Creating ghosts from scratch, as opposed to ghostifying a non-ghost is rather tricky. IPeristent doesn’t really provide the right interface given that:
Note
The current cache implementation is intimately tied up with the persistence implementation and has internal access to the persistence state. The cache implementation can update the persistence state for newly created and ininitialized objects directly.
The future persistence and cache implementations will be far more decoupled. The persistence implementation will only manage object state and generate object-usage events. The cache implemnentation(s) will be rersponsible for managing persistence-related (meta-)state, such as _p_state, _p_changed, _p_oid, etc. So in that future implemention, the cache will be more central to managing object persistence information.
Caches have a new_ghost() method that:
>>> import persistent
>>> from persistent.tests.utils import ResettingJar
>>> class C(persistent.Persistent):
... pass
>>> jar = ResettingJar()
>>> cache = persistent.PickleCache(jar, 10, 100)
>>> ob = C.__new__(C)
>>> cache.new_ghost('1', ob)
>>> ob._p_changed
>>> ob._p_jar is jar
True
>>> ob._p_oid
'1'
>>> cache.cache_non_ghost_count
0