# Copyright Kevin Deldycke <kevin@deldycke.com> and contributors.
#
# This program is Free Software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation; either version 2
# of the License, or (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
"""Logging utilities."""
from __future__ import annotations
import logging
import sys
from gettext import gettext as _
from logging import (
WARNING,
Formatter,
Handler,
Logger,
LogRecord,
_levelToName,
)
from typing import TYPE_CHECKING, Literal, TypeVar
import click
from . import Choice, Context, Parameter
from .colorize import default_theme
from .parameters import ExtraOption
if TYPE_CHECKING:
from collections.abc import Generator, Iterable, Sequence
_original_get_logger = logging.getLogger
def _patched_get_logger(name: str | None = None) -> Logger:
"""Patch ``logging.getLogger`` to return the right root logger object.
.. warning::
This is a bugfix for Python 3.8 and earlier for which the ``root`` logger
cannot be fetched with its plain ``root`` name.
See:
- `cpython#81923 <https://github.com/python/cpython/issues/81923>`_
- `cpython@cb65b3a <https://github.com/python/cpython/commit/cb65b3a>`_
"""
if name == "root":
name = None
return _original_get_logger(name)
if sys.version_info < (3, 9):
logging.getLogger = _patched_get_logger
LOG_LEVELS: dict[str, int] = {
name: value
for value, name in sorted(_levelToName.items(), reverse=True)
if name != "NOTSET"
}
"""Mapping of canonical log level names to their IDs.
Sorted from lowest to highest verbosity.
Are ignored:
- ``NOTSET``, which is considered internal
- ``WARN``, which `is obsolete
<https://docs.python.org/3/library/logging.html?highlight=warn#logging.Logger.warning>`_
- ``FATAL``, which `shouldn't be used <https://github.com/python/cpython/issues/85013>`_
and `replaced by CRITICAL
<https://github.com/python/cpython/blob/0df7c3a/Lib/logging/__init__.py#L1538-L1541>`_
"""
DEFAULT_LEVEL: int = WARNING
DEFAULT_LEVEL_NAME: str = _levelToName[DEFAULT_LEVEL]
"""``WARNING`` is the default level we expect any loggers to starts their lives at.
``WARNING`` has been chosen as it is `the level at which the default Python's global
root logger is set up
<https://github.com/python/cpython/blob/0df7c3a/Lib/logging/__init__.py#L1945>`_.
This value is also used as the default level of the ``--verbosity`` option below.
"""
TFormatter = TypeVar("TFormatter", bound=Formatter)
THandler = TypeVar("THandler", bound=Handler)
"""Custom types to be used in type hints below."""
[docs]class ExtraLogHandler(Handler):
"""A handler to output logs to console's ``<stderr>``."""
[docs] def emit(self, record: LogRecord) -> None:
"""Use ``click.echo`` to print to ``<stderr>`` and supports colors."""
try:
msg = self.format(record)
click.echo(msg, err=True)
# If exception occurs format it to the stream.
except Exception:
self.handleError(record)
[docs]class VerbosityOption(ExtraOption):
"""A pre-configured ``--verbosity``/``-v`` option.
Sets the level of the provided logger.
The selected verbosity level name is made available in the context in
``ctx.meta["click_extra.verbosity"]``.
.. important::
The internal ``click_extra`` logger level will be aligned to the value set via
this option.
"""
logger_name: str
"""The ID of the logger to set the level to.
This will be provided to
`logging.getLogger <https://docs.python.org/3/library/logging.html?highlight=getlogger#logging.getLogger>`_
method to fetch the logger object, and as such, can be a dot-separated string to
build hierarchical loggers.
"""
@property
def all_loggers(self) -> Generator[Logger, None, None]:
"""Returns the list of logger IDs affected by the verbosity option.
Will returns Click Extra's internal logger first, then the option's custom
logger.
"""
for name in ("click_extra", self.logger_name):
yield logging.getLogger(name)
[docs] def reset_loggers(self) -> None:
"""Forces all loggers managed by the option to be reset to the default level.
Reset loggers in reverse order to ensure the internal logger is reset last.
.. danger::
Resseting loggers is extremely important for unittests. Because they're
global, loggers have tendency to leak and pollute their state between
multiple test calls.
"""
for logger in list(self.all_loggers)[::-1]:
logging.getLogger("click_extra").debug(
f"Reset {logger} to {DEFAULT_LEVEL_NAME}.",
)
logger.setLevel(DEFAULT_LEVEL)
[docs] def set_levels(self, ctx: Context, param: Parameter, value: str) -> None:
"""Set level of all loggers configured on the option.
Save the verbosity level name in the context.
Also prints the chosen value as a debug message via the internal
``click_extra`` logger.
"""
ctx.meta["click_extra.verbosity"] = value
for logger in self.all_loggers:
logger.setLevel(LOG_LEVELS[value])
logging.getLogger("click_extra").debug(f"Set {logger} to {value}.")
ctx.call_on_close(self.reset_loggers)
def __init__(
self,
param_decls: Sequence[str] | None = None,
default_logger: Logger | str | None = None,
default: str = DEFAULT_LEVEL_NAME,
metavar="LEVEL",
type=Choice(LOG_LEVELS, case_sensitive=False), # type: ignore[arg-type]
expose_value=False,
help=_("Either {log_levels}.").format(log_levels=", ".join(LOG_LEVELS)),
is_eager=True,
**kwargs,
) -> None:
"""Set up the verbosity option.
:param default_logger: If an instance of ``logging.Logger`` is provided, that's
the instance to which we will set the level set via the option. If the
parameter is a string, we will fetch it with `logging.getLogger
<https://docs.python.org/3/library/logging.html?highlight=getlogger#logging.getLogger>`_.
If not provided or ``None``, the `default Python root logger
<https://github.com/python/cpython/blob/2b5dbd1/Lib/logging/__init__.py#L1945>`_
is used.
.. todo::
Write more documentation to detail in which case the user is responsible
for setting up the logger, and when ``extra_basic_config`` is used.
"""
if not param_decls:
param_decls = ("--verbosity", "-v")
# Use the provided logger instance as-is.
if isinstance(default_logger, Logger):
logger = default_logger
# If a string is provided, use it as the logger name.
elif isinstance(default_logger, str):
logger = logging.getLogger(default_logger)
# ``None`` will produce a default root logger.
else:
logger = extra_basic_config(default_logger)
# Store the logger name for later use.
self.logger_name = logger.name
kwargs.setdefault("callback", self.set_levels)
super().__init__(
param_decls=param_decls,
default=default,
metavar=metavar,
type=type,
expose_value=expose_value,
help=help,
is_eager=is_eager,
**kwargs,
)