diff options
Diffstat (limited to 'lib/sqlalchemy/orm/dependency.py')
| -rw-r--r-- | lib/sqlalchemy/orm/dependency.py | 69 |
1 files changed, 34 insertions, 35 deletions
diff --git a/lib/sqlalchemy/orm/dependency.py b/lib/sqlalchemy/orm/dependency.py index 707165215..8b41d93dd 100644 --- a/lib/sqlalchemy/orm/dependency.py +++ b/lib/sqlalchemy/orm/dependency.py @@ -10,10 +10,10 @@ dependencies at flush time. """ -from sqlalchemy.orm import sync, attributes +from sqlalchemy.orm import sync from sqlalchemy.orm.sync import ONETOMANY,MANYTOONE,MANYTOMANY from sqlalchemy import sql, util, exceptions -from sqlalchemy.orm import session as sessionlib + def create_dependency_processor(prop): types = { @@ -28,7 +28,7 @@ def create_dependency_processor(prop): class DependencyProcessor(object): no_dependencies = False - + def __init__(self, prop): self.prop = prop self.cascade = prop.cascade @@ -55,12 +55,12 @@ class DependencyProcessor(object): return getattr(self.parent.class_, self.key) def hasparent(self, state): - """return True if the given object instance has a parent, + """return True if the given object instance has a parent, according to the ``InstrumentedAttribute`` handled by this ``DependencyProcessor``.""" - + # TODO: use correct API for this return self._get_instrumented_attribute().impl.hasparent(state) - + def register_dependencies(self, uowcommit): """Tell a ``UOWTransaction`` what mappers are dependent on which, with regards to the two or three mappers handled by @@ -113,7 +113,7 @@ class DependencyProcessor(object): return if state is not None and not self.mapper._canload(state): raise exceptions.FlushError("Attempting to flush an item of type %s on collection '%s', which is handled by mapper '%s' and does not load items of that type. Did you mean to use a polymorphic mapper for this relationship ? Set 'enable_typechecks=False' on the relation() to disable this exception. Mismatched typeloading may cause bi-directional relationships (backrefs) to not function properly." % (state.class_, self.prop, self.mapper)) - + def _synchronize(self, state, child, associationrow, clearkeys, uowcommit): """Called during a flush to synchronize primary key identifier values between a parent/child object, as well as to an @@ -124,7 +124,7 @@ class DependencyProcessor(object): def _compile_synchronizers(self): """Assemble a list of *synchronization rules*. - + These are fired to populate attributes from one side of a relation to another. """ @@ -156,10 +156,10 @@ class DependencyProcessor(object): if x is not None: uowcommit.register_object(state, postupdate=True, post_update_cols=self.syncrules.dest_columns()) break - + def _pks_changed(self, uowcommit, state): return self.syncrules.source_changes(uowcommit, state) - + def __str__(self): return "%s(%s)" % (self.__class__.__name__, str(self.prop)) @@ -205,12 +205,12 @@ class OneToManyDP(DependencyProcessor): for child in deleted: if not self.cascade.delete_orphan and not self.hasparent(child): self._synchronize(state, child, None, True, uowcommit) - + if self._pks_changed(uowcommit, state): if unchanged: for child in unchanged: self._synchronize(state, child, None, False, uowcommit) - + def preprocess_dependencies(self, task, deplist, uowcommit, delete = False): #print self.mapper.mapped_table.name + " " + self.key + " " + repr(len(deplist)) + " preprocess_dep isdelete " + repr(delete) + " direction " + repr(self.direction) @@ -247,7 +247,7 @@ class OneToManyDP(DependencyProcessor): if unchanged: for child in unchanged: uowcommit.register_object(child) - + def _synchronize(self, state, child, associationrow, clearkeys, uowcommit): if child is not None: child = getattr(child, '_state', child) @@ -263,45 +263,45 @@ class DetectKeySwitch(DependencyProcessor): child items who have changed their referenced key.""" no_dependencies = True - + def register_dependencies(self, uowcommit): uowcommit.register_processor(self.parent, self, self.mapper) - + def preprocess_dependencies(self, task, deplist, uowcommit, delete=False): # for non-passive updates, register in the preprocess stage # so that mapper save_obj() gets a hold of changes if not delete and not self.passive_updates: self._process_key_switches(deplist, uowcommit) - + def process_dependencies(self, task, deplist, uowcommit, delete=False): # for passive updates, register objects in the process stage - # so that we avoid ManyToOneDP's registering the object without + # so that we avoid ManyToOneDP's registering the object without # the listonly flag in its own preprocess stage (results in UPDATE) # statements being emitted if not delete and self.passive_updates: self._process_key_switches(deplist, uowcommit) - - def _process_key_switches(self, deplist, uowcommit): + + def _process_key_switches(self, deplist, uowcommit): switchers = util.Set([s for s in deplist if self._pks_changed(uowcommit, s)]) if switchers: - # yes, we're doing a linear search right now through the UOW. only + # yes, we're doing a linear search right now through the UOW. only # takes effect when primary key values have actually changed. # a possible optimization might be to enhance the "hasparents" capability of # attributes to actually store all parent references, but this introduces # more complicated attribute accounting. - for s in [elem for elem in uowcommit.session.identity_map.all_states() - if issubclass(elem.class_, self.parent.class_) and - self.key in elem.dict and + for s in [elem for elem in uowcommit.session.identity_map.all_states() + if issubclass(elem.class_, self.parent.class_) and + self.key in elem.dict and elem.dict[self.key]._state in switchers ]: uowcommit.register_object(s, listonly=self.passive_updates) self.syncrules.execute(s.dict[self.key]._state, s, None, None, False) - + class ManyToOneDP(DependencyProcessor): def __init__(self, prop): DependencyProcessor.__init__(self, prop) self.mapper._dependency_processors.append(DetectKeySwitch(prop)) - + def register_dependencies(self, uowcommit): if self.post_update: if not self.is_backref: @@ -312,7 +312,7 @@ class ManyToOneDP(DependencyProcessor): else: uowcommit.register_dependency(self.mapper, self.parent) uowcommit.register_processor(self.mapper, self, self.parent) - + def process_dependencies(self, task, deplist, uowcommit, delete = False): #print self.mapper.mapped_table.name + " " + self.key + " " + repr(len(deplist)) + " process_dep isdelete " + repr(delete) + " direction " + repr(self.direction) @@ -387,12 +387,12 @@ class ManyToManyDP(DependencyProcessor): secondary_delete = [] secondary_insert = [] secondary_update = [] - + if self.prop._reverse_property: reverse_dep = getattr(self.prop._reverse_property, '_dependency_processor', None) else: reverse_dep = None - + if delete: for state in deplist: (added, unchanged, deleted) = uowcommit.get_attribute_history(state, self.key,passive=self.passive_deletes) @@ -422,13 +422,13 @@ class ManyToManyDP(DependencyProcessor): self._synchronize(state, child, associationrow, False, uowcommit) uowcommit.attributes[(self, "manytomany", state, child)] = True secondary_delete.append(associationrow) - + if not self.passive_updates and unchanged and self._pks_changed(uowcommit, state): for child in unchanged: associationrow = {} self.syncrules.update(associationrow, state, child, "old_") secondary_update.append(associationrow) - + if secondary_delete: secondary_delete.sort() # TODO: precompile the delete/insert queries? @@ -436,13 +436,13 @@ class ManyToManyDP(DependencyProcessor): result = connection.execute(statement, secondary_delete) if result.supports_sane_multi_rowcount() and result.rowcount != len(secondary_delete): raise exceptions.ConcurrentModificationError("Deleted rowcount %d does not match number of secondary table rows deleted from table '%s': %d" % (result.rowcount, self.secondary.description, len(secondary_delete))) - + if secondary_update: statement = self.secondary.update(sql.and_(*[c == sql.bindparam("old_" + c.key, type_=c.type) for c in self.secondary.c if c.key in associationrow])) result = connection.execute(statement, secondary_update) if result.supports_sane_multi_rowcount() and result.rowcount != len(secondary_update): raise exceptions.ConcurrentModificationError("Updated rowcount %d does not match number of secondary table rows updated from table '%s': %d" % (result.rowcount, self.secondary.description, len(secondary_update))) - + if secondary_insert: statement = self.secondary.insert() connection.execute(statement, secondary_insert) @@ -481,7 +481,7 @@ class MapperStub(object): """ __metaclass__ = util.ArgSingleton - + def __init__(self, parent, mapper, key): self.mapper = mapper self.base_mapper = self @@ -490,7 +490,7 @@ class MapperStub(object): def polymorphic_iterator(self): return iter([self]) - + def _register_dependencies(self, uowcommit): pass @@ -502,4 +502,3 @@ class MapperStub(object): def primary_mapper(self): return self - |