Bug 1568277 - [taskgraph] Create optimize strategy aliases for the 'test' kind r=tomprince

This allows test tasks to declare a static optimization name, which can then be
swapped in and out from the optimize code without needing to update the
transforms. This will make it easier to change optimization strategies or run
experimental ones.

Differential Revision: https://phabricator.services.mozilla.com/D40204

--HG--
extra : moz-landing-system : lando

taskcluster/taskgraph/optimize/__init__.py

@@ -75,7 +75,10 @@ def _get_optimizations(target_task_graph, strategies):
         task = target_task_graph.tasks[label]
         if task.optimization:
             opt_by, arg = task.optimization.items()[0]
-            return (opt_by, strategies[opt_by], arg)
+            strategy = strategies[opt_by]
+            if hasattr(strategy, 'description'):
+                opt_by += " ({})".format(strategy.description)
+            return (opt_by, strategy, arg)
         else:
             return ('never', strategies['never'], None)
     return optimizations
@@ -261,6 +264,7 @@ class Either(OptimizationStrategy):
             raise TypeError("substrategies aren't registered: {}".format(
                 ",  ".join(sorted(missing))))
 
+        self.description = "-or-".join(substrategies)
         self.substrategies = [registry[sub] for sub in substrategies]
         self.split_args = kwargs.pop('split_args', None)
         if not self.split_args:
@@ -286,9 +290,21 @@ class Either(OptimizationStrategy):
             lambda sub, arg: sub.should_replace_task(task, params, arg))
 
 
+class Alias(Either):
+    """Provides an alias to an existing strategy.
+
+    This can be useful to swap strategies in and out without needing to modify
+    the task transforms.
+    """
+    def __init__(self, strategy):
+        super(Alias, self).__init__(strategy)
+
+
 # Trigger registration in sibling modules.
 import_sibling_modules()
 
 
 # Register composite strategies.
-register_strategy('skip-unless-schedules-or-seta', args=('skip-unless-schedules', 'seta'))(Either)
+register_strategy('test', args=('skip-unless-schedules', 'seta'))(Either)
+register_strategy('test-inclusive', args=('skip-unless-schedules',))(Alias)
+register_strategy('test-try', args=('skip-unless-schedules',))(Alias)

taskcluster/taskgraph/test/test_optimize.py

@@ -70,6 +70,7 @@ class TestOptimize(unittest.TestCase):
             ('t2', 't1', 'dep'))
 
     def assert_remove_tasks(self, graph, exp_removed, do_not_optimize=set()):
+        optimize.registry = self.strategies
         got_removed = optimize.remove_tasks(
             target_task_graph=graph,
             optimizations=optimize._get_optimizations(graph, self.strategies),

taskcluster/taskgraph/transforms/tests.py

@@ -1416,15 +1416,16 @@ def make_job_description(config, tests):
             schedules = [category, platform_family(test['build-platform'])]
 
         if test.get('when'):
+            # This may still be used by comm-central.
             jobdesc['when'] = test['when']
         elif 'optimization' in test:
             jobdesc['optimization'] = test['optimization']
-        elif not config.params.is_try() and category not in INCLUSIVE_COMPONENTS:
-            # for non-try branches and non-inclusive suites, include SETA
-            jobdesc['optimization'] = {'skip-unless-schedules-or-seta': schedules}
+        elif config.params.is_try():
+            jobdesc['optimization'] = {'test-try': schedules}
+        elif category in INCLUSIVE_COMPONENTS:
+            jobdesc['optimization'] = {'test-inclusive': schedules}
         else:
-            # otherwise just use skip-unless-schedules
-            jobdesc['optimization'] = {'skip-unless-schedules': schedules}
+            jobdesc['optimization'] = {'test': schedules}
 
         run = jobdesc['run'] = {}
         run['using'] = 'mozharness-test'

taskcluster/taskgraph/util/schema.py

@@ -203,8 +203,10 @@ OptimizationSchema = voluptuous.Any(
     {'skip-unless-changed': [basestring]},
     # skip this task if unless the change files' SCHEDULES contains any of these components
     {'skip-unless-schedules': list(schedules.ALL_COMPONENTS)},
-    # skip if SETA or skip-unless-schedules says to
-    {'skip-unless-schedules-or-seta': list(schedules.ALL_COMPONENTS)},
+    # optimize strategy aliases for the test kind
+    {'test': list(schedules.ALL_COMPONENTS)},
+    {'test-inclusive': list(schedules.ALL_COMPONENTS)},
+    {'test-try': list(schedules.ALL_COMPONENTS)},
 )
 
 # shortcut for a string where task references are allowed