CatalogTool: Avoid computing user's roles when just testing existence.

Global role computation is very expensive, don't do it when all we are
interested in is user existence.
Also, list all users having local roles in one call to reduce the effect
of per-call overhead.
This should improve indexation speed by a large fraction: pprofile
statistical run on and activity node busy reindexing objects shows:
- 57% of time spend generating (13%) and executing (44%) SQL
- 42% of time spent preparing object for indexation:
  - 29% in _getSecurityParameterList, all in getUserById
  - 12% in getCatalogVariablesFor (workflow variables to index)
So an improvement of close to 30% is expected.

product/ERP5Catalog/CatalogTool.py

@@ -98,13 +98,27 @@ class IndexableObjectWrapper(object):
               skip_role(role[1:])
             elif role not in skip_role_set:
               new_role(role)
-          if len(new_role_list)>0:
-            localroles[key] = new_role_list
+          if new_role_list:
+            localroles[key] = [new_role_list, False]
 
         portal = ob.getPortalObject()
         role_dict = dict(portal.portal_catalog.getSQLCatalog().\
                                               getSQLCatalogRoleKeysList())
-        getUserById = portal.acl_users.getUserById
+        for user_info in portal.acl_users.searchUsers(id=tuple(localroles), exact_match=True):
+          key = user_info['id']
+          try:
+            localroles[key][1] = True
+          except KeyError:
+            # We found a bug, report it but do not make indexation fail.
+            LOG(
+              'CatalogTool.IndexableObjectWrapper',
+              PROBLEM,
+              'searchUser(id=%r, exact_match=True) returned an entry with '
+              'id=%r. This is very likely a bugin a PAS plugin !' % (
+                tuple(localroles),
+                key,
+              ),
+            )
 
         allowed_dict = {}
 
@@ -161,8 +175,7 @@ class IndexableObjectWrapper(object):
               optimized_role_set.add((user, role))
 
         # Then parse other roles
-        for user, roles in localroles.iteritems():
-          user_exists = getUserById(user) is not None
+        for user, (roles, user_exists) in localroles.iteritems():
           prefix = 'user:' + user
           for role in roles:
             if user_exists and role in role_dict: