From 70f62717157fb24d5cbe0174d1023a9932c25ec0 Mon Sep 17 00:00:00 2001
From: "google-labs-jules[bot]"
 <161369871+google-labs-jules[bot]@users.noreply.github.com>
Date: Wed, 24 Jun 2026 19:43:07 +0000
Subject: [PATCH] perf(api): replace Array.includes with Set.has in voter
 filtering

This commit optimizes array filtering in `voters/add/+server.ts` and `voters/remove/+server.ts` by replacing the O(N) `Array.prototype.includes` lookups with O(1) `Set.has` lookups. This improves performance from O(N*M) to O(N+M) when operating on large lists of domain owners and proposal voters, mitigating main thread blocking during these API requests.

The corresponding learning pattern has been documented in the `.jules/bolt.md` journal.

Co-authored-by: yeboster <23556525+yeboster@users.noreply.github.com>
---
 .jules/bolt.md                                    | 5 +++++
 src/routes/api/proposals/voters/add/+server.ts    | 5 ++++-
 src/routes/api/proposals/voters/remove/+server.ts | 5 ++++-
 3 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/.jules/bolt.md b/.jules/bolt.md
index 91541609..74b936c6 100644
--- a/.jules/bolt.md
+++ b/.jules/bolt.md
@@ -9,3 +9,8 @@
 
 **Learning:** Using `on:keyup` for search input debouncing triggers unnecessary API calls on navigation keys (arrows, home, end) and misses changes from paste/cut. Svelte's reactive statements `$: debounce(value)` provide a robust, declarative way to trigger debouncing only when the value actually changes.
 **Action:** Replace `on:keyup` handlers with reactive statements for input debouncing to improve performance and correctness.
+
+## 2024-11-20 - Set.prototype.has over Array.prototype.includes
+
+**Learning:** Using `Array.prototype.includes` inside `Array.prototype.filter` or loop iterations over large datasets creates an O(N*M) time complexity, potentially blocking the main thread significantly.
+**Action:** Always precompute a `Set` before loop operations and replace O(N) `Array.includes` with O(1) `Set.has` to keep time complexity to O(N+M).
diff --git a/src/routes/api/proposals/voters/add/+server.ts b/src/routes/api/proposals/voters/add/+server.ts
index 62f2caf8..87a2fd68 100644
--- a/src/routes/api/proposals/voters/add/+server.ts
+++ b/src/routes/api/proposals/voters/add/+server.ts
@@ -23,7 +23,10 @@ export async function GET() {
 			?.setValue()
 			.values.map((voter) => voter.addressValue().value.toString('hex')) ?? [];
 
-	const newVoters = owners.filter((owner) => !voters.includes(owner)).slice(0, 50);
+	// Performance optimization: Precompute a Set for O(1) lookups instead of O(N) Array.prototype.includes
+	// This reduces time complexity from O(N*M) to O(N+M)
+	const votersSet = new Set(voters);
+	const newVoters = owners.filter((owner) => !votersSet.has(owner)).slice(0, 50);
 	if (newVoters.length === 0) return json({ newVoters }, { status: 200 });
 
 	const votingContract = await metaNamesSdk.contractRepository.getContract({
diff --git a/src/routes/api/proposals/voters/remove/+server.ts b/src/routes/api/proposals/voters/remove/+server.ts
index d024e90f..04737e78 100644
--- a/src/routes/api/proposals/voters/remove/+server.ts
+++ b/src/routes/api/proposals/voters/remove/+server.ts
@@ -25,7 +25,10 @@ export async function GET() {
 			?.setValue()
 			.values.map((voter) => voter.addressValue().value.toString('hex')) ?? [];
 
-	const votersToRemove = voters.filter((voter) => !owners.includes(voter)).slice(0, 50);
+	// Performance optimization: Precompute a Set for O(1) lookups instead of O(N) Array.prototype.includes
+	// This reduces time complexity from O(N*M) to O(N+M)
+	const ownersSet = new Set(owners);
+	const votersToRemove = voters.filter((voter) => !ownersSet.has(voter)).slice(0, 50);
 	if (votersToRemove.length === 0) return json({ newVoters: votersToRemove }, { status: 200 });
 
 	const votingContract = await metaNamesSdk.contractRepository.getContract({