config_service: fetch repos and metadata concurrently

appengine/config_service/api.py

 # Copyright 2015 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.
 
 import logging
 
 from google.appengine.api import memcache
 from google.appengine.ext import ndb
 from protorpc import messages
 from protorpc import message_types
@@ skipping 383 matching lines @@
   Does not return projects that have no repo information. It might happen due
   to eventual consistency.
 
   Does not check access.
 
   Caches results in memcache for 1 min.
   """
   result = []
   projs = projects.get_projects()
   project_ids = [p.id for p in projs]
-  repos = projects.get_repos(project_ids)
-  metadata = projects.get_metadata(project_ids)
+  repos_fut = projects.get_repos_async(project_ids)
+  metadata_fut = projects.get_metadata_async(project_ids)
+  ndb.Future.wait_all([repos_fut, metadata_fut])
+  repos, metadata = repos_fut.get_result(), metadata_fut.get_result()
   for p in projs:
     repo_type, repo_url = repos.get(p.id, (None, None))
     if repo_type is None:
       # Not yet consistent.
       continue
     name = None
     if metadata.get(p.id) and metadata[p.id].name:
       name = metadata[p.id].name
     result.append(Project(
         id=p.id,
@@ skipping 77 matching lines @@
 
 def can_read_config_sets(config_sets):
   try:
     return acl.can_read_config_sets(config_sets)
   except ValueError as ex:
     raise endpoints.BadRequestException(ex.message)
 
 
 def can_read_config_set(config_set):
   return can_read_config_sets([config_set]).get(config_set)