⚡ Bolt: Replace multiple array reduce calls with a single loop in session APIs

.jules/bolt.md

@@ -0,0 +1,4 @@
+
+## 2024-05-18 - Single Loop Over Prisma Relations
+**Learning:** When processing large datasets from Prisma `include` blocks, multiple iteration passes (like chained `.reduce()` calls) over the in-memory relations add unnecessary iteration overhead and can cause performance bottlenecks.
+**Action:** Avoid chaining array methods (`.map()`, `.reduce()`, `.filter()`) on large datasets fetched via Prisma. Prefer a single loop (like a `for...of` loop) to calculate multiple derived values simultaneously.

packages/web/src/app/api/orgs/[orgSlug]/dashboard/sessions/[sessionId]/route.ts

@@ -43,9 +43,16 @@ export async function GET(
       return forbiddenByRole(access.role, '본인 세션만 열람 가능')
     }
 
-    const totalInput = session.usageRecords.reduce((sum, r) => sum + r.inputTokens, 0)
-    const totalOutput = session.usageRecords.reduce((sum, r) => sum + r.outputTokens, 0)
-    const totalCost = session.usageRecords.reduce((sum, r) => sum + (r.estimatedCostUsd ?? 0), 0)
+    // ⚡ Bolt: Use a single loop to calculate totals, avoiding 3 iteration passes over the array.
+    let totalInput = 0
+    let totalOutput = 0
+    let totalCost = 0
+
+    for (const r of session.usageRecords) {
+      totalInput += r.inputTokens
+      totalOutput += r.outputTokens
+      totalCost += r.estimatedCostUsd ?? 0
+    }
 
     const usageTimeline: SessionTimelineUsage[] = session.usageRecords.map((r) => ({
       timestamp: r.timestamp.toISOString(),

packages/web/src/app/api/orgs/[orgSlug]/dashboard/sessions/route.ts

@@ -33,13 +33,21 @@ const sessionInclude = {
 type SessionWithInclude = Prisma.ClaudeSessionGetPayload<{ include: typeof sessionInclude }>
 
 function getSessionTotals(session: SessionWithInclude) {
+  // ⚡ Bolt: Use a single loop to calculate totals, avoiding 3 iteration passes over the array.
+  let inputTokens = 0
+  let outputTokens = 0
+  let estimatedCostUsd = 0
+
+  for (const r of session.usageRecords) {
+    inputTokens += r.inputTokens
+    outputTokens += r.outputTokens
+    estimatedCostUsd += r.estimatedCostUsd ?? 0
+  }
+
   return {
-    inputTokens: session.usageRecords.reduce((sum, r) => sum + r.inputTokens, 0),
-    outputTokens: session.usageRecords.reduce((sum, r) => sum + r.outputTokens, 0),
-    estimatedCostUsd: session.usageRecords.reduce(
-      (sum, r) => sum + (r.estimatedCostUsd ?? 0),
-      0,
-    ),
+    inputTokens,
+    outputTokens,
+    estimatedCostUsd,
   }
 }