Module: ActiveRecord::Locking::Optimistic::ClassMethods

Defined in:
lib/gems/activerecord-2.2.2/lib/active_record/locking/optimistic.rb

Constant Summary collapse

DEFAULT_LOCKING_COLUMN = 
'lock_version'

Class Method Summary collapse

Instance Method Summary collapse

Class Method Details

.extended(base) ⇒ Object 



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# File 'lib/gems/activerecord-2.2.2/lib/active_record/locking/optimistic.rb', line 104

def self.extended(base)
  class <<base
    alias_method_chain :update_counters, :lock
  end
end

Instance Method Details

#locking_column ⇒ Object

The version column used for optimistic locking. Defaults to lock_version.



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# File 'lib/gems/activerecord-2.2.2/lib/active_record/locking/optimistic.rb', line 125

def locking_column
  reset_locking_column
end

#locking_enabled? ⇒ Boolean

Is optimistic locking enabled for this table? Returns true if the lock_optimistically flag is set to true (which it is, by default) and the table includes the locking_column column (defaults to lock_version).

Returns:

  • (Boolean) 


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# File 'lib/gems/activerecord-2.2.2/lib/active_record/locking/optimistic.rb', line 114

def locking_enabled?
  lock_optimistically && columns_hash[locking_column]
end

#quoted_locking_column ⇒ Object

Quote the column name used for optimistic locking.



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# File 'lib/gems/activerecord-2.2.2/lib/active_record/locking/optimistic.rb', line 130

def quoted_locking_column
  connection.quote_column_name(locking_column)
end

#reset_locking_column ⇒ Object

Reset the column used for optimistic locking back to the lock_version default.



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# File 'lib/gems/activerecord-2.2.2/lib/active_record/locking/optimistic.rb', line 135

def reset_locking_column
  set_locking_column DEFAULT_LOCKING_COLUMN
end

#set_locking_column(value = nil, &block) ⇒ Object

Set the column to use for optimistic locking. Defaults to lock_version.



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# File 'lib/gems/activerecord-2.2.2/lib/active_record/locking/optimistic.rb', line 119

def set_locking_column(value = nil, &block)
  define_attr_method :locking_column, value, &block
  value
end

#update_counters_with_lock(id, counters) ⇒ Object

Make sure the lock version column gets updated when counters are updated.



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# File 'lib/gems/activerecord-2.2.2/lib/active_record/locking/optimistic.rb', line 141

def update_counters_with_lock(id, counters)
  counters = counters.merge(locking_column => 1) if locking_enabled?
  update_counters_without_lock(id, counters)
end