From 5e9dcadb625719fbe9907d96155e84baa0c11475 Mon Sep 17 00:00:00 2001
From: karel26 <41538366+karel26@users.noreply.github.com>
Date: Mon, 20 Jan 2025 18:57:47 +0100
Subject: [PATCH] HOTFIX: - LogAnalyser: performance issue fixed

---
 extensions/loganalyser/extension.py | 61 +++++++++++++++++++----------
 1 file changed, 40 insertions(+), 21 deletions(-)

diff --git a/extensions/loganalyser/extension.py b/extensions/loganalyser/extension.py
index d1d93254..b4df72a5 100644
--- a/extensions/loganalyser/extension.py
+++ b/extensions/loganalyser/extension.py
@@ -54,6 +54,7 @@ async def do_startup(self):
         asyncio.create_task(self.check_log())
 
     async def prepare(self) -> bool:
+        os.remove(self.logfile)
         await self.do_startup()
         self.running = True
         return await super().startup()
@@ -71,6 +72,12 @@ def shutdown(self) -> bool:
         self.stop_event.set()
         return super().shutdown()
 
+    @property
+    def logfile(self) -> str:
+        return os.path.expandvars(
+            self.config.get('log', os.path.join(self.server.instance.home, 'Logs', 'dcs.log'))
+        )
+
     async def check_log(self):
         try:
             logfile = os.path.expandvars(
@@ -83,28 +90,40 @@ async def check_log(self):
 
             self.log_pos = 0
             while not self.stop_event.is_set():
-                if not os.path.exists(logfile):
-                    self.log_pos = 0
-                    await asyncio.sleep(1)
-                    continue
-
-                async with aiofiles.open(logfile, mode='r', encoding='utf-8', errors='ignore') as file:
-                    await file.seek(self.log_pos, 0)
-                    async for line in file:
-                        if '=== Log closed.' in line:
-                            self.log_pos = -1
-                            return
-                        match = combined_pattern.search(line)
-                        if match:
-                            for key, value in match.groupdict().items():
-                                if value:
-                                    callback = callback_map[key]
-                                    if asyncio.iscoroutinefunction(callback):
-                                        asyncio.create_task(callback(self.log_pos, line, match))
-                                    else:
-                                        self.loop.run_in_executor(None, callback, self.log_pos, line, match)
+                try:
+                    if not os.path.exists(logfile):
+                        self.log_pos = 0
+                        continue
+
+                    async with aiofiles.open(logfile, mode='r', encoding='utf-8', errors='ignore') as file:
+                        max_pos = os.fstat(file.fileno()).st_size
+                        if self.log_pos == -1 or max_pos == self.log_pos:
+                            self.log_pos = max_pos
+                            continue
+                        # if the logfile was rotated, seek to the beginning of the file
+                        elif max_pos < self.log_pos:
+                            self.log_pos = 0
+
+                        self.log_pos = await file.seek(self.log_pos, 0)
+                        await file.seek(self.log_pos, 0)
+                        async for line in file:
+                            if '=== Log closed.' in line:
+                                self.log_pos = -1
+                                return
+                            match = combined_pattern.search(line)
+                            if match:
+                                for key, value in match.groupdict().items():
+                                    if value:
+                                        callback = callback_map[key]
+                                        if asyncio.iscoroutinefunction(callback):
+                                            asyncio.create_task(callback(self.log_pos, line, match))
+                                        else:
+                                            self.loop.run_in_executor(None, callback, self.log_pos, line, match)
                         self.log_pos = await file.tell()
-
+                except FileNotFoundError as ex:
+                    pass
+                finally:
+                    await asyncio.sleep(1)
         except Exception as ex:
             self.log.exception(ex)
         finally: