Merge pull request #24 from harlowja/task-naming-versions

Task naming versions

taskflow/job.py

@@ -26,14 +26,28 @@ from taskflow.openstack.common import uuidutils
 
 
 def task_and_state(task, state):
+    name_pieces = []
     try:
-        name = task.name
+        name_pieces.append(task.name)
+        if isinstance(task.version, (list, tuple)):
+            name_pieces.append(utils.join(task.version, "."))
+        else:
+            name_pieces.append(task.version)
     except AttributeError:
-        try:
-            name = task.__name__
-        except AttributeError:
-            name = str(task)
-    return "%s:%s" % (name, state)
+        pass
+    if not name_pieces:
+        # Likely a function and not a task object so let us search for these
+        # attributes to get a good name for this task.
+        name_pieces = [a for a in utils.get_many_attr(task,
+                                                      '__module__',
+                                                      '__name__',
+                                                      '__version__')
+                       if a is not None]
+    if not name_pieces:
+        # Ok, unsure what this task is, just use whatever its string
+        # representation is.
+        name_pieces.append(task)
+    return "%s;%s" % (utils.join(name_pieces, ':'), state)
 
 
 class Claimer(object):

taskflow/task.py

@@ -18,6 +18,8 @@
 
 import abc
 
+from taskflow import utils
+
 
 class Task(object):
     """An abstraction that defines a potential piece of work that can be
@@ -33,9 +35,14 @@ class Task(object):
         # An *immutable* output 'resource' name set this task
         # produces that other tasks may depend on this task providing.
         self.provides = set()
+        # This identifies the version of the task to be ran which
+        # can be useful in resuming older versions of tasks. Standard
+        # major, minor version semantics apply.
+        self.version = (1, 0)
 
     def __str__(self):
-        return "Task: %s" % (self.name)
+        return "Task: %s v%s" % (self.name, utils.join(self.version,
+                                                       with_what="."))
 
     @abc.abstractmethod
     def __call__(self, context, *args, **kwargs):

taskflow/utils.py

@@ -24,6 +24,18 @@ import time
 LOG = logging.getLogger(__name__)
 
 
+def join(itr, with_what=","):
+    pieces = [str(i) for i in itr]
+    return with_what.join(pieces)
+
+
+def get_many_attr(obj, *attrs):
+    many = []
+    for a in attrs:
+        many.append(getattr(obj, a, None))
+    return many
+
+
 def await(check_functor, timeout=None):
     if timeout is not None:
         end_time = time.time() + max(0, timeout)