16813: Avoid writing db when nothing is changing in a batch update.

Avoids superfluous log entries and potentially costly permission graph
updates.

Arvados-DCO-1.1-Signed-off-by: Tom Clegg <tom@tomclegg.ca>

diff --git a/services/api/app/controllers/arvados/v1/users_controller.rb b/services/api/app/controllers/arvados/v1/users_controller.rb
index 867b9a6e6abfdf0ae050a668f4340d1664608586..cd23706d08140f2176fccb063ed5b4070202536a 100644 (file)
--- a/services/api/app/controllers/arvados/v1/users_controller.rb
+++ b/services/api/app/controllers/arvados/v1/users_controller.rb
@@ -22,7 +22,15 @@ class Arvados::V1::UsersController < ApplicationController
       rescue ActiveRecord::RecordNotUnique
         retry
       end
-      u.update_attributes!(nullify_attrs(attrs))
+      needupdate = {}
+      nullify_attrs(attrs).each do |k,v|
+        if !v.nil? && u.send(k) != v
+          needupdate[k] = v
+        end
+      end
+      if needupdate.length > 0
+        u.update_attributes!(needupdate)
+      end
       @objects << u
     end
     @offset = 0

diff --git a/services/api/test/functional/arvados/v1/users_controller_test.rb b/services/api/test/functional/arvados/v1/users_controller_test.rb
index 0ce9f1137f3fad8592e16318720c3b13d00406d3..ea5d5b1436bd256506cc1c23061dfd81eb8a763f 100644 (file)
--- a/services/api/test/functional/arvados/v1/users_controller_test.rb
+++ b/services/api/test/functional/arvados/v1/users_controller_test.rb
@@ -1039,9 +1039,12 @@ class Arvados::V1::UsersControllerTest < ActionController::TestCase
   test "batch update" do
     existinguuid = 'remot-tpzed-foobarbazwazqux'
     newuuid = 'remot-tpzed-newnarnazwazqux'
+    unchanginguuid = 'remot-tpzed-nochangingattrs'
     act_as_system_user do
       User.create!(uuid: existinguuid, email: 'root@existing.example.com')
+      User.create!(uuid: unchanginguuid, email: 'root@unchanging.example.com', prefs: {'foo' => {'bar' => 'baz'}})
     end
+    assert_equal(1, Log.where(object_uuid: unchanginguuid).count)
 
     authorize_with(:admin)
     patch(:batch_update,
@@ -1059,6 +1062,10 @@ class Arvados::V1::UsersControllerTest < ActionController::TestCase
                 'email' => 'root@remot.example.com',
                 'username' => '',
               },
+              unchanginguuid => {
+                'email' => 'root@unchanging.example.com',
+                'prefs' => {'foo' => {'bar' => 'baz'}},
+              },
             }})
     assert_response(:success)
 
@@ -1070,6 +1077,8 @@ class Arvados::V1::UsersControllerTest < ActionController::TestCase
 
     assert_equal('noot', User.find_by_uuid(newuuid).first_name)
     assert_equal('root@remot.example.com', User.find_by_uuid(newuuid).email)
+
+    assert_equal(1, Log.where(object_uuid: unchanginguuid).count)
   end
 
   NON_ADMIN_USER_DATA = ["uuid", "kind", "is_active", "email", "first_name",