X-Git-Url: https://wannabe.guru.org/gitweb/?a=blobdiff_plain;f=logging_utils.py;h=39453b4bb1e9a59ed6b2940372ac19255c7ae4ac;hb=02302bbd9363facb59c4df2c1f4013087702cfa6;hp=8875b2fcb3d833f900c1107e7203abc27a49f54c;hpb=b6dd2da4aecbc5d4690023d5a5e4f63052425444;p=python_utils.git diff --git a/logging_utils.py b/logging_utils.py index 8875b2f..39453b4 100644 --- a/logging_utils.py +++ b/logging_utils.py @@ -1,6 +1,31 @@ #!/usr/bin/env python3 - -"""Utilities related to logging.""" +# -*- coding: utf-8 -*- + +# © Copyright 2021-2022, Scott Gasch + +"""Utilities related to logging. To use it you must invoke +:meth:`initialize_logging`. If you use the +:meth:`bootstrap.initialize` decorator on your program's entry point, +it will call this for you. See :meth:`python_modules.bootstrap.initialize` +for more details. If you use this you get: + +* Ability to set logging level, +* ability to define the logging format, +* ability to tee all logging on stderr, +* ability to tee all logging into a file, +* ability to rotate said file as it grows, +* ability to tee all logging into the system log (syslog) and + define the facility and level used to do so, +* easy automatic pid/tid stamp on logging for debugging threads, +* ability to squelch repeated log messages, +* ability to log probabilistically in code, +* ability to only see log messages from a particular module or + function, +* ability to clear logging handlers added by earlier loaded modules. + +All of these are controlled via commandline arguments to your program, +see the code below for details. +""" import collections import contextlib @@ -13,7 +38,7 @@ import random import sys from logging.config import fileConfig from logging.handlers import RotatingFileHandler, SysLogHandler -from typing import Any, Callable, Dict, Iterable, List, Mapping, Optional +from typing import Any, Callable, Dict, Iterable, List, Optional import pytz from overrides import overrides @@ -174,8 +199,8 @@ cfg.add_argument( ), ) -built_in_print = print -logging_initialized = False +BUILT_IN_PRINT = print +LOGGING_INITIALIZED = False # A map from logging_callsite_id -> count of logged messages. @@ -188,11 +213,13 @@ def squelch_repeated_log_messages(squelch_after_n_repeats: int) -> Callable: messages that it produces be squelched (ignored) after it logs the same message more than N times. - Note: this decorator affects *ALL* logging messages produced - within the decorated function. That said, messages must be - identical in order to be squelched. For example, if the same line - of code produces different messages (because of, e.g., a format - string), the messages are considered to be different. + .. note:: + + This decorator affects *ALL* logging messages produced + within the decorated function. That said, messages must be + identical in order to be squelched. For example, if the same line + of code produces different messages (because of, e.g., a format + string), the messages are considered to be different. """ @@ -207,19 +234,17 @@ def squelch_repeated_log_messages(squelch_after_n_repeats: int) -> Callable: class SquelchRepeatedMessagesFilter(logging.Filter): - """ - A filter that only logs messages from a given site with the same + """A filter that only logs messages from a given site with the same (exact) message at the same logging level N times and ignores subsequent attempts to log. - This filter only affects logging messages that repeat more than - a threshold number of times from functions that are tagged with - the @logging_utils.squelched_logging_ok decorator; others are - ignored. + This filter only affects logging messages that repeat more than a + threshold number of times from functions that are tagged with the + @logging_utils.squelched_logging_ok decorator (see above); others + are ignored. This functionality is enabled by default but can be disabled via - the --no_logging_squelch_repeats commandline flag. - + the :code:`--no_logging_squelch_repeats` commandline flag. """ def __init__(self) -> None: @@ -240,8 +265,7 @@ class SquelchRepeatedMessagesFilter(logging.Filter): class DynamicPerScopeLoggingLevelFilter(logging.Filter): """This filter only allows logging messages from an allow list of - module names or module:function names. Blocks others. - + module names or module:function names. Blocks all others. """ @staticmethod @@ -257,9 +281,7 @@ class DynamicPerScopeLoggingLevelFilter(logging.Filter): per_scope_logging_levels: str, ) -> None: super().__init__() - self.valid_levels = set( - ['NOTSET', 'DEBUG', 'INFO', 'WARNING', 'ERROR', 'CRITICAL'] - ) + self.valid_levels = set(['NOTSET', 'DEBUG', 'INFO', 'WARNING', 'ERROR', 'CRITICAL']) self.default_logging_level = default_logging_level self.level_by_scope = {} if per_scope_logging_levels is not None: @@ -286,12 +308,14 @@ class DynamicPerScopeLoggingLevelFilter(logging.Filter): file=sys.stderr, ) continue - self.level_by_scope[ - scope - ] = DynamicPerScopeLoggingLevelFilter.level_name_to_level(level) + self.level_by_scope[scope] = DynamicPerScopeLoggingLevelFilter.level_name_to_level( + level + ) @overrides def filter(self, record: logging.LogRecord) -> bool: + """Decides whether or not to log based on an allow list.""" + # First try to find a logging level by scope (--lmodule) if len(self.level_by_scope) > 0: min_level = None @@ -318,18 +342,17 @@ probabilistic_logging_levels: Dict[str, float] = {} def logging_is_probabilistic(probability_of_logging: float) -> Callable: - """ - A decorator that indicates that all logging statements within the + """A decorator that indicates that all logging statements within the scope of a particular (marked) function are not deterministic (i.e. they do not always unconditionally log) but rather are - probabilistic (i.e. they log N% of the time randomly). - - Note that this functionality can be disabled (forcing all logged - messages to produce output) via the --no_logging_probabilistically - cmdline argument. + probabilistic (i.e. they log N% of the time, randomly). - This affects *ALL* logging statements within the marked function. + .. note:: + This affects *ALL* logging statements within the marked function. + That this functionality can be disabled (forcing all logged + messages to produce output) via the + :code:`--no_logging_probabilistically` cmdline argument. """ def probabilistic_logging_wrapper(f: Callable): @@ -349,7 +372,6 @@ class ProbabilisticFilter(logging.Filter): This filter only affects logging messages from functions that have been tagged with the @logging_utils.probabilistic_logging decorator. - """ @overrides @@ -362,12 +384,10 @@ class ProbabilisticFilter(logging.Filter): class OnlyInfoFilter(logging.Filter): - """ - A filter that only logs messages produced at the INFO logging - level. This is used by the logging_info_is_print commandline - option to select a subset of the logging stream to send to a - stdout handler. - + """A filter that only logs messages produced at the INFO logging + level. This is used by the ::code`--logging_info_is_print` + commandline option to select a subset of the logging stream to + send to a stdout handler. """ @overrides @@ -379,99 +399,131 @@ class MillisecondAwareFormatter(logging.Formatter): """ A formatter for adding milliseconds to log messages which, for whatever reason, the default python logger doesn't do. - """ converter = datetime.datetime.fromtimestamp # type: ignore @overrides def formatTime(self, record, datefmt=None): - ct = MillisecondAwareFormatter.converter( - record.created, pytz.timezone("US/Pacific") - ) + ct = MillisecondAwareFormatter.converter(record.created, pytz.timezone("US/Pacific")) if datefmt: s = ct.strftime(datefmt) else: t = ct.strftime("%Y-%m-%d %H:%M:%S") - s = "%s,%03d" % (t, record.msecs) + s = f"{t},{record.msecs:%03d}" return s def log_about_logging( - logger, default_logging_level, preexisting_handlers_count, fmt, facility_name + logger, + default_logging_level, + preexisting_handlers_count, + fmt, + facility_name, ): - level_name = logging._levelToName.get( - default_logging_level, str(default_logging_level) - ) - logger.debug(f'Initialized global logging; default logging level is {level_name}.') - if ( - config.config['logging_clear_preexisting_handlers'] - and preexisting_handlers_count > 0 - ): - msg = f'Logging cleared {preexisting_handlers_count} global handlers (--logging_clear_preexisting_handlers)' - logger.warning(msg) - logger.debug(f'Logging format specification is "{fmt}"') - if config.config['logging_debug_threads']: - logger.debug( - '...Logging format spec captures tid/pid (--logging_debug_threads)' + """Some of the initial messages in the debug log are about how we + have set up logging itself.""" + + level_name = logging._levelToName.get(default_logging_level, str(default_logging_level)) + logger.debug('Initialized global logging; default logging level is %s.', level_name) + if config.config['logging_clear_preexisting_handlers'] and preexisting_handlers_count > 0: + logger.warning( + 'Logging cleared %d global handlers (--logging_clear_preexisting_handlers)', + preexisting_handlers_count, ) + logger.debug('Logging format specification is "%s"', fmt) + if config.config['logging_debug_threads']: + logger.debug('...Logging format spec captures tid/pid. (--logging_debug_threads)') if config.config['logging_debug_modules']: logger.debug( - '...Logging format spec captures files/functions/lineno (--logging_debug_modules)' + '...Logging format spec captures files/functions/lineno. (--logging_debug_modules)' ) if config.config['logging_syslog']: logger.debug( - f'Logging to syslog as {facility_name} with priority mapping based on level' + 'Logging to syslog as %s with priority mapping based on level. (--logging_syslog)', + facility_name, ) if config.config['logging_filename']: - logger.debug(f'Logging to filename {config.config["logging_filename"]}') logger.debug( - f'...with {config.config["logging_filename_maxsize"]} bytes max file size.' + 'Logging to file "%s". (--logging_filename)', config.config["logging_filename"] ) logger.debug( - f'...and {config.config["logging_filename_count"]} rotating backup file count.' + '...with %d bytes max file size. (--logging_filename_maxsize)', + config.config["logging_filename_maxsize"], + ) + logger.debug( + '...and %d rotating backup file count. (--logging_filename_count)', + config.config["logging_filename_count"], ) if config.config['logging_console']: - logger.debug('Logging to the console (stderr).') + logger.debug('Logging to the console (stderr). (--logging_console)') if config.config['logging_info_is_print']: logger.debug( - 'Logging logger.info messages will be repeated on stdout (--logging_info_is_print)' + 'Logging logger.info messages will be repeated on stdout. (--logging_info_is_print)' ) if config.config['logging_squelch_repeats']: logger.debug( - 'Logging code allowed to request repeated messages be squelched (--logging_squelch_repeats)' + 'Logging code allowed to request repeated messages be squelched. (--logging_squelch_repeats)' ) else: logger.debug( - 'Logging code forbidden to request messages be squelched; all messages logged (--no_logging_squelch_repeats)' + 'Logging code forbidden to request messages be squelched; all messages logged. (--no_logging_squelch_repeats)' ) if config.config['logging_probabilistically']: logger.debug( - 'Logging code is allowed to request probabilistic logging (--logging_probabilistically)' + 'Logging code is allowed to request probabilistic logging. (--logging_probabilistically)' ) else: logger.debug( - 'Logging code is forbidden to request probabilistic logging; messages always logged (--no_logging_probabilistically)' + 'Logging code is forbidden to request probabilistic logging; messages always logged. (--no_logging_probabilistically)' ) if config.config['lmodule']: logger.debug( - f'Logging dynamic per-module logging enabled (--lmodule={config.config["lmodule"]})' + f'Logging dynamic per-module logging enabled. (--lmodule={config.config["lmodule"]})' ) if config.config['logging_captures_prints']: logger.debug( - 'Logging will capture printed data as logger.info messages (--logging_captures_prints)' + 'Logging will capture printed data as logger.info messages. (--logging_captures_prints)' ) def initialize_logging(logger=None) -> logging.Logger: - global logging_initialized - if logging_initialized: + """Initialize logging for the program. This must be called if you want + to use any of the functionality provided by this module such as: + + * Ability to set logging level, + * ability to define the logging format, + * ability to tee all logging on stderr, + * ability to tee all logging into a file, + * ability to rotate said file as it grows, + * ability to tee all logging into the system log (syslog) and + define the facility and level used to do so, + * easy automatic pid/tid stamp on logging for debugging threads, + * ability to squelch repeated log messages, + * ability to log probabilistically in code, + * ability to only see log messages from a particular module or + function, + * ability to clear logging handlers added by earlier loaded modules. + + All of these are controlled via commandline arguments to your program, + see the code below for details. + + If you use the + :meth:`bootstrap.initialize` decorator on your program's entry point, + it will call this for you. See :meth:`python_modules.bootstrap.initialize` + for more details. + """ + global LOGGING_INITIALIZED + if LOGGING_INITIALIZED: return logging.getLogger() - logging_initialized = True + LOGGING_INITIALIZED = True if logger is None: logger = logging.getLogger() + # --logging_clear_preexisting_handlers removes logging handlers + # that were registered by global statements during imported module + # setup. preexisting_handlers_count = 0 assert config.has_been_parsed() if config.config['logging_clear_preexisting_handlers']: @@ -479,6 +531,8 @@ def initialize_logging(logger=None) -> logging.Logger: logger.removeHandler(logger.handlers[0]) preexisting_handlers_count += 1 + # --logging_config_file pulls logging settings from a config file + # skipping the rest of this setup. if config.config['logging_config_file'] is not None: fileConfig(config.config['logging_config_file']) return logger @@ -486,13 +540,13 @@ def initialize_logging(logger=None) -> logging.Logger: handlers: List[logging.Handler] = [] handler: Optional[logging.Handler] = None - # Global default logging level (--logging_level) - default_logging_level = getattr( - logging, config.config['logging_level'].upper(), None - ) + # Global default logging level (--logging_level); messages below + # this level will be silenced. + default_logging_level = getattr(logging, config.config['logging_level'].upper(), None) if not isinstance(default_logging_level, int): - raise ValueError('Invalid level: %s' % config.config['logging_level']) + raise ValueError(f'Invalid level: {config.config["logging_level"]}') + # Custom or default --logging_format? if config.config['logging_format']: fmt = config.config['logging_format'] else: @@ -500,11 +554,18 @@ def initialize_logging(logger=None) -> logging.Logger: fmt = '%(levelname).1s:%(filename)s[%(process)d]: %(message)s' else: fmt = '%(levelname).1s:%(asctime)s: %(message)s' + + # --logging_debug_threads and --logging_debug_modules both affect + # the format by prepending information about the pid/tid or + # file/function. if config.config['logging_debug_threads']: fmt = f'%(process)d.%(thread)d|{fmt}' if config.config['logging_debug_modules']: fmt = f'%(filename)s:%(funcName)s:%(lineno)s|{fmt}' + # --logging_syslog (optionally with --logging_syslog_facility) + # sets up for logging to use the standard system syslogd as a + # sink. facility_name = None if config.config['logging_syslog']: if sys.platform not in ('win32', 'cygwin'): @@ -521,6 +582,9 @@ def initialize_logging(logger=None) -> logging.Logger: ) handlers.append(handler) + # --logging_filename (with friends --logging_filename_count and + # --logging_filename_maxsize) set up logging to a file on the + # filesystem with automatic rotation when it gets too big. if config.config['logging_filename']: handler = RotatingFileHandler( config.config['logging_filename'], @@ -535,6 +599,7 @@ def initialize_logging(logger=None) -> logging.Logger: ) handlers.append(handler) + # --logging_console is, ahem, logging to the console. if config.config['logging_console']: handler = logging.StreamHandler(sys.stderr) handler.setFormatter( @@ -547,23 +612,37 @@ def initialize_logging(logger=None) -> logging.Logger: if len(handlers) == 0: handlers.append(logging.NullHandler()) - for handler in handlers: logger.addHandler(handler) + # --logging_info_is_print echoes any message to logger.info(x) as + # a print statement on stdout. if config.config['logging_info_is_print']: handler = logging.StreamHandler(sys.stdout) handler.addFilter(OnlyInfoFilter()) logger.addHandler(handler) + # --logging_squelch_repeats allows code to request repeat logging + # messages (identical log site and message contents) to be + # silenced. Logging code must request this explicitly, it isn't + # automatic. This option just allows the silencing to happen. if config.config['logging_squelch_repeats']: for handler in handlers: handler.addFilter(SquelchRepeatedMessagesFilter()) + # --logging_probabilistically allows code to request + # non-deterministic logging where messages have some probability + # of being produced. Logging code must request this explicitly. + # This option just allows the non-deterministic behavior to + # happen. Disabling it will cause every log message to be + # produced. if config.config['logging_probabilistically']: for handler in handlers: handler.addFilter(ProbabilisticFilter()) + # --lmodule is a way to have a special logging level for just on + # module or one set of modules that is different than the one set + # globally via --logging_level. for handler in handlers: handler.addFilter( DynamicPerScopeLoggingLevelFilter( @@ -574,8 +653,9 @@ def initialize_logging(logger=None) -> logging.Logger: logger.setLevel(0) logger.propagate = False + # --logging_captures_prints, if set, will capture and log.info + # anything printed on stdout. if config.config['logging_captures_prints']: - global built_in_print import builtins def print_and_also_log(*arg, **kwarg): @@ -584,7 +664,7 @@ def initialize_logging(logger=None) -> logging.Logger: logger.warning(*arg) else: logger.info(*arg) - built_in_print(*arg, **kwarg) + BUILT_IN_PRINT(*arg, **kwarg) builtins.print = print_and_also_log @@ -601,6 +681,7 @@ def initialize_logging(logger=None) -> logging.Logger: def get_logger(name: str = ""): + """Get the global logger""" logger = logging.getLogger(name) return initialize_logging(logger) @@ -609,7 +690,6 @@ def tprint(*args, **kwargs) -> None: """Legacy function for printing a message augmented with thread id still needed by some code. Please use --logging_debug_threads in new code. - """ if config.config['logging_debug_threads']: from thread_utils import current_thread_id @@ -624,18 +704,15 @@ def dprint(*args, **kwargs) -> None: """Legacy function used to print to stderr still needed by some code. Please just use normal logging with --logging_console which accomplishes the same thing in new code. - """ print(*args, file=sys.stderr, **kwargs) class OutputMultiplexer(object): - """ - A class that broadcasts printed messages to several sinks (including - various logging levels, different files, different file handles, - the house log, etc...). See also OutputMultiplexerContext for an - easy usage pattern. - + """A class that broadcasts printed messages to several sinks + (including various logging levels, different files, different file + handles, the house log, etc...). See also + :class:`OutputMultiplexerContext` for an easy usage pattern. """ class Destination(enum.IntEnum): @@ -665,6 +742,20 @@ class OutputMultiplexer(object): filenames: Optional[Iterable[str]] = None, handles: Optional[Iterable[io.TextIOWrapper]] = None, ): + """ + Constructs the OutputMultiplexer instance. + + Args: + destination_bitv: a bitvector where each bit represents an + output destination. Multiple bits may be set. + logger: if LOG_* bits are set, you must pass a logger here. + filenames: if FILENAMES bit is set, this should be a list of + files you'd like to output into. This code handles opening + and closing said files. + handles: if FILEHANDLES bit is set, this should be a list of + already opened filehandles you'd like to output into. The + handles will remain open after the scope of the multiplexer. + """ if logger is None: logger = logging.getLogger(None) self.logger = logger @@ -679,7 +770,7 @@ class OutputMultiplexer(object): self.h: Optional[List[Any]] = None if handles is not None: - self.h = [handle for handle in handles] + self.h = list(handles) else: if destination_bitv & OutputMultiplexer.Destination.FILEHANDLES: raise ValueError("Handle argument is required if bitv & FILEHANDLES") @@ -688,9 +779,11 @@ class OutputMultiplexer(object): self.set_destination_bitv(destination_bitv) def get_destination_bitv(self): + """Where are we outputting?""" return self.destination_bitv def set_destination_bitv(self, destination_bitv: int): + """Change the output destination_bitv to the one provided.""" if destination_bitv & self.Destination.FILENAMES and self.f is None: raise ValueError("Filename argument is required if bitv & FILENAMES") if destination_bitv & self.Destination.FILEHANDLES and self.h is None: @@ -698,6 +791,7 @@ class OutputMultiplexer(object): self.destination_bitv = destination_bitv def print(self, *args, **kwargs): + """Produce some output to all sinks.""" from string_utils import sprintf, strip_escape_sequences end = kwargs.pop("end", None) @@ -743,6 +837,7 @@ class OutputMultiplexer(object): hlog(buf) def close(self): + """Close all open files.""" if self.f is not None: for _ in self.f: _.close() @@ -750,7 +845,7 @@ class OutputMultiplexer(object): class OutputMultiplexerContext(OutputMultiplexer, contextlib.ContextDecorator): """ - A context that uses an OutputMultiplexer. e.g. + A context that uses an :class:`OutputMultiplexer`. e.g.:: with OutputMultiplexerContext( OutputMultiplexer.LOG_INFO | @@ -761,7 +856,6 @@ class OutputMultiplexerContext(OutputMultiplexer, contextlib.ContextDecorator): handles = [ f, g ] ) as mplex: mplex.print("This is a log message!") - """ def __init__( @@ -793,9 +887,8 @@ def hlog(message: str) -> None: """Write a message to the house log (syslog facility local7 priority info) by calling /usr/bin/logger. This is pretty hacky but used by a bunch of code. Another way to do this would be to use - --logging_syslog and --logging_syslog_facility but I can't - actually say that's easier. - + :code:`--logging_syslog` and :code:`--logging_syslog_facility` but + I can't actually say that's easier. """ message = message.replace("'", "'\"'\"'") os.system(f"/usr/bin/logger -p local7.info -- '{message}'")