klipper update

klippy/queuelogger.py

@@ -0,0 +1,75 @@
+# Code to implement asynchronous logging from a background thread
+#
+# Copyright (C) 2016-2019  Kevin O'Connor <kevin@koconnor.net>
+#
+# This file may be distributed under the terms of the GNU GPLv3 license.
+import logging, logging.handlers, threading, queue, time
+
+# Class to forward all messages through a queue to a background thread
+class QueueHandler(logging.Handler):
+    def __init__(self, queue):
+        logging.Handler.__init__(self)
+        self.queue = queue
+    def emit(self, record):
+        try:
+            self.format(record)
+            record.msg = record.message
+            record.args = None
+            record.exc_info = None
+            self.queue.put_nowait(record)
+        except Exception:
+            self.handleError(record)
+
+# Class to poll a queue in a background thread and log each message
+class QueueListener(logging.handlers.TimedRotatingFileHandler):
+    def __init__(self, filename):
+        logging.handlers.TimedRotatingFileHandler.__init__(
+            self, filename, when='midnight', backupCount=5)
+        self.bg_queue = queue.Queue()
+        self.bg_thread = threading.Thread(target=self._bg_thread)
+        self.bg_thread.start()
+        self.rollover_info = {}
+    def _bg_thread(self):
+        while 1:
+            record = self.bg_queue.get(True)
+            if record is None:
+                break
+            self.handle(record)
+    def stop(self):
+        self.bg_queue.put_nowait(None)
+        self.bg_thread.join()
+    def set_rollover_info(self, name, info):
+        if info is None:
+            self.rollover_info.pop(name, None)
+            return
+        self.rollover_info[name] = info
+    def clear_rollover_info(self):
+        self.rollover_info.clear()
+    def doRollover(self):
+        logging.handlers.TimedRotatingFileHandler.doRollover(self)
+        lines = [self.rollover_info[name]
+                 for name in sorted(self.rollover_info)]
+        lines.append(
+            "=============== Log rollover at %s ===============" % (
+                time.asctime(),))
+        self.emit(logging.makeLogRecord(
+            {'msg': "\n".join(lines), 'level': logging.INFO}))
+
+MainQueueHandler = None
+
+def setup_bg_logging(filename, debuglevel):
+    global MainQueueHandler
+    ql = QueueListener(filename)
+    MainQueueHandler = QueueHandler(ql.bg_queue)
+    root = logging.getLogger()
+    root.addHandler(MainQueueHandler)
+    root.setLevel(debuglevel)
+    return ql
+
+def clear_bg_logging():
+    global MainQueueHandler
+    if MainQueueHandler is not None:
+        root = logging.getLogger()
+        root.removeHandler(MainQueueHandler)
+        root.setLevel(logging.WARNING)
+        MainQueueHandler = None