From d979eeda9f11f017b034f844df06493c00618212 Mon Sep 17 00:00:00 2001
From: Peter Steinberger <steipete@gmail.com>
Date: Mon, 2 Mar 2026 19:47:38 +0000
Subject: [PATCH] perf(runtime): reduce slack prep and qmd cache-key overhead

---
 src/memory/search-manager.ts                 | 34 ++++++++------------
 src/slack/monitor/message-handler/prepare.ts | 12 ++++---
 2 files changed, 21 insertions(+), 25 deletions(-)

diff --git a/src/memory/search-manager.ts b/src/memory/search-manager.ts
index 95b23379e..64c48078a 100644
--- a/src/memory/search-manager.ts
+++ b/src/memory/search-manager.ts
@@ -24,8 +24,9 @@ export async function getMemorySearchManager(params: {
   const resolved = resolveMemoryBackendConfig(params);
   if (resolved.backend === "qmd" && resolved.qmd) {
     const statusOnly = params.purpose === "status";
-    const cacheKey = buildQmdCacheKey(params.agentId, resolved.qmd);
+    let cacheKey: string | undefined;
     if (!statusOnly) {
+      cacheKey = buildQmdCacheKey(params.agentId, resolved.qmd);
       const cached = QMD_MANAGER_CACHE.get(cacheKey);
       if (cached) {
         return { manager: cached };
@@ -51,9 +52,15 @@ export async function getMemorySearchManager(params: {
               return await MemoryIndexManager.get(params);
             },
           },
-          () => QMD_MANAGER_CACHE.delete(cacheKey),
+          () => {
+            if (cacheKey) {
+              QMD_MANAGER_CACHE.delete(cacheKey);
+            }
+          },
         );
-        QMD_MANAGER_CACHE.set(cacheKey, wrapper);
+        if (cacheKey) {
+          QMD_MANAGER_CACHE.set(cacheKey, wrapper);
+        }
         return { manager: wrapper };
       }
     } catch (err) {
@@ -217,22 +224,7 @@ class FallbackMemoryManager implements MemorySearchManager {
 }
 
 function buildQmdCacheKey(agentId: string, config: ResolvedQmdConfig): string {
-  return `${agentId}:${stableSerialize(config)}`;
-}
-
-function stableSerialize(value: unknown): string {
-  return JSON.stringify(sortValue(value));
-}
-
-function sortValue(value: unknown): unknown {
-  if (Array.isArray(value)) {
-    return value.map((entry) => sortValue(entry));
-  }
-  if (value && typeof value === "object") {
-    const sortedEntries = Object.keys(value as Record<string, unknown>)
-      .toSorted((a, b) => a.localeCompare(b))
-      .map((key) => [key, sortValue((value as Record<string, unknown>)[key])]);
-    return Object.fromEntries(sortedEntries);
-  }
-  return value;
+  // ResolvedQmdConfig is assembled in a stable field order in resolveMemoryBackendConfig.
+  // Fast stringify avoids deep key-sorting overhead on this hot path.
+  return `${agentId}:${JSON.stringify(config)}`;
 }
diff --git a/src/slack/monitor/message-handler/prepare.ts b/src/slack/monitor/message-handler/prepare.ts
index 13ca763c1..2819d5e59 100644
--- a/src/slack/monitor/message-handler/prepare.ts
+++ b/src/slack/monitor/message-handler/prepare.ts
@@ -66,13 +66,17 @@ export async function prepareSlackMessage(params: {
     topic?: string;
     purpose?: string;
   } = {};
-  let channelType = message.channel_type;
-  if (!channelType || channelType !== "im") {
+  let resolvedChannelType = normalizeSlackChannelType(message.channel_type, message.channel);
+  // D-prefixed channels are always direct messages. Skip channel lookups in
+  // that common path to avoid an unnecessary API round-trip.
+  if (resolvedChannelType !== "im" && (!message.channel_type || message.channel_type !== "im")) {
     channelInfo = await ctx.resolveChannelName(message.channel);
-    channelType = channelType ?? channelInfo.type;
+    resolvedChannelType = normalizeSlackChannelType(
+      message.channel_type ?? channelInfo.type,
+      message.channel,
+    );
   }
   const channelName = channelInfo?.name;
-  const resolvedChannelType = normalizeSlackChannelType(channelType, message.channel);
   const isDirectMessage = resolvedChannelType === "im";
   const isGroupDm = resolvedChannelType === "mpim";
   const isRoom = resolvedChannelType === "channel" || resolvedChannelType === "group";