correcting logic to discern the lowest logging level

thespian/system/multiprocCommon.py

@@ -2,24 +2,20 @@
 python 'multiprocess' module.  Intended as a base class, not for
 direct usage."""
 
+import signal
+import sys
+from functools import partial
 
-import logging
 from thespian.actors import *
-from thespian.system.systemBase import systemBase
-from thespian.system.systemCommon import actorStartupFailed
-from thespian.system.utilis import thesplog, checkActorCapabilities, partition
-from thespian.system.transport import *
-from thespian.system.logdirector import *
-from thespian.system.utilis import setProcName, StatsManager
 from thespian.system.addressManager import ActorLocalAddress, CannotPickleAddress
+from thespian.system.logdirector import *
 from thespian.system.messages.multiproc import *
 from thespian.system.sourceLoader import loadModuleFromHashSource
-from functools import partial
-import multiprocessing
-import signal
-from datetime import timedelta
-import sys
-
+from thespian.system.systemBase import systemBase
+from thespian.system.systemCommon import actorStartupFailed
+from thespian.system.transport import *
+from thespian.system.utilis import checkActorCapabilities, partition
+from thespian.system.utilis import setProcName, _name_to_level
 
 MAX_ADMIN_STARTUP_DELAY = timedelta(seconds=5)
 
@@ -512,6 +508,94 @@ def shutdown_signal_detected(signum, frame):
     return shutdown_signal_detected
 
 
+def get_min_log_level(logDefs):
+    """
+    Determine the minimum logging level based on the rules in:
+    https://docs.python.org/3/library/logging.config.html#logging.config.dictConfig
+
+    Note: The level and handlers entries are interpreted as for the root logger,
+    except that if a non-root logger's level is specified as NOTSET, the system
+    consults loggers higher up the hierarchy to determine the effective
+    level of the logger.
+
+    :param logDefs: a logging configuration dictionary object
+    :return: integer value of the lowest log level, or the default level: logging.WARNING.
+
+    >>> import logging
+    >>> import logging.config
+    >>> logDefs = {'version': 1, 'handlers': {
+    ... 'h1': {'class': 'logging.FileHandler', 'filename': 'example.log', 'filters': [],
+    ...        'level': "INFO"},
+    ... 'h2': {'class': 'logging.FileHandler', 'filename': 'example.log', 'filters': [],
+    ...        'level': "INFO"}}, 'loggers': {'': {'handlers': ['h1', 'h2'], 'level': "DEBUG"}}}
+    >>> logging.config.dictConfig(logDefs) # prove the config is considered valid
+    >>> get_min_log_level(logDefs) # logging.DEBUG
+    10
+
+    >>> logDefs = {'version': 1, 'root': {'level': 10}, 'loggers': {'one': {'level': 20}}}
+    >>> logging.config.dictConfig(logDefs)
+    >>> min1 = get_min_log_level(logDefs)
+    >>> logDefs = {'version': 1, 'root': {'level': 20}, 'loggers': {'one': {'level': 10}}}
+    >>> logging.config.dictConfig(logDefs)
+    >>> min2 = get_min_log_level(logDefs)
+    >>> min1 == min2 == 10
+    True
+
+    >>> get_min_log_level({'version' : 1}) # logging.WARNING is default log level
+    30
+
+    >>> logDefs = {'version': 1,
+    ...            'loggers': {'root': {'level': "INFO"}, 'handler2': {'level': logging.NOTSET}}}
+    >>> logging.config.dictConfig(logDefs)
+    >>> get_min_log_level(logDefs) # logging.INFO
+    20
+
+    >>> logDefs = {'version': 1, 'loggers': {'one': {'level': logging.NOTSET}}}
+    >>> logging.config.dictConfig(logDefs)
+    >>> get_min_log_level(logDefs) # logging.WARNING
+    30
+
+    >>> logDefs = {'version': 1,
+    ...                            'root': {'level': None},
+    ...                            'loggers': {'one': {'level': logging.NOTSET}}}
+    >>> logging.config.dictConfig(logDefs)
+    >>> get_min_log_level(logDefs) # logging.WARNING
+    30
+
+    """
+
+    levels = []
+    root_data = logDefs.get('root')
+    if root_data and root_data.get('level'):
+        if isinstance( root_data.get('level'), str):
+            root_val = _name_to_level.get(root_data.get('level'). upper())
+        else:
+            root_val = root_data.get('level')
+    else:
+        loggers = logDefs.get('loggers', {})
+        root_val_empty = loggers.get("", {}).get("level")
+        root_val_named = loggers.get("root", {}).get("level")
+        root_val = root_val_empty if root_val_empty else root_val_named
+    if root_val:
+        root_val = _name_to_level.get(root_val, root_val)
+
+    def dfs(mapping):
+        """Traverse and collect"""
+        for key, val in mapping.items():
+            if isinstance(val, dict):
+                dfs(val)
+            if key == 'level':
+                if isinstance(val, str):
+                    val = _name_to_level[val.upper()]
+                if val == logging.NOTSET and root_val and root_val > logging.NOTSET:
+                    continue
+                levels.append(val)
+
+    dfs(logDefs)
+    levels = [tmp for tmp in levels if tmp] # swallow None values
+    return min(levels) if levels else logging.WARNING
+
+
 def startChild(childClass, globalName, endpoint, transportClass,
                sourceHash, sourceToLoad,
                parentAddr, adminAddr, notifyAddr, loggerAddr,
@@ -544,24 +628,7 @@ def startChild(childClass, globalName, endpoint, transportClass,
     # logging.shutdown() because (a) that does not do enough to reset,
     # and (b) it shuts down handlers, but we want to leave the parent's
     # handlers alone.
-    if logDefs:
-        levelIn = lambda d: d.get('level', 0)
-        minLevelIn = lambda l: min(list(l)) if list(l) else 0
-        levels = list(
-            filter(None,
-                   ([ minLevelIn([levelIn(logDefs[key][subkey])
-                                  for subkey in logDefs[key]
-                                  # if subkey in [ 'loggers', 'handlers'
-                                  if isinstance(logDefs[key][subkey], dict)
-                   ])
-                      if key in ['loggers', 'handlers'] and isinstance(logDefs[key], dict)
-                      else (levelIn(logDefs[key]) if key == 'root'
-                            else (logDefs[key] if key == 'level'
-                                  else None))
-                      for key in logDefs ])))
-        lowestLevel = minLevelIn(levels)
-    else:
-        lowestLevel = 0
+    lowestLevel = get_min_log_level(logDefs)
     logging.root = ThespianLogForwarder(loggerAddr, transport, logLevel=lowestLevel)
     logging.Logger.root = logging.root
     logging.Logger.manager = logging.Manager(logging.Logger.root)

thespian/system/utilis.py

@@ -17,7 +17,8 @@
     "ERROR": logging.ERROR,
     "WARNING": logging.WARNING,
     "INFO": logging.INFO,
-    "DEBUG": logging.DEBUG
+    "DEBUG": logging.DEBUG,
+    "NOTSET": logging.NOTSET
 }
 
 # Default/current logging controls