code: package it.unibz.inf.ontop.injection;
  
  
  import java.util.Optional;
  
  public interface OntopSystemSettings extends OntopReformulationSettings {
  
      /**
       * Query EVALUATION timeout (executed on the DB engine)
       *
       * Has no effect if negative or equal to 0.
       */
      Optional<Integer> getDefaultQueryTimeout();
  
      /**
       * Needed by some in-memory DBs
       *  (e.g. an H2 DB storing a semantic index)
       */
      boolean isPermanentDBConnectionEnabled();
  
      // HTTP Caching
      Optional<String> getHttpCacheControl();
  
      //--------------------------
      // Keys
      //--------------------------
  
      String DEFAULT_QUERY_TIMEOUT = "ontop.query.defaultTimeout";
      String PERMANENT_DB_CONNECTION = "ontop.permanentConnection";
  
      // HTTP caching
      String HTTP_CACHE_CONTROL = "ontop.http.cacheControl";
      @Deprecated
      String HTTP_CACHE_MAX_AGE = "ontop.http.cache.maxAge";
      @Deprecated
      String HTTP_CACHE_STALE_WHILE_REVALIDATE = "ontop.http.cache.staleWhileRevalidate";
      @Deprecated
      String HTTP_CACHE_STALE_IF_ERROR = "ontop.http.cache.staleIfError";
  }
  