QueryPath 1.3 module released, now has an XML cache
The QueryPath module, version 1.3 is now available. This release adds a new submodule called QP Cache.
QP Cache is a cache system optimized for XML storage. It supports keys of arbitrary type and length (objects, strings, arrays) as well as fuzzy expiration dates ("2 weeks"). Cache lookups are very fast. Cache maintenance is left to the implementor. (In other words, Drupal cache clears have no impact on this cache, by design). The main use case, it is anticipated, is to store local copies of documents retrieved from remote web services. While QP Cache can be used without QueryPath, it provides integrated functions that make it trivially easy to work with QueryPath objects.
The Amplify module uses QP Cache to store OpenAmplify data. The code there is a good place to start when developing for QP Cache.