Add support for repeated keys in TaskRequest.

appengine/swarming/server/task_request.py

Index: appengine/swarming/server/task_request.py
diff --git a/appengine/swarming/server/task_request.py b/appengine/swarming/server/task_request.py
index f9c0674fb834b31bc67f3ccb26799b8f5da96958..b8e6bc04a4f34c2e8f35525542de88b521380f78 100644
--- a/appengine/swarming/server/task_request.py
+++ b/appengine/swarming/server/task_request.py
@@ -542,10 +542,11 @@ class TaskProperties(ndb.Model):
 
   @property
   def dimensions(self):
-    """Returns a dict(key, value)."""
+    """Returns a list of tuple(key, value)."""
     if self.dimensions_dict:
-      return self.dimensions_dict
-    return dict(i.split(u':', 1) for i in self.dimensions_flat)
+      return sorted(self.dimensions_dict.items())
+    # Data is already sorted.
+    return [tuple(i.split(u':', 1)) for i in self.dimensions_flat]
 
   @property
   def is_terminate(self):
@@ -553,7 +554,7 @@ class TaskProperties(ndb.Model):
     return (
         not self.caches and
         not self.command and
-        self.dimensions.keys() == [u'id'] and
+        [i[0] for i in self.dimensions] == [u'id'] and
         not (self.inputs_ref and self.inputs_ref.isolated) and
         not self.cipd_input and
         not self.env and
@@ -579,9 +580,12 @@ class TaskProperties(ndb.Model):
       return
 
     # Dimensions.
-    if not self.dimensions:
+    if self.dimensions_dict:
+      raise datastore_errors.BadValueError(
+          u'internal error: dimensions_dict cannot be stored anymore')
+    if not self.dimensions_flat:
       raise datastore_errors.BadValueError(u'dimensions are required')
-    keys = self.dimensions.keys()
+    keys = [i.split(u':', 1)[0] for i in self.dimensions_flat]
     count_pool = sum(1 for k in keys if k == u'pool')
     count_id = sum(1 for k in keys if k == u'id')
     if not count_pool and not count_id:
@@ -590,7 +594,7 @@ class TaskProperties(ndb.Model):
     if count_id > 1:
       raise datastore_errors.BadValueError(
           u'\'id\' cannot be specified more than once in dimensions')
-    if len(keys) > 64:
+    if len(self.dimensions_flat) > 64:
       raise datastore_errors.BadValueError(
           'dimensions can have up to 64 entries')
     if not _is_sorted(self.dimensions_flat):
@@ -827,7 +831,7 @@ def create_termination_task(bot_id, allow_high_priority):
     TaskRequest for priority 0 (highest) termination task.
   """
   properties = TaskProperties(
-      dimensions_dict={u'id': unicode(bot_id)},
+      dimensions_flat=[u'id:%s' % unicode(bot_id)],
       execution_timeout_secs=0,
       grace_period_secs=0,
       io_timeout_secs=0)
@@ -994,7 +998,7 @@ def init_new_request(request, allow_high_priority, secret_bytes_ent):
   request.tags.append('priority:%s' % request.priority)
   request.tags.append('user:%s' % request.user)
   request.tags.append('service_account:%s' % request.service_account)
-  for key, value in request.properties.dimensions.iteritems():
+  for key, value in request.properties.dimensions:
     request.tags.append('%s:%s' % (key, value))
   request.tags = sorted(set(request.tags))
 
@@ -1036,8 +1040,10 @@ def new_request_clone(original_request, original_secret_bytes,
   if original_request.properties.is_terminate:
     raise ValueError('cannot clone a terminate request')
   orig_props = original_request.properties.to_dict()
-  dimensions_dict = orig_props.pop(u'dimensions')
-  properties = TaskProperties(dimensions_dict=dimensions_dict, **orig_props)
+  dimensions_flat = [
+    u'%s:%s' % (k, v) for k, v in orig_props.pop(u'dimensions')
+  ]
+  properties = TaskProperties(dimensions_flat=dimensions_flat, **orig_props)
   properties.idempotent = False
   expiration_ts = (
       now + (original_request.expiration_ts - original_request.created_ts))