Add support for repeated keys in TaskRequest.

appengine/swarming/server/task_to_run.py

 # coding=utf-8
 # Copyright 2014 The LUCI Authors. All rights reserved.
 # Use of this source code is governed under the Apache License, Version 2.0
 # that can be found in the LICENSE file.
 
 """Task entity that describe when a task is to be scheduled.
 
 This module doesn't do the scheduling itself. It only describes the tasks ready
 to be scheduled.
 
@@ skipping 409 matching lines @@
   request_key = task_to_run_key_to_request_key(task_key)
   key_id = task_key.integer_id()
   if not key_id or key_id >= 2**32:
     raise ValueError(
         'TaskToRun key id should be between 1 and 2**32, found %s' %
         task_key.id())
   task_request.validate_request_key(request_key)
 
 
 def match_dimensions(request_dimensions, bot_dimensions):
-  """Returns True if the bot dimensions satisfies the request dimensions."""
-  assert isinstance(request_dimensions, dict), request_dimensions
+  """Returns True if the bot dimensions satisfies the request dimensions.
+
+  Arguments:
+    request_dimensions: list(tuple(unicode, unicode)).
+    bot_dimensions: dict(unicode: list(unicode)).
+  """
+  assert isinstance(request_dimensions, list), request_dimensions
   assert isinstance(bot_dimensions, dict), bot_dimensions
-  if frozenset(request_dimensions).difference(bot_dimensions):
-    return False
-  for key, required in request_dimensions.iteritems():
-    bot_value = bot_dimensions[key]
-    if isinstance(bot_value, (list, tuple)):
-      if required not in bot_value:
-        return False
-    elif required != bot_value:
+  for key, required in request_dimensions:
+    bot_value = bot_dimensions.get(key)
+    if not bot_value or required not in bot_value:
       return False
   return True
 
 
 def set_lookup_cache(task_key, is_available_to_schedule):
   """Updates the quick lookup cache to mark an item as available or not.
 
   This cache is a blacklist of items that are already reaped, so it is not worth
   trying to reap it with a DB transaction. This saves on DB contention when a
   high number (>1000) of concurrent bots with similar dimension are reaping
@@ skipping 64 matching lines @@
   """Yields all the expired TaskToRun still marked as available."""
   # The reason it is done this way as an iteration over all the pending entities
   # instead of using a composite index with 'queue_number' and 'expiration_ts'
   # is that TaskToRun entities are very hot and it is important to not require
   # composite indexes on it. It is expected that the number of pending task is
   # 'relatively low', in the orders of 100,000 entities.
   now = utils.utcnow()
   for task in TaskToRun.query(TaskToRun.queue_number > 0):
     if task.expiration_ts < now:
       yield task