diff options
Diffstat (limited to 'logutils/dictconfig.py')
| -rw-r--r-- | logutils/dictconfig.py | 581 |
1 files changed, 581 insertions, 0 deletions
diff --git a/logutils/dictconfig.py b/logutils/dictconfig.py new file mode 100644 index 0000000..3516f75 --- /dev/null +++ b/logutils/dictconfig.py @@ -0,0 +1,581 @@ +# Copyright 2009-2010 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, +# provided that the above copyright notice appear in all copies and that +# both that copyright notice and this permission notice appear in +# supporting documentation, and that the name of Vinay Sajip +# not be used in advertising or publicity pertaining to distribution +# of the software without specific, written prior permission. +# VINAY SAJIP DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING +# ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL +# VINAY SAJIP BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR +# ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER +# IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT +# OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. + +import logging.handlers +import re +import sys +import types + +try: + basestring +except NameError: + basestring = str +try: + StandardError +except NameError: + StandardError = Exception + +IDENTIFIER = re.compile('^[a-z_][a-z0-9_]*$', re.I) + +def valid_ident(s): + m = IDENTIFIER.match(s) + if not m: + raise ValueError('Not a valid Python identifier: %r' % s) + return True + +# +# This function is defined in logging only in recent versions of Python +# +try: + from logging import _checkLevel +except ImportError: + def _checkLevel(level): + if isinstance(level, int): + rv = level + elif str(level) == level: + if level not in logging._levelNames: + raise ValueError('Unknown level: %r' % level) + rv = logging._levelNames[level] + else: + raise TypeError('Level not an integer or a ' + 'valid string: %r' % level) + return rv + +# The ConvertingXXX classes are wrappers around standard Python containers, +# and they serve to convert any suitable values in the container. The +# conversion converts base dicts, lists and tuples to their wrapped +# equivalents, whereas strings which match a conversion format are converted +# appropriately. +# +# Each wrapper should have a configurator attribute holding the actual +# configurator to use for conversion. + +class ConvertingDict(dict): + """A converting dictionary wrapper.""" + + def __getitem__(self, key): + value = dict.__getitem__(self, key) + result = self.configurator.convert(value) + #If the converted value is different, save for next time + if value is not result: + self[key] = result + if type(result) in (ConvertingDict, ConvertingList, + ConvertingTuple): + result.parent = self + result.key = key + return result + + def get(self, key, default=None): + value = dict.get(self, key, default) + result = self.configurator.convert(value) + #If the converted value is different, save for next time + if value is not result: + self[key] = result + if type(result) in (ConvertingDict, ConvertingList, + ConvertingTuple): + result.parent = self + result.key = key + return result + + def pop(self, key, default=None): + value = dict.pop(self, key, default) + result = self.configurator.convert(value) + if value is not result: + if type(result) in (ConvertingDict, ConvertingList, + ConvertingTuple): + result.parent = self + result.key = key + return result + +class ConvertingList(list): + """A converting list wrapper.""" + def __getitem__(self, key): + value = list.__getitem__(self, key) + result = self.configurator.convert(value) + #If the converted value is different, save for next time + if value is not result: + self[key] = result + if type(result) in (ConvertingDict, ConvertingList, + ConvertingTuple): + result.parent = self + result.key = key + return result + + def pop(self, idx=-1): + value = list.pop(self, idx) + result = self.configurator.convert(value) + if value is not result: + if type(result) in (ConvertingDict, ConvertingList, + ConvertingTuple): + result.parent = self + return result + +class ConvertingTuple(tuple): + """A converting tuple wrapper.""" + def __getitem__(self, key): + value = tuple.__getitem__(self, key) + result = self.configurator.convert(value) + if value is not result: + if type(result) in (ConvertingDict, ConvertingList, + ConvertingTuple): + result.parent = self + result.key = key + return result + +class BaseConfigurator(object): + """ + The configurator base class which defines some useful defaults. + """ + + CONVERT_PATTERN = re.compile(r'^(?P<prefix>[a-z]+)://(?P<suffix>.*)$') + + WORD_PATTERN = re.compile(r'^\s*(\w+)\s*') + DOT_PATTERN = re.compile(r'^\.\s*(\w+)\s*') + INDEX_PATTERN = re.compile(r'^\[\s*(\w+)\s*\]\s*') + DIGIT_PATTERN = re.compile(r'^\d+$') + + value_converters = { + 'ext' : 'ext_convert', + 'cfg' : 'cfg_convert', + } + + # We might want to use a different one, e.g. importlib + importer = __import__ + + def __init__(self, config): + self.config = ConvertingDict(config) + self.config.configurator = self + + def resolve(self, s): + """ + Resolve strings to objects using standard import and attribute + syntax. + """ + name = s.split('.') + used = name.pop(0) + try: + found = self.importer(used) + for frag in name: + used += '.' + frag + try: + found = getattr(found, frag) + except AttributeError: + self.importer(used) + found = getattr(found, frag) + return found + except ImportError: + e, tb = sys.exc_info()[1:] + v = ValueError('Cannot resolve %r: %s' % (s, e)) + v.__cause__, v.__traceback__ = e, tb + raise v + + def ext_convert(self, value): + """Default converter for the ext:// protocol.""" + return self.resolve(value) + + def cfg_convert(self, value): + """Default converter for the cfg:// protocol.""" + rest = value + m = self.WORD_PATTERN.match(rest) + if m is None: + raise ValueError("Unable to convert %r" % value) + else: + rest = rest[m.end():] + d = self.config[m.groups()[0]] + #print d, rest + while rest: + m = self.DOT_PATTERN.match(rest) + if m: + d = d[m.groups()[0]] + else: + m = self.INDEX_PATTERN.match(rest) + if m: + idx = m.groups()[0] + if not self.DIGIT_PATTERN.match(idx): + d = d[idx] + else: + try: + n = int(idx) # try as number first (most likely) + d = d[n] + except TypeError: + d = d[idx] + if m: + rest = rest[m.end():] + else: + raise ValueError('Unable to convert ' + '%r at %r' % (value, rest)) + #rest should be empty + return d + + def convert(self, value): + """ + Convert values to an appropriate type. dicts, lists and tuples are + replaced by their converting alternatives. Strings are checked to + see if they have a conversion format and are converted if they do. + """ + if not isinstance(value, ConvertingDict) and isinstance(value, dict): + value = ConvertingDict(value) + value.configurator = self + elif not isinstance(value, ConvertingList) and isinstance(value, list): + value = ConvertingList(value) + value.configurator = self + elif not isinstance(value, ConvertingTuple) and\ + isinstance(value, tuple): + value = ConvertingTuple(value) + value.configurator = self + elif isinstance(value, basestring): + m = self.CONVERT_PATTERN.match(value) + if m: + d = m.groupdict() + prefix = d['prefix'] + converter = self.value_converters.get(prefix, None) + if converter: + suffix = d['suffix'] + converter = getattr(self, converter) + value = converter(suffix) + return value + + def configure_custom(self, config): + """Configure an object with a user-supplied factory.""" + c = config.pop('()') + if isinstance(c, basestring): + c = self.resolve(c) + props = config.pop('.', None) + # Check for valid identifiers + kwargs = dict([(k, config[k]) for k in config if valid_ident(k)]) + result = c(**kwargs) + if props: + for name, value in props.items(): + setattr(result, name, value) + return result + + def as_tuple(self, value): + """Utility function which converts lists to tuples.""" + if isinstance(value, list): + value = tuple(value) + return value + +def named_handlers_supported(): + major, minor = sys.version_info[:2] + if major == 2: + result = minor >= 7 + elif major == 3: + result = minor >= 2 + else: + result = (major > 3) + return result + +class DictConfigurator(BaseConfigurator): + """ + Configure logging using a dictionary-like object to describe the + configuration. + """ + + def configure(self): + """Do the configuration.""" + + config = self.config + if 'version' not in config: + raise ValueError("dictionary doesn't specify a version") + if config['version'] != 1: + raise ValueError("Unsupported version: %s" % config['version']) + incremental = config.pop('incremental', False) + EMPTY_DICT = {} + logging._acquireLock() + try: + if incremental: + handlers = config.get('handlers', EMPTY_DICT) + # incremental handler config only if handler name + # ties in to logging._handlers (Python 2.7, 3.2+) + if named_handlers_supported(): + for name in handlers: + if name not in logging._handlers: + raise ValueError('No handler found with ' + 'name %r' % name) + else: + try: + handler = logging._handlers[name] + handler_config = handlers[name] + level = handler_config.get('level', None) + if level: + handler.setLevel(_checkLevel(level)) + except StandardError: + e = sys.exc_info()[1] + raise ValueError('Unable to configure handler ' + '%r: %s' % (name, e)) + loggers = config.get('loggers', EMPTY_DICT) + for name in loggers: + try: + self.configure_logger(name, loggers[name], True) + except StandardError: + e = sys.exc_info()[1] + raise ValueError('Unable to configure logger ' + '%r: %s' % (name, e)) + root = config.get('root', None) + if root: + try: + self.configure_root(root, True) + except StandardError: + e = sys.exc_info()[1] + raise ValueError('Unable to configure root ' + 'logger: %s' % e) + else: + disable_existing = config.pop('disable_existing_loggers', True) + + logging._handlers.clear() + del logging._handlerList[:] + + # Do formatters first - they don't refer to anything else + formatters = config.get('formatters', EMPTY_DICT) + for name in formatters: + try: + formatters[name] = self.configure_formatter( + formatters[name]) + except StandardError: + e = sys.exc_info()[1] + raise ValueError('Unable to configure ' + 'formatter %r: %s' % (name, e)) + # Next, do filters - they don't refer to anything else, either + filters = config.get('filters', EMPTY_DICT) + for name in filters: + try: + filters[name] = self.configure_filter(filters[name]) + except StandardError: + e = sys.exc_info()[1] + raise ValueError('Unable to configure ' + 'filter %r: %s' % (name, e)) + + # Next, do handlers - they refer to formatters and filters + # As handlers can refer to other handlers, sort the keys + # to allow a deterministic order of configuration + handlers = config.get('handlers', EMPTY_DICT) + for name in sorted(handlers): + try: + handler = self.configure_handler(handlers[name]) + handler.name = name + handlers[name] = handler + except StandardError: + e = sys.exc_info()[1] + raise ValueError('Unable to configure handler ' + '%r: %s' % (name, e)) + # Next, do loggers - they refer to handlers and filters + + #we don't want to lose the existing loggers, + #since other threads may have pointers to them. + #existing is set to contain all existing loggers, + #and as we go through the new configuration we + #remove any which are configured. At the end, + #what's left in existing is the set of loggers + #which were in the previous configuration but + #which are not in the new configuration. + root = logging.root + existing = sorted(root.manager.loggerDict.keys()) + #The list needs to be sorted so that we can + #avoid disabling child loggers of explicitly + #named loggers. With a sorted list it is easier + #to find the child loggers. + #We'll keep the list of existing loggers + #which are children of named loggers here... + child_loggers = [] + #now set up the new ones... + loggers = config.get('loggers', EMPTY_DICT) + for name in loggers: + if name in existing: + i = existing.index(name) + prefixed = name + "." + pflen = len(prefixed) + num_existing = len(existing) + i = i + 1 # look at the entry after name + while (i < num_existing) and\ + (existing[i][:pflen] == prefixed): + child_loggers.append(existing[i]) + i = i + 1 + existing.remove(name) + try: + self.configure_logger(name, loggers[name]) + except StandardError: + e = sys.exc_info()[1] + raise ValueError('Unable to configure logger ' + '%r: %s' % (name, e)) + + #Disable any old loggers. There's no point deleting + #them as other threads may continue to hold references + #and by disabling them, you stop them doing any logging. + #However, don't disable children of named loggers, as that's + #probably not what was intended by the user. + for log in existing: + logger = root.manager.loggerDict[log] + if log in child_loggers: + logger.level = logging.NOTSET + logger.handlers = [] + logger.propagate = True + elif disable_existing: + logger.disabled = True + + # And finally, do the root logger + root = config.get('root', None) + if root: + try: + self.configure_root(root) + except StandardError: + e = sys.exc_info()[1] + raise ValueError('Unable to configure root ' + 'logger: %s' % e) + finally: + logging._releaseLock() + + def configure_formatter(self, config): + """Configure a formatter from a dictionary.""" + if '()' in config: + factory = config['()'] # for use in exception handler + try: + result = self.configure_custom(config) + except TypeError: + te = sys.exc_info()[1] + if "'format'" not in str(te): + raise + #Name of parameter changed from fmt to format. + #Retry with old name. + #This is so that code can be used with older Python versions + #(e.g. by Django) + config['fmt'] = config.pop('format') + config['()'] = factory + result = self.configure_custom(config) + else: + fmt = config.get('format', None) + dfmt = config.get('datefmt', None) + result = logging.Formatter(fmt, dfmt) + return result + + def configure_filter(self, config): + """Configure a filter from a dictionary.""" + if '()' in config: + result = self.configure_custom(config) + else: + name = config.get('name', '') + result = logging.Filter(name) + return result + + def add_filters(self, filterer, filters): + """Add filters to a filterer from a list of names.""" + for f in filters: + try: + filterer.addFilter(self.config['filters'][f]) + except StandardError: + e = sys.exc_info()[1] + raise ValueError('Unable to add filter %r: %s' % (f, e)) + + def configure_handler(self, config): + """Configure a handler from a dictionary.""" + formatter = config.pop('formatter', None) + if formatter: + try: + formatter = self.config['formatters'][formatter] + except StandardError: + e = sys.exc_info()[1] + raise ValueError('Unable to set formatter ' + '%r: %s' % (formatter, e)) + level = config.pop('level', None) + filters = config.pop('filters', None) + if '()' in config: + c = config.pop('()') + if isinstance(c, basestring): + c = self.resolve(c) + factory = c + else: + klass = self.resolve(config.pop('class')) + #Special case for handler which refers to another handler + if issubclass(klass, logging.handlers.MemoryHandler) and\ + 'target' in config: + try: + config['target'] = self.config['handlers'][config['target']] + except StandardError: + e = sys.exc_info()[1] + raise ValueError('Unable to set target handler ' + '%r: %s' % (config['target'], e)) + 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 + kwargs = dict([(k, config[k]) for k in config if valid_ident(k)]) + try: + result = factory(**kwargs) + except TypeError: + te = sys.exc_info()[1] + if "'stream'" not in str(te): + raise + #The argument name changed from strm to stream + #Retry with old name. + #This is so that code can be used with older Python versions + #(e.g. by Django) + kwargs['strm'] = kwargs.pop('stream') + result = factory(**kwargs) + if formatter: + result.setFormatter(formatter) + if level is not None: + result.setLevel(_checkLevel(level)) + if filters: + self.add_filters(result, filters) + return result + + def add_handlers(self, logger, handlers): + """Add handlers to a logger from a list of names.""" + for h in handlers: + try: + logger.addHandler(self.config['handlers'][h]) + except StandardError: + e = sys.exc_info()[1] + raise ValueError('Unable to add handler %r: %s' % (h, e)) + + def common_logger_config(self, logger, config, incremental=False): + """ + Perform configuration which is common to root and non-root loggers. + """ + level = config.get('level', None) + if level is not None: + logger.setLevel(_checkLevel(level)) + if not incremental: + #Remove any existing handlers + for h in logger.handlers[:]: + logger.removeHandler(h) + handlers = config.get('handlers', None) + if handlers: + self.add_handlers(logger, handlers) + filters = config.get('filters', None) + if filters: + self.add_filters(logger, filters) + + def configure_logger(self, name, config, incremental=False): + """Configure a non-root logger from a dictionary.""" + logger = logging.getLogger(name) + self.common_logger_config(logger, config, incremental) + propagate = config.get('propagate', None) + if propagate is not None: + logger.propagate = propagate + + def configure_root(self, config, incremental=False): + """Configure a root logger from a dictionary.""" + root = logging.getLogger() + self.common_logger_config(root, config, incremental) + +dictConfigClass = DictConfigurator + +def dictConfig(config): + """Configure logging using a dictionary.""" + dictConfigClass(config).configure() |