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mitogen/mitogen/utils.py

237 lines
7.5 KiB
Python

# Copyright 2019, David Wilson
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are met:
#
# 1. Redistributions of source code must retain the above copyright notice,
# this list of conditions and the following disclaimer.
#
# 2. Redistributions in binary form must reproduce the above copyright notice,
# this list of conditions and the following disclaimer in the documentation
# and/or other materials provided with the distribution.
#
# 3. Neither the name of the copyright holder nor the names of its contributors
# may be used to endorse or promote products derived from this software without
# specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
# ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
# LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
# CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
# SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
# CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
# ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
# POSSIBILITY OF SUCH DAMAGE.
# !mitogen: minify_safe
import datetime
import functools
import logging
import os
import sys
import mitogen.core
import mitogen.master
iteritems = getattr(dict, 'iteritems', dict.items)
if mitogen.core.PY3:
iteritems = dict.items
else:
iteritems = dict.iteritems
def setup_gil():
"""
Set extremely long GIL release interval to let threads naturally progress
through CPU-heavy sequences without forcing the wake of another thread that
may contend trying to run the same CPU-heavy code. For the new-style
Ansible work, this drops runtime ~33% and involuntary context switches by
>80%, essentially making threads cooperatively scheduled.
"""
try:
# Python 2.
sys.setcheckinterval(100000)
except AttributeError:
pass
try:
# Python 3.
sys.setswitchinterval(10)
except AttributeError:
pass
def disable_site_packages():
"""
Remove all entries mentioning ``site-packages`` or ``Extras`` from
:attr:sys.path. Used primarily for testing on OS X within a virtualenv,
where OS X bundles some ancient version of the :mod:`six` module.
"""
for entry in sys.path[:]:
if 'site-packages' in entry or 'Extras' in entry:
sys.path.remove(entry)
def _formatTime(record, datefmt=None):
dt = datetime.datetime.fromtimestamp(record.created)
return dt.strftime(datefmt)
def log_get_formatter():
datefmt = '%H:%M:%S'
if sys.version_info > (2, 6):
datefmt += '.%f'
fmt = '%(asctime)s %(levelname).1s %(name)s: %(message)s'
formatter = logging.Formatter(fmt, datefmt)
formatter.formatTime = _formatTime
return formatter
def log_to_file(path=None, io=False, level='INFO'):
"""
Install a new :class:`logging.Handler` writing applications logs to the
filesystem. Useful when debugging slave IO problems.
Parameters to this function may be overridden at runtime using environment
variables. See :ref:`logging-env-vars`.
:param str path:
If not :data:`None`, a filesystem path to write logs to. Otherwise,
logs are written to :data:`sys.stderr`.
:param bool io:
If :data:`True`, include extremely verbose IO logs in the output.
Useful for debugging hangs, less useful for debugging application code.
:param str level:
Name of the :mod:`logging` package constant that is the minimum level
to log at. Useful levels are ``DEBUG``, ``INFO``, ``WARNING``, and
``ERROR``.
"""
log = logging.getLogger('')
if path:
fp = open(path, 'w', 1)
mitogen.core.set_cloexec(fp.fileno())
else:
fp = sys.stderr
level = os.environ.get('MITOGEN_LOG_LEVEL', level).upper()
io = level == 'IO'
if io:
level = 'DEBUG'
logging.getLogger('mitogen.io').setLevel(level)
level = getattr(logging, level, logging.INFO)
log.setLevel(level)
# Prevent accidental duplicate log_to_file() calls from generating
# duplicate output.
for handler_ in reversed(log.handlers):
if getattr(handler_, 'is_mitogen', None):
log.handlers.remove(handler_)
handler = logging.StreamHandler(fp)
handler.is_mitogen = True
handler.formatter = log_get_formatter()
log.handlers.insert(0, handler)
def run_with_router(func, *args, **kwargs):
"""
Arrange for `func(router, *args, **kwargs)` to run with a temporary
:class:`mitogen.master.Router`, ensuring the Router and Broker are
correctly shut down during normal or exceptional return.
:returns:
`func`'s return value.
"""
broker = mitogen.master.Broker()
router = mitogen.master.Router(broker)
try:
return func(router, *args, **kwargs)
finally:
broker.shutdown()
broker.join()
def with_router(func):
"""
Decorator version of :func:`run_with_router`. Example:
.. code-block:: python
@with_router
def do_stuff(router, arg):
pass
do_stuff(blah, 123)
"""
@functools.wraps(func)
def wrapper(*args, **kwargs):
return run_with_router(func, *args, **kwargs)
return wrapper
PASSTHROUGH = (
int, float, bool,
type(None),
mitogen.core.Context,
mitogen.core.CallError,
mitogen.core.Blob,
mitogen.core.Secret,
)
def cast(obj):
"""
Return obj (or a copy) with subtypes of builtins cast to their supertype.
Subtypes of those in :data:`PASSTHROUGH` are not modified.
Many tools love to subclass built-in types in order to implement useful
functionality, such as annotating the safety of a Unicode string, or adding
additional methods to a dict. However :py:mod:`pickle` serializes these
exactly, leading to :exc:`mitogen.CallError` during :meth:`Context.call
<mitogen.parent.Context.call>` in the target when it tries to deserialize
the data.
This function walks the object graph `obj`, producing a copy with any
custom sub-types removed. The functionality is not default since the
resulting walk may be computationally expensive given a large enough graph.
Raises :py:exc:`TypeError` if an unknown subtype is encountered, or
casting does not return the desired supertype.
See :ref:`serialization-rules` for a list of supported types.
:param obj:
Object to undecorate.
:returns:
Undecorated object.
"""
if isinstance(obj, dict):
return dict((cast(k), cast(v)) for k, v in iteritems(obj))
if isinstance(obj, (list, tuple)):
return [cast(v) for v in obj]
if isinstance(obj, PASSTHROUGH):
return obj
if isinstance(obj, mitogen.core.UnicodeType):
return _cast(obj, mitogen.core.UnicodeType)
if isinstance(obj, mitogen.core.BytesType):
return _cast(obj, mitogen.core.BytesType)
raise TypeError("Cannot serialize: %r: %r" % (type(obj), obj))
def _cast(obj, desired_type):
result = desired_type(obj)
if type(result) is not desired_type:
raise TypeError("Cast of %r to %r failed, got %r"
% (type(obj), desired_type, type(result)))
return result