Store results by add() uuid instead of in array format.

Instead of storing the results in the previous linear
format, just store the results indexed by the uuid
returned from the add() method instead. This allows
for easier access to individual task result as well
as makes it easier to support non-linear result
insertation.

Change-Id: Id7461cb74eb1a380b05cf23643e7120df5682224

2 files changed, 18 insertions, 4 deletions

diff --git a/taskflow/patterns/linear_flow.py b/taskflow/patterns/linear_flow.py
index 00ce34a..fd04501 100644
--- a/taskflow/patterns/linear_flow.py
+++ b/taskflow/patterns/linear_flow.py
@@ -54,8 +54,9 @@ class Flow(base.Flow):
         # the contract we have with tasks that they will be given the value
         # they returned if reversion is triggered.
         self.result_fetcher = None
-        # Tasks results are stored here...
-        self.results = []
+        # Tasks results are stored here. Lookup is by the uuid that was
+        # returned from the add function.
+        self.results = {}
         # The last index in the order we left off at before being
         # interrupted (or failing).
         self._left_off_at = 0
@@ -173,7 +174,7 @@ class Flow(base.Flow):
                 runner.result = result
                 # Alter the index we have ran at.
                 self._left_off_at += 1
-                self.results.append((runner.task, copy.deepcopy(result)))
+                self.results[runner.uuid] = copy.deepcopy(result)
                 self._on_task_finish(context, runner.task, result)
             except Exception as e:
                 cause = utils.FlowFailure(runner.task, self, e)
@@ -225,7 +226,7 @@ class Flow(base.Flow):
     @decorators.locked
     def reset(self):
         super(Flow, self).reset()
-        self.results = []
+        self.results = {}
         self.result_fetcher = None
         self._accumulator.reset()
         self._left_off_at = 0
diff --git a/taskflow/tests/unit/test_linear_flow.py b/taskflow/tests/unit/test_linear_flow.py
index 6d5f36c..c2cccb7 100644
--- a/taskflow/tests/unit/test_linear_flow.py
+++ b/taskflow/tests/unit/test_linear_flow.py
@@ -57,6 +57,19 @@ class LinearFlowTest(unittest2.TestCase):
 
         return do_interrupt
 
+    def test_result_access(self):
+        wf = lw.Flow("the-test-action")
+
+        @decorators.task
+        def do_apply1(context):
+            return [1, 2]
+
+        result_id = wf.add(do_apply1)
+        ctx = {}
+        wf.run(ctx)
+        self.assertTrue(result_id in wf.results)
+        self.assertEquals([1, 2], wf.results[result_id])
+
     def test_functor_flow(self):
         wf = lw.Flow("the-test-action")