diff options
Diffstat (limited to 'activerecord/lib/active_record/locking/optimistic.rb')
| -rw-r--r-- | activerecord/lib/active_record/locking/optimistic.rb | 51 |
1 files changed, 24 insertions, 27 deletions
diff --git a/activerecord/lib/active_record/locking/optimistic.rb b/activerecord/lib/active_record/locking/optimistic.rb index d9ad7e4132..e643c0d437 100644 --- a/activerecord/lib/active_record/locking/optimistic.rb +++ b/activerecord/lib/active_record/locking/optimistic.rb @@ -37,6 +37,9 @@ module ActiveRecord # You're then responsible for dealing with the conflict by rescuing the exception and either rolling back, merging, # or otherwise apply the business logic needed to resolve the conflict. # + # This locking mechanism will function inside a single Ruby process. To make it work across all + # web requests, the recommended approach is to add +lock_version+ as a hidden field to your form. + # # You must ensure that your database schema defaults the +lock_version+ column to 0. # # This behavior can be turned off by setting <tt>ActiveRecord::Base.lock_optimistically = false</tt>. @@ -46,12 +49,8 @@ module ActiveRecord extend ActiveSupport::Concern included do - cattr_accessor :lock_optimistically, :instance_writer => false + config_attribute :lock_optimistically, :global => true self.lock_optimistically = true - - class << self - alias_method :locking_column=, :set_locking_column - end end def locking_enabled? #:nodoc: @@ -65,21 +64,6 @@ module ActiveRecord send(lock_col + '=', previous_lock_value + 1) end - def attributes_from_column_definition - result = super - - # If the locking column has no default value set, - # start the lock version at zero. Note we can't use - # <tt>locking_enabled?</tt> at this point as - # <tt>@attributes</tt> may not have been initialized yet. - - if result.key?(self.class.locking_column) && lock_optimistically - result[self.class.locking_column] ||= 0 - end - - result - end - def update(attribute_names = @attributes.keys) #:nodoc: return super unless locking_enabled? return 0 if attribute_names.empty? @@ -103,7 +87,7 @@ module ActiveRecord affected_rows = connection.update stmt unless affected_rows == 1 - raise ActiveRecord::StaleObjectError, "Attempted to update a stale object: #{self.class.name}" + raise ActiveRecord::StaleObjectError.new(self, "update") end affected_rows @@ -127,7 +111,7 @@ module ActiveRecord affected_rows = self.class.unscoped.where(predicate).delete_all unless affected_rows == 1 - raise ActiveRecord::StaleObjectError, "Attempted to delete a stale object: #{self.class.name}" + raise ActiveRecord::StaleObjectError.new(self, "destroy") end end @@ -146,14 +130,15 @@ module ActiveRecord end # Set the column to use for optimistic locking. Defaults to +lock_version+. - def set_locking_column(value = nil, &block) - define_attr_method :locking_column, value, &block - value + def locking_column=(value) + @original_locking_column = @locking_column if defined?(@locking_column) + @locking_column = value.to_s end # The version column used for optimistic locking. Defaults to +lock_version+. def locking_column - reset_locking_column + reset_locking_column unless defined?(@locking_column) + @locking_column end # Quote the column name used for optimistic locking. @@ -163,7 +148,7 @@ module ActiveRecord # Reset the column used for optimistic locking back to the +lock_version+ default. def reset_locking_column - set_locking_column DEFAULT_LOCKING_COLUMN + self.locking_column = DEFAULT_LOCKING_COLUMN end # Make sure the lock version column gets updated when counters are @@ -172,6 +157,18 @@ module ActiveRecord counters = counters.merge(locking_column => 1) if locking_enabled? super end + + # If the locking column has no default value set, + # start the lock version at zero. Note we can't use + # <tt>locking_enabled?</tt> at this point as + # <tt>@attributes</tt> may not have been initialized yet. + def initialize_attributes(attributes) #:nodoc: + if attributes.key?(locking_column) && lock_optimistically + attributes[locking_column] ||= 0 + end + + attributes + end end end end |