Module: ActiveRecordShards::DefaultSlavePatches

Included in:
ActiveRecord::Base
Defined in:
lib/active_record_shards/default_slave_patches.rb

Defined Under Namespace

Modules: ActiveRelationPatches, InstanceMethods, Rails41HasAndBelongsToManyBuilderExtension

Constant Summary collapse

CLASS_SLAVE_METHODS = 
[:find_by_sql, :count_by_sql, :calculate, :find_one, :find_some, :find_every, :exists?].freeze

Class Method Summary collapse

Instance Method Summary collapse

Class Method Details

.extended(base) ⇒ Object 



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# File 'lib/active_record_shards/default_slave_patches.rb', line 63

def self.extended(base)
  CLASS_SLAVE_METHODS.each { |m| ActiveRecordShards::DefaultSlavePatches.wrap_method_in_on_slave(true, base, m) }

  base.class_eval do
    include InstanceMethods

    class << self
      alias_method :columns_without_force_slave, :columns
      alias_method :columns, :columns_with_force_slave

      alias_method :table_exists_without_force_slave?, :table_exists?
      alias_method :table_exists?, :table_exists_with_force_slave?

      alias_method :transaction_without_slave_off, :transaction
      alias_method :transaction, :transaction_with_slave_off
    end
  end
  if ActiveRecord::Associations.const_defined?(:HasAndBelongsToManyAssociation)
    ActiveRecordShards::DefaultSlavePatches.wrap_method_in_on_slave(false, ActiveRecord::Associations::HasAndBelongsToManyAssociation, :construct_sql)
    ActiveRecordShards::DefaultSlavePatches.wrap_method_in_on_slave(false, ActiveRecord::Associations::HasAndBelongsToManyAssociation, :construct_find_options!)
  end
end

.wrap_method_in_on_slave(class_method, base, method) ⇒ Object 



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# File 'lib/active_record_shards/default_slave_patches.rb', line 4

def self.wrap_method_in_on_slave(class_method, base, method)
  base_methods =
    if class_method
      base.methods + base.private_methods
    else
      base.instance_methods + base.private_instance_methods
    end

  return unless base_methods.include?(method)
  _, method, punctuation = method.to_s.match(/^(.*?)([\?\!]?)$/).to_a
  base.class_eval <<-RUBY, __FILE__, __LINE__ + 1
    #{class_method ? 'class << self' : ''}
      def #{method}_with_default_slave#{punctuation}(*args, &block)
        on_slave_unless_tx do
          #{method}_without_default_slave#{punctuation}(*args, &block)
        end
      end

      alias_method :#{method}_without_default_slave#{punctuation}, :#{method}#{punctuation}
      alias_method :#{method}#{punctuation}, :#{method}_with_default_slave#{punctuation}
    #{class_method ? 'end' : ''}
  RUBY
end

Instance Method Details

#columns_with_force_slave(*args, &block) ⇒ Object 



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# File 'lib/active_record_shards/default_slave_patches.rb', line 28

def columns_with_force_slave(*args, &block)
  on_cx_switch_block(:slave, construct_ro_scope: false, force: true) do
    columns_without_force_slave(*args, &block)
  end
end

#on_slave_unless_tx ⇒ Object 



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# File 'lib/active_record_shards/default_slave_patches.rb', line 86

def on_slave_unless_tx
  if on_slave_by_default? && !Thread.current[:_active_record_shards_slave_off]
    on_slave { yield }
  else
    yield
  end
end

#table_exists_with_force_slave?(*args, &block) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/active_record_shards/default_slave_patches.rb', line 34

def table_exists_with_force_slave?(*args, &block)
  on_cx_switch_block(:slave, construct_ro_scope: false, force: true) do
    table_exists_without_force_slave?(*args, &block)
  end
end

#transaction_with_slave_off(*args, &block) ⇒ Object 



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# File 'lib/active_record_shards/default_slave_patches.rb', line 40

def transaction_with_slave_off(*args, &block)
  if on_slave_by_default?
    begin
      old_val = Thread.current[:_active_record_shards_slave_off]
      Thread.current[:_active_record_shards_slave_off] = true
      transaction_without_slave_off(*args, &block)
    ensure
      Thread.current[:_active_record_shards_slave_off] = old_val
    end
  else
    transaction_without_slave_off(*args, &block)
  end
end