#!/usr/bin/env python3
# -*- coding: utf-8 -*-
-"""Utilities related to logging."""
+# © 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
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.
"""
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:
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
@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
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):
This filter only affects logging messages from functions that have
been tagged with the @logging_utils.probabilistic_logging decorator.
-
"""
@overrides
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
"""
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
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:
- logger.warning(
+ logger.debug(
'Logging cleared %d global handlers (--logging_clear_preexisting_handlers)',
preexisting_handlers_count,
)
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()
def get_logger(name: str = ""):
+ """Get the global logger"""
logger = logging.getLogger(name)
return initialize_logging(logger)
"""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
"""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):
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
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:
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)
hlog(buf)
def close(self):
+ """Close all open files."""
if self.f is not None:
for _ in self.f:
_.close()
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 |
handles = [ f, g ]
) as mplex:
mplex.print("This is a log message!")
-
"""
def __init__(
"""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}'")
projects / python_utils.git / blobdiff