gh-93162: Add ability to configure QueueHandler/QueueListener together (GH-93269)

Also, provide getHandlerByName() and getHandlerNames() APIs.

Closes #93162.

1 files changed, 83 insertions, 9 deletions

diff --git a/Lib/logging/config.py b/Lib/logging/config.py
index 86a1e4e..2b9d90c 100644
--- a/Lib/logging/config.py
+++ b/Lib/logging/config.py
@@ -1,4 +1,4 @@
-# Copyright 2001-2019 by Vinay Sajip. All Rights Reserved.
+# Copyright 2001-2022 by Vinay Sajip. All Rights Reserved.
 #
 # Permission to use, copy, modify, and distribute this software and its
 # documentation for any purpose and without fee is hereby granted,
@@ -19,15 +19,17 @@ Configuration functions for the logging package for Python. The core package
 is based on PEP 282 and comments thereto in comp.lang.python, and influenced
 by Apache's log4j system.
 
-Copyright (C) 2001-2019 Vinay Sajip. All Rights Reserved.
+Copyright (C) 2001-2022 Vinay Sajip. All Rights Reserved.
 
 To use, simply 'import logging' and log away!
 """
 
 import errno
+import functools
 import io
 import logging
 import logging.handlers
+import queue
 import re
 import struct
 import threading
@@ -563,7 +565,7 @@ class DictConfigurator(BaseConfigurator):
                         handler.name = name
                         handlers[name] = handler
                     except Exception as e:
-                        if 'target not configured yet' in str(e.__cause__):
+                        if ' not configured yet' in str(e.__cause__):
                             deferred.append(name)
                         else:
                             raise ValueError('Unable to configure handler '
@@ -702,6 +704,21 @@ class DictConfigurator(BaseConfigurator):
             except Exception as e:
                 raise ValueError('Unable to add filter %r' % f) from e
 
+    def _configure_queue_handler(self, klass, **kwargs):
+        if 'queue' in kwargs:
+            q = kwargs['queue']
+        else:
+            q = queue.Queue()  # unbounded
+        rhl = kwargs.get('respect_handler_level', False)
+        if 'listener' in kwargs:
+            lklass = kwargs['listener']
+        else:
+            lklass = logging.handlers.QueueListener
+        listener = lklass(q, *kwargs['handlers'], respect_handler_level=rhl)
+        handler = klass(q)
+        handler.listener = listener
+        return handler
+
     def configure_handler(self, config):
         """Configure a handler from a dictionary."""
         config_copy = dict(config)  # for restoring in case of error
@@ -721,26 +738,83 @@ class DictConfigurator(BaseConfigurator):
             factory = c
         else:
             cname = config.pop('class')
-            klass = self.resolve(cname)
-            #Special case for handler which refers to another handler
+            if callable(cname):
+                klass = cname
+            else:
+                klass = self.resolve(cname)
             if issubclass(klass, logging.handlers.MemoryHandler) and\
                 'target' in config:
+                # Special case for handler which refers to another handler
                 try:
-                    th = self.config['handlers'][config['target']]
+                    tn = config['target']
+                    th = self.config['handlers'][tn]
                     if not isinstance(th, logging.Handler):
                         config.update(config_copy)  # restore for deferred cfg
                         raise TypeError('target not configured yet')
                     config['target'] = th
                 except Exception as e:
-                    raise ValueError('Unable to set target handler '
-                                     '%r' % config['target']) from e
+                    raise ValueError('Unable to set target handler %r' % tn) from e
+            elif issubclass(klass, logging.handlers.QueueHandler):
+                # Another special case for handler which refers to other handlers
+                if 'handlers' not in config:
+                    raise ValueError('No handlers specified for a QueueHandler')
+                if 'queue' in config:
+                    qspec = config['queue']
+                    if not isinstance(qspec, queue.Queue):
+                        if isinstance(qspec, str):
+                            q = self.resolve(qspec)
+                            if not callable(q):
+                                raise TypeError('Invalid queue specifier %r' % qspec)
+                            q = q()
+                        elif isinstance(qspec, dict):
+                            if '()' not in qspec:
+                                raise TypeError('Invalid queue specifier %r' % qspec)
+                            q = self.configure_custom(dict(qspec))
+                        else:
+                            raise TypeError('Invalid queue specifier %r' % qspec)
+                        config['queue'] = q
+                if 'listener' in config:
+                    lspec = config['listener']
+                    if isinstance(lspec, type):
+                        if not issubclass(lspec, logging.handlers.QueueListener):
+                            raise TypeError('Invalid listener specifier %r' % lspec)
+                    else:
+                        if isinstance(lspec, str):
+                            listener = self.resolve(lspec)
+                            if isinstance(listener, type) and\
+                                not issubclass(listener, logging.handlers.QueueListener):
+                                raise TypeError('Invalid listener specifier %r' % lspec)
+                        elif isinstance(lspec, dict):
+                            if '()' not in lspec:
+                                raise TypeError('Invalid listener specifier %r' % lspec)
+                            listener = self.configure_custom(dict(lspec))
+                        else:
+                            raise TypeError('Invalid listener specifier %r' % lspec)
+                        if not callable(listener):
+                            raise TypeError('Invalid listener specifier %r' % lspec)
+                        config['listener'] = listener
+                hlist = []
+                try:
+                    for hn in config['handlers']:
+                        h = self.config['handlers'][hn]
+                        if not isinstance(h, logging.Handler):
+                            config.update(config_copy)  # restore for deferred cfg
+                            raise TypeError('Required handler %r '
+                                            'is not configured yet' % hn)
+                        hlist.append(h)
+                except Exception as e:
+                    raise ValueError('Unable to set required handler %r' % hn) from e
+                config['handlers'] = hlist
             elif issubclass(klass, logging.handlers.SMTPHandler) and\
                 'mailhost' in config:
                 config['mailhost'] = self.as_tuple(config['mailhost'])
             elif issubclass(klass, logging.handlers.SysLogHandler) and\
                 'address' in config:
                 config['address'] = self.as_tuple(config['address'])
-            factory = klass
+            if issubclass(klass, logging.handlers.QueueHandler):
+                factory = functools.partial(self._configure_queue_handler, klass)
+            else:
+                factory = klass
         props = config.pop('.', None)
         kwargs = {k: config[k] for k in config if valid_ident(k)}
         try: