diff options
| -rw-r--r-- | activerecord/CHANGELOG | 2 | ||||
| -rw-r--r-- | activerecord/lib/active_record/locking/optimistic.rb | 39 | ||||
| -rw-r--r-- | activerecord/test/locking_test.rb | 14 |
3 files changed, 39 insertions, 16 deletions
diff --git a/activerecord/CHANGELOG b/activerecord/CHANGELOG index 0bed07029b..a0a1addd62 100644 --- a/activerecord/CHANGELOG +++ b/activerecord/CHANGELOG @@ -1,5 +1,7 @@ *SVN* +* Optimistic locking: revert the lock version when an update fails. #7840 [plang] + * Migrations: add_column supports custom column types. #7742 [jsgarvin, Theory] * Load database adapters on demand. Eliminates config.connection_adapters and RAILS_CONNECTION_ADAPTERS. Add your lib directory to the $LOAD_PATH and put your custom adapter in lib/active_record/connection_adapters/adaptername_adapter.rb. This way you can provide custom adapters as plugins or gems without modifying Rails. [Jeremy Kemper] diff --git a/activerecord/lib/active_record/locking/optimistic.rb b/activerecord/lib/active_record/locking/optimistic.rb index 23e7239d5e..d8f9dee372 100644 --- a/activerecord/lib/active_record/locking/optimistic.rb +++ b/activerecord/lib/active_record/locking/optimistic.rb @@ -2,7 +2,7 @@ module ActiveRecord module Locking # == What is Optimistic Locking # - # Optimistic locking allows multiple users to access the same record for edits, and assumes a minimum of + # Optimistic locking allows multiple users to access the same record for edits, and assumes a minimum of # conflicts with the data. It does this by checking whether another process has made changes to a record since # it was opened, an ActiveRecord::StaleObjectError is thrown if that has occurred and the update is ignored. # @@ -16,10 +16,10 @@ module ActiveRecord # # p1 = Person.find(1) # p2 = Person.find(1) - # + # # p1.first_name = "Michael" # p1.save - # + # # p2.first_name = "should fail" # p2.save # Raises a ActiveRecord::StaleObjectError # @@ -53,16 +53,16 @@ module ActiveRecord private def attributes_from_column_definition_with_lock result = attributes_from_column_definition_without_lock - + # If the locking column has no default value set, # start the lock version at zero. Note we can't use # locking_enabled? at this point as @attributes may # not have been initialized yet - + if lock_optimistically && result.include?(self.class.locking_column) result[self.class.locking_column] ||= 0 end - + return result end @@ -73,18 +73,25 @@ module ActiveRecord previous_value = send(lock_col) send(lock_col + '=', previous_value + 1) - affected_rows = connection.update(<<-end_sql, "#{self.class.name} Update with optimistic locking") - UPDATE #{self.class.table_name} - SET #{quoted_comma_pair_list(connection, attributes_with_quotes(false))} - WHERE #{self.class.primary_key} = #{quote_value(id)} - AND #{self.class.quoted_locking_column} = #{quote_value(previous_value)} - end_sql + begin + affected_rows = connection.update(<<-end_sql, "#{self.class.name} Update with optimistic locking") + UPDATE #{self.class.table_name} + SET #{quoted_comma_pair_list(connection, attributes_with_quotes(false))} + WHERE #{self.class.primary_key} = #{quote_value(id)} + AND #{self.class.quoted_locking_column} = #{quote_value(previous_value)} + end_sql - unless affected_rows == 1 - raise ActiveRecord::StaleObjectError, "Attempted to update a stale object" - end + unless affected_rows == 1 + raise ActiveRecord::StaleObjectError, "Attempted to update a stale object" + end - return true + affected_rows + + # If something went wrong, revert the version. + rescue Exception + send(lock_col + '=', previous_value) + raise + end end module ClassMethods diff --git a/activerecord/test/locking_test.rb b/activerecord/test/locking_test.rb index f62f1ac61c..3194727822 100644 --- a/activerecord/test/locking_test.rb +++ b/activerecord/test/locking_test.rb @@ -30,6 +30,20 @@ class OptimisticLockingTest < Test::Unit::TestCase assert_raises(ActiveRecord::StaleObjectError) { p2.save! } end + + def test_lock_repeating + p1 = Person.find(1) + p2 = Person.find(1) + assert_equal 0, p1.lock_version + assert_equal 0, p2.lock_version + + p1.save! + assert_equal 1, p1.lock_version + assert_equal 0, p2.lock_version + + assert_raises(ActiveRecord::StaleObjectError) { p2.save! } + assert_raises(ActiveRecord::StaleObjectError) { p2.save! } + end def test_lock_new p1 = Person.new(:first_name => 'anika') |