Manages the internal state of a unit of work flush operation.
| 154 | |
| 155 | |
| 156 | class UOWTransaction: |
| 157 | """Manages the internal state of a unit of work flush operation.""" |
| 158 | |
| 159 | session: Session |
| 160 | transaction: SessionTransaction |
| 161 | attributes: Dict[str, Any] |
| 162 | deps: util.defaultdict[Mapper[Any], Set[_DependencyProcessor]] |
| 163 | mappers: util.defaultdict[Mapper[Any], Set[InstanceState[Any]]] |
| 164 | |
| 165 | def __init__(self, session: Session): |
| 166 | self.session = session |
| 167 | |
| 168 | # dictionary used by external actors to |
| 169 | # store arbitrary state information. |
| 170 | self.attributes = {} |
| 171 | |
| 172 | # dictionary of mappers to sets of |
| 173 | # DependencyProcessors, which are also |
| 174 | # set to be part of the sorted flush actions, |
| 175 | # which have that mapper as a parent. |
| 176 | self.deps = util.defaultdict(set) |
| 177 | |
| 178 | # dictionary of mappers to sets of InstanceState |
| 179 | # items pending for flush which have that mapper |
| 180 | # as a parent. |
| 181 | self.mappers = util.defaultdict(set) |
| 182 | |
| 183 | # a dictionary of Preprocess objects, which gather |
| 184 | # additional states impacted by the flush |
| 185 | # and determine if a flush action is needed |
| 186 | self.presort_actions = {} |
| 187 | |
| 188 | # dictionary of PostSortRec objects, each |
| 189 | # one issues work during the flush within |
| 190 | # a certain ordering. |
| 191 | self.postsort_actions = {} |
| 192 | |
| 193 | # a set of 2-tuples, each containing two |
| 194 | # PostSortRec objects where the second |
| 195 | # is dependent on the first being executed |
| 196 | # first |
| 197 | self.dependencies = set() |
| 198 | |
| 199 | # dictionary of InstanceState-> (isdelete, listonly) |
| 200 | # tuples, indicating if this state is to be deleted |
| 201 | # or insert/updated, or just refreshed |
| 202 | self.states = {} |
| 203 | |
| 204 | # tracks InstanceStates which will be receiving |
| 205 | # a "post update" call. Keys are mappers, |
| 206 | # values are a set of states and a set of the |
| 207 | # columns which should be included in the update. |
| 208 | self.post_update_states = util.defaultdict(lambda: (set(), set())) |
| 209 | |
| 210 | @property |
| 211 | def has_work(self): |
| 212 | return bool(self.states) |
| 213 |