56413aa3c5
Replace abc.abstractproperty with property and abc.abstractmethod, as abc.abstractproperty has been deprecated since python3.3[1] [1]https://docs.python.org/3.8/whatsnew/3.3.html?highlight=deprecated#abc Change-Id: I1bcecd99d8856c26621a5304d9f7f01f8f111918
135 lines
4.7 KiB
Python
135 lines
4.7 KiB
Python
# -*- coding: utf-8 -*-
|
|
|
|
# Copyright (C) 2012 Yahoo! Inc. All Rights Reserved.
|
|
#
|
|
# Licensed under the Apache License, Version 2.0 (the "License"); you may
|
|
# not use this file except in compliance with the License. You may obtain
|
|
# a copy of the License at
|
|
#
|
|
# http://www.apache.org/licenses/LICENSE-2.0
|
|
#
|
|
# Unless required by applicable law or agreed to in writing, software
|
|
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
|
|
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
|
|
# License for the specific language governing permissions and limitations
|
|
# under the License.
|
|
|
|
import abc
|
|
|
|
from oslo_utils import reflection
|
|
|
|
# Link metadata keys that have inherent/special meaning.
|
|
#
|
|
# This key denotes the link is an invariant that ensures the order is
|
|
# correctly preserved.
|
|
LINK_INVARIANT = 'invariant'
|
|
# This key denotes the link is a manually/user-specified.
|
|
LINK_MANUAL = 'manual'
|
|
# This key denotes the link was created when resolving/compiling retries.
|
|
LINK_RETRY = 'retry'
|
|
# This key denotes the link was created due to symbol constraints and the
|
|
# value will be a set of names that the constraint ensures are satisfied.
|
|
LINK_REASONS = 'reasons'
|
|
#
|
|
# This key denotes a callable that will determine if the target is visited.
|
|
LINK_DECIDER = 'decider'
|
|
|
|
# Chop off full module names of patterns that are built-in to taskflow...
|
|
_CHOP_PAT = "taskflow.patterns."
|
|
_CHOP_PAT_LEN = len(_CHOP_PAT)
|
|
|
|
# This key denotes the depth the decider will apply (defaulting to all).
|
|
LINK_DECIDER_DEPTH = 'decider_depth'
|
|
|
|
|
|
class Flow(object, metaclass=abc.ABCMeta):
|
|
"""The base abstract class of all flow implementations.
|
|
|
|
A flow is a structure that defines relationships between tasks. You can
|
|
add tasks and other flows (as subflows) to the flow, and the flow provides
|
|
a way to implicitly or explicitly define how they are interdependent.
|
|
Exact structure of the relationships is defined by concrete
|
|
implementation, while this class defines common interface and adds
|
|
human-readable (not necessary unique) name.
|
|
|
|
NOTE(harlowja): if a flow is placed in another flow as a subflow, a desired
|
|
way to compose flows together, then it is valid and permissible that during
|
|
compilation the subflow & parent flow *may* be flattened into a new flow.
|
|
"""
|
|
|
|
def __init__(self, name, retry=None):
|
|
self._name = str(name)
|
|
self._retry = retry
|
|
# NOTE(akarpinska): if retry doesn't have a name,
|
|
# the name of its owner will be assigned
|
|
if self._retry is not None and self._retry.name is None:
|
|
self._retry.name = self.name + "_retry"
|
|
|
|
@property
|
|
def name(self):
|
|
"""A non-unique name for this flow (human readable)."""
|
|
return self._name
|
|
|
|
@property
|
|
def retry(self):
|
|
"""The associated flow retry controller.
|
|
|
|
This retry controller object will affect & control how (and if) this
|
|
flow and its contained components retry when execution is underway and
|
|
a failure occurs.
|
|
"""
|
|
return self._retry
|
|
|
|
@abc.abstractmethod
|
|
def add(self, *items):
|
|
"""Adds a given item/items to this flow."""
|
|
|
|
@abc.abstractmethod
|
|
def __len__(self):
|
|
"""Returns how many items are in this flow."""
|
|
|
|
@abc.abstractmethod
|
|
def __iter__(self):
|
|
"""Iterates over the children of the flow."""
|
|
|
|
@abc.abstractmethod
|
|
def iter_links(self):
|
|
"""Iterates over dependency links between children of the flow.
|
|
|
|
Iterates over 3-tuples ``(A, B, meta)``, where
|
|
* ``A`` is a child (atom or subflow) link starts from;
|
|
* ``B`` is a child (atom or subflow) link points to; it is
|
|
said that ``B`` depends on ``A`` or ``B`` requires ``A``;
|
|
* ``meta`` is link metadata, a dictionary.
|
|
"""
|
|
|
|
@abc.abstractmethod
|
|
def iter_nodes(self):
|
|
"""Iterate over nodes of the flow.
|
|
|
|
Iterates over 2-tuples ``(A, meta)``, where
|
|
* ``A`` is a child (atom or subflow) of current flow;
|
|
* ``meta`` is link metadata, a dictionary.
|
|
"""
|
|
|
|
def __str__(self):
|
|
cls_name = reflection.get_class_name(self)
|
|
if cls_name.startswith(_CHOP_PAT):
|
|
cls_name = cls_name[_CHOP_PAT_LEN:]
|
|
return '"%s: %s(len=%d)"' % (cls_name, self.name, len(self))
|
|
|
|
@property
|
|
def provides(self):
|
|
"""Set of symbol names provided by the flow."""
|
|
provides = set()
|
|
if self._retry is not None:
|
|
provides.update(self._retry.provides)
|
|
for item in self:
|
|
provides.update(item.provides)
|
|
return frozenset(provides)
|
|
|
|
@property
|
|
@abc.abstractmethod
|
|
def requires(self):
|
|
"""Set of *unsatisfied* symbol names required by the flow."""
|