diff options
| -rw-r--r-- | django/db/migrations/executor.py | 21 | ||||
| -rw-r--r-- | django/db/migrations/graph.py | 2 | ||||
| -rw-r--r-- | django/db/migrations/migration.py | 10 | ||||
| -rw-r--r-- | django/db/migrations/state.py | 6 |
4 files changed, 28 insertions, 11 deletions
diff --git a/django/db/migrations/executor.py b/django/db/migrations/executor.py index 57b1e297a5..d1da524aeb 100644 --- a/django/db/migrations/executor.py +++ b/django/db/migrations/executor.py @@ -74,20 +74,27 @@ class MigrationExecutor(object): migrations_to_run = {m[0] for m in plan} # Create the forwards plan Django would follow on an empty database full_plan = self.migration_plan(self.loader.graph.leaf_nodes(), clean_start=True) - # Holds all states right before and right after a migration is applied + # Holds all states right before a migration is applied # if the migration is being run. states = {} state = ProjectState(real_apps=list(self.loader.unmigrated_apps)) if self.progress_callback: self.progress_callback("render_start") - state.apps # Render all real_apps -- performance critical - if self.progress_callback: - self.progress_callback("render_success") - # Phase 1 -- Store all required states + # Phase 1 -- Store all project states of migrations right before they + # are applied. The first migration that will be applied in phase 2 will + # trigger the rendering of the initial project state. From this time on + # models will be recursively reloaded as explained in + # `django.db.migrations.state.get_related_models_recursive()`. for migration, _ in full_plan: - if migration in migrations_to_run: + do_run = migration in migrations_to_run + if do_run: + if 'apps' not in state.__dict__: + state.apps # Render all real_apps -- performance critical states[migration] = state.clone() - state = migration.mutate_state(state) # state is cloned inside + # Only preserve the state if the migration is being run later + state = migration.mutate_state(state, preserve=do_run) + if self.progress_callback: + self.progress_callback("render_success") # Phase 2 -- Run the migrations for migration, backwards in plan: if not backwards: diff --git a/django/db/migrations/graph.py b/django/db/migrations/graph.py index 46b6485300..673996381b 100644 --- a/django/db/migrations/graph.py +++ b/django/db/migrations/graph.py @@ -271,7 +271,7 @@ class MigrationGraph(object): plan.append(migration) project_state = ProjectState(real_apps=real_apps) for node in plan: - project_state = self.nodes[node].mutate_state(project_state) + project_state = self.nodes[node].mutate_state(project_state, preserve=False) return project_state def __contains__(self, node): diff --git a/django/db/migrations/migration.py b/django/db/migrations/migration.py index 59f89afd08..885ee2f921 100644 --- a/django/db/migrations/migration.py +++ b/django/db/migrations/migration.py @@ -69,12 +69,16 @@ class Migration(object): def __hash__(self): return hash("%s.%s" % (self.app_label, self.name)) - def mutate_state(self, project_state): + def mutate_state(self, project_state, preserve=True): """ Takes a ProjectState and returns a new one with the migration's - operations applied to it. + operations applied to it. Preserves the original object state by + default and will return a mutated state from a copy. """ - new_state = project_state.clone() + new_state = project_state + if preserve: + new_state = project_state.clone() + for operation in self.operations: operation.state_forwards(self.app_label, new_state) return new_state diff --git a/django/db/migrations/state.py b/django/db/migrations/state.py index a9f60885f4..606fbef20d 100644 --- a/django/db/migrations/state.py +++ b/django/db/migrations/state.py @@ -34,6 +34,12 @@ def get_related_models_recursive(model): """ Returns all models that have a direct or indirect relationship to the given model. + + Relationships are either defined by explicit relational fields, like + ForeignKey, ManyToManyField or OneToOneField, or by inheriting from another + model (a superclass is related to its subclasses, but not vice versa). Note, + however, that a model inheriting from a concrete model is also related to + its superclass through the implicit *_ptr OneToOneField on the subclass. """ def _related_models(m): return [ |