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Mike Bayer
8693d4b287
- topological.py cleaned up, presents three public facing functions which return list/tuple based structures, without exposing any internals. only the third function returns the "hierarchical" structure. when results include "cycles" or "child" items, 2- or 3- tuples are used to represent results. - unitofwork uses InstanceState almost exclusively now. new and deleted lists are now dicts which ref the actual object to provide a strong ref for the duration that they're in those lists. IdentitySet is only used for the public facing versions of "new" and "deleted". - unitofwork topological sort no longer uses the "hierarchical" version of the sort for the base sort, only for the "per-object" secondary sort where it still helps to group non-dependent operations together and provides expected insert order. the default sort deals with UOWTasks in a straight list and is greatly simplified. Tests all pass but need to see if svilen's stuff still works, one block of code in _sort_cyclical_dependencies() seems to not be needed anywhere but i definitely put it there for a reason at some point; if not hopefully we can derive more test coverage from that. - the UOWEventHandler is only applied to object-storing attributes, not scalar (i.e. column-based) ones. cuts out a ton of overhead when setting non-object based attributes. - InstanceState also used throughout the flush process, i.e. dependency.py, mapper.save_obj()/delete_obj(), sync.execute() all expect InstanceState objects in most cases now. - mapper/property cascade_iterator() takes InstanceState as its argument, but still returns lists of object instances so that they are not dereferenced. - a few tricks needed when dealing with InstanceState, i.e. when loading a list of items that are possibly fresh from the DB, you *have* to get the actual objects into a strong-referencing datastructure else they fall out of scope immediately. dependency.py caches lists of dependent objects which it loads now (i.e. history collections). - AttributeHistory is gone, replaced by a function that returns a 3-tuple of added, unchanged, deleted. these collections still reference the object instances directly for the strong-referencing reasons mentiontioned, but it uses less IdentitySet logic to generate.