diff --git a/src/python/grpcio/grpc/framework/interfaces/base/__init__.py b/src/python/grpcio/grpc/framework/interfaces/base/__init__.py new file mode 100644 index 00000000000..70865191060 --- /dev/null +++ b/src/python/grpcio/grpc/framework/interfaces/base/__init__.py @@ -0,0 +1,30 @@ +# 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. + + diff --git a/src/python/grpcio/grpc/framework/interfaces/base/base.py b/src/python/grpcio/grpc/framework/interfaces/base/base.py new file mode 100644 index 00000000000..9d1651daace --- /dev/null +++ b/src/python/grpcio/grpc/framework/interfaces/base/base.py @@ -0,0 +1,273 @@ +# 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. + +"""The base interface of RPC Framework.""" + +import abc +import enum + +# abandonment is referenced from specification in this module. +from grpc.framework.foundation import abandonment # pylint: disable=unused-import + + +class NoSuchMethodError(Exception): + """Indicates that an unrecognized operation has been called.""" + + +@enum.unique +class Outcome(enum.Enum): + """Operation outcomes.""" + + COMPLETED = 'completed' + CANCELLED = 'cancelled' + EXPIRED = 'expired' + LOCAL_SHUTDOWN = 'local shutdown' + REMOTE_SHUTDOWN = 'remote shutdown' + RECEPTION_FAILURE = 'reception failure' + TRANSMISSION_FAILURE = 'transmission failure' + LOCAL_FAILURE = 'local failure' + REMOTE_FAILURE = 'remote failure' + + +class Completion(object): + """An aggregate of the values exchanged upon operation completion. + + Attributes: + terminal_metadata: A terminal metadata value for the operaton. + code: A code value for the operation. + message: A message value for the operation. + """ + __metaclass__ = abc.ABCMeta + + +class OperationContext(object): + """Provides operation-related information and action.""" + __metaclass__ = abc.ABCMeta + + @abc.abstractmethod + def outcome(self): + """Indicates the operation's outcome (or that the operation is ongoing). + + Returns: + None if the operation is still active or the Outcome value for the + operation if it has terminated. + """ + raise NotImplementedError() + + @abc.abstractmethod + def add_termination_callback(self, callback): + """Adds a function to be called upon operation termination. + + Args: + callback: A callable to be passed an Outcome value on operation + termination. + + Returns: + None if the operation has not yet terminated and the passed callback will + later be called when it does terminate, or if the operation has already + terminated an Outcome value describing the operation termination and the + passed callback will not be called as a result of this method call. + """ + raise NotImplementedError() + + @abc.abstractmethod + def time_remaining(self): + """Describes the length of allowed time remaining for the operation. + + Returns: + A nonnegative float indicating the length of allowed time in seconds + remaining for the operation to complete before it is considered to have + timed out. Zero is returned if the operation has terminated. + """ + raise NotImplementedError() + + @abc.abstractmethod + def cancel(self): + """Cancels the operation if the operation has not yet terminated.""" + raise NotImplementedError() + + @abc.abstractmethod + def fail(self, exception): + """Indicates that the operation has failed. + + Args: + exception: An exception germane to the operation failure. May be None. + """ + raise NotImplementedError() + + +class Operator(object): + """An interface through which to participate in an operation.""" + __metaclass__ = abc.ABCMeta + + @abc.abstractmethod + def advance( + self, initial_metadata=None, payload=None, completion=None, + allowance=None): + """Progresses the operation. + + Args: + initial_metadata: An initial metadata value. Only one may ever be + communicated in each direction for an operation, and they must be + communicated no later than either the first payload or the completion. + payload: A payload value. + completion: A Completion value. May only ever be non-None once in either + direction, and no payloads may be passed after it has been communicated. + allowance: A positive integer communicating the number of additional + payloads allowed to be passed by the remote side of the operation. + """ + raise NotImplementedError() + + +class Subscription(object): + """Describes customer code's interest in values from the other side. + + Attributes: + kind: A Kind value describing the overall kind of this value. + termination_callback: A callable to be passed the Outcome associated with + the operation after it has terminated. Must be non-None if kind is + Kind.TERMINATION_ONLY. Must be None otherwise. + allowance: A callable behavior that accepts positive integers representing + the number of additional payloads allowed to be passed to the other side + of the operation. Must be None if kind is Kind.FULL. Must not be None + otherwise. + operator: An Operator to be passed values from the other side of the + operation. Must be non-None if kind is Kind.FULL. Must be None otherwise. + """ + + @enum.unique + class Kind(enum.Enum): + + NONE = 'none' + TERMINATION_ONLY = 'termination only' + FULL = 'full' + + +class Servicer(object): + """Interface for service implementations.""" + __metaclass__ = abc.ABCMeta + + @abc.abstractmethod + def service(self, group, method, context, output_operator): + """Services an operation. + + Args: + group: The group identifier of the operation to be serviced. + method: The method identifier of the operation to be serviced. + context: An OperationContext object affording contextual information and + actions. + output_operator: An Operator that will accept output values of the + operation. + + Returns: + A Subscription via which this object may or may not accept more values of + the operation. + + Raises: + NoSuchMethodError: If this Servicer does not handle operations with the + given group and method. + abandonment.Abandoned: If the operation has been aborted and there no + longer is any reason to service the operation. + """ + raise NotImplementedError() + + +class End(object): + """Common type for entry-point objects on both sides of an operation.""" + __metaclass__ = abc.ABCMeta + + @abc.abstractmethod + def start(self): + """Starts this object's service of operations.""" + raise NotImplementedError() + + @abc.abstractmethod + def stop_gracefully(self): + """Gracefully stops this object's service of operations. + + Operations in progress will be allowed to complete, and this method blocks + until all of them have. + """ + raise NotImplementedError() + + @abc.abstractmethod + def stop_immediately(self): + """Immediately stops this object's service of operations. + + Operations in progress will not be allowed to complete. + """ + raise NotImplementedError() + + @abc.abstractmethod + def operate( + self, group, method, subscription, timeout, initial_metadata=None, + payload=None, completion=None): + """Commences an operation. + + Args: + group: The group identifier of the invoked operation. + method: The method identifier of the invoked operation. + subscription: A Subscription to which the results of the operation will be + passed. + timeout: A length of time in seconds to allow for the operation. + initial_metadata: An initial metadata value to be sent to the other side + of the operation. May be None if the initial metadata will be later + passed via the returned operator or if there will be no initial metadata + passed at all. + payload: An initial payload for the operation. + completion: A Completion value indicating the end of transmission to the + other side of the operation. + + Returns: + A pair of objects affording information about the operation and action + continuing the operation. The first element of the returned pair is an + OperationContext for the operation and the second element of the + returned pair is an Operator to which operation values not passed in + this call should later be passed. + """ + raise NotImplementedError() + + @abc.abstractmethod + def operation_stats(self): + """Reports the number of terminated operations broken down by outcome. + + Returns: + A dictionary from Outcome value to an integer identifying the number + of operations that terminated with that outcome. + """ + raise NotImplementedError() + + @abc.abstractmethod + def add_idle_action(self, action): + """Adds an action to be called when this End has no ongoing operations. + + Args: + action: A callable that accepts no arguments. + """ + raise NotImplementedError() diff --git a/src/python/grpcio/grpc/framework/interfaces/base/utilities.py b/src/python/grpcio/grpc/framework/interfaces/base/utilities.py new file mode 100644 index 00000000000..a9ee1a09816 --- /dev/null +++ b/src/python/grpcio/grpc/framework/interfaces/base/utilities.py @@ -0,0 +1,79 @@ +# 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. + +"""Utilities for use with the base interface of RPC Framework.""" + +import collections + +from grpc.framework.interfaces.base import base + + +class _Completion( + base.Completion, + collections.namedtuple( + '_Completion', ('terminal_metadata', 'code', 'message',))): + """A trivial implementation of base.Completion.""" + + +class _Subscription( + base.Subscription, + collections.namedtuple( + '_Subscription', + ('kind', 'termination_callback', 'allowance', 'operator',))): + """A trivial implementation of base.Subscription.""" + +_NONE_SUBSCRIPTION = _Subscription( + base.Subscription.Kind.NONE, None, None, None) + + +def completion(terminal_metadata, code, message): + """Creates a base.Completion aggregating the given operation values. + + Args: + terminal_metadata: A terminal metadata value for an operaton. + code: A code value for an operation. + message: A message value for an operation. + + Returns: + A base.Completion aggregating the given operation values. + """ + return _Completion(terminal_metadata, code, message) + + +def full_subscription(operator): + """Creates a "full" base.Subscription for the given base.Operator. + + Args: + operator: A base.Operator to be used in an operation. + + Returns: + A base.Subscription of kind base.Subscription.Kind.FULL wrapping the given + base.Operator. + """ + return _Subscription(base.Subscription.Kind.FULL, None, None, operator)