"""Utilities related to logging."""
+import collections
import contextlib
import datetime
import enum
from logging.handlers import RotatingFileHandler, SysLogHandler
import os
import pytz
+import random
import sys
-from typing import Iterable, Optional
+from typing import Callable, Iterable, Mapping, Optional
+
+from overrides import overrides
# This module is commonly used by others in here and should avoid
# taking any unnecessary dependencies back on them.
default='INFO',
choices=['NOTSET', 'DEBUG', 'INFO', 'WARNING', 'ERROR', 'CRITICAL'],
metavar='LEVEL',
- help='The level below which to squelch log messages.',
+ help='The global default level below which to squelch log messages; see also --lmodule',
)
cfg.add_argument(
'--logging_format',
cfg.add_argument(
'--logging_filename_count',
type=int,
- default=2,
+ default=7,
metavar='COUNT',
help='The number of logging_filename copies to keep before deleting.'
)
default=False,
help='Should we prepend pid/tid data to all log messages?'
)
+cfg.add_argument(
+ '--logging_debug_modules',
+ action=argparse_utils.ActionNoYes,
+ default=False,
+ help='Should we prepend module/function data to all log messages?'
+)
cfg.add_argument(
'--logging_info_is_print',
action=argparse_utils.ActionNoYes,
default=False,
help='logging.info also prints to stdout.'
)
-
-# See also: OutputMultiplexer/OutputContext
+cfg.add_argument(
+ '--logging_squelch_repeats_enabled',
+ action=argparse_utils.ActionNoYes,
+ default=True,
+ help='Do we allow code to indicate that it wants to squelch repeated logging messages or should we always log?'
+)
+cfg.add_argument(
+ '--logging_probabilistically_enabled',
+ action=argparse_utils.ActionNoYes,
+ default=True,
+ help='Do we allow probabilistic logging (for code that wants it) or should we always log?'
+)
+# See also: OutputMultiplexer
cfg.add_argument(
'--logging_captures_prints',
action=argparse_utils.ActionNoYes,
default=False,
- help='When calling print also log.info too'
+ help='When calling print, also log.info automatically.'
+)
+cfg.add_argument(
+ '--lmodule',
+ type=str,
+ metavar='<SCOPE>=<LEVEL>[,<SCOPE>=<LEVEL>...]',
+ help=(
+ 'Allows per-scope logging levels which override the global level set with --logging-level.' +
+ 'Pass a space separated list of <scope>=<level> where <scope> is one of: module, ' +
+ 'module:function, or :function and <level> is a logging level (e.g. INFO, DEBUG...)'
+ )
)
+
built_in_print = print
+def function_identifier(f: Callable) -> str:
+ """
+ Given a callable function, return a string that identifies it.
+ Usually that string is just __module__:__name__ but there's a
+ corner case: when __module__ is __main__ (i.e. the callable is
+ defined in the same module as __main__). In this case,
+ f.__module__ returns "__main__" instead of the file that it is
+ defined in. Work around this using pathlib.Path (see below).
+
+ >>> function_identifier(function_identifier)
+ 'logging_utils:function_identifier'
+
+ """
+ if f.__module__ == '__main__':
+ from pathlib import Path
+ import __main__
+ module = __main__.__file__
+ module = Path(module).stem
+ return f'{module}:{f.__name__}'
+ else:
+ return f'{f.__module__}:{f.__name__}'
+
+
+# A map from logging_callsite_id -> count of logged messages.
+squelched_logging_counts: Mapping[str, int] = {}
+
+
+def squelch_repeated_log_messages(squelch_after_n_repeats: int) -> Callable:
+ """
+ A decorator that marks a function as interested in having the logging
+ 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.
+
+ """
+ def squelch_logging_wrapper(f: Callable):
+ identifier = function_identifier(f)
+ squelched_logging_counts[identifier] = squelch_after_n_repeats
+ return f
+ return squelch_logging_wrapper
+
+
+class SquelchRepeatedMessagesFilter(logging.Filter):
+ """
+ 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.
+
+ """
+ def __init__(self) -> None:
+ self.counters = collections.Counter()
+ super().__init__()
+
+ @overrides
+ def filter(self, record: logging.LogRecord) -> bool:
+ id1 = f'{record.module}:{record.funcName}'
+ if id1 not in squelched_logging_counts:
+ return True
+ threshold = squelched_logging_counts[id1]
+ logsite = f'{record.pathname}+{record.lineno}+{record.levelno}+{record.msg}'
+ count = self.counters[logsite]
+ self.counters[logsite] += 1
+ return count < threshold
+
+
+class DynamicPerScopeLoggingLevelFilter(logging.Filter):
+ """Only interested in seeing logging messages from an allow list of
+ module names or module:function names. Block others.
+
+ """
+ @staticmethod
+ def level_name_to_level(name: str) -> int:
+ numeric_level = getattr(
+ logging,
+ name,
+ None
+ )
+ if not isinstance(numeric_level, int):
+ raise ValueError('Invalid level: {name}')
+ return numeric_level
+
+ def __init__(
+ self,
+ default_logging_level: int,
+ per_scope_logging_levels: str,
+ ) -> None:
+ super().__init__()
+ 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:
+ for chunk in per_scope_logging_levels.split(','):
+ if '=' not in chunk:
+ print(
+ f'Malformed lmodule directive: "{chunk}", missing "=". Ignored.',
+ file=sys.stderr
+ )
+ continue
+ try:
+ (scope, level) = chunk.split('=')
+ except ValueError:
+ print(
+ f'Malformed lmodule directive: "{chunk}". Ignored.',
+ file=sys.stderr
+ )
+ continue
+ scope = scope.strip()
+ level = level.strip().upper()
+ if level not in self.valid_levels:
+ print(
+ f'Malformed lmodule directive: "{chunk}", bad level. Ignored.',
+ file=sys.stderr
+ )
+ continue
+ self.level_by_scope[scope] = (
+ DynamicPerScopeLoggingLevelFilter.level_name_to_level(
+ level
+ )
+ )
+
+ @overrides
+ def filter(self, record: logging.LogRecord) -> bool:
+ # First try to find a logging level by scope (--lmodule)
+ if len(self.level_by_scope) > 0:
+ min_level = None
+ for scope in (
+ record.module,
+ f'{record.module}:{record.funcName}',
+ f':{record.funcName}'
+ ):
+ level = self.level_by_scope.get(scope, None)
+ if level is not None:
+ if min_level is None or level < min_level:
+ min_level = level
+
+ # If we found one, use it instead of the global default level.
+ if min_level is not None:
+ return record.levelno >= min_level
+
+ # Otherwise, use the global logging level (--logging_level)
+ return record.levelno >= self.default_logging_level
+
+
+# A map from function_identifier -> probability of logging (0.0%..100.0%)
+probabilistic_logging_levels: Mapping[str, float] = {}
+
+
+def logging_is_probabilistic(probability_of_logging: float) -> Callable:
+ """
+ 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).
+
+ This affects *ALL* logging statements within the marked function.
+
+ """
+ def probabilistic_logging_wrapper(f: Callable):
+ identifier = function_identifier(f)
+ probabilistic_logging_levels[identifier] = probability_of_logging
+ return f
+ return probabilistic_logging_wrapper
+
+
+class ProbabilisticFilter(logging.Filter):
+ """
+ A filter that logs messages probabilistically (i.e. randomly at some
+ percent chance).
+
+ This filter only affects logging messages from functions that have
+ been tagged with the @logging_utils.probabilistic_logging decorator.
+
+ """
+ @overrides
+ def filter(self, record: logging.LogRecord) -> bool:
+ id1 = f'{record.module}:{record.funcName}'
+ if id1 not in probabilistic_logging_levels:
+ return True
+ threshold = probabilistic_logging_levels[id1]
+ return (random.random() * 100.0) <= threshold
+
+
class OnlyInfoFilter(logging.Filter):
- def filter(self, record):
+ """
+ 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.
+
+ """
+ @overrides
+ def filter(self, record: logging.LogRecord):
return record.levelno == logging.INFO
class MillisecondAwareFormatter(logging.Formatter):
+ """
+ A formatter for adding milliseconds to log messages.
+
+ """
converter = datetime.datetime.fromtimestamp
+ @overrides
def formatTime(self, record, datefmt=None):
ct = MillisecondAwareFormatter.converter(
record.created, pytz.timezone("US/Pacific")
return logger
handlers = []
- numeric_level = getattr(
+
+ # Global default logging level (--logging_level)
+ default_logging_level = getattr(
logging,
config.config['logging_level'].upper(),
None
)
- if not isinstance(numeric_level, int):
+ if not isinstance(default_logging_level, int):
raise ValueError('Invalid level: %s' % config.config['logging_level'])
fmt = config.config['logging_format']
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}'
if config.config['logging_syslog']:
if sys.platform not in ('win32', 'cygwin'):
handler = SysLogHandler()
-# for k, v in encoded_priorities.items():
-# handler.encodePriority(k, v)
handler.setFormatter(
MillisecondAwareFormatter(
fmt=fmt,
datefmt=config.config['logging_date_format'],
)
)
- handler.setLevel(numeric_level)
handlers.append(handler)
if config.config['logging_filename']:
maxBytes = config.config['logging_filename_maxsize'],
backupCount = config.config['logging_filename_count'],
)
- handler.setLevel(numeric_level)
handler.setFormatter(
MillisecondAwareFormatter(
fmt=fmt,
if config.config['logging_console']:
handler = logging.StreamHandler(sys.stderr)
- handler.setLevel(numeric_level)
handler.setFormatter(
MillisecondAwareFormatter(
fmt=fmt,
handler.addFilter(OnlyInfoFilter())
logger.addHandler(handler)
- logger.setLevel(numeric_level)
+ if config.config['logging_squelch_repeats_enabled']:
+ for handler in handlers:
+ handler.addFilter(SquelchRepeatedMessagesFilter())
+
+ if config.config['logging_probabilistically_enabled']:
+ for handler in handlers:
+ handler.addFilter(ProbabilisticFilter())
+
+ for handler in handlers:
+ handler.addFilter(
+ DynamicPerScopeLoggingLevelFilter(
+ default_logging_level,
+ config.config['lmodule'],
+ )
+ )
+ logger.setLevel(0)
logger.propagate = False
if config.config['logging_captures_prints']:
def tprint(*args, **kwargs) -> None:
+ """Legacy function for printing a message augmented with thread id."""
+
if config.config['logging_debug_threads']:
from thread_utils import current_thread_id
print(f'{current_thread_id()}', end="")
def dprint(*args, **kwargs) -> None:
+ """Legacy function used to print to stderr."""
+
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...)
+ """
class Destination(enum.IntEnum):
"""Bits in the destination_bitv bitvector. Used to indicate the
output destination."""
- LOG_DEBUG = 0x01 # -\
- LOG_INFO = 0x02 # |
- LOG_WARNING = 0x04 # > Should provide logger to the c'tor.
- LOG_ERROR = 0x08 # |
- LOG_CRITICAL = 0x10 # _/
+ LOG_DEBUG = 0x01 # ⎫
+ LOG_INFO = 0x02 # ⎪
+ LOG_WARNING = 0x04 # ⎬ Must provide logger to the c'tor.
+ LOG_ERROR = 0x08 # ⎪
+ LOG_CRITICAL = 0x10 # ⎭
FILENAMES = 0x20 # Must provide a filename to the c'tor.
FILEHANDLES = 0x40 # Must provide a handle to the c'tor.
HLOG = 0x80
open(filename, 'wb', buffering=0) for filename in filenames
]
else:
- if self.destination_bitv & OutputMultiplexer.FILENAMES:
+ if destination_bitv & OutputMultiplexer.FILENAMES:
raise ValueError(
"Filenames argument is required if bitv & FILENAMES"
)
if handles is not None:
self.h = [handle for handle in handles]
else:
- if self.destination_bitv & OutputMultiplexer.FILEHANDLES:
+ if destination_bitv & OutputMultiplexer.Destination.FILEHANDLES:
raise ValueError(
"Handle argument is required if bitv & FILEHANDLES"
)
class OutputMultiplexerContext(OutputMultiplexer, contextlib.ContextDecorator):
+ """
+ A context that uses an OutputMultiplexer. e.g.
+
+ with OutputMultiplexerContext(
+ OutputMultiplexer.LOG_INFO |
+ OutputMultiplexer.LOG_DEBUG |
+ OutputMultiplexer.FILENAMES |
+ OutputMultiplexer.FILEHANDLES,
+ filenames = [ '/tmp/foo.log', '/var/log/bar.log' ],
+ handles = [ f, g ]
+ ) as mplex:
+ mplex.print("This is a log message!")
+
+ """
def __init__(self,
destination_bitv: OutputMultiplexer.Destination,
*,
def hlog(message: str) -> None:
+ """Write a message to the house log."""
+
message = message.replace("'", "'\"'\"'")
os.system(f"/usr/bin/logger -p local7.info -- '{message}'")
+
+
+if __name__ == '__main__':
+ import doctest
+ doctest.testmod()
projects / python_utils.git / blobdiff