1183 lines
41 KiB
Python
1183 lines
41 KiB
Python
# Copyright 2019, David Wilson
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#
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# Redistribution and use in source and binary forms, with or without
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# modification, are permitted provided that the following conditions are met:
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#
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# 1. Redistributions of source code must retain the above copyright notice,
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# this list of conditions and the following disclaimer.
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#
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# 2. Redistributions in binary form must reproduce the above copyright notice,
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# this list of conditions and the following disclaimer in the documentation
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# and/or other materials provided with the distribution.
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#
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# 3. Neither the name of the copyright holder nor the names of its contributors
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# may be used to endorse or promote products derived from this software without
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# specific prior written permission.
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#
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# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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# ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
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# LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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# CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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# SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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# CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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# ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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# POSSIBILITY OF SUCH DAMAGE.
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# !mitogen: minify_safe
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import grp
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import logging
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import os
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import pprint
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import pwd
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import stat
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import sys
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import threading
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import mitogen.core
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import mitogen.select
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from mitogen.core import b
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from mitogen.core import str_rpartition
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try:
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all
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except NameError:
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def all(it):
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for elem in it:
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if not elem:
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return False
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return True
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LOG = logging.getLogger(__name__)
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_pool = None
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_pool_pid = None
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#: Serialize pool construction.
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_pool_lock = threading.Lock()
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if mitogen.core.PY3:
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def func_code(func):
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return func.__code__
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def func_name(func):
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return func.__name__
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else:
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def func_code(func):
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return func.func_code
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def func_name(func):
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return func.func_name
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@mitogen.core.takes_router
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def get_or_create_pool(size=None, router=None, context=None):
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global _pool
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global _pool_pid
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my_pid = os.getpid()
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if _pool is None or _pool.closed or my_pid != _pool_pid:
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# Avoid acquiring heavily contended lock if possible.
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_pool_lock.acquire()
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try:
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if _pool_pid != my_pid:
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if router is None:
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# fallback to trying to get router from context if that exists
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if context is not None:
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router = context.router
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else:
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raise ValueError("Unable to create Pool! Missing router.")
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_pool = Pool(
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router,
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services=[],
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size=size or 2,
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overwrite=True,
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recv=mitogen.core.Dispatcher._service_recv,
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)
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# In case of Broker shutdown crash, Pool can cause 'zombie'
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# processes.
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mitogen.core.listen(router.broker, 'shutdown',
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lambda: _pool.stop(join=True))
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_pool_pid = os.getpid()
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finally:
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_pool_lock.release()
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return _pool
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def get_thread_name():
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thread = mitogen.core.threading__current_thread()
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return mitogen.core.threading__thread_name(thread)
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def call(service_name, method_name, call_context=None, **kwargs):
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"""
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Call a service registered with this pool, using the calling thread as a
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host.
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"""
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if isinstance(service_name, mitogen.core.BytesType):
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service_name = service_name.encode('utf-8')
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elif not isinstance(service_name, mitogen.core.UnicodeType):
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service_name = service_name.name() # Service.name()
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if call_context:
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return call_context.call_service(service_name, method_name, **kwargs)
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else:
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pool = get_or_create_pool(context=kwargs.get('context'))
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invoker = pool.get_invoker(service_name, msg=None)
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return getattr(invoker.service, method_name)(**kwargs)
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def validate_arg_spec(spec, args):
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for name in spec:
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try:
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obj = args[name]
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except KeyError:
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raise mitogen.core.CallError(
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'Required argument %r missing.' % (name,)
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)
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if not isinstance(obj, spec[name]):
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raise mitogen.core.CallError(
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'Argument %r type incorrect, got %r, expected %r' % (
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name,
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type(obj),
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spec[name]
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)
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)
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def arg_spec(spec):
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"""
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Annotate a method as requiring arguments with a specific type. This only
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validates required arguments. For optional arguments, write a manual check
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within the function.
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::
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@mitogen.service.arg_spec({
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'path': str
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})
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def fetch_path(self, path, optional=None):
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...
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:param dict spec:
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Mapping from argument name to expected type.
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"""
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def wrapper(func):
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func.mitogen_service__arg_spec = spec
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return func
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return wrapper
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def expose(policy):
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"""
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Annotate a method to permit access to contexts matching an authorization
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policy. The annotation may be specified multiple times. Methods lacking any
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authorization policy are not accessible.
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::
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@mitogen.service.expose(policy=mitogen.service.AllowParents())
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def unsafe_operation(self):
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...
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:param mitogen.service.Policy policy:
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The policy to require.
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"""
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def wrapper(func):
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func.mitogen_service__policies = (
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[policy] +
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getattr(func, 'mitogen_service__policies', [])
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)
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return func
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return wrapper
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def no_reply():
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"""
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Annotate a method as one that does not generate a response. Messages sent
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by the method are done so explicitly. This can be used for fire-and-forget
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endpoints where the requestee never receives a reply.
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"""
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def wrapper(func):
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func.mitogen_service__no_reply = True
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return func
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return wrapper
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class Error(Exception):
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"""
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Raised when an error occurs configuring a service or pool.
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"""
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pass # cope with minify_source() bug.
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class Policy(object):
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"""
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Base security policy.
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"""
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def is_authorized(self, service, msg):
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raise NotImplementedError()
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class AllowAny(Policy):
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def is_authorized(self, service, msg):
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return True
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class AllowParents(Policy):
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def is_authorized(self, service, msg):
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return (msg.auth_id in mitogen.parent_ids or
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msg.auth_id == mitogen.context_id)
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class Activator(object):
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"""
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"""
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def is_permitted(self, mod_name, class_name, msg):
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return mitogen.core.has_parent_authority(msg)
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not_active_msg = (
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'Service %r is not yet activated in this context, and the '
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'caller is not privileged, therefore autoactivation is disabled.'
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)
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def activate(self, pool, service_name, msg):
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mod_name, _, class_name = str_rpartition(service_name, '.')
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if msg and not self.is_permitted(mod_name, class_name, msg):
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raise mitogen.core.CallError(self.not_active_msg, service_name)
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module = mitogen.core.import_module(mod_name)
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klass = getattr(module, class_name)
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service = klass(router=pool.router)
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pool.add(service)
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return service
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class Invoker(object):
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def __init__(self, service):
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self.service = service
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def __repr__(self):
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return '%s(%s)' % (type(self).__name__, self.service)
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unauthorized_msg = (
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'Caller is not authorized to invoke %r of service %r'
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)
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def _validate(self, method_name, kwargs, msg):
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method = getattr(self.service, method_name, None)
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if method is None:
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raise mitogen.core.CallError('No such method: %r', method_name)
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policies = getattr(method, 'mitogen_service__policies', None)
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if not policies:
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raise mitogen.core.CallError('Method has no policies set.')
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if msg is not None:
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if not all(p.is_authorized(self.service, msg) for p in policies):
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raise mitogen.core.CallError(
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self.unauthorized_msg,
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method_name,
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self.service.name()
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)
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required = getattr(method, 'mitogen_service__arg_spec', {})
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validate_arg_spec(required, kwargs)
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def _invoke(self, method_name, kwargs, msg):
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method = getattr(self.service, method_name)
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if 'msg' in func_code(method).co_varnames:
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kwargs['msg'] = msg # TODO: hack
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no_reply = getattr(method, 'mitogen_service__no_reply', False)
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ret = None
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try:
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ret = method(**kwargs)
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if no_reply:
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return Service.NO_REPLY
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return ret
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except Exception:
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if no_reply:
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LOG.exception('While calling no-reply method %s.%s',
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self.service.name(),
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func_name(method))
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else:
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raise
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def invoke(self, method_name, kwargs, msg):
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self._validate(method_name, kwargs, msg)
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response = self._invoke(method_name, kwargs, msg)
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if response is not Service.NO_REPLY:
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msg.reply(response)
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class SerializedInvoker(Invoker):
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def __init__(self, **kwargs):
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super(SerializedInvoker, self).__init__(**kwargs)
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self._lock = threading.Lock()
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self._queue = []
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self._running = False
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def _pop(self):
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self._lock.acquire()
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try:
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try:
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return self._queue.pop(0)
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except IndexError:
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self._running = False
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finally:
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self._lock.release()
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def _run(self):
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while True:
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tup = self._pop()
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if tup is None:
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return
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method_name, kwargs, msg = tup
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try:
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super(SerializedInvoker, self).invoke(method_name, kwargs, msg)
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except mitogen.core.CallError:
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e = sys.exc_info()[1]
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LOG.warning('%r: call error: %s: %s', self, msg, e)
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msg.reply(e)
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except Exception:
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LOG.exception('%r: while invoking %s()', self, method_name)
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msg.reply(mitogen.core.Message.dead())
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def invoke(self, method_name, kwargs, msg):
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self._lock.acquire()
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try:
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self._queue.append((method_name, kwargs, msg))
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first = not self._running
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self._running = True
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finally:
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self._lock.release()
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if first:
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self._run()
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return Service.NO_REPLY
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class DeduplicatingInvoker(Invoker):
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"""
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A service that deduplicates and caches expensive responses. Requests are
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deduplicated according to a customizable key, and the single expensive
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response is broadcast to all requestors.
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A side effect of this class is that processing of the single response is
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always serialized according to the result of :py:meth:`key_from_request`.
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Only one pool thread is blocked during generation of the response,
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regardless of the number of requestors.
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"""
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def __init__(self, service):
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super(DeduplicatingInvoker, self).__init__(service)
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self._responses = {}
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self._waiters = {}
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self._lock = threading.Lock()
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def key_from_request(self, method_name, kwargs):
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"""
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Generate a deduplication key from the request. The default
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implementation returns a string based on a stable representation of the
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input dictionary generated by :py:func:`pprint.pformat`.
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"""
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return pprint.pformat((method_name, kwargs))
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def get_response(self, args):
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raise NotImplementedError()
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def _produce_response(self, key, response):
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self._lock.acquire()
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try:
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assert key not in self._responses
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assert key in self._waiters
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self._responses[key] = response
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for msg in self._waiters.pop(key):
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msg.reply(response)
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finally:
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self._lock.release()
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def _invoke(self, method_name, kwargs, msg):
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key = self.key_from_request(method_name, kwargs)
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self._lock.acquire()
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try:
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if key in self._responses:
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return self._responses[key]
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if key in self._waiters:
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self._waiters[key].append(msg)
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return Service.NO_REPLY
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self._waiters[key] = [msg]
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finally:
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self._lock.release()
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# I'm the unlucky thread that must generate the response.
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try:
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response = getattr(self, method_name)(**kwargs)
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self._produce_response(key, response)
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except mitogen.core.CallError:
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e = sys.exc_info()[1]
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self._produce_response(key, e)
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except Exception:
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e = sys.exc_info()[1]
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self._produce_response(key, mitogen.core.CallError(e))
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return Service.NO_REPLY
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class Service(object):
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#: Sentinel object to suppress reply generation, since returning
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#: :data:`None` will trigger a response message containing the pickled
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#: :data:`None`.
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NO_REPLY = object()
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invoker_class = Invoker
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@classmethod
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def name(cls):
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return u'%s.%s' % (cls.__module__, cls.__name__)
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def __init__(self, router):
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self.router = router
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self.select = mitogen.select.Select()
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def __repr__(self):
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return '%s()' % (self.__class__.__name__,)
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def on_message(self, event):
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"""
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Called when a message arrives on any of :attr:`select`'s registered
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receivers.
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:param mitogen.select.Event event:
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"""
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pass
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def on_shutdown(self):
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"""
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Called by Pool.shutdown() once the last worker thread has exitted.
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"""
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pass
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|
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class Pool(object):
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"""
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Manage a pool of at least one thread that will be used to process messages
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for a collection of services.
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Internally this is implemented by subscribing every :py:class:`Service`'s
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:py:class:`mitogen.core.Receiver` using a single
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:py:class:`mitogen.select.Select`, then arranging for every thread to
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consume messages delivered to that select.
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In this way the threads are fairly shared by all available services, and no
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resources are dedicated to a single idle service.
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There is no penalty for exposing large numbers of services; the list of
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exposed services could even be generated dynamically in response to your
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program's configuration or its input data.
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:param mitogen.core.Router router:
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:class:`mitogen.core.Router` to listen for
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:data:`mitogen.core.CALL_SERVICE` messages.
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:param list services:
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Initial list of services to register.
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:param mitogen.core.Receiver recv:
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:data:`mitogen.core.CALL_SERVICE` receiver to reuse. This is used by
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:func:`get_or_create_pool` to hand off a queue of messages from the
|
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Dispatcher stub handler while avoiding a race.
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"""
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activator_class = Activator
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|
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def __init__(self, router, services=(), size=1, overwrite=False,
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recv=None):
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self.router = router
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self._activator = self.activator_class()
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self._ipc_latch = mitogen.core.Latch()
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self._receiver = mitogen.core.Receiver(
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router=router,
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handle=mitogen.core.CALL_SERVICE,
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overwrite=overwrite,
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)
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self._select = mitogen.select.Select(oneshot=False)
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self._select.add(self._receiver)
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self._select.add(self._ipc_latch)
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#: Serialize service construction.
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self._lock = threading.Lock()
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self._func_by_source = {
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self._receiver: self._on_service_call,
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self._ipc_latch: self._on_ipc_latch,
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}
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self._invoker_by_name = {}
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|
|
|
if recv is not None:
|
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# When inheriting from mitogen.core.Dispatcher, we must remove its
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# stub notification function before adding it to our Select. We
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# always overwrite this receiver since the standard service.Pool
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# handler policy differs from the one inherited from
|
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# core.Dispatcher.
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recv.notify = None
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self._select.add(recv)
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self._func_by_source[recv] = self._on_service_call
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|
|
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for service in services:
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self.add(service)
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self._py_24_25_compat()
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|
self._threads = []
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for x in range(size):
|
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name = 'mitogen.Pool.%04x.%d' % (id(self) & 0xffff, x,)
|
|
thread = threading.Thread(
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name=name,
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target=mitogen.core._profile_hook,
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args=('mitogen.service.pool', self._worker_main),
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)
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thread.start()
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self._threads.append(thread)
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LOG.debug('%r: initialized', self)
|
|
|
|
def _py_24_25_compat(self):
|
|
if sys.version_info < (2, 6):
|
|
# import_module() is used to avoid dep scanner sending mitogen.fork
|
|
# to all mitogen.service importers.
|
|
os_fork = mitogen.core.import_module('mitogen.os_fork')
|
|
os_fork._notice_broker_or_pool(self)
|
|
|
|
@property
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|
def size(self):
|
|
return len(self._threads)
|
|
|
|
def add(self, service):
|
|
name = service.name()
|
|
if name in self._invoker_by_name:
|
|
raise Error('service named %r already registered' % (name,))
|
|
assert service.select not in self._func_by_source
|
|
invoker = service.invoker_class(service=service)
|
|
self._invoker_by_name[name] = invoker
|
|
self._func_by_source[service.select] = service.on_message
|
|
|
|
closed = False
|
|
|
|
def stop(self, join=True):
|
|
self.closed = True
|
|
self._receiver.close()
|
|
self._select.close()
|
|
if join:
|
|
self.join()
|
|
|
|
def join(self):
|
|
for th in self._threads:
|
|
th.join()
|
|
for invoker in self._invoker_by_name.values():
|
|
invoker.service.on_shutdown()
|
|
|
|
def get_invoker(self, name, msg):
|
|
invoker = self._invoker_by_name.get(name)
|
|
if invoker is None:
|
|
# Avoid acquiring lock if possible.
|
|
self._lock.acquire()
|
|
try:
|
|
invoker = self._invoker_by_name.get(name)
|
|
if not invoker:
|
|
service = self._activator.activate(self, name, msg)
|
|
invoker = service.invoker_class(service=service)
|
|
self._invoker_by_name[name] = invoker
|
|
finally:
|
|
self._lock.release()
|
|
|
|
return invoker
|
|
|
|
def get_service(self, name):
|
|
invoker = self.get_invoker(name, None)
|
|
return invoker.service
|
|
|
|
def _validate(self, msg):
|
|
tup = msg.unpickle(throw=False)
|
|
if not (isinstance(tup, tuple) and
|
|
len(tup) == 3 and
|
|
isinstance(tup[0], mitogen.core.AnyTextType) and
|
|
isinstance(tup[1], mitogen.core.AnyTextType) and
|
|
isinstance(tup[2], dict)):
|
|
raise mitogen.core.CallError('Invalid message format.')
|
|
|
|
def defer(self, func, *args, **kwargs):
|
|
"""
|
|
Arrange for `func(*args, **kwargs)` to be invoked in the context of a
|
|
service pool thread.
|
|
"""
|
|
self._ipc_latch.put(lambda: func(*args, **kwargs))
|
|
|
|
def _on_ipc_latch(self, event):
|
|
event.data()
|
|
|
|
def _on_service_call(self, event):
|
|
msg = event.data
|
|
service_name = None
|
|
method_name = None
|
|
try:
|
|
self._validate(msg)
|
|
service_name, method_name, kwargs = msg.unpickle()
|
|
invoker = self.get_invoker(service_name, msg)
|
|
return invoker.invoke(method_name, kwargs, msg)
|
|
except mitogen.core.CallError:
|
|
e = sys.exc_info()[1]
|
|
LOG.warning('%r: call error: %s: %s', self, msg, e)
|
|
msg.reply(e)
|
|
except Exception:
|
|
LOG.exception('%r: while invoking %r of %r',
|
|
self, method_name, service_name)
|
|
e = sys.exc_info()[1]
|
|
msg.reply(mitogen.core.CallError(e))
|
|
|
|
def _worker_run(self):
|
|
while not self.closed:
|
|
try:
|
|
event = self._select.get_event()
|
|
except mitogen.core.LatchError:
|
|
LOG.debug('thread %s exiting gracefully', get_thread_name())
|
|
return
|
|
except mitogen.core.ChannelError:
|
|
LOG.debug('thread %s exiting with error: %s',
|
|
get_thread_name(), sys.exc_info()[1])
|
|
return
|
|
|
|
func = self._func_by_source[event.source]
|
|
try:
|
|
func(event)
|
|
except Exception:
|
|
LOG.exception('While handling %r using %r', event.data, func)
|
|
|
|
def _worker_main(self):
|
|
try:
|
|
self._worker_run()
|
|
except Exception:
|
|
LOG.exception('%r: worker %r crashed', self, get_thread_name())
|
|
raise
|
|
|
|
def __repr__(self):
|
|
return 'Pool(%04x, size=%d, th=%r)' % (
|
|
id(self) & 0xffff,
|
|
len(self._threads),
|
|
get_thread_name(),
|
|
)
|
|
|
|
|
|
class FileStreamState(object):
|
|
def __init__(self):
|
|
#: List of [(Sender, file object)]
|
|
self.jobs = []
|
|
self.completing = {}
|
|
#: In-flight byte count.
|
|
self.unacked = 0
|
|
#: Lock.
|
|
self.lock = threading.Lock()
|
|
|
|
|
|
class PushFileService(Service):
|
|
"""
|
|
Push-based file service. Files are delivered and cached in RAM, sent
|
|
recursively from parent to child. A child that requests a file via
|
|
:meth:`get` will block until it has been delivered by a parent.
|
|
|
|
This service will eventually be merged into FileService.
|
|
"""
|
|
def __init__(self, **kwargs):
|
|
super(PushFileService, self).__init__(**kwargs)
|
|
self._lock = threading.Lock()
|
|
self._cache = {}
|
|
self._extra_sys_paths = set()
|
|
self._waiters = {}
|
|
self._sent_by_stream = {}
|
|
|
|
def get(self, path):
|
|
"""
|
|
Fetch a file from the cache.
|
|
"""
|
|
assert isinstance(path, mitogen.core.UnicodeType)
|
|
self._lock.acquire()
|
|
try:
|
|
if path in self._cache:
|
|
return self._cache[path]
|
|
latch = mitogen.core.Latch()
|
|
waiters = self._waiters.setdefault(path, [])
|
|
waiters.append(lambda: latch.put(None))
|
|
finally:
|
|
self._lock.release()
|
|
|
|
LOG.debug('%r.get(%r) waiting for uncached file to arrive', self, path)
|
|
latch.get()
|
|
LOG.debug('%r.get(%r) -> %r', self, path, self._cache[path])
|
|
return self._cache[path]
|
|
|
|
def _forward(self, context, path):
|
|
stream = self.router.stream_by_id(context.context_id)
|
|
child = self.router.context_by_id(stream.protocol.remote_id)
|
|
sent = self._sent_by_stream.setdefault(stream, set())
|
|
if path in sent:
|
|
if child.context_id != context.context_id:
|
|
LOG.debug('requesting %s forward small file to %s: %s',
|
|
child, context, path)
|
|
child.call_service_async(
|
|
service_name=self.name(),
|
|
method_name='forward',
|
|
path=path,
|
|
context=context
|
|
).close()
|
|
else:
|
|
LOG.debug('requesting %s cache and forward small file to %s: %s',
|
|
child, context, path)
|
|
child.call_service_async(
|
|
service_name=self.name(),
|
|
method_name='store_and_forward',
|
|
path=path,
|
|
data=self._cache[path],
|
|
context=context
|
|
).close()
|
|
sent.add(path)
|
|
|
|
@expose(policy=AllowParents())
|
|
@arg_spec({
|
|
'context': mitogen.core.Context,
|
|
'paths': list,
|
|
# 'modules': list, TODO, modules was passed into this func but it's not used yet
|
|
})
|
|
def propagate_paths_and_modules(self, context, paths, overridden_sources=None, extra_sys_paths=None):
|
|
"""
|
|
One size fits all method to ensure a target context has been preloaded
|
|
with a set of small files and Python modules.
|
|
|
|
:param dict overridden_sources:
|
|
Optional dict containing source code to override path's source code
|
|
:param extra_sys_paths:
|
|
Loads additional sys paths for use in finding modules; beneficial
|
|
in situations like loading Ansible Collections because source code
|
|
dependencies come from different file paths than where the source lives
|
|
"""
|
|
for path in paths:
|
|
overridden_source = None
|
|
if overridden_sources is not None and path in overridden_sources:
|
|
overridden_source = overridden_sources[path]
|
|
self.propagate_to(context, mitogen.core.to_text(path), overridden_source)
|
|
# self.router.responder.forward_modules(context, modules) TODO
|
|
|
|
# NOTE: could possibly be handled by the above TODO, but not sure how forward_modules works enough
|
|
# to know for sure, so for now going to pass the sys paths themselves and have `propagate_to`
|
|
# load them up in sys.path for later import
|
|
# ensure we don't add to sys.path the same path we've already seen
|
|
for extra_path in extra_sys_paths:
|
|
# store extra paths in cached set for O(1) lookup
|
|
if extra_path not in self._extra_sys_paths:
|
|
# not sure if it matters but we could prepend to sys.path instead if we need to
|
|
sys.path.append(extra_path)
|
|
self._extra_sys_paths.add(extra_path)
|
|
|
|
@expose(policy=AllowParents())
|
|
@arg_spec({
|
|
'context': mitogen.core.Context,
|
|
'path': mitogen.core.FsPathTypes,
|
|
})
|
|
def propagate_to(self, context, path, overridden_source=None):
|
|
"""
|
|
If the optional parameter 'overridden_source' is passed, use
|
|
that instead of the path's code as source code. This works around some bugs
|
|
of source modules such as relative imports on unsupported Python versions
|
|
"""
|
|
if path not in self._cache:
|
|
LOG.debug('caching small file %s', path)
|
|
if overridden_source is None:
|
|
fp = open(path, 'rb')
|
|
try:
|
|
self._cache[path] = mitogen.core.Blob(fp.read())
|
|
finally:
|
|
fp.close()
|
|
else:
|
|
self._cache[path] = mitogen.core.Blob(overridden_source)
|
|
self._forward(context, path)
|
|
|
|
@expose(policy=AllowParents())
|
|
@no_reply()
|
|
@arg_spec({
|
|
'path': mitogen.core.UnicodeType,
|
|
'data': mitogen.core.Blob,
|
|
'context': mitogen.core.Context,
|
|
})
|
|
def store_and_forward(self, path, data, context):
|
|
LOG.debug('%r.store_and_forward(%r, %r, %r) %r',
|
|
self, path, data, context,
|
|
get_thread_name())
|
|
self._lock.acquire()
|
|
try:
|
|
self._cache[path] = data
|
|
waiters = self._waiters.pop(path, [])
|
|
finally:
|
|
self._lock.release()
|
|
|
|
if context.context_id != mitogen.context_id:
|
|
self._forward(context, path)
|
|
for callback in waiters:
|
|
callback()
|
|
|
|
@expose(policy=AllowParents())
|
|
@no_reply()
|
|
@arg_spec({
|
|
'path': mitogen.core.FsPathTypes,
|
|
'context': mitogen.core.Context,
|
|
})
|
|
def forward(self, path, context):
|
|
LOG.debug('%r.forward(%r, %r)', self, path, context)
|
|
func = lambda: self._forward(context, path)
|
|
|
|
self._lock.acquire()
|
|
try:
|
|
if path in self._cache:
|
|
func()
|
|
else:
|
|
LOG.debug('%r: %r not cached yet, queueing', self, path)
|
|
self._waiters.setdefault(path, []).append(func)
|
|
finally:
|
|
self._lock.release()
|
|
|
|
|
|
class FileService(Service):
|
|
"""
|
|
Streaming file server, used to serve small and huge files alike. Paths must
|
|
be registered by a trusted context before they will be served to a child.
|
|
|
|
Transfers are divided among the physical streams that connect external
|
|
contexts, ensuring each stream never has excessive data buffered in RAM,
|
|
while still maintaining enough to fully utilize available bandwidth. This
|
|
is achieved by making an initial bandwidth assumption, enqueueing enough
|
|
chunks to fill that assumed pipe, then responding to delivery
|
|
acknowledgements from the receiver by scheduling new chunks.
|
|
|
|
Transfers proceed one-at-a-time per stream. When multiple contexts exist on
|
|
a stream (e.g. one is the SSH account, another is a sudo account, and a
|
|
third is a proxied SSH connection), each request is satisfied in turn
|
|
before subsequent requests start flowing. This ensures when a stream is
|
|
contended, priority is given to completing individual transfers rather than
|
|
potentially aborting many partial transfers, causing the bandwidth to be
|
|
wasted.
|
|
|
|
Theory of operation:
|
|
1. Trusted context (i.e. WorkerProcess) calls register(), making a
|
|
file available to any untrusted context.
|
|
2. Requestee context creates a mitogen.core.Receiver() to receive
|
|
chunks, then calls fetch(path, recv.to_sender()), to set up the
|
|
transfer.
|
|
3. fetch() replies to the call with the file's metadata, then
|
|
schedules an initial burst up to the window size limit (1MiB).
|
|
4. Chunks begin to arrive in the requestee, which calls acknowledge()
|
|
for each 128KiB received.
|
|
5. The acknowledge() call arrives at FileService, which scheduled a new
|
|
chunk to refill the drained window back to the size limit.
|
|
6. When the last chunk has been pumped for a single transfer,
|
|
Sender.close() is called causing the receive loop in
|
|
target.py::_get_file() to exit, allowing that code to compare the
|
|
transferred size with the total file size from the metadata.
|
|
7. If the sizes mismatch, _get_file()'s caller is informed which will
|
|
discard the result and log/raise an error.
|
|
|
|
Shutdown:
|
|
1. process.py calls service.Pool.shutdown(), which arranges for the
|
|
service pool threads to exit and be joined, guranteeing no new
|
|
requests can arrive, before calling Service.on_shutdown() for each
|
|
registered service.
|
|
2. FileService.on_shutdown() walks every in-progress transfer and calls
|
|
Sender.close(), causing Receiver loops in the requestees to exit
|
|
early. The size check fails and any partially downloaded file is
|
|
discarded.
|
|
3. Control exits _get_file() in every target, and graceful shutdown can
|
|
proceed normally, without the associated thread needing to be
|
|
forcefully killed.
|
|
"""
|
|
unregistered_msg = 'Path %r is not registered with FileService.'
|
|
context_mismatch_msg = 'sender= kwarg context must match requestee context'
|
|
|
|
#: Burst size. With 1MiB and 10ms RTT max throughput is 100MiB/sec, which
|
|
#: is 5x what SSH can handle on a 2011 era 2.4Ghz Core i5.
|
|
window_size_bytes = 1048576
|
|
|
|
def __init__(self, router):
|
|
super(FileService, self).__init__(router)
|
|
#: Set of registered paths.
|
|
self._paths = set()
|
|
#: Set of registered directory prefixes.
|
|
self._prefixes = set()
|
|
#: Mapping of Stream->FileStreamState.
|
|
self._state_by_stream = {}
|
|
|
|
def _name_or_none(self, func, n, attr):
|
|
try:
|
|
return getattr(func(n), attr)
|
|
except KeyError:
|
|
return None
|
|
|
|
@expose(policy=AllowParents())
|
|
@arg_spec({
|
|
'path': mitogen.core.FsPathTypes,
|
|
})
|
|
def register(self, path):
|
|
"""
|
|
Authorize a path for access by children. Repeat calls with the same
|
|
path has no effect.
|
|
|
|
:param str path:
|
|
File path.
|
|
"""
|
|
if path not in self._paths:
|
|
LOG.debug('%r: registering %r', self, path)
|
|
self._paths.add(path)
|
|
|
|
@expose(policy=AllowParents())
|
|
@arg_spec({
|
|
'path': mitogen.core.FsPathTypes,
|
|
})
|
|
def register_prefix(self, path):
|
|
"""
|
|
Authorize a path and any subpaths for access by children. Repeat calls
|
|
with the same path has no effect.
|
|
|
|
:param str path:
|
|
File path.
|
|
"""
|
|
if path not in self._prefixes:
|
|
LOG.debug('%r: registering prefix %r', self, path)
|
|
self._prefixes.add(path)
|
|
|
|
def _generate_stat(self, path):
|
|
st = os.stat(path)
|
|
if not stat.S_ISREG(st.st_mode):
|
|
raise IOError('%r is not a regular file.' % (path,))
|
|
|
|
return {
|
|
u'size': st.st_size,
|
|
u'mode': st.st_mode,
|
|
u'owner': self._name_or_none(pwd.getpwuid, 0, 'pw_name'),
|
|
u'group': self._name_or_none(grp.getgrgid, 0, 'gr_name'),
|
|
u'mtime': float(st.st_mtime), # Python 2.4 uses int.
|
|
u'atime': float(st.st_atime), # Python 2.4 uses int.
|
|
}
|
|
|
|
def on_shutdown(self):
|
|
"""
|
|
Respond to shutdown by sending close() to every target, allowing their
|
|
receive loop to exit and clean up gracefully.
|
|
"""
|
|
LOG.debug('%r.on_shutdown()', self)
|
|
for stream, state in self._state_by_stream.items():
|
|
state.lock.acquire()
|
|
try:
|
|
for sender, fp in reversed(state.jobs):
|
|
sender.close()
|
|
fp.close()
|
|
state.jobs.pop()
|
|
finally:
|
|
state.lock.release()
|
|
|
|
# The IO loop pumps 128KiB chunks. An ideal message is a multiple of this,
|
|
# odd-sized messages waste one tiny write() per message on the trailer.
|
|
# Therefore subtract 10 bytes pickle overhead + 24 bytes header.
|
|
IO_SIZE = mitogen.core.CHUNK_SIZE - (mitogen.core.Message.HEADER_LEN + (
|
|
len(
|
|
mitogen.core.Message.pickled(
|
|
mitogen.core.Blob(b(' ') * mitogen.core.CHUNK_SIZE)
|
|
).data
|
|
) - mitogen.core.CHUNK_SIZE
|
|
))
|
|
|
|
def _schedule_pending_unlocked(self, state):
|
|
"""
|
|
Consider the pending transfers for a stream, pumping new chunks while
|
|
the unacknowledged byte count is below :attr:`window_size_bytes`. Must
|
|
be called with the FileStreamState lock held.
|
|
|
|
:param FileStreamState state:
|
|
Stream to schedule chunks for.
|
|
"""
|
|
while state.jobs and state.unacked < self.window_size_bytes:
|
|
sender, fp = state.jobs[0]
|
|
s = fp.read(self.IO_SIZE)
|
|
if s:
|
|
state.unacked += len(s)
|
|
sender.send(mitogen.core.Blob(s))
|
|
else:
|
|
# File is done. Cause the target's receive loop to exit by
|
|
# closing the sender, close the file, and remove the job entry.
|
|
sender.close()
|
|
fp.close()
|
|
state.jobs.pop(0)
|
|
|
|
def _prefix_is_authorized(self, path):
|
|
"""
|
|
Return the set of all possible directory prefixes for `path`.
|
|
:func:`os.path.abspath` is used to ensure the path is absolute.
|
|
|
|
:param str path:
|
|
The path.
|
|
:returns: Set of prefixes.
|
|
"""
|
|
path = os.path.abspath(path)
|
|
while True:
|
|
if path in self._prefixes:
|
|
return True
|
|
if path == '/':
|
|
break
|
|
path = os.path.dirname(path)
|
|
return False
|
|
|
|
@expose(policy=AllowAny())
|
|
@no_reply()
|
|
@arg_spec({
|
|
'path': mitogen.core.FsPathTypes,
|
|
'sender': mitogen.core.Sender,
|
|
})
|
|
def fetch(self, path, sender, msg):
|
|
"""
|
|
Start a transfer for a registered path.
|
|
|
|
:param str path:
|
|
File path.
|
|
:param mitogen.core.Sender sender:
|
|
Sender to receive file data.
|
|
:returns:
|
|
Dict containing the file metadata:
|
|
|
|
* ``size``: File size in bytes.
|
|
* ``mode``: Integer file mode.
|
|
* ``owner``: Owner account name on host machine.
|
|
* ``group``: Owner group name on host machine.
|
|
* ``mtime``: Floating point modification time.
|
|
* ``ctime``: Floating point change time.
|
|
:raises Error:
|
|
Unregistered path, or Sender did not match requestee context.
|
|
"""
|
|
if (
|
|
(path not in self._paths) and
|
|
(not self._prefix_is_authorized(path)) and
|
|
(not mitogen.core._has_parent_authority(msg.auth_id))
|
|
):
|
|
msg.reply(mitogen.core.CallError(
|
|
Error(self.unregistered_msg % (path,))
|
|
))
|
|
return
|
|
|
|
if msg.src_id != sender.context.context_id:
|
|
msg.reply(mitogen.core.CallError(
|
|
Error(self.context_mismatch_msg)
|
|
))
|
|
return
|
|
|
|
LOG.debug('Serving %r', path)
|
|
|
|
# Response must arrive first so requestee can begin receive loop,
|
|
# otherwise first ack won't arrive until all pending chunks were
|
|
# delivered. In that case max BDP would always be 128KiB, aka. max
|
|
# ~10Mbit/sec over a 100ms link.
|
|
try:
|
|
fp = open(path, 'rb', self.IO_SIZE)
|
|
msg.reply(self._generate_stat(path))
|
|
except IOError:
|
|
msg.reply(mitogen.core.CallError(
|
|
sys.exc_info()[1]
|
|
))
|
|
return
|
|
|
|
stream = self.router.stream_by_id(sender.context.context_id)
|
|
state = self._state_by_stream.setdefault(stream, FileStreamState())
|
|
state.lock.acquire()
|
|
try:
|
|
state.jobs.append((sender, fp))
|
|
self._schedule_pending_unlocked(state)
|
|
finally:
|
|
state.lock.release()
|
|
|
|
@expose(policy=AllowAny())
|
|
@no_reply()
|
|
@arg_spec({
|
|
'size': int,
|
|
})
|
|
@no_reply()
|
|
def acknowledge(self, size, msg):
|
|
"""
|
|
Acknowledge bytes received by a transfer target, scheduling new chunks
|
|
to keep the window full. This should be called for every chunk received
|
|
by the target.
|
|
"""
|
|
stream = self.router.stream_by_id(msg.src_id)
|
|
state = self._state_by_stream[stream]
|
|
state.lock.acquire()
|
|
try:
|
|
if state.unacked < size:
|
|
LOG.error('%r.acknowledge(src_id %d): unacked=%d < size %d',
|
|
self, msg.src_id, state.unacked, size)
|
|
state.unacked -= min(state.unacked, size)
|
|
self._schedule_pending_unlocked(state)
|
|
finally:
|
|
state.lock.release()
|
|
|
|
@classmethod
|
|
def get(cls, context, path, out_fp):
|
|
"""
|
|
Streamily download a file from the connection multiplexer process in
|
|
the controller.
|
|
|
|
:param mitogen.core.Context context:
|
|
Reference to the context hosting the FileService that will be used
|
|
to fetch the file.
|
|
:param bytes path:
|
|
FileService registered name of the input file.
|
|
:param bytes out_path:
|
|
Name of the output path on the local disk.
|
|
:returns:
|
|
Tuple of (`ok`, `metadata`), where `ok` is :data:`True` on success,
|
|
or :data:`False` if the transfer was interrupted and the output
|
|
should be discarded.
|
|
|
|
`metadata` is a dictionary of file metadata as documented in
|
|
:meth:`fetch`.
|
|
"""
|
|
LOG.debug('get_file(): fetching %r from %r', path, context)
|
|
t0 = mitogen.core.now()
|
|
recv = mitogen.core.Receiver(router=context.router)
|
|
metadata = context.call_service(
|
|
service_name=cls.name(),
|
|
method_name='fetch',
|
|
path=path,
|
|
sender=recv.to_sender(),
|
|
)
|
|
|
|
received_bytes = 0
|
|
for chunk in recv:
|
|
s = chunk.unpickle()
|
|
LOG.debug('get_file(%r): received %d bytes', path, len(s))
|
|
context.call_service_async(
|
|
service_name=cls.name(),
|
|
method_name='acknowledge',
|
|
size=len(s),
|
|
).close()
|
|
out_fp.write(s)
|
|
received_bytes += len(s)
|
|
|
|
ok = received_bytes == metadata['size']
|
|
if received_bytes < metadata['size']:
|
|
LOG.error('get_file(%r): receiver was closed early, controller '
|
|
'may be shutting down, or the file was truncated '
|
|
'during transfer. Expected %d bytes, received %d.',
|
|
path, metadata['size'], received_bytes)
|
|
elif received_bytes > metadata['size']:
|
|
LOG.error('get_file(%r): the file appears to have grown '
|
|
'while transfer was in progress. Expected %d '
|
|
'bytes, received %d.',
|
|
path, metadata['size'], received_bytes)
|
|
|
|
LOG.debug('target.get_file(): fetched %d bytes of %r from %r in %dms',
|
|
metadata['size'], path, context,
|
|
1000 * (mitogen.core.now() - t0))
|
|
return ok, metadata
|