Initial commit

src/pypdevs/logger.py

@@ -0,0 +1,108 @@
+# Copyright 2014 Modelling, Simulation and Design Lab (MSDL) at 
+# McGill University and the University of Antwerp (http://msdl.cs.mcgill.ca/)
+# 
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#    http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""
+Logger for Syslog
+"""
+
+logger = None
+location = None
+queue = []
+import threading
+loglock = threading.Lock()
+
+def setLogger(loc, address, loglevel):
+    """
+    Sets the logger object
+
+    :param loc: location of the server, to prepend to every logged message
+    :param address: the address of the syslog server in the form of (ip-address, port)
+    :param loglevel: the level of logging to perform, should be one specified in the logging module
+    """
+    if loglevel is None:
+        return
+    global logger
+    if logger is not None:
+        # A logger is already set, so ignore this one
+        return
+    import logging
+    import logging.handlers
+    handler = logging.handlers.SysLogHandler(address, facility=19)
+    local_logger = logging.getLogger('PyPDEVS-logging')
+    local_logger.addHandler(handler)
+    local_logger.setLevel(loglevel)
+    global location
+    location = loc
+    # Now make the logger 'public'
+    logger = local_logger
+
+def log(level, msg, logger):
+    """
+    Do the actual logging at the specified level, but save it in case no logger exists yet
+
+    :param level: string representation of the function to call on the logger
+    :param msg: the message to log
+    :returns: True -- to allow it as an #assert statement
+    """
+    with loglock:
+        global location
+        global queue
+        if len(msg) > 80:
+            msg = msg[:79]
+        if logger is not None:
+            # Flush the queue first
+            for level1, msg1 in queue:
+                getattr(logger, level1)("%s -- %s" % (location, msg1))
+            queue = []
+            getattr(logger, level)("%s -- %s" % (location, msg))
+        else:
+            queue.append((level, msg))
+        return True
+
+def debug(msg):
+    """
+    Debug logging statement
+
+    :param msg: the message to print
+    :returns: True -- to allow it as an #assert statement
+    """
+    return log("debug", msg, logger)
+
+def info(msg):
+    """
+    Informational logging statement
+
+    :param msg: the message to print
+    :returns: True -- to allow it as an #assert statement
+    """
+    return log("info", msg, logger)
+
+def warn(msg):
+    """
+    Warning logging statement
+
+    :param msg: the message to print
+    :returns: True -- to allow it as an #assert statement
+    """
+    return log("warn", msg, logger)
+
+def error(msg):
+    """
+    Error logging statement
+
+    :param msg: the message to print
+    :returns: True -- to allow it as an #assert statement
+    """
+    return log("error", msg, logger)