Module: ActiveRecord::OnDemand::Reading::ClassMethods

Defined in:
lib/ar-ondemand/for_reading.rb

Instance Method Summary collapse

Instance Method Details

#for_reading(options = {}) ⇒ Object

Ripped from the find_in_batches function, but customized to return an ::ActiveRecord::OnDemand::ResultSet



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# File 'lib/ar-ondemand/for_reading.rb', line 16

def for_reading(options = {})
  if options.empty?
    res = query_for_reading self, readonly: true
    if block_given?
      yield res
      return
    end
    return res
  end

  relation = self

  unless self.arel.orders.blank? && self.arel.taken.blank?
    ::ActiveRecord::Base.logger.warn("Scoped order and limit are ignored, it's forced to be batch order and batch size")
  end

  start = options.delete(:start)
  batch_size = options.delete(:batch_size) || 1000

  relation = relation.reorder(batch_order_for_reading).limit(batch_size)
  records = query_for_reading(start ? relation.where(table[primary_key].gteq(start)) : relation, readonly: true)

  while records.any?
    records_size = records.size
    primary_key_offset = records.last.id

    yield records

    break if records_size < batch_size

    if primary_key_offset
      records = query_for_reading relation.where(table[primary_key].gt(primary_key_offset)), readonly: true
    else
      raise 'Primary key not included in the custom select clause'
    end
  end
end

#raw_results ⇒ Object 



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# File 'lib/ar-ondemand/for_reading.rb', line 11

def raw_results
  query_for_reading self, readonly: true, raw: true
end