Panu's custom handler.

Signed-off-by: Martin Raspaud <martin.raspaud@smhi.se>

trollduction/custom_handler.py

@@ -0,0 +1,120 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+
+# Copyright (c) 2014 Martin Raspaud
+
+# Author(s):
+
+#   Martin Raspaud <martin.raspaud@smhi.se>
+
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+"""For Panu
+"""
+
+from logging.handlers import TimedRotatingFileHandler
+import re
+import time
+import os
+keys = {"%Y": r"\d{4}",
+        "%y": r"\d{2}",
+        "%m": r"\d{2}",
+        "%d": r"\d{2}",
+        "%H": r"\d{2}",
+        "%M": r"\d{2}",
+        "%S": r"\d{2}",
+        "%j": r"\d{3}"}
+
+class PanusTimedRotatingFileHandler(TimedRotatingFileHandler):
+    """Like TimedRotatingFileHandler with a custom filename template.
+    """
+
+    def __init__(self, template, *args, **kwargs):
+
+        self.template = template
+        current_time = int(time.time())
+        if kwargs.get("utc", False):
+            time_tuple = time.gmtime(current_time)
+        else:
+            time_tuple = time.localtime(current_time)
+        filename = time.strftime(self.template, time_tuple)
+
+        self.match = os.path.basename(self.template)
+        for key, val in keys.iteritems():
+            self.match = self.match.replace(key, val)
+
+        self.match = re.compile(self.match)
+        TimedRotatingFileHandler.__init__(self, filename, *args, **kwargs)
+
+    def getFilesToDelete(self):
+        """
+        Determine the files to delete when rolling over.
+
+        More specific than the earlier method, which assumed the date to be a
+        suffix.
+        """
+        dirname, basename = os.path.split(self.baseFilename)
+        del basename
+        filenames = os.listdir(dirname)
+        result = []
+        for filename in filenames:
+            if self.match.match(filename):
+                result.append(os.path.join(dirname, filename))
+        result.sort(reverse=True)
+        print result
+        if len(result) < self.backupCount:
+            result = []
+        else:
+            result = result[:len(result) - self.backupCount]
+        print result
+        return result
+
+    def doRollover(self):
+        """
+        do a rollover; If there is a backup count, then we have to get a list of
+        matching filenames, sort them and remove the oldest ones.
+        """
+        if self.stream:
+            self.stream.close()
+            self.stream = None
+        # get the time that this sequence started at and make it a TimeTuple
+        current_time = int(time.time())
+        now = time.localtime(current_time)[-1]
+        if self.utc:
+            time_tuple = time.gmtime(current_time)
+        else:
+            time_tuple = time.localtime(current_time)
+        self.baseFilename = time.strftime(self.template, time_tuple)
+        if self.backupCount > 0:
+            for old_file in self.getFilesToDelete():
+                os.remove(old_file)
+        self.stream = self._open()
+        new_rollover_at = self.computeRollover(current_time)
+        while new_rollover_at <= current_time:
+            new_rollover_at = new_rollover_at + self.interval
+        #If DST changes and midnight or weekly rollover, adjust for this.
+        if ((self.when == 'MIDNIGHT' or self.when.startswith('W'))
+            and not self.utc):
+            dst_at_rollover = time.localtime(new_rollover_at)[-1]
+            if now != dst_at_rollover:
+                if not now:  # DST kicks in before next rollover,
+                             # so we need to deduct an hour
+                    addend = -3600
+                else:           # DST bows out before next rollover,
+                                # so we need to add an hour
+                    addend = 3600
+                new_rollover_at += addend
+        self.rolloverAt = new_rollover_at
+
+