Permit and Deny lists in PurpleAccount

[Ankit Vani]

Hi

Currently, in account.h, there's a TODO:

  /*
   * TODO: Supplementing the next two linked lists with hash tables
   * should help performance a lot when these lists are long.  This
   * matters quite a bit for protocols like MSN, where all your
   * buddies are added to your permit list.  Currently we have to
   * iterate through the entire list if we want to check if someone
   * is permitted or denied.  We should do this for 3.0.0.
   * Or maybe use a GTree.
   */
  GSList *permit;             /**< Permit list.                           */
  GSList *deny;               /**< Deny list.                             */

I had started with hash tables to supplement the linked lists, and soon found
the linked lists to no longer be of any use. I am therefore considering
replacing them with hash tables, and making the appropriate changes to whoever
uses these.

I would like to know if there are any disadvantages to doing so. Such as, would
any protocol depend on the order of values in these lists? Or anything else?

Ankit