IdentityCacheMiddleware for ThinkingSphinx

identity_cache_middleware.rb

require 'thinking_sphinx/middlewares'

module ThinkingSphinx
  module Middlewares
    class IdentityCacheMiddleware < ActiveRecordTranslator

      def call(contexts)
        contexts.each do |context|
          Inner.new(context).call
        end
        app.call contexts
      end

      class Inner < ActiveRecordTranslator::Inner
        def results_for_models
          @results_for_models ||= model_names.inject({}) do |hash, name|
            model = name.constantize
            if model < ::IdentityCache
              Rails.logger.debug "Using IdentityCache"
              hash[name] = model.fetch_multi(ids_for_model(name))
            else
              Rails.logger.debug "Using ActiveRecord"
              hash[name] = model_relation_with_sql_options(model.unscoped).where(
                model.primary_key => ids_for_model(name)
              )
            end
            hash
          end
        end
      end
    end
  end
end

ThinkingSphinx::Middlewares::DEFAULT.replace(ThinkingSphinx::Middlewares::ActiveRecordTranslator, ThinkingSphinx::Middlewares::IdentityCacheMiddleware)