From 6b34e849bedd62deb8ef4964c399f3e6ebd87bb7 Mon Sep 17 00:00:00 2001
From: Alexander Schmidt <alex@treefish.org>
Date: Tue, 6 Oct 2020 22:50:30 +0200
Subject: [PATCH] major refactoring

---
 src/logalert.py | 56 +++++++++++++++++++++++++++++++++----------------
 src/misc.py     |  8 +++++++
 2 files changed, 46 insertions(+), 18 deletions(-)

diff --git a/src/logalert.py b/src/logalert.py
index c8eed19..73e5660 100755
--- a/src/logalert.py
+++ b/src/logalert.py
@@ -2,13 +2,26 @@
 
 import argparse
 import logging
+import os
+import signal
 import time
 
 import misc
 
-MAX_LINES = 10
+LINES_TO_KEEP = 10
 ALERT_INTERVAL = 86400
 
+def handleInterrupt(sig, frame):
+    global stop
+    if os.getpid() == mainPid:
+        logging.info( "Got stop signal." )
+        stop = True
+
+mainPid = os.getpid()
+signal.signal(signal.SIGINT, handleInterrupt)
+
+stop = False
+
 parser = argparse.ArgumentParser(description='Alert on excessive number of error log lines.')
 parser.add_argument('logfile', type=str, help='logfile to be watched')
 parser.add_argument('handler', type=str,
@@ -26,35 +39,39 @@ logging.basicConfig(format='[%(asctime)s] %(levelname)s: %(message)s',
                     level=logging.getLevelName(args.log_lvl),
                     datefmt='%m/%d/%Y %H:%M:%S')
 
-kept_times = []
+num_intervals = (args.num_intervals + 1)
+intervals = [False] * num_intervals
 lines = []
-last_slot_time = None
+last_time_slot = 0
+interval_ptr = 0
 error_state = False
 last_alert_time = 0
 
 for line in misc.follow_file(args.logfile):
     time_now = time.time()
-    slot_now = int(time_now) // args.interval_size
+    time_slot = int(time_now) // args.interval_size
+    time_slot_diff = time_slot - last_time_slot
+    last_time_slot = time_slot
 
-    if line != None:
-        if not last_slot_time or slot_now > last_slot_time:
-            kept_times.append(slot_now)
-            last_slot_time = slot_now
+    interval_ptr = (interval_ptr + time_slot_diff) % num_intervals
+    for i in range(0, min(num_intervals, time_slot_diff)):
+        intervals[(interval_ptr + i ) % num_intervals] = False
+
+    if line:
+        intervals[interval_ptr] = True
         lines.append(line)
-        if len(lines) > MAX_LINES:
+        if len(lines) > LINES_TO_KEEP:
             lines.pop(0)
 
-    while len(kept_times) > 0 and \
-          kept_times[0] <= slot_now - (args.num_intervals + 1):
-        kept_times.pop(0)
-
-    intervals = [False] * (args.num_intervals + 1)
-    for kept_time in kept_times:
-        intervals[slot_now - kept_time] = True
+    logging.debug( misc.print_list(intervals, interval_ptr) )
 
-    logging.debug(intervals)
+    intervals_error_state = True
+    for i in range(1, num_intervals):
+        if not intervals[(interval_ptr + i) % num_intervals]:
+            intervals_error_state = False
+            break
 
-    if not False in intervals[1:]:
+    if intervals_error_state:
         if not error_state or time_now - last_alert_time > ALERT_INTERVAL:
             last_alert_time = time_now
             misc.feed_handler( args.handler,
@@ -71,3 +88,6 @@ for line in misc.follow_file(args.logfile):
         if error_state:
             logging.info("Leaving error state.")
             error_state = False
+
+    if stop:
+        break
diff --git a/src/misc.py b/src/misc.py
index 8d8253d..821159f 100644
--- a/src/misc.py
+++ b/src/misc.py
@@ -48,3 +48,11 @@ def create_msg(title, icon, logfile, text, lines):
     for line in lines: msg += line + "\n"
     msg += "</pre>"
     return msg
+
+def print_list(lst, ptr):
+    txt = '['
+    for i in range(0, len(lst)):
+        txt += str( lst[(ptr + i) % len(lst)] )
+        if i < len(lst) - 1: txt += ', '
+    txt += ']'
+    return txt
-- 
2.39.5