Contents

module GraphQL
  module Cache
    # Represents the "instrumenter" passed to GraphQL::Schema#instrument
    # when the plugin in initialized (i.e. `use GraphQL::Cache`)
    class Fetcher
      # Redefines the given field's resolve proc to use our
      # custom cache wrapping resolver proc. Called from
      # graphql-ruby internals. This is the "instrumenter"
      # entrypoint.
      #
      # @param type [GraphQL::Schema::Object] graphql-ruby passes the defined type for the field being instrumented
      # @param field [GraphQL::Schema::Field] graphql-ruby passes the field definition to be re-defined
      # @return [GraphQL::Schema::Field]
      def instrument(type, field)
        return field unless field.metadata[:cache]

        cached_resolve_proc = cached_resolve(type, field)

        # Return a copy of `field`, with the new resolve proc
        field.redefine { resolve(cached_resolve_proc) }
      end

      # @private
      def cache_key(obj, args, type, field)
        Key.new(obj, args, type, field).to_s
      end

      # @private
      def cached_resolve(type, field)
        old_resolve_proc = field.resolve_proc

        lambda do |obj, args, ctx|
          key = cache_key(obj, args, type, field)

          Marshal[key].read(field.metadata[:cache], force: ctx[:force_cache]) do
            old_resolve_proc.call(obj, args, ctx)
          end
        end
      end
    end
  end
end

Version data entries

2 entries across 2 versions & 1 rubygems

Version	Path
graphql-cache-0.6.0	lib/graphql/cache/fetcher.rb
graphql-cache-0.5.0	lib/graphql/cache/fetcher.rb