From 5a20953a81c1e58e45ad2a2472f4306bf8c4db00 Mon Sep 17 00:00:00 2001
From: KnugiHK <24708955+KnugiHK@users.noreply.github.com>
Date: Tue, 6 Jan 2026 20:51:29 +0800
Subject: [PATCH] Optimize quoted message lookups via global in-memory mapping

This change replaces the inefficient N+1 SQL query pattern with a pre-computed hash map. By fetching `ZSTANZAID` and `ZTEXT` pairs globally before processing, the exporter can resolve quoted message content in O(1) time.

Crucially, this maintains parity with the Android exporter by ensuring that replies to messages outside the current date or chat filters are still correctly rendered, providing full conversational context without the performance penalty of repeated database hits.
---
 Whatsapp_Chat_Exporter/ios_handler.py | 17 +++++++----------
 1 file changed, 7 insertions(+), 10 deletions(-)

diff --git a/Whatsapp_Chat_Exporter/ios_handler.py b/Whatsapp_Chat_Exporter/ios_handler.py
index 0501ac5..243ae58 100644
--- a/Whatsapp_Chat_Exporter/ios_handler.py
+++ b/Whatsapp_Chat_Exporter/ios_handler.py
@@ -178,6 +178,10 @@ def messages(db, data, media_folder, timezone_offset, filter_date, filter_chat,
     """
     c.execute(messages_query)
 
+    reply_query = """SELECT ZSTANZAID, ZTEXT FROM ZWAMESSAGE WHERE ZTEXT IS NOT NULL"""
+    cursor2.execute(reply_query)
+    message_map = {row[0][:17]: row[1] for row in cursor2.fetchall() if row[0]}
+
     # Process each message
     i = 0
     content = c.fetchone()
@@ -207,7 +211,7 @@ def messages(db, data, media_folder, timezone_offset, filter_date, filter_chat,
         )
 
         # Process message data
-        invalid = process_message_data(message, content, is_group_message, data, cursor2, no_reply)
+        invalid = process_message_data(message, content, is_group_message, data, message_map, no_reply)
 
         # Add valid messages to chat
         if not invalid:
@@ -221,7 +225,7 @@ def messages(db, data, media_folder, timezone_offset, filter_date, filter_chat,
     logger.info(f"Processed {total_row_number} messages{CLEAR_LINE}")
 
 
-def process_message_data(message, content, is_group_message, data, cursor2, no_reply):
+def process_message_data(message, content, is_group_message, data, message_map, no_reply):
     """Process and set message data from content row."""
     # Handle group sender info
     if is_group_message and content["ZISFROMME"] == 0:
@@ -247,14 +251,7 @@ def process_message_data(message, content, is_group_message, data, cursor2, no_r
     if content["ZMETADATA"] is not None and content["ZMETADATA"].startswith(b"\x2a\x14") and not no_reply:
         quoted = content["ZMETADATA"][2:19]
         message.reply = quoted.decode()
-        cursor2.execute(f"""SELECT ZTEXT
-                            FROM ZWAMESSAGE
-                            WHERE ZSTANZAID LIKE '{message.reply}%'""")
-        quoted_content = cursor2.fetchone()
-        if quoted_content and "ZTEXT" in quoted_content:
-            message.quoted_data = quoted_content["ZTEXT"]
-        else:
-            message.quoted_data = None
+        message.quoted_data = message_map.get(message.reply)
 
     # Handle stickers
     if content["ZMESSAGETYPE"] == 15: