515 lines
25 KiB
Python
515 lines
25 KiB
Python
from __future__ import unicode_literals
|
|
|
|
import re
|
|
import datetime
|
|
|
|
from django.db import models
|
|
from django.db.migrations import operations
|
|
from django.db.migrations.migration import Migration
|
|
from django.db.migrations.questioner import MigrationQuestioner
|
|
|
|
|
|
class MigrationAutodetector(object):
|
|
"""
|
|
Takes a pair of ProjectStates, and compares them to see what the
|
|
first would need doing to make it match the second (the second
|
|
usually being the project's current state).
|
|
|
|
Note that this naturally operates on entire projects at a time,
|
|
as it's likely that changes interact (for example, you can't
|
|
add a ForeignKey without having a migration to add the table it
|
|
depends on first). A user interface may offer single-app usage
|
|
if it wishes, with the caveat that it may not always be possible.
|
|
"""
|
|
|
|
def __init__(self, from_state, to_state, questioner=None):
|
|
self.from_state = from_state
|
|
self.to_state = to_state
|
|
self.questioner = questioner or MigrationQuestioner()
|
|
|
|
def changes(self, graph, trim_to_apps=None):
|
|
"""
|
|
Main entry point to produce a list of appliable changes.
|
|
Takes a graph to base names on and an optional set of apps
|
|
to try and restrict to (restriction is not guaranteed)
|
|
"""
|
|
changes = self._detect_changes()
|
|
changes = self.arrange_for_graph(changes, graph)
|
|
if trim_to_apps:
|
|
changes = self._trim_to_apps(changes, trim_to_apps)
|
|
return changes
|
|
|
|
def _detect_changes(self):
|
|
"""
|
|
Returns a dict of migration plans which will achieve the
|
|
change from from_state to to_state. The dict has app labels
|
|
as keys and a list of migrations as values.
|
|
|
|
The resulting migrations aren't specially named, but the names
|
|
do matter for dependencies inside the set.
|
|
"""
|
|
# We'll store migrations as lists by app names for now
|
|
self.migrations = {}
|
|
old_apps = self.from_state.render()
|
|
new_apps = self.to_state.render()
|
|
# Prepare lists of old/new model keys that we care about
|
|
# (i.e. ignoring proxy ones and unmigrated ones)
|
|
|
|
old_model_keys = []
|
|
for al, mn in self.from_state.models.keys():
|
|
model = old_apps.get_model(al, mn)
|
|
if not model._meta.proxy and model._meta.managed and al not in self.from_state.real_apps:
|
|
old_model_keys.append((al, mn))
|
|
|
|
new_model_keys = []
|
|
for al, mn in self.to_state.models.keys():
|
|
model = new_apps.get_model(al, mn)
|
|
if not model._meta.proxy and model._meta.managed and al not in self.to_state.real_apps:
|
|
new_model_keys.append((al, mn))
|
|
|
|
def _deep_deconstruct(obj, field=True):
|
|
"""
|
|
Recursive deconstruction for a field and its arguments.
|
|
"""
|
|
if not hasattr(obj, 'deconstruct'):
|
|
return obj
|
|
deconstructed = obj.deconstruct()
|
|
if field:
|
|
deconstructed = deconstructed[1:]
|
|
name, args, kwargs = deconstructed
|
|
return (
|
|
name,
|
|
[_deep_deconstruct(value, field=False) for value in args],
|
|
dict([(key, _deep_deconstruct(value, field=False))
|
|
for key, value in kwargs.items()])
|
|
)
|
|
|
|
def _rel_agnostic_fields_def(fields):
|
|
"""
|
|
Return a definition of the fields that ignores field names and
|
|
what related fields actually relate to.
|
|
"""
|
|
fields_def = []
|
|
for name, field in fields:
|
|
deconstruction = _deep_deconstruct(field)
|
|
if field.rel and field.rel.to:
|
|
del deconstruction[2]['to']
|
|
fields_def.append(deconstruction)
|
|
return fields_def
|
|
|
|
# Find any renamed models.
|
|
renamed_models = {}
|
|
renamed_models_rel = {}
|
|
added_models = set(new_model_keys) - set(old_model_keys)
|
|
for app_label, model_name in added_models:
|
|
model_state = self.to_state.models[app_label, model_name]
|
|
model_fields_def = _rel_agnostic_fields_def(model_state.fields)
|
|
|
|
removed_models = set(old_model_keys) - set(new_model_keys)
|
|
for rem_app_label, rem_model_name in removed_models:
|
|
if rem_app_label == app_label:
|
|
rem_model_state = self.from_state.models[rem_app_label, rem_model_name]
|
|
rem_model_fields_def = _rel_agnostic_fields_def(rem_model_state.fields)
|
|
if model_fields_def == rem_model_fields_def:
|
|
if self.questioner.ask_rename_model(rem_model_state, model_state):
|
|
self.add_to_migration(
|
|
app_label,
|
|
operations.RenameModel(
|
|
old_name=rem_model_state.name,
|
|
new_name=model_state.name,
|
|
)
|
|
)
|
|
renamed_models[app_label, model_name] = rem_model_name
|
|
renamed_models_rel['%s.%s' % (rem_model_state.app_label, rem_model_state.name)] = '%s.%s' % (model_state.app_label, model_state.name)
|
|
old_model_keys.remove((rem_app_label, rem_model_name))
|
|
old_model_keys.append((app_label, model_name))
|
|
break
|
|
|
|
# Adding models. Phase 1 is adding models with no outward relationships.
|
|
added_models = set(new_model_keys) - set(old_model_keys)
|
|
pending_add = {}
|
|
for app_label, model_name in added_models:
|
|
model_state = self.to_state.models[app_label, model_name]
|
|
# Are there any relationships out from this model? if so, punt it to the next phase.
|
|
related_fields = []
|
|
for field in new_apps.get_model(app_label, model_name)._meta.local_fields:
|
|
if field.rel:
|
|
if field.rel.to:
|
|
related_fields.append((field.name, field.rel.to._meta.app_label, field.rel.to._meta.model_name))
|
|
if hasattr(field.rel, "through") and not field.rel.through._meta.auto_created:
|
|
related_fields.append((field.name, field.rel.through._meta.app_label, field.rel.through._meta.model_name))
|
|
for field in new_apps.get_model(app_label, model_name)._meta.local_many_to_many:
|
|
if field.rel.to:
|
|
related_fields.append((field.name, field.rel.to._meta.app_label, field.rel.to._meta.model_name))
|
|
if hasattr(field.rel, "through") and not field.rel.through._meta.auto_created:
|
|
related_fields.append((field.name, field.rel.through._meta.app_label, field.rel.through._meta.model_name))
|
|
if related_fields:
|
|
pending_add[app_label, model_name] = related_fields
|
|
else:
|
|
self.add_to_migration(
|
|
app_label,
|
|
operations.CreateModel(
|
|
name=model_state.name,
|
|
fields=model_state.fields,
|
|
options=model_state.options,
|
|
bases=model_state.bases,
|
|
)
|
|
)
|
|
|
|
# Phase 2 is progressively adding pending models, splitting up into two
|
|
# migrations if required.
|
|
pending_new_fks = []
|
|
pending_unique_together = []
|
|
added_phase_2 = set()
|
|
while pending_add:
|
|
# Is there one we can add that has all dependencies satisfied?
|
|
satisfied = [
|
|
(m, rf)
|
|
for m, rf in pending_add.items()
|
|
if all((al, mn) not in pending_add for f, al, mn in rf)
|
|
]
|
|
if satisfied:
|
|
(app_label, model_name), related_fields = sorted(satisfied)[0]
|
|
model_state = self.to_state.models[app_label, model_name]
|
|
self.add_to_migration(
|
|
app_label,
|
|
operations.CreateModel(
|
|
name=model_state.name,
|
|
fields=model_state.fields,
|
|
options=model_state.options,
|
|
bases=model_state.bases,
|
|
),
|
|
# If it's already been added in phase 2 put it in a new
|
|
# migration for safety.
|
|
new=any((al, mn) in added_phase_2 for f, al, mn in related_fields),
|
|
)
|
|
added_phase_2.add((app_label, model_name))
|
|
# Ah well, we'll need to split one. Pick deterministically.
|
|
else:
|
|
(app_label, model_name), related_fields = sorted(pending_add.items())[0]
|
|
model_state = self.to_state.models[app_label, model_name]
|
|
# Defer unique together constraints creation, see ticket #22275
|
|
unique_together_constraints = model_state.options.pop('unique_together', None)
|
|
if unique_together_constraints:
|
|
pending_unique_together.append((app_label, model_name,
|
|
unique_together_constraints))
|
|
# Work out the fields that need splitting out
|
|
bad_fields = dict((f, (al, mn)) for f, al, mn in related_fields if (al, mn) in pending_add)
|
|
# Create the model, without those
|
|
self.add_to_migration(
|
|
app_label,
|
|
operations.CreateModel(
|
|
name=model_state.name,
|
|
fields=[(n, f) for n, f in model_state.fields if n not in bad_fields],
|
|
options=model_state.options,
|
|
bases=model_state.bases,
|
|
)
|
|
)
|
|
# Add the bad fields to be made in a phase 3
|
|
for field_name, (other_app_label, other_model_name) in bad_fields.items():
|
|
pending_new_fks.append((app_label, model_name, field_name, other_app_label))
|
|
for field_name, other_app_label, other_model_name in related_fields:
|
|
# If it depends on a swappable something, add a dynamic depend'cy
|
|
swappable_setting = new_apps.get_model(app_label, model_name)._meta.get_field_by_name(field_name)[0].swappable_setting
|
|
if swappable_setting is not None:
|
|
self.add_swappable_dependency(app_label, swappable_setting)
|
|
elif app_label != other_app_label:
|
|
self.add_dependency(app_label, other_app_label)
|
|
del pending_add[app_label, model_name]
|
|
|
|
# Phase 3 is adding the final set of FKs as separate new migrations.
|
|
for app_label, model_name, field_name, other_app_label in pending_new_fks:
|
|
model_state = self.to_state.models[app_label, model_name]
|
|
self.add_to_migration(
|
|
app_label,
|
|
operations.AddField(
|
|
model_name=model_name,
|
|
name=field_name,
|
|
field=model_state.get_field_by_name(field_name),
|
|
),
|
|
new=True,
|
|
)
|
|
# If it depends on a swappable something, add a dynamic depend'cy
|
|
swappable_setting = new_apps.get_model(app_label, model_name)._meta.get_field_by_name(field_name)[0].swappable_setting
|
|
if swappable_setting is not None:
|
|
self.add_swappable_dependency(app_label, swappable_setting)
|
|
elif app_label != other_app_label:
|
|
self.add_dependency(app_label, other_app_label)
|
|
# Phase 3.1 - unique together constraints
|
|
for app_label, model_name, unique_together in pending_unique_together:
|
|
self.add_to_migration(
|
|
app_label,
|
|
operations.AlterUniqueTogether(
|
|
name=model_name,
|
|
unique_together=unique_together
|
|
)
|
|
)
|
|
# Changes within models
|
|
kept_models = set(old_model_keys).intersection(new_model_keys)
|
|
old_fields = set()
|
|
new_fields = set()
|
|
unique_together_operations = []
|
|
for app_label, model_name in kept_models:
|
|
old_model_name = renamed_models.get((app_label, model_name), model_name)
|
|
old_model_state = self.from_state.models[app_label, old_model_name]
|
|
new_model_state = self.to_state.models[app_label, model_name]
|
|
# Collect field changes for later global dealing with (so AddFields
|
|
# always come before AlterFields even on separate models)
|
|
old_fields.update((app_label, model_name, x) for x, y in old_model_state.fields)
|
|
new_fields.update((app_label, model_name, x) for x, y in new_model_state.fields)
|
|
# Unique_together changes. Operations will be added to migration a
|
|
# bit later, after fields creation. See ticket #22035.
|
|
if old_model_state.options.get("unique_together", set()) != new_model_state.options.get("unique_together", set()):
|
|
unique_together_operations.append((
|
|
app_label,
|
|
operations.AlterUniqueTogether(
|
|
name=model_name,
|
|
unique_together=new_model_state.options.get("unique_together", set()),
|
|
)
|
|
))
|
|
# New fields
|
|
renamed_fields = {}
|
|
for app_label, model_name, field_name in new_fields - old_fields:
|
|
old_model_name = renamed_models.get((app_label, model_name), model_name)
|
|
old_model_state = self.from_state.models[app_label, old_model_name]
|
|
new_model_state = self.to_state.models[app_label, model_name]
|
|
field = new_model_state.get_field_by_name(field_name)
|
|
# Scan to see if this is actually a rename!
|
|
field_dec = _deep_deconstruct(field)
|
|
found_rename = False
|
|
for rem_app_label, rem_model_name, rem_field_name in (old_fields - new_fields):
|
|
if rem_app_label == app_label and rem_model_name == model_name:
|
|
old_field_dec = _deep_deconstruct(old_model_state.get_field_by_name(rem_field_name))
|
|
if field.rel and field.rel.to and 'to' in old_field_dec[2]:
|
|
old_rel_to = old_field_dec[2]['to']
|
|
if old_rel_to in renamed_models_rel:
|
|
old_field_dec[2]['to'] = renamed_models_rel[old_rel_to]
|
|
if old_field_dec == field_dec:
|
|
if self.questioner.ask_rename(model_name, rem_field_name, field_name, field):
|
|
self.add_to_migration(
|
|
app_label,
|
|
operations.RenameField(
|
|
model_name=model_name,
|
|
old_name=rem_field_name,
|
|
new_name=field_name,
|
|
)
|
|
)
|
|
old_fields.remove((rem_app_label, rem_model_name, rem_field_name))
|
|
old_fields.add((app_label, model_name, field_name))
|
|
renamed_fields[app_label, model_name, field_name] = rem_field_name
|
|
found_rename = True
|
|
break
|
|
if found_rename:
|
|
continue
|
|
# You can't just add NOT NULL fields with no default
|
|
if not field.null and not field.has_default() and not isinstance(field, models.ManyToManyField):
|
|
field = field.clone()
|
|
field.default = self.questioner.ask_not_null_addition(field_name, model_name)
|
|
self.add_to_migration(
|
|
app_label,
|
|
operations.AddField(
|
|
model_name=model_name,
|
|
name=field_name,
|
|
field=field,
|
|
preserve_default=False,
|
|
)
|
|
)
|
|
else:
|
|
self.add_to_migration(
|
|
app_label,
|
|
operations.AddField(
|
|
model_name=model_name,
|
|
name=field_name,
|
|
field=field,
|
|
)
|
|
)
|
|
new_field = new_apps.get_model(app_label, model_name)._meta.get_field_by_name(field_name)[0]
|
|
swappable_setting = getattr(new_field, 'swappable_setting', None)
|
|
if swappable_setting is not None:
|
|
self.add_swappable_dependency(app_label, swappable_setting)
|
|
# Old fields
|
|
for app_label, model_name, field_name in old_fields - new_fields:
|
|
old_model_name = renamed_models.get((app_label, model_name), model_name)
|
|
old_model_state = self.from_state.models[app_label, old_model_name]
|
|
new_model_state = self.to_state.models[app_label, model_name]
|
|
self.add_to_migration(
|
|
app_label,
|
|
operations.RemoveField(
|
|
model_name=model_name,
|
|
name=field_name,
|
|
)
|
|
)
|
|
# The same fields
|
|
for app_label, model_name, field_name in old_fields.intersection(new_fields):
|
|
# Did the field change?
|
|
old_model_name = renamed_models.get((app_label, model_name), model_name)
|
|
old_model_state = self.from_state.models[app_label, old_model_name]
|
|
new_model_state = self.to_state.models[app_label, model_name]
|
|
old_field_name = renamed_fields.get((app_label, model_name, field_name), field_name)
|
|
old_field_dec = _deep_deconstruct(old_model_state.get_field_by_name(old_field_name))
|
|
new_field_dec = _deep_deconstruct(new_model_state.get_field_by_name(field_name))
|
|
if old_field_dec != new_field_dec:
|
|
self.add_to_migration(
|
|
app_label,
|
|
operations.AlterField(
|
|
model_name=model_name,
|
|
name=field_name,
|
|
field=new_model_state.get_field_by_name(field_name),
|
|
)
|
|
)
|
|
for app_label, operation in unique_together_operations:
|
|
self.add_to_migration(app_label, operation)
|
|
# Removing models
|
|
removed_models = set(old_model_keys) - set(new_model_keys)
|
|
for app_label, model_name in removed_models:
|
|
model_state = self.from_state.models[app_label, model_name]
|
|
self.add_to_migration(
|
|
app_label,
|
|
operations.DeleteModel(
|
|
model_state.name,
|
|
)
|
|
)
|
|
# Alright, now add internal dependencies
|
|
for app_label, migrations in self.migrations.items():
|
|
for m1, m2 in zip(migrations, migrations[1:]):
|
|
m2.dependencies.append((app_label, m1.name))
|
|
# Clean up dependencies
|
|
for app_label, migrations in self.migrations.items():
|
|
for migration in migrations:
|
|
migration.dependencies = list(set(migration.dependencies))
|
|
return self.migrations
|
|
|
|
def add_to_migration(self, app_label, operation, new=False):
|
|
migrations = self.migrations.setdefault(app_label, [])
|
|
if not migrations or new:
|
|
subclass = type(str("Migration"), (Migration,), {"operations": [], "dependencies": []})
|
|
instance = subclass("auto_%i" % (len(migrations) + 1), app_label)
|
|
migrations.append(instance)
|
|
migrations[-1].operations.append(operation)
|
|
|
|
def add_dependency(self, app_label, other_app_label):
|
|
"""
|
|
Adds a dependency to app_label's newest migration on
|
|
other_app_label's latest migration.
|
|
"""
|
|
if self.migrations.get(other_app_label):
|
|
dependency = (other_app_label, self.migrations[other_app_label][-1].name)
|
|
else:
|
|
dependency = (other_app_label, "__first__")
|
|
self.migrations[app_label][-1].dependencies.append(dependency)
|
|
|
|
def add_swappable_dependency(self, app_label, setting_name):
|
|
"""
|
|
Adds a dependency to the value of a swappable model setting.
|
|
"""
|
|
dependency = ("__setting__", setting_name)
|
|
self.migrations[app_label][-1].dependencies.append(dependency)
|
|
|
|
def arrange_for_graph(self, changes, graph):
|
|
"""
|
|
Takes in a result from changes() and a MigrationGraph,
|
|
and fixes the names and dependencies of the changes so they
|
|
extend the graph from the leaf nodes for each app.
|
|
"""
|
|
leaves = graph.leaf_nodes()
|
|
name_map = {}
|
|
for app_label, migrations in list(changes.items()):
|
|
if not migrations:
|
|
continue
|
|
# Find the app label's current leaf node
|
|
app_leaf = None
|
|
for leaf in leaves:
|
|
if leaf[0] == app_label:
|
|
app_leaf = leaf
|
|
break
|
|
# Do they want an initial migration for this app?
|
|
if app_leaf is None and not self.questioner.ask_initial(app_label):
|
|
# They don't.
|
|
for migration in migrations:
|
|
name_map[(app_label, migration.name)] = (app_label, "__first__")
|
|
del changes[app_label]
|
|
continue
|
|
# Work out the next number in the sequence
|
|
if app_leaf is None:
|
|
next_number = 1
|
|
else:
|
|
next_number = (self.parse_number(app_leaf[1]) or 0) + 1
|
|
# Name each migration
|
|
for i, migration in enumerate(migrations):
|
|
if i == 0 and app_leaf:
|
|
migration.dependencies.append(app_leaf)
|
|
if i == 0 and not app_leaf:
|
|
new_name = "0001_initial"
|
|
else:
|
|
new_name = "%04i_%s" % (
|
|
next_number,
|
|
self.suggest_name(migration.operations)[:100],
|
|
)
|
|
name_map[(app_label, migration.name)] = (app_label, new_name)
|
|
next_number += 1
|
|
migration.name = new_name
|
|
# Now fix dependencies
|
|
for app_label, migrations in changes.items():
|
|
for migration in migrations:
|
|
migration.dependencies = [name_map.get(d, d) for d in migration.dependencies]
|
|
return changes
|
|
|
|
def _trim_to_apps(self, changes, app_labels):
|
|
"""
|
|
Takes changes from arrange_for_graph and set of app labels and
|
|
returns a modified set of changes which trims out as many migrations
|
|
that are not in app_labels as possible.
|
|
Note that some other migrations may still be present, as they may be
|
|
required dependencies.
|
|
"""
|
|
# Gather other app dependencies in a first pass
|
|
app_dependencies = {}
|
|
for app_label, migrations in changes.items():
|
|
for migration in migrations:
|
|
for dep_app_label, name in migration.dependencies:
|
|
app_dependencies.setdefault(app_label, set()).add(dep_app_label)
|
|
required_apps = set(app_labels)
|
|
# Keep resolving till there's no change
|
|
old_required_apps = None
|
|
while old_required_apps != required_apps:
|
|
old_required_apps = set(required_apps)
|
|
for app_label in list(required_apps):
|
|
required_apps.update(app_dependencies.get(app_label, set()))
|
|
# Remove all migrations that aren't needed
|
|
for app_label in list(changes.keys()):
|
|
if app_label not in required_apps:
|
|
del changes[app_label]
|
|
return changes
|
|
|
|
@classmethod
|
|
def suggest_name(cls, ops):
|
|
"""
|
|
Given a set of operations, suggests a name for the migration
|
|
they might represent. Names are not guaranteed to be unique,
|
|
but we put some effort in to the fallback name to avoid VCS conflicts
|
|
if we can.
|
|
"""
|
|
if len(ops) == 1:
|
|
if isinstance(ops[0], operations.CreateModel):
|
|
return ops[0].name.lower()
|
|
elif isinstance(ops[0], operations.DeleteModel):
|
|
return "delete_%s" % ops[0].name.lower()
|
|
elif isinstance(ops[0], operations.AddField):
|
|
return "%s_%s" % (ops[0].model_name.lower(), ops[0].name.lower())
|
|
elif isinstance(ops[0], operations.RemoveField):
|
|
return "remove_%s_%s" % (ops[0].model_name.lower(), ops[0].name.lower())
|
|
elif len(ops) > 1:
|
|
if all(isinstance(o, operations.CreateModel) for o in ops):
|
|
return "_".join(sorted(o.name.lower() for o in ops))
|
|
return "auto_%s" % datetime.datetime.now().strftime("%Y%m%d_%H%M")
|
|
|
|
@classmethod
|
|
def parse_number(cls, name):
|
|
"""
|
|
Given a migration name, tries to extract a number from the
|
|
beginning of it. If no number found, returns None.
|
|
"""
|
|
if re.match(r"^\d+_", name):
|
|
return int(name.split("_")[0])
|
|
return None
|