delta/openstack/taskflow.git/taskflow/patterns/linear_flow.py, branch 2.9.0

Use graphs as the underlying structure of patterns

2015-09-18T17:39:04+00:00

This unifies all the patterns to be graph based so
that they are more uniform and there underlying constraints
are more easy to understand (taskflow basically processes
graphs).

Change-Id: Ib2ab07c1c87165cf40a06508128010887f658391

iter_nodes method added to flows

2015-08-28T14:54:25+00:00

New method allows to iterate over flow node and
get access to node metadata during iteration.

Change-Id: Ib0fc77f0597961602fbc3b49ba09e4df815d8230

Use constants for link metadata keys

2014-10-18T20:24:12+00:00

Instead of using strings (which can be easy to
mistype and get wrong), provide a set of constants
that can be used to attach and use these keys in
flows and at compilation.

This also helps make it more clear what the keys
do and where they are used.

Change-Id: I5283b27617961136a4582bbcfce4617f05e8dd1d

Relax the linear flow symbol constraints

2014-09-08T20:55:26+00:00

In order to make it possible to have a symbol
tree we need to relax and remove the constraints
that are being imposed by the linear constraints
and later move those constraint checks and validations
into the engines compilation stage.

Part of blueprint taskflow-improved-scoping

Change-Id: I6efdc821ff991e83572d89f56be5c678d007f9f8

Be smarter about required flow symbols

2014-09-08T19:14:51+00:00

Instead of blindly assuming all the symbols that
are provided automatically work for all flows even
if the flow has ordering constraints we should set
the base flow class requires property to be abstract
and provide flow specific properties that can do the
appropriate analysis to determine what the flows
unsatisfied symbol requirements actually are.

Part of blueprint taskflow-improved-scoping

Change-Id: Ie149c05b3305c5bfff9d9f2c05e7e064c3a6d0c7

Put provides and requires code to basic Flow

2014-05-07T07:17:50+00:00

Code that calculates provides and requires for flow is almost
identical for all patterns, so this change makes it completely
identical and puts it to the base class. Other patterns are
still allowed to override these properties for sake of customization
or optimization.

Change-Id: I6e875e863047b5287ec727fc9a491f252f144ecf

Adjust the exception hierachy

2014-03-25T03:42:30+00:00

Group the exceptions into the following groups
  * Storage
  * Jobs
  * Execution
  * Other (wrapped failure here)

This grouping makes it easier to understand where
one type of exception should be used vs using another
type of exception.

Backwards incompatible changes:
  * StorageError -> StorageFailure
  * AlreadyExists -> Duplicate
  * WrappedFailure now inherits from Exception
    and not directly from TaskFlowException since it
    wraps arbitrary other exceptions and is not
    specific to taskflow.

Cleanups:
  * JobNotFound -> NotFound
  * EmptyFlow -> Empty
  * JobAlreadyExists -> AlreadyExists
  * InvariantViolation (X)
  * ConnectionFailure (X)

Change-Id: I0e1e81b513fbbc7adb8bfaa1244993e345ab70d3

Merge "Linear flow: mark links and rework unit tests"

2014-03-24T11:00:33+00:00

Linear flow: mark links and rework unit tests

2014-03-21T10:26:24+00:00

- add 'invariant': True to all links produced by linear flow;
- write new unit tests for basic functionality of linear flow
  pattern;
- remove some simple now-redundant unit tests from
  test_flow_dependencies.

Change-Id: I1f4fa8a1dfc61485555a10e8d0629a67aab1997f

Drop indexing operator from linear flow

2014-03-21T09:06:36+00:00

It is not needed. Also, using it complicates transitioning
to another pattern (e.g. graph flow) and encourages bad
programming practices.

Change-Id: I9d0a4646a27df1a11ed436f26a0cb074b717647e