Source code for taskflow.persistence.models

# -*- coding: utf-8 -*-

#    Copyright (C) 2012 Yahoo! Inc. All Rights Reserved.
#    Copyright (C) 2013 Rackspace Hosting 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
import copy
import os

from oslo_utils import timeutils
from oslo_utils import uuidutils
import six

from taskflow import exceptions as exc
from taskflow import states
from taskflow.types import failure as ft
from taskflow.utils import misc


# Internal helpers...


def _format_meta(metadata, indent):
    """Format the common metadata dictionary in the same manner."""
    if not metadata:
        return []
    lines = [
        '%s- metadata:' % (" " * indent),
    ]
    for (k, v) in metadata.items():
        # Progress for now is a special snowflake and will be formatted
        # in percent format.
        if k == 'progress' and isinstance(v, misc.NUMERIC_TYPES):
            v = "%0.2f%%" % (v * 100.0)
        lines.append("%s+ %s = %s" % (" " * (indent + 2), k, v))
    return lines


def _format_shared(obj, indent):
    """Format the common shared attributes in the same manner."""
    if obj is None:
        return []
    lines = []
    for attr_name in ("uuid", "state"):
        if not hasattr(obj, attr_name):
            continue
        lines.append("%s- %s = %s" % (" " * indent, attr_name,
                                      getattr(obj, attr_name)))
    return lines


def _is_all_none(arg, *args):
    if arg is not None:
        return False
    for more_arg in args:
        if more_arg is not None:
            return False
    return True


def _copy_function(deep_copy):
    if deep_copy:
        return copy.deepcopy
    else:
        return lambda x: x


def _safe_marshal_time(when):
    if not when:
        return None
    return timeutils.marshall_now(now=when)


def _safe_unmarshal_time(when):
    if not when:
        return None
    return timeutils.unmarshall_time(when)


def _fix_meta(data):
    # Handle the case where older schemas allowed this to be non-dict by
    # correcting this case by replacing it with a dictionary when a non-dict
    # is found.
    meta = data.get('meta')
    if not isinstance(meta, dict):
        meta = {}
    return meta


[docs]class LogBook(object): """A collection of flow details and associated metadata. Typically this class contains a collection of flow detail entries for a given engine (or job) so that those entities can track what 'work' has been completed for resumption, reverting and miscellaneous tracking purposes. The data contained within this class need **not** be persisted to the backend storage in real time. The data in this class will only be guaranteed to be persisted when a save occurs via some backend connection. NOTE(harlowja): the naming of this class is analogous to a ship's log or a similar type of record used in detailing work that has been completed (or work that has not been completed). :ivar created_at: A ``datetime.datetime`` object of when this logbook was created. :ivar updated_at: A ``datetime.datetime`` object of when this logbook was last updated at. :ivar meta: A dictionary of meta-data associated with this logbook. """ def __init__(self, name, uuid=None): if uuid: self._uuid = uuid else: self._uuid = uuidutils.generate_uuid() self._name = name self._flowdetails_by_id = {} self.created_at = timeutils.utcnow() self.updated_at = None self.meta = {}
[docs] def pformat(self, indent=0, linesep=os.linesep): """Pretty formats this logbook into a string. >>> from taskflow.persistence import models >>> tmp = models.LogBook("example") >>> print(tmp.pformat()) LogBook: 'example' - uuid = ... - created_at = ... """ cls_name = self.__class__.__name__ lines = ["%s%s: '%s'" % (" " * indent, cls_name, self.name)] lines.extend(_format_shared(self, indent=indent + 1)) lines.extend(_format_meta(self.meta, indent=indent + 1)) if self.created_at is not None: lines.append("%s- created_at = %s" % (" " * (indent + 1), self.created_at.isoformat())) if self.updated_at is not None: lines.append("%s- updated_at = %s" % (" " * (indent + 1), self.updated_at.isoformat())) for flow_detail in self: lines.append(flow_detail.pformat(indent=indent + 1, linesep=linesep)) return linesep.join(lines)
[docs] def add(self, fd): """Adds a new flow detail into this logbook. NOTE(harlowja): if an existing flow detail exists with the same uuid the existing one will be overwritten with the newly provided one. Does not *guarantee* that the details will be immediately saved. """ self._flowdetails_by_id[fd.uuid] = fd self.updated_at = timeutils.utcnow()
[docs] def find(self, flow_uuid): """Locate the flow detail corresponding to the given uuid. :returns: the flow detail with that uuid :rtype: :py:class:`.FlowDetail` (or ``None`` if not found) """ return self._flowdetails_by_id.get(flow_uuid, None)
[docs] def merge(self, lb, deep_copy=False): """Merges the current object state with the given ones state. If ``deep_copy`` is provided as truthy then the local object will use ``copy.deepcopy`` to replace this objects local attributes with the provided objects attributes (**only** if there is a difference between this objects attributes and the provided attributes). If ``deep_copy`` is falsey (the default) then a reference copy will occur instead when a difference is detected. NOTE(harlowja): If the provided object is this object itself then **no** merging is done. Also note that this does **not** merge the flow details contained in either. :returns: this logbook (freshly merged with the incoming object) :rtype: :py:class:`.LogBook` """ if lb is self: return self copy_fn = _copy_function(deep_copy) if self.meta != lb.meta: self.meta = copy_fn(lb.meta) if lb.created_at != self.created_at: self.created_at = copy_fn(lb.created_at) if lb.updated_at != self.updated_at: self.updated_at = copy_fn(lb.updated_at) return self
[docs] def to_dict(self, marshal_time=False): """Translates the internal state of this object to a ``dict``. NOTE(harlowja): The returned ``dict`` does **not** include any contained flow details. :returns: this logbook in ``dict`` form """ if not marshal_time: marshal_fn = lambda x: x else: marshal_fn = _safe_marshal_time return { 'name': self.name, 'meta': self.meta, 'uuid': self.uuid, 'updated_at': marshal_fn(self.updated_at), 'created_at': marshal_fn(self.created_at), }
[docs] @classmethod def from_dict(cls, data, unmarshal_time=False): """Translates the given ``dict`` into an instance of this class. NOTE(harlowja): the ``dict`` provided should come from a prior call to :meth:`.to_dict`. :returns: a new logbook :rtype: :py:class:`.LogBook` """ if not unmarshal_time: unmarshal_fn = lambda x: x else: unmarshal_fn = _safe_unmarshal_time obj = cls(data['name'], uuid=data['uuid']) obj.updated_at = unmarshal_fn(data['updated_at']) obj.created_at = unmarshal_fn(data['created_at']) obj.meta = _fix_meta(data) return obj
@property def uuid(self): """The unique identifer of this logbook.""" return self._uuid @property def name(self): """The name of this logbook.""" return self._name def __iter__(self): for fd in six.itervalues(self._flowdetails_by_id): yield fd def __len__(self): return len(self._flowdetails_by_id)
[docs] def copy(self, retain_contents=True): """Copies this logbook. Creates a shallow copy of this logbook. If this logbook contains flow details and ``retain_contents`` is truthy (the default) then the flow details container will be shallow copied (the flow details contained there-in will **not** be copied). If ``retain_contents`` is falsey then the copied logbook will have **no** contained flow details (but it will have the rest of the local objects attributes copied). :returns: a new logbook :rtype: :py:class:`.LogBook` """ clone = copy.copy(self) if not retain_contents: clone._flowdetails_by_id = {} else: clone._flowdetails_by_id = self._flowdetails_by_id.copy() if self.meta: clone.meta = self.meta.copy() return clone
[docs]class FlowDetail(object): """A collection of atom details and associated metadata. Typically this class contains a collection of atom detail entries that represent the atoms in a given flow structure (along with any other needed metadata relevant to that flow). The data contained within this class need **not** be persisted to the backend storage in real time. The data in this class will only be guaranteed to be persisted when a save (or update) occurs via some backend connection. :ivar meta: A dictionary of meta-data associated with this flow detail. """ def __init__(self, name, uuid): self._uuid = uuid self._name = name self._atomdetails_by_id = {} # TODO(bnemec): This should be documented as an ivar, but can't be due # to https://github.com/sphinx-doc/sphinx/issues/2549 #: The state of the flow associated with this flow detail. self.state = None self.meta = {}
[docs] def update(self, fd): """Updates the objects state to be the same as the given one. This will assign the private and public attributes of the given flow detail directly to this object (replacing any existing attributes in this object; even if they are the **same**). NOTE(harlowja): If the provided object is this object itself then **no** update is done. :returns: this flow detail :rtype: :py:class:`.FlowDetail` """ if fd is self: return self self._atomdetails_by_id = fd._atomdetails_by_id self.state = fd.state self.meta = fd.meta return self
[docs] def pformat(self, indent=0, linesep=os.linesep): """Pretty formats this flow detail into a string. >>> from oslo_utils import uuidutils >>> from taskflow.persistence import models >>> flow_detail = models.FlowDetail("example", ... uuid=uuidutils.generate_uuid()) >>> print(flow_detail.pformat()) FlowDetail: 'example' - uuid = ... - state = ... """ cls_name = self.__class__.__name__ lines = ["%s%s: '%s'" % (" " * indent, cls_name, self.name)] lines.extend(_format_shared(self, indent=indent + 1)) lines.extend(_format_meta(self.meta, indent=indent + 1)) for atom_detail in self: lines.append(atom_detail.pformat(indent=indent + 1, linesep=linesep)) return linesep.join(lines)
[docs] def merge(self, fd, deep_copy=False): """Merges the current object state with the given one's state. If ``deep_copy`` is provided as truthy then the local object will use ``copy.deepcopy`` to replace this objects local attributes with the provided objects attributes (**only** if there is a difference between this objects attributes and the provided attributes). If ``deep_copy`` is falsey (the default) then a reference copy will occur instead when a difference is detected. NOTE(harlowja): If the provided object is this object itself then **no** merging is done. Also this does **not** merge the atom details contained in either. :returns: this flow detail (freshly merged with the incoming object) :rtype: :py:class:`.FlowDetail` """ if fd is self: return self copy_fn = _copy_function(deep_copy) if self.meta != fd.meta: self.meta = copy_fn(fd.meta) if self.state != fd.state: # NOTE(imelnikov): states are just strings, no need to copy. self.state = fd.state return self
[docs] def copy(self, retain_contents=True): """Copies this flow detail. Creates a shallow copy of this flow detail. If this detail contains flow details and ``retain_contents`` is truthy (the default) then the atom details container will be shallow copied (the atom details contained there-in will **not** be copied). If ``retain_contents`` is falsey then the copied flow detail will have **no** contained atom details (but it will have the rest of the local objects attributes copied). :returns: a new flow detail :rtype: :py:class:`.FlowDetail` """ clone = copy.copy(self) if not retain_contents: clone._atomdetails_by_id = {} else: clone._atomdetails_by_id = self._atomdetails_by_id.copy() if self.meta: clone.meta = self.meta.copy() return clone
[docs] def to_dict(self): """Translates the internal state of this object to a ``dict``. NOTE(harlowja): The returned ``dict`` does **not** include any contained atom details. :returns: this flow detail in ``dict`` form """ return { 'name': self.name, 'meta': self.meta, 'state': self.state, 'uuid': self.uuid, }
[docs] @classmethod def from_dict(cls, data): """Translates the given ``dict`` into an instance of this class. NOTE(harlowja): the ``dict`` provided should come from a prior call to :meth:`.to_dict`. :returns: a new flow detail :rtype: :py:class:`.FlowDetail` """ obj = cls(data['name'], data['uuid']) obj.state = data.get('state') obj.meta = _fix_meta(data) return obj
[docs] def add(self, ad): """Adds a new atom detail into this flow detail. NOTE(harlowja): if an existing atom detail exists with the same uuid the existing one will be overwritten with the newly provided one. Does not *guarantee* that the details will be immediately saved. """ self._atomdetails_by_id[ad.uuid] = ad
[docs] def find(self, ad_uuid): """Locate the atom detail corresponding to the given uuid. :returns: the atom detail with that uuid :rtype: :py:class:`.AtomDetail` (or ``None`` if not found) """ return self._atomdetails_by_id.get(ad_uuid)
@property def uuid(self): """The unique identifer of this flow detail.""" return self._uuid @property def name(self): """The name of this flow detail.""" return self._name def __iter__(self): for ad in six.itervalues(self._atomdetails_by_id): yield ad def __len__(self): return len(self._atomdetails_by_id)
[docs]@six.add_metaclass(abc.ABCMeta) class AtomDetail(object): """A collection of atom specific runtime information and metadata. This is a base **abstract** class that contains attributes that are used to connect a atom to the persistence layer before, during, or after it is running. It includes any results it may have produced, any state that it may be in (for example ``FAILURE``), any exception that occurred when running, and any associated stacktrace that may have occurring during an exception being thrown. It may also contain any other metadata that should also be stored along-side the details about the connected atom. The data contained within this class need **not** be persisted to the backend storage in real time. The data in this class will only be guaranteed to be persisted when a save (or update) occurs via some backend connection. :ivar intention: The execution strategy of the atom associated with this atom detail (used by an engine/others to determine if the associated atom needs to be executed, reverted, retried and so-on). :ivar meta: A dictionary of meta-data associated with this atom detail. :ivar version: A version tuple or string that represents the atom version this atom detail is associated with (typically used for introspection and any data migration strategies). :ivar results: Any results the atom produced from either its ``execute`` method or from other sources. :ivar revert_results: Any results the atom produced from either its ``revert`` method or from other sources. :ivar AtomDetail.failure: If the atom failed (due to its ``execute`` method raising) this will be a :py:class:`~taskflow.types.failure.Failure` object that represents that failure (if there was no failure this will be set to none). :ivar revert_failure: If the atom failed (possibly due to its ``revert`` method raising) this will be a :py:class:`~taskflow.types.failure.Failure` object that represents that failure (if there was no failure this will be set to none). """ def __init__(self, name, uuid): self._uuid = uuid self._name = name # TODO(bnemec): This should be documented as an ivar, but can't be due # to https://github.com/sphinx-doc/sphinx/issues/2549 #: The state of the atom associated with this atom detail. self.state = None self.intention = states.EXECUTE self.results = None self.failure = None self.revert_results = None self.revert_failure = None self.meta = {} self.version = None @property def last_results(self): """Gets the atoms last result. If the atom has produced many results (for example if it has been retried, reverted, executed and ...) this returns the last one of many results. """ return self.results
[docs] def update(self, ad): """Updates the object's state to be the same as the given one. This will assign the private and public attributes of the given atom detail directly to this object (replacing any existing attributes in this object; even if they are the **same**). NOTE(harlowja): If the provided object is this object itself then **no** update is done. :returns: this atom detail :rtype: :py:class:`.AtomDetail` """ if ad is self: return self self.state = ad.state self.intention = ad.intention self.meta = ad.meta self.failure = ad.failure self.results = ad.results self.revert_results = ad.revert_results self.revert_failure = ad.revert_failure self.version = ad.version return self
[docs] @abc.abstractmethod def merge(self, other, deep_copy=False): """Merges the current object state with the given ones state. If ``deep_copy`` is provided as truthy then the local object will use ``copy.deepcopy`` to replace this objects local attributes with the provided objects attributes (**only** if there is a difference between this objects attributes and the provided attributes). If ``deep_copy`` is falsey (the default) then a reference copy will occur instead when a difference is detected. NOTE(harlowja): If the provided object is this object itself then **no** merging is done. Do note that **no** results are merged in this method. That operation **must** to be the responsibilty of subclasses to implement and override this abstract method and provide that merging themselves as they see fit. :returns: this atom detail (freshly merged with the incoming object) :rtype: :py:class:`.AtomDetail` """ copy_fn = _copy_function(deep_copy) # NOTE(imelnikov): states and intentions are just strings, # so there is no need to copy them (strings are immutable in python). self.state = other.state self.intention = other.intention if self.failure != other.failure: # NOTE(imelnikov): we can't just deep copy Failures, as they # contain tracebacks, which are not copyable. if other.failure: if deep_copy: self.failure = other.failure.copy() else: self.failure = other.failure else: self.failure = None if self.revert_failure != other.revert_failure: # NOTE(imelnikov): we can't just deep copy Failures, as they # contain tracebacks, which are not copyable. if other.revert_failure: if deep_copy: self.revert_failure = other.revert_failure.copy() else: self.revert_failure = other.revert_failure else: self.revert_failure = None if self.meta != other.meta: self.meta = copy_fn(other.meta) if self.version != other.version: self.version = copy_fn(other.version) return self
[docs] @abc.abstractmethod def put(self, state, result): """Puts a result (acquired in the given state) into this detail."""
[docs] def to_dict(self): """Translates the internal state of this object to a ``dict``. :returns: this atom detail in ``dict`` form """ if self.failure: failure = self.failure.to_dict() else: failure = None if self.revert_failure: revert_failure = self.revert_failure.to_dict() else: revert_failure = None return { 'failure': failure, 'revert_failure': revert_failure, 'meta': self.meta, 'name': self.name, 'results': self.results, 'revert_results': self.revert_results, 'state': self.state, 'version': self.version, 'intention': self.intention, 'uuid': self.uuid, }
[docs] @classmethod def from_dict(cls, data): """Translates the given ``dict`` into an instance of this class. NOTE(harlowja): the ``dict`` provided should come from a prior call to :meth:`.to_dict`. :returns: a new atom detail :rtype: :py:class:`.AtomDetail` """ obj = cls(data['name'], data['uuid']) obj.state = data.get('state') obj.intention = data.get('intention') obj.results = data.get('results') obj.revert_results = data.get('revert_results') obj.version = data.get('version') obj.meta = _fix_meta(data) failure = data.get('failure') if failure: obj.failure = ft.Failure.from_dict(failure) revert_failure = data.get('revert_failure') if revert_failure: obj.revert_failure = ft.Failure.from_dict(revert_failure) return obj
@property def uuid(self): """The unique identifer of this atom detail.""" return self._uuid @property def name(self): """The name of this atom detail.""" return self._name
[docs] @abc.abstractmethod def reset(self, state): """Resets this atom detail and sets ``state`` attribute value."""
[docs] @abc.abstractmethod def copy(self): """Copies this atom detail."""
[docs] def pformat(self, indent=0, linesep=os.linesep): """Pretty formats this atom detail into a string.""" cls_name = self.__class__.__name__ lines = ["%s%s: '%s'" % (" " * (indent), cls_name, self.name)] lines.extend(_format_shared(self, indent=indent + 1)) lines.append("%s- version = %s" % (" " * (indent + 1), misc.get_version_string(self))) lines.append("%s- results = %s" % (" " * (indent + 1), self.results)) lines.append("%s- failure = %s" % (" " * (indent + 1), bool(self.failure))) lines.extend(_format_meta(self.meta, indent=indent + 1)) return linesep.join(lines)
[docs]class TaskDetail(AtomDetail): """A task detail (an atom detail typically associated with a |tt| atom). .. |tt| replace:: :py:class:`~taskflow.task.Task` """
[docs] def reset(self, state): """Resets this task detail and sets ``state`` attribute value. This sets any previously set ``results``, ``failure``, and ``revert_results`` attributes back to ``None`` and sets the state to the provided one, as well as setting this task details ``intention`` attribute to ``EXECUTE``. """ self.results = None self.failure = None self.revert_results = None self.revert_failure = None self.state = state self.intention = states.EXECUTE
[docs] def put(self, state, result): """Puts a result (acquired in the given state) into this detail. Returns whether this object was modified (or whether it was not). """ was_altered = False if state != self.state: self.state = state was_altered = True if state == states.REVERT_FAILURE: if self.revert_failure != result: self.revert_failure = result was_altered = True if not _is_all_none(self.results, self.revert_results): self.results = None self.revert_results = None was_altered = True elif state == states.FAILURE: if self.failure != result: self.failure = result was_altered = True if not _is_all_none(self.results, self.revert_results, self.revert_failure): self.results = None self.revert_results = None self.revert_failure = None was_altered = True elif state == states.SUCCESS: if not _is_all_none(self.revert_results, self.revert_failure, self.failure): self.revert_results = None self.revert_failure = None self.failure = None was_altered = True # We don't really have the ability to determine equality of # task (user) results at the current time, without making # potentially bad guesses, so assume the task detail always needs # to be saved if they are not exactly equivalent... if result is not self.results: self.results = result was_altered = True elif state == states.REVERTED: if not _is_all_none(self.revert_failure): self.revert_failure = None was_altered = True if result is not self.revert_results: self.revert_results = result was_altered = True return was_altered
[docs] def merge(self, other, deep_copy=False): """Merges the current task detail with the given one. NOTE(harlowja): This merge does **not** copy and replace the ``results`` or ``revert_results`` if it differs. Instead the current objects ``results`` and ``revert_results`` attributes directly becomes (via assignment) the other objects attributes. Also note that if the provided object is this object itself then **no** merging is done. See: https://bugs.launchpad.net/taskflow/+bug/1452978 for what happens if this is copied at a deeper level (for example by using ``copy.deepcopy`` or by using ``copy.copy``). :returns: this task detail (freshly merged with the incoming object) :rtype: :py:class:`.TaskDetail` """ if not isinstance(other, TaskDetail): raise exc.NotImplementedError("Can only merge with other" " task details") if other is self: return self super(TaskDetail, self).merge(other, deep_copy=deep_copy) self.results = other.results self.revert_results = other.revert_results return self
[docs] def copy(self): """Copies this task detail. Creates a shallow copy of this task detail (any meta-data and version information that this object maintains is shallow copied via ``copy.copy``). NOTE(harlowja): This copy does **not** copy and replace the ``results`` or ``revert_results`` attribute if it differs. Instead the current objects ``results`` and ``revert_results`` attributes directly becomes (via assignment) the cloned objects attributes. See: https://bugs.launchpad.net/taskflow/+bug/1452978 for what happens if this is copied at a deeper level (for example by using ``copy.deepcopy`` or by using ``copy.copy``). :returns: a new task detail :rtype: :py:class:`.TaskDetail` """ clone = copy.copy(self) clone.results = self.results clone.revert_results = self.revert_results if self.meta: clone.meta = self.meta.copy() if self.version: clone.version = copy.copy(self.version) return clone
[docs]class RetryDetail(AtomDetail): """A retry detail (an atom detail typically associated with a |rt| atom). .. |rt| replace:: :py:class:`~taskflow.retry.Retry` """ def __init__(self, name, uuid): super(RetryDetail, self).__init__(name, uuid) self.results = []
[docs] def reset(self, state): """Resets this retry detail and sets ``state`` attribute value. This sets any previously added ``results`` back to an empty list and resets the ``failure`` and ``revert_failure`` and ``revert_results`` attributes back to ``None`` and sets the state to the provided one, as well as setting this retry details ``intention`` attribute to ``EXECUTE``. """ self.results = [] self.revert_results = None self.failure = None self.revert_failure = None self.state = state self.intention = states.EXECUTE
[docs] def copy(self): """Copies this retry detail. Creates a shallow copy of this retry detail (any meta-data and version information that this object maintains is shallow copied via ``copy.copy``). NOTE(harlowja): This copy does **not** copy the incoming objects ``results`` or ``revert_results`` attributes. Instead this objects ``results`` attribute list is iterated over and a new list is constructed with each ``(data, failures)`` element in that list having its ``failures`` (a dictionary of each named :py:class:`~taskflow.types.failure.Failure` object that occured) copied but its ``data`` is left untouched. After this is done that new list becomes (via assignment) the cloned objects ``results`` attribute. The ``revert_results`` is directly assigned to the cloned objects ``revert_results`` attribute. See: https://bugs.launchpad.net/taskflow/+bug/1452978 for what happens if the ``data`` in ``results`` is copied at a deeper level (for example by using ``copy.deepcopy`` or by using ``copy.copy``). :returns: a new retry detail :rtype: :py:class:`.RetryDetail` """ clone = copy.copy(self) results = [] # NOTE(imelnikov): we can't just deep copy Failures, as they # contain tracebacks, which are not copyable. for (data, failures) in self.results: copied_failures = {} for (key, failure) in six.iteritems(failures): copied_failures[key] = failure results.append((data, copied_failures)) clone.results = results clone.revert_results = self.revert_results if self.meta: clone.meta = self.meta.copy() if self.version: clone.version = copy.copy(self.version) return clone
@property def last_results(self): """The last result that was produced.""" try: return self.results[-1][0] except IndexError: exc.raise_with_cause(exc.NotFound, "Last results not found") @property def last_failures(self): """The last failure dictionary that was produced. NOTE(harlowja): This is **not** the same as the local ``failure`` attribute as the obtained failure dictionary in the ``results`` attribute (which is what this returns) is from associated atom failures (which is different from the directly related failure of the retry unit associated with this atom detail). """ try: return self.results[-1][1] except IndexError: exc.raise_with_cause(exc.NotFound, "Last failures not found")
[docs] def put(self, state, result): """Puts a result (acquired in the given state) into this detail. Returns whether this object was modified (or whether it was not). """ # Do not clean retry history (only on reset does this happen). was_altered = False if state != self.state: self.state = state was_altered = True if state == states.REVERT_FAILURE: if result != self.revert_failure: self.revert_failure = result was_altered = True if not _is_all_none(self.revert_results): self.revert_results = None was_altered = True elif state == states.FAILURE: if result != self.failure: self.failure = result was_altered = True if not _is_all_none(self.revert_results, self.revert_failure): self.revert_results = None self.revert_failure = None was_altered = True elif state == states.SUCCESS: if not _is_all_none(self.failure, self.revert_failure, self.revert_results): self.failure = None self.revert_failure = None self.revert_results = None # Track what we produced, so that we can examine it (or avoid # using it again). self.results.append((result, {})) was_altered = True elif state == states.REVERTED: # We don't really have the ability to determine equality of # task (user) results at the current time, without making # potentially bad guesses, so assume the retry detail always needs # to be saved if they are not exactly equivalent... if result is not self.revert_results: self.revert_results = result was_altered = True if not _is_all_none(self.revert_failure): self.revert_failure = None was_altered = True return was_altered
[docs] @classmethod def from_dict(cls, data): """Translates the given ``dict`` into an instance of this class.""" def decode_results(results): if not results: return [] new_results = [] for (data, failures) in results: new_failures = {} for (key, data) in six.iteritems(failures): new_failures[key] = ft.Failure.from_dict(data) new_results.append((data, new_failures)) return new_results obj = super(RetryDetail, cls).from_dict(data) obj.results = decode_results(obj.results) return obj
[docs] def to_dict(self): """Translates the internal state of this object to a ``dict``.""" def encode_results(results): if not results: return [] new_results = [] for (data, failures) in results: new_failures = {} for (key, failure) in six.iteritems(failures): new_failures[key] = failure.to_dict() new_results.append((data, new_failures)) return new_results base = super(RetryDetail, self).to_dict() base['results'] = encode_results(base.get('results')) return base
[docs] def merge(self, other, deep_copy=False): """Merges the current retry detail with the given one. NOTE(harlowja): This merge does **not** deep copy the incoming objects ``results`` attribute (if it differs). Instead the incoming objects ``results`` attribute list is **always** iterated over and a new list is constructed with each ``(data, failures)`` element in that list having its ``failures`` (a dictionary of each named :py:class:`~taskflow.types.failure.Failure` objects that occurred) copied but its ``data`` is left untouched. After this is done that new list becomes (via assignment) this objects ``results`` attribute. Also note that if the provided object is this object itself then **no** merging is done. See: https://bugs.launchpad.net/taskflow/+bug/1452978 for what happens if the ``data`` in ``results`` is copied at a deeper level (for example by using ``copy.deepcopy`` or by using ``copy.copy``). :returns: this retry detail (freshly merged with the incoming object) :rtype: :py:class:`.RetryDetail` """ if not isinstance(other, RetryDetail): raise exc.NotImplementedError("Can only merge with other" " retry details") if other is self: return self super(RetryDetail, self).merge(other, deep_copy=deep_copy) results = [] # NOTE(imelnikov): we can't just deep copy Failures, as they # contain tracebacks, which are not copyable. for (data, failures) in other.results: copied_failures = {} for (key, failure) in six.iteritems(failures): if deep_copy: copied_failures[key] = failure.copy() else: copied_failures[key] = failure results.append((data, copied_failures)) self.results = results return self
_DETAIL_TO_NAME = { RetryDetail: 'RETRY_DETAIL', TaskDetail: 'TASK_DETAIL', } _NAME_TO_DETAIL = dict((name, cls) for (cls, name) in six.iteritems(_DETAIL_TO_NAME)) ATOM_TYPES = list(six.iterkeys(_NAME_TO_DETAIL)) def atom_detail_class(atom_type): try: return _NAME_TO_DETAIL[atom_type] except KeyError: raise TypeError("Unknown atom type '%s'" % (atom_type)) def atom_detail_type(atom_detail): try: return _DETAIL_TO_NAME[type(atom_detail)] except KeyError: raise TypeError("Unknown atom '%s' (%s)" % (atom_detail, type(atom_detail)))