openstack/deb-python-taskflow
Code Issues Proposed changes

Merge "Add warning about transient arguments and worker-based-engines"

Browse Source
This commit is contained in:
Jenkins
2015-03-07 05:20:07 +00:00
committed by Gerrit Code Review
parent 641596a445 c738693ca4
commit 41f31423f0
1 changed files with 42 additions and 7 deletions
Download Patch File Download Diff File Expand all files Collapse all files

49
taskflow/storage.py
View File

@@ -506,15 +506,34 @@ class Storage(object):
self._with_connection(self._save_atom_detail, ad)
def inject_atom_args(self, atom_name, pairs):
"""Add *transient* values into storage for a specific atom only.
"""Add **transient** values into storage for a specific atom only.
This method injects a dictionary/pairs of arguments for an atom so that
when that atom is scheduled for execution it will have immediate access
to these arguments.
NOTE(harlowja): injected atom arguments take precedence over arguments
provided by predecessor atoms or arguments provided by injecting into
the flow scope (using the inject() method).
.. note::
Injected atom arguments take precedence over arguments
provided by predecessor atoms or arguments provided by injecting
into the flow scope (using
the :py:meth:`~taskflow.storage.Storage.inject` method).
.. warning::
It should be noted that injected atom arguments (that are scoped
to the atom with the given name) *should* be serializable
whenever possible. This is a **requirement** for the
:doc:`worker based engine <workers>` which **must**
serialize (typically using ``json``) all
atom :py:meth:`~taskflow.atom.Atom.execute` and
:py:meth:`~taskflow.atom.Atom.revert` arguments to
be able to transmit those arguments to the target worker(s). If
the use-case being applied/desired is to later use the worker
based engine then it is highly recommended to ensure all injected
atoms (even transient ones) are serializable to avoid issues
that *may* appear later (when a object turned out to not actually
be serializable).
"""
if atom_name not in self._atom_name_to_uuid:
raise exceptions.NotFound("Unknown atom name: %s" % atom_name)
@@ -526,11 +545,27 @@ class Storage(object):
"""Add values into storage.
This method should be used to put flow parameters (requirements that
are not satisfied by any task in the flow) into storage.
are not satisfied by any atom in the flow) into storage.
:param: transient save the data in-memory only instead of persisting
:param transient: save the data in-memory only instead of persisting
the data to backend storage (useful for resource-like objects
or similar objects which should *not* be persisted)
or similar objects which can **not** be persisted)
.. warning::
It should be noted that injected flow arguments (that are scoped
to all atoms in this flow) *should* be serializable whenever
possible. This is a **requirement** for
the :doc:`worker based engine <workers>` which **must**
serialize (typically using ``json``) all
atom :py:meth:`~taskflow.atom.Atom.execute` and
:py:meth:`~taskflow.atom.Atom.revert` arguments to
be able to transmit those arguments to the target worker(s). If
the use-case being applied/desired is to later use the worker
based engine then it is highly recommended to ensure all injected
atoms (even transient ones) are serializable to avoid issues
that *may* appear later (when a object turned out to not actually
be serializable).
"""
def save_persistent():