Avoid repeated Element dependency graph traversal #2176

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1. nathanwilliams-ct commented on Aug 17, 2026

   

   nathanwilliams-ct

   on Aug 17, 2026

   Last edited by nathanwilliams-ct

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   """
   hmm.. Instead of storing the result of _dependencies here, it might be worth refactoring _dependencies to directly cache it's own results, so it can return the cached result after the first call, whenever it's called anywhere instead of just here. I don't think __build_dependencies or __runtime_dependencies is ever updated after an Element is first initialised in _new_from_load_element. (Although _add_build_dependency might be a problem? that would need investigating, but you could clear the cache, in that method..)

   ...
     __dependency_set_cache: dict[str,set[Element]] = {}
   
   def __dependencies(...) -> ...:
   
     # Check if we already calculated this set of dependencies
     dependency_set_cache_key = f"{scope}, {recurse}" # (probably need to include the _dependencies 'visited' argument here too...)
     if (dependencies := self.__dependency_set_cache.get(dependency_set_cache_key)) is not None:
        for element in dependencies:
          yield element
        return
     
      # Calculate result/visited
      .... 
   
   
      # Store result for next time
      self.__build_dependencies_set[dependency_set_cache_key] = result # ( or 'visited' from the recursive visit function)
   
   

   It will need some thinking, but maybe it would even be appropriate to use functools @cache annotation? https://docs.python.org/3/library/functools.html The recursive visit function might also benefit from the @cache annotation..
   """