remote logging (issue 46)

Change-Id: Id92e66280811b1f871157b5c2ceca65085d2c15b
Reviewed-on: https://forge.frm2.tum.de/review/c/sine2020/secop/playground/+/27346
Tested-by: Jenkins Automated Tests <pedersen+jenkins@frm2.tum.de>
Reviewed-by: Enrico Faulhaber <enrico.faulhaber@frm2.tum.de>
Reviewed-by: Markus Zolliker <markus.zolliker@psi.ch>

secop/logging.py

@@ -0,0 +1,66 @@
+#!/usr/bin/env python
+#  -*- coding: utf-8 -*-
+# *****************************************************************************
+# 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 2 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, write to the Free Software Foundation, Inc.,
+# 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+#
+# Module authors:
+#   Markus Zolliker <markus.zolliker@psi.ch>
+# *****************************************************************************
+
+
+from logging import LoggerAdapter
+from mlzlog import LOGLEVELS
+
+OFF = 99
+LOG_LEVELS = dict(LOGLEVELS, off=OFF)
+LEVEL_NAMES = {v: k for k, v in LOG_LEVELS.items()}
+
+
+def check_level(level):
+    try:
+        if isinstance(level, str):
+            return LOG_LEVELS[level.lower()]
+        if level in LEVEL_NAMES:
+            return level
+    except KeyError:
+        pass
+    raise ValueError('%r is not a valid level' % level)
+
+
+class Adapter(LoggerAdapter):
+    def __init__(self, modobj):
+        super().__init__(modobj.log, {})
+        self.subscriptions = {}  # dict [conn] of level
+        self.modobj = modobj
+
+    def log(self, level, msg, *args, **kwargs):
+        super().log(level, msg, *args, **kwargs)
+        for conn, lev in self.subscriptions.items():
+            if level >= lev:
+                self.modobj.DISPATCHER.send_log_msg(
+                    conn, self.modobj.name, LEVEL_NAMES[level], msg % args)
+
+    def set_log_level(self, conn, level):
+        level = check_level(level)
+        if level == OFF:
+            self.subscriptions.pop(conn, None)
+        else:
+            self.subscriptions[conn] = level
+
+
+def set_log_level(modobj, conn, level):
+    if not isinstance(modobj.log, Adapter):
+        modobj.log = Adapter(modobj)
+    modobj.log.set_log_level(conn, level)