root: Uint8Array | string): string {
   const str = typeof root === "string" ? root : toHexString(root);
   return str.slice(0, 14);
 }
+
+/**
+ * Format a bigint value as a decimal string
+ */
+export function formatBigDecimal(numerator: bigint, denominator: bigint, maxDecimalFactor: bigint): string {
+  const full = numerator / denominator;
+  const fraction = ((numerator - full * denominator) * maxDecimalFactor) / denominator;
+
+  // zeros to be added post decimal are number of zeros in maxDecimalFactor - number of digits in fraction
+  const zerosPostDecimal = String(maxDecimalFactor).length - 1 - String(fraction).length;
+  return `${full}.${"0".repeat(zerosPostDecimal)}${fraction}`;
+}