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# Copyright 2015, Google Inc.
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are
# met:
#
# * Redistributions of source code must retain the above copyright
# notice, this list of conditions and the following disclaimer.
# * 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.
# * Neither the name of Google Inc. 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
# OWNER 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.
"""State and behavior for operation expiration."""
import time
from _framework.base.packets import _interfaces
from _framework.base.packets import packets
from _framework.foundation import later
class _ExpirationManager(_interfaces.ExpirationManager):
"""An implementation of _interfaces.ExpirationManager."""
def __init__(
self, lock, termination_manager, transmission_manager, ingestion_manager,
commencement, timeout, maximum_timeout):
"""Constructor.
Args:
lock: The operation-wide lock.
termination_manager: The _interfaces.TerminationManager for the operation.
transmission_manager: The _interfaces.TransmissionManager for the
operation.
ingestion_manager: The _interfaces.IngestionManager for the operation.
commencement: The time in seconds since the epoch at which the operation
began.
timeout: A length of time in seconds to allow for the operation to run.
maximum_timeout: The maximum length of time in seconds to allow for the
operation to run despite what is requested via this object's
change_timout method.
"""
self._lock = lock
self._termination_manager = termination_manager
self._transmission_manager = transmission_manager
self._ingestion_manager = ingestion_manager
self._commencement = commencement
self._maximum_timeout = maximum_timeout
self._timeout = timeout
self._deadline = commencement + timeout
self._index = None
self._future = None
def _expire(self, index):
with self._lock:
if self._future is not None and index == self._index:
self._future = None
self._termination_manager.abort(packets.Kind.EXPIRATION)
self._transmission_manager.abort(packets.Kind.EXPIRATION)
self._ingestion_manager.abort()
def start(self):
self._index = 0
self._future = later.later(self._timeout, lambda: self._expire(0))
def change_timeout(self, timeout):
if self._future is not None and timeout != self._timeout:
self._future.cancel()
new_timeout = min(timeout, self._maximum_timeout)
new_index = self._index + 1
self._timeout = new_timeout
self._deadline = self._commencement + new_timeout
self._index = new_index
delay = self._deadline - time.time()
self._future = later.later(
delay, lambda: self._expire(new_index))
def deadline(self):
return self._deadline
def abort(self):
if self._future:
self._future.cancel()
self._future = None
self._deadline_index = None
def front_expiration_manager(
lock, termination_manager, transmission_manager, ingestion_manager,
timeout):
"""Creates an _interfaces.ExpirationManager appropriate for front-side use.
Args:
lock: The operation-wide lock.
termination_manager: The _interfaces.TerminationManager for the operation.
transmission_manager: The _interfaces.TransmissionManager for the
operation.
ingestion_manager: The _interfaces.IngestionManager for the operation.
timeout: A length of time in seconds to allow for the operation to run.
Returns:
An _interfaces.ExpirationManager appropriate for front-side use.
"""
commencement = time.time()
expiration_manager = _ExpirationManager(
lock, termination_manager, transmission_manager, ingestion_manager,
commencement, timeout, timeout)
expiration_manager.start()
return expiration_manager
def back_expiration_manager(
lock, termination_manager, transmission_manager, ingestion_manager,
timeout, default_timeout, maximum_timeout):
"""Creates an _interfaces.ExpirationManager appropriate for back-side use.
Args:
lock: The operation-wide lock.
termination_manager: The _interfaces.TerminationManager for the operation.
transmission_manager: The _interfaces.TransmissionManager for the
operation.
ingestion_manager: The _interfaces.IngestionManager for the operation.
timeout: A length of time in seconds to allow for the operation to run. May
be None in which case default_timeout will be used.
default_timeout: The default length of time in seconds to allow for the
operation to run if the front-side customer has not specified such a value
(or if the value they specified is not yet known).
maximum_timeout: The maximum length of time in seconds to allow for the
operation to run.
Returns:
An _interfaces.ExpirationManager appropriate for back-side use.
"""
commencement = time.time()
expiration_manager = _ExpirationManager(
lock, termination_manager, transmission_manager, ingestion_manager,
commencement, default_timeout if timeout is None else timeout,
maximum_timeout)
expiration_manager.start()
return expiration_manager
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