From aaa766b2ba48b0e75d1c944f4ac56ac6feb12130 Mon Sep 17 00:00:00 2001
From: iliya <iliyazelenkog@gmail.com>
Date: Wed, 25 Mar 2026 13:59:03 +0200
Subject: [PATCH] perf: replace 8 filter passes with single-pass message
 categorization

Cherry-picked from upstream 9fa2590e
---
 src/main/services/parsing/SessionParser.ts | 45 ++++++++++++++++------
 1 file changed, 33 insertions(+), 12 deletions(-)

diff --git a/src/main/services/parsing/SessionParser.ts b/src/main/services/parsing/SessionParser.ts
index 093dcaaf..fc5c85bd 100644
--- a/src/main/services/parsing/SessionParser.ts
+++ b/src/main/services/parsing/SessionParser.ts
@@ -85,21 +85,42 @@ export class SessionParser {
    * Process parsed messages into structured data.
    */
   private processMessages(messages: ParsedMessage[]): ParsedSession {
-    // Group by type
+    // Single-pass categorization instead of 8 separate filter passes
     const byType = {
-      user: messages.filter((m) => m.type === 'user'),
-      realUser: messages.filter(isParsedRealUserMessage),
-      internalUser: messages.filter(isParsedInternalUserMessage),
-      assistant: messages.filter((m) => m.type === 'assistant'),
-      system: messages.filter((m) => m.type === 'system'),
-      other: messages.filter(
-        (m) => m.type !== 'user' && m.type !== 'assistant' && m.type !== 'system'
-      ),
+      user: [] as ParsedMessage[],
+      realUser: [] as ParsedMessage[],
+      internalUser: [] as ParsedMessage[],
+      assistant: [] as ParsedMessage[],
+      system: [] as ParsedMessage[],
+      other: [] as ParsedMessage[],
     };
+    const sidechainMessages: ParsedMessage[] = [];
+    const mainMessages: ParsedMessage[] = [];
 
-    // Separate sidechain and main messages
-    const sidechainMessages = messages.filter((m) => m.isSidechain);
-    const mainMessages = messages.filter((m) => !m.isSidechain);
+    for (const m of messages) {
+      switch (m.type) {
+        case 'user':
+          byType.user.push(m);
+          if (isParsedRealUserMessage(m)) byType.realUser.push(m);
+          if (isParsedInternalUserMessage(m)) byType.internalUser.push(m);
+          break;
+        case 'assistant':
+          byType.assistant.push(m);
+          break;
+        case 'system':
+          byType.system.push(m);
+          break;
+        default:
+          byType.other.push(m);
+          break;
+      }
+
+      if (m.isSidechain) {
+        sidechainMessages.push(m);
+      } else {
+        mainMessages.push(m);
+      }
+    }
 
     // Calculate metrics
     const metrics = calculateMetrics(messages);