X-Git-Url: https://wannabe.guru.org/gitweb/?a=blobdiff_plain;f=logging_utils.py;fp=logging_utils.py;h=39453b4bb1e9a59ed6b2940372ac19255c7ae4ac;hb=02302bbd9363facb59c4df2c1f4013087702cfa6;hp=78785ba4d621601af6c65478c913b9a04accf672;hpb=f3dbc7dc19ba5703f8f5aa9bf8af3c491b3510f6;p=python_utils.git diff --git a/logging_utils.py b/logging_utils.py index 78785ba..39453b4 100644 --- a/logging_utils.py +++ b/logging_utils.py @@ -3,7 +3,29 @@ # © Copyright 2021-2022, Scott Gasch -"""Utilities related to logging.""" +"""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 @@ -191,11 +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. """ @@ -210,19 +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: @@ -243,8 +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 @@ -293,6 +314,8 @@ class DynamicPerScopeLoggingLevelFilter(logging.Filter): @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 @@ -319,18 +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): @@ -350,7 +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 @@ -363,12 +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 @@ -380,7 +399,6 @@ 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 @@ -403,6 +421,9 @@ def log_about_logging( fmt, facility_name, ): + """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: @@ -467,6 +488,31 @@ def log_about_logging( def initialize_logging(logger=None) -> logging.Logger: + """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() @@ -635,6 +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) @@ -643,7 +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 @@ -658,17 +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): @@ -698,6 +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 @@ -721,9 +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: @@ -731,6 +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) @@ -776,6 +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() @@ -783,7 +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 | @@ -825,9 +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}'")