Implementing the map association with a file


  • Anonymous


    I want to implement a constructor that allows to associate a map to a pre-existing file in the same way that it is possible to do with a vector today. I didn't expend much time going though the code yet, but it seems to me that I have to change the classes
    - node_cache
    - btree
    - map
    Particularly node_cache would have to work both with block_manager and file.

    Is that more or less right or am I being to naive?

    I'd appreciate any advice on that.

    Thanks! :-)

  • The internal structure of the map is not designed for this approach of persistency.

    What about loading the contents from a file by binding an stxxl::vector to it on program start and saving the updated map content later again to a vector bound to a file? Adding a (sorted-)bulk insert to the map would be easier.



  • Anonymous

    Yes, I understand that today it isn't designed to work in this way. But is there a fundamental issue that prevents me from changing the code so it would work like the vector?
    Using an intermediate vector is not an option because the time consumed to load it into a map is exactly what I want to avoid.
    I wanted to use it as a simple key/value database which allows sorting, range search and is potentially large.
    Thanks for your comment, Andreas.