diff options
author | Arthur Koziel <arthur@arthurkoziel.com> | 2010-08-06 13:46:02 +0000 |
---|---|---|
committer | Arthur Koziel <arthur@arthurkoziel.com> | 2010-08-06 13:46:02 +0000 |
commit | 56d7859e2588b31e9083f014a894993d6d99cd2b (patch) | |
tree | e9c4a273033c98ff3a602b35d09e6acf46437de8 | |
parent | 60c5f63d5a458fab1578e63069dad6fba8c968cc (diff) | |
download | django-56d7859e2588b31e9083f014a894993d6d99cd2b.tar.gz |
[soc2010/app-loading] re-adding files after failed dcommit
git-svn-id: http://code.djangoproject.com/svn/django/branches/soc2010/app-loading@13496 bcc190cf-cafb-0310-a4f2-bffc1f526a37
-rw-r--r-- | django/core/apps.py | 297 | ||||
-rw-r--r-- | django/db/models/loading.py | 225 | ||||
-rw-r--r-- | tests/appcachetests/model_app/__init__.py | 0 | ||||
-rw-r--r-- | tests/appcachetests/model_app/models.py | 5 | ||||
-rw-r--r-- | tests/appcachetests/nomodel_app/__init__.py | 6 | ||||
-rw-r--r-- | tests/appcachetests/runtests.py (renamed from tests/appcachetests.py) | 110 | ||||
-rw-r--r-- | tests/appcachetests/same_label/__init__.py | 0 | ||||
-rw-r--r-- | tests/appcachetests/same_label/model_app/__init__.py | 0 | ||||
-rw-r--r-- | tests/appcachetests/same_label/model_app/models.py | 5 | ||||
-rw-r--r-- | tests/appcachetests/same_label/nomodel_app/__init__.py | 6 |
10 files changed, 414 insertions, 240 deletions
diff --git a/django/core/apps.py b/django/core/apps.py index a70ad68b06..15d5e17946 100644 --- a/django/core/apps.py +++ b/django/core/apps.py @@ -1,12 +1,299 @@ +from django.conf import settings +from django.core.exceptions import ImproperlyConfigured +from django.utils.datastructures import SortedDict +from django.utils.importlib import import_module +from django.utils.module_loading import module_has_submodule + +import imp +import sys +import os +import threading + + +class MultipleInstancesReturned(Exception): + "The function returned multiple App instances with the same label" + pass + class App(object): - def __init__(self, label): - if '.' in label: - label = label.split('.')[-1] - self.label = label + """ + An App in Django is a python package that: + - is listen in the INSTALLED_APPS setting + - has a models.py file that with class(es) subclassing ModelBase + """ + def __init__(self, name): + self.name = name + try: + self.label = name.rsplit('.', 1)[1] + except IndexError: + self.label = name # errors raised when trying to import the app self.errors = [] self.models = [] self.models_module = None def __repr__(self): - return '<App: %s>' % self.label + return '<App: %s>' % self.name + +class AppCache(object): + """ + A cache that stores installed applications and their models. Used to + provide reverse-relations and for app introspection (e.g. admin). + """ + # Use the Borg pattern to share state between all instances. Details at + # http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/66531. + __shared_state = dict( + # List of App instances + app_instances = [], + + # Mapping of app_labels to a dictionary of model names to model code. + app_models = SortedDict(), + + # -- Everything below here is only used when populating the cache -- + loaded = False, + handled = {}, + postponed = [], + nesting_level = 0, + write_lock = threading.RLock(), + _get_models_cache = {}, + ) + + def __init__(self): + self.__dict__ = self.__shared_state + + def _populate(self): + """ + Fill in all the cache information. This method is threadsafe, in the + sense that every caller will see the same state upon return, and if the + cache is already initialised, it does no work. + """ + if self.loaded: + return + self.write_lock.acquire() + try: + if self.loaded: + return + for app_name in settings.INSTALLED_APPS: + if app_name in self.handled: + continue + self.load_app(app_name, True) + if not self.nesting_level: + for app_name in self.postponed: + self.load_app(app_name) + self.loaded = True + finally: + self.write_lock.release() + + def load_app(self, app_name, can_postpone=False): + """ + Loads the app with the provided fully qualified name, and returns the + model module. + """ + self.handled[app_name] = None + self.nesting_level += 1 + + try: + app_module = import_module(app_name) + except ImportError: + # If the import fails, we assume it was because an path to a + # class was passed (e.g. "foo.bar.MyApp") + # We split the app_name by the rightmost dot to get the path + # and classname, and then try importing it again + if not '.' in app_name: + raise + app_name, app_classname = app_name.rsplit('.', 1) + app_module = import_module(app_name) + app_class = getattr(app_module, app_classname) + else: + app_class = App + + # check if an app instance with that name already exists + app_instance = self.find_app(app_name) + if not app_instance: + app_instance = app_class(app_name) + self.app_instances.append(app_instance) + + try: + models = import_module('.models', app_name) + except ImportError: + self.nesting_level -= 1 + # If the app doesn't have a models module, we can just ignore the + # ImportError and return no models for it. + if not module_has_submodule(app_module, 'models'): + return None + # But if the app does have a models module, we need to figure out + # whether to suppress or propagate the error. If can_postpone is + # True then it may be that the package is still being imported by + # Python and the models module isn't available yet. So we add the + # app to the postponed list and we'll try it again after all the + # recursion has finished (in populate). If can_postpone is False + # then it's time to raise the ImportError. + else: + if can_postpone: + self.postponed.append(app_name) + return None + else: + raise + + self.nesting_level -= 1 + app = self.find_app(app_name.split('.')[-1]) + if app and models is not app.models_module: + app.models_module = models + return models + + def find_app(self, name): + "Returns the App instance that matches name" + for app in self.app_instances: + if app.name == name: + return app + + def create_app(self, name): + """create an app instance""" + name = name.split('.')[-1] + app = self.find_app(name) + if not app: + app = App(name) + self.app_instances.append(app) + return app + + def app_cache_ready(self): + """ + Returns true if the model cache is fully populated. + + Useful for code that wants to cache the results of get_models() for + themselves once it is safe to do so. + """ + return self.loaded + + def get_apps(self): + "Returns a list of all installed modules that contain models." + self._populate() + + # Ensure the returned list is always in the same order (with new apps + # added at the end). This avoids unstable ordering on the admin app + # list page, for example. + return [app.models_module for app in self.app_instances\ + if app.models_module] + + def get_app(self, app_label, emptyOK=False): + """ + Returns the module containing the models for the given app_label. If + the app has no models in it and 'emptyOK' is True, returns None. + """ + self._populate() + self.write_lock.acquire() + try: + for app_name in settings.INSTALLED_APPS: + if app_label == app_name.split('.')[-1]: + mod = self.load_app(app_name, False) + if mod is None: + if emptyOK: + return None + else: + return mod + raise ImproperlyConfigured("App with label %s could not be found" % app_label) + finally: + self.write_lock.release() + + def get_app_errors(self): + "Returns the map of known problems with the INSTALLED_APPS." + self._populate() + errors = {} + for app in self.app_instances: + if app.errors: + errors.update({app.label: app.errors}) + return errors + + def get_models(self, app_mod=None, include_auto_created=False, include_deferred=False): + """ + Given a module containing models, returns a list of the models. + Otherwise returns a list of all installed models. + + By default, auto-created models (i.e., m2m models without an + explicit intermediate table) are not included. However, if you + specify include_auto_created=True, they will be. + + By default, models created to satisfy deferred attribute + queries are *not* included in the list of models. However, if + you specify include_deferred, they will be. + """ + cache_key = (app_mod, include_auto_created, include_deferred) + try: + return self._get_models_cache[cache_key] + except KeyError: + pass + self._populate() + if app_mod: + app_label = app_mod.__name__.split('.')[-2] + app = self.find_app(app_label) + if app: + app_list = [app] + else: + app_list = self.app_instances + model_list = [] + for app in app_list: + models = app.models + model_list.extend( + model for model in models + if ((not model._deferred or include_deferred) + and (not model._meta.auto_created or include_auto_created)) + ) + self._get_models_cache[cache_key] = model_list + return model_list + + def get_model(self, app_label, model_name, seed_cache=True): + """ + Returns the model matching the given app_label and case-insensitive + model_name. + + Returns None if no model is found. + """ + if seed_cache: + self._populate() + app = self.find_app(app_label) + if app: + for model in app.models: + if model_name.lower() == model._meta.object_name.lower(): + return model + + def register_models(self, app_label, *models): + """ + Register a set of models as belonging to an app. + """ + # Check if there is an existing app instance + # If there are more than one app instance with the + # app_label, an MultipleInstancesReturned is raised + app_instances = [app for app in self.app_instances\ + if app.label == app_label] + if len(app_instances) > 1: + raise MultipleInstancesReturned + else: + try: + app_instance = app_instances[0] + except IndexError: + app_instance = None + + # Create a new App instance if the ModelBase tries to register + # an app that isn't listed in INSTALLED_APPS + if not app_instance: + app_instance = App(app_label) + self.app_instances.append(app_instance) + + for model in models: + # Store as 'name: model' pair in a dictionary + # in the models list of the App instance + model_name = model._meta.object_name.lower() + model_dict = self.app_models.setdefault(app_label, SortedDict()) + if model_name in model_dict: + # The same model may be imported via different paths (e.g. + # appname.models and project.appname.models). We use the source + # filename as a means to detect identity. + fname1 = os.path.abspath(sys.modules[model.__module__].__file__) + fname2 = os.path.abspath(sys.modules[model_dict[model_name].__module__].__file__) + # Since the filename extension could be .py the first time and + # .pyc or .pyo the second time, ignore the extension when + # comparing. + if os.path.splitext(fname1)[0] == os.path.splitext(fname2)[0]: + continue + model_dict[model_name] = model + app_instance.models.append(model) + self._get_models_cache.clear() diff --git a/django/db/models/loading.py b/django/db/models/loading.py index 20ebba633b..48e5236905 100644 --- a/django/db/models/loading.py +++ b/django/db/models/loading.py @@ -15,230 +15,7 @@ import threading __all__ = ('get_apps', 'get_app', 'get_models', 'get_model', 'register_models', 'load_app', 'app_cache_ready') -class AppCache(object): - """ - A cache that stores installed applications and their models. Used to - provide reverse-relations and for app introspection (e.g. admin). - """ - # Use the Borg pattern to share state between all instances. Details at - # http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/66531. - __shared_state = dict( - # List of App instances - app_instances = [], - - # Mapping of app_labels to a dictionary of model names to model code. - app_models = SortedDict(), - - # -- Everything below here is only used when populating the cache -- - loaded = False, - handled = {}, - postponed = [], - nesting_level = 0, - write_lock = threading.RLock(), - _get_models_cache = {}, - ) - - def __init__(self): - self.__dict__ = self.__shared_state - # Create App instances for the apps in INSTALLED_APPS - for app_name in settings.INSTALLED_APPS: - self.app_instances.append(App(app_name)) - - def _populate(self): - """ - Fill in all the cache information. This method is threadsafe, in the - sense that every caller will see the same state upon return, and if the - cache is already initialised, it does no work. - """ - if self.loaded: - return - self.write_lock.acquire() - try: - if self.loaded: - return - for app_name in settings.INSTALLED_APPS: - if app_name in self.handled: - continue - self.load_app(app_name, True) - if not self.nesting_level: - for app_name in self.postponed: - self.load_app(app_name) - self.loaded = True - finally: - self.write_lock.release() - - def load_app(self, app_name, can_postpone=False): - """ - Loads the app with the provided fully qualified name, and returns the - model module. - """ - self.handled[app_name] = None - self.nesting_level += 1 - app_module = import_module(app_name) - try: - models = import_module('.models', app_name) - except ImportError: - self.nesting_level -= 1 - # If the app doesn't have a models module, we can just ignore the - # ImportError and return no models for it. - if not module_has_submodule(app_module, 'models'): - return None - # But if the app does have a models module, we need to figure out - # whether to suppress or propagate the error. If can_postpone is - # True then it may be that the package is still being imported by - # Python and the models module isn't available yet. So we add the - # app to the postponed list and we'll try it again after all the - # recursion has finished (in populate). If can_postpone is False - # then it's time to raise the ImportError. - else: - if can_postpone: - self.postponed.append(app_name) - return None - else: - raise - - self.nesting_level -= 1 - app = self.find_app(app_name.split('.')[-1]) - if app and models is not app.models_module: - app.models_module = models - return models - - def find_app(self, app_label): - "Returns the App instance that matches app_label" - for app in self.app_instances: - if app.label == app_label: - return app - - def app_cache_ready(self): - """ - Returns true if the model cache is fully populated. - - Useful for code that wants to cache the results of get_models() for - themselves once it is safe to do so. - """ - return self.loaded - - def get_apps(self): - "Returns a list of all installed modules that contain models." - self._populate() - - # Ensure the returned list is always in the same order (with new apps - # added at the end). This avoids unstable ordering on the admin app - # list page, for example. - return [app.models_module for app in self.app_instances\ - if app.models_module] - - def get_app(self, app_label, emptyOK=False): - """ - Returns the module containing the models for the given app_label. If - the app has no models in it and 'emptyOK' is True, returns None. - """ - self._populate() - self.write_lock.acquire() - try: - for app_name in settings.INSTALLED_APPS: - if app_label == app_name.split('.')[-1]: - mod = self.load_app(app_name, False) - if mod is None: - if emptyOK: - return None - else: - return mod - raise ImproperlyConfigured("App with label %s could not be found" % app_label) - finally: - self.write_lock.release() - - def get_app_errors(self): - "Returns the map of known problems with the INSTALLED_APPS." - self._populate() - errors = {} - for app in self.app_instances: - if app.errors: - errors.update({app.label: app.errors}) - return errors - - def get_models(self, app_mod=None, include_auto_created=False, include_deferred=False): - """ - Given a module containing models, returns a list of the models. - Otherwise returns a list of all installed models. - - By default, auto-created models (i.e., m2m models without an - explicit intermediate table) are not included. However, if you - specify include_auto_created=True, they will be. - - By default, models created to satisfy deferred attribute - queries are *not* included in the list of models. However, if - you specify include_deferred, they will be. - """ - cache_key = (app_mod, include_auto_created, include_deferred) - try: - return self._get_models_cache[cache_key] - except KeyError: - pass - self._populate() - if app_mod: - app_label = app_mod.__name__.split('.')[-2] - app = self.find_app(app_label) - if app: - app_list = [app] - else: - app_list = self.app_instances - model_list = [] - for app in app_list: - models = app.models - model_list.extend( - model for model in models - if ((not model._deferred or include_deferred) - and (not model._meta.auto_created or include_auto_created)) - ) - self._get_models_cache[cache_key] = model_list - return model_list - - def get_model(self, app_label, model_name, seed_cache=True): - """ - Returns the model matching the given app_label and case-insensitive - model_name. - - Returns None if no model is found. - """ - if seed_cache: - self._populate() - app = self.find_app(app_label) - if app: - for model in app.models: - if model_name.lower() == model._meta.object_name.lower(): - return model - - def register_models(self, app_label, *models): - """ - Register a set of models as belonging to an app. - """ - # Create a new App instance if an app in INSTALLED_APPS - # imports another package that has models - app = self.find_app(app_label) - if not app: - app = App(app_label) - self.app_instances.append(app) - for model in models: - # Store as 'name: model' pair in a dictionary - # in the models list of the App instance - model_name = model._meta.object_name.lower() - model_dict = self.app_models.setdefault(app_label, SortedDict()) - if model_name in model_dict: - # The same model may be imported via different paths (e.g. - # appname.models and project.appname.models). We use the source - # filename as a means to detect identity. - fname1 = os.path.abspath(sys.modules[model.__module__].__file__) - fname2 = os.path.abspath(sys.modules[model_dict[model_name].__module__].__file__) - # Since the filename extension could be .py the first time and - # .pyc or .pyo the second time, ignore the extension when - # comparing. - if os.path.splitext(fname1)[0] == os.path.splitext(fname2)[0]: - continue - model_dict[model_name] = model - app.models.append(model) - self._get_models_cache.clear() - +from django.core.apps import AppCache cache = AppCache() # These methods were always module level, so are kept that way for backwards diff --git a/tests/appcachetests/model_app/__init__.py b/tests/appcachetests/model_app/__init__.py new file mode 100644 index 0000000000..e69de29bb2 --- /dev/null +++ b/tests/appcachetests/model_app/__init__.py diff --git a/tests/appcachetests/model_app/models.py b/tests/appcachetests/model_app/models.py new file mode 100644 index 0000000000..ffb04e89c4 --- /dev/null +++ b/tests/appcachetests/model_app/models.py @@ -0,0 +1,5 @@ +from django.db import models + +class Person(models.Model): + first_name = models.CharField(max_length=30) + last_name = models.CharField(max_length=30) diff --git a/tests/appcachetests/nomodel_app/__init__.py b/tests/appcachetests/nomodel_app/__init__.py new file mode 100644 index 0000000000..8e455462ad --- /dev/null +++ b/tests/appcachetests/nomodel_app/__init__.py @@ -0,0 +1,6 @@ +from django.core.apps import App + +class MyApp(App): + + def __repr__(self): + return '<MyApp: %s>' % self.name diff --git a/tests/appcachetests.py b/tests/appcachetests/runtests.py index 5ac09a9178..0d05702d06 100644 --- a/tests/appcachetests.py +++ b/tests/appcachetests/runtests.py @@ -5,6 +5,7 @@ import threading from django.conf import settings from django.utils.datastructures import SortedDict from django.core.exceptions import ImproperlyConfigured +from django.core.apps import MultipleInstancesReturned # remove when tests are integrated into the django testsuite settings.configure() @@ -15,6 +16,7 @@ class AppCacheTestCase(unittest.TestCase): """ TestCase that resets the AppCache after each test. """ + def setUp(self): self.old_installed_apps = settings.INSTALLED_APPS settings.INSTALLED_APPS = () @@ -48,12 +50,15 @@ class AppCacheTestCase(unittest.TestCase): cache.nesting_level = 0 cache.write_lock = threading.RLock() cache._get_models_cache = {} + + cache.app_instances = [] class AppCacheReadyTests(AppCacheTestCase): """ Tests for the app_cache_ready function that indicates if the cache is fully populated. """ + def test_not_initialized(self): """Should return False if the AppCache hasn't been initialized""" self.assertFalse(cache.app_cache_ready()) @@ -67,6 +72,7 @@ class AppCacheReadyTests(AppCacheTestCase): class GetAppsTests(AppCacheTestCase): """Tests for the get_apps function""" + def test_get_apps(self): """Test that the correct models modules are returned""" settings.INSTALLED_APPS = ('django.contrib.auth', @@ -85,6 +91,7 @@ class GetAppsTests(AppCacheTestCase): class GetAppTests(AppCacheTestCase): """Tests for the get_app function""" + def test_get_app(self): """Test that the correct module is returned""" settings.INSTALLED_APPS = ('django.contrib.auth',) @@ -123,6 +130,7 @@ class GetAppTests(AppCacheTestCase): class GetAppErrorsTests(AppCacheTestCase): """Tests for the get_app_errors function""" + def test_get_app_errors(self): """Test that the function returns an empty dict""" self.assertEqual(cache.get_app_errors(), {}) @@ -130,6 +138,7 @@ class GetAppErrorsTests(AppCacheTestCase): class GetModelsTests(AppCacheTestCase): """Tests for the get_models function""" + def test_get_models(self): """Test that the correct model classes are returned""" settings.INSTALLED_APPS = ('django.contrib.flatpages',) @@ -169,6 +178,7 @@ class GetModelsTests(AppCacheTestCase): class GetModelTests(AppCacheTestCase): """Tests for the get_model function""" + def test_get_model(self): """Test that the correct model is returned""" settings.INSTALLED_APPS = ('django.contrib.flatpages',) @@ -188,20 +198,98 @@ class GetModelTests(AppCacheTestCase): self.assertEqual(rv, None) self.assertFalse(cache.app_cache_ready()) +class LoadAppTests(AppCacheTestCase): + """Tests for the load_app function""" + + def test_with_models(self): + """ + Test that an app instance is created and the models + module is returned + """ + rv = cache.load_app('model_app') + app = cache.app_instances[0] + self.assertEqual(len(cache.app_instances), 1) + self.assertEqual(app.name, 'model_app') + self.assertEqual(app.models_module.__name__, 'model_app.models') + self.assertEqual(rv.__name__, 'model_app.models') + + def test_without_models(self): + """ + Test that an app instance is created when there are no models + """ + rv = cache.load_app('nomodel_app') + app = cache.app_instances[0] + self.assertEqual(len(cache.app_instances), 1) + self.assertEqual(app.name, 'nomodel_app') + self.assertEqual(app.models_module, None) + self.assertEqual(rv, None) + + def test_load_app_custom(self): + """ + Test that a custom app instance is created if the function + gets passed a classname + """ + from nomodel_app import MyApp + rv = cache.load_app('nomodel_app.MyApp') + app = cache.app_instances[0] + self.assertEqual(len(cache.app_instances), 1) + self.assertEqual(app.name, 'nomodel_app') + self.assertTrue(isinstance(app, MyApp)) + self.assertEqual(app.models_module, None) + self.assertEqual(rv, None) + + def test_load_app_twice(self): + """ + Test that loading an app twice results in only one app instance + """ + rv = cache.load_app('model_app') + rv2 = cache.load_app('model_app') + self.assertEqual(len(cache.app_instances), 1) + self.assertEqual(rv.__name__, 'model_app.models') + self.assertEqual(rv2.__name__, 'model_app.models') + + def test_load_app_importerror(self): + """ + Test that an ImportError exception is raised if a package cannot + be imported + """ + self.assertRaises(ImportError, cache.load_app, 'garageland') + class RegisterModelsTests(AppCacheTestCase): """Tests for the register_models function""" + def test_register_models(self): - from django.contrib.flatpages.models import FlatPage, Site - cache.register_models('foo', *(FlatPage, Site,)) - self.assertFalse(cache.app_cache_ready()) - rv = cache.get_models() - # we have 4 models since the above import will trigger the - # ModelBase.__new__, which will call the register_models function - self.assertEqual(len(rv), 4) - self.assertEqual(rv[0], Site) - self.assertEqual(rv[1], FlatPage) - self.assertEqual(rv[2], FlatPage) - self.assertEqual(rv[3], Site) + """ + Test that register_models attaches the models to an existing + app instance + """ + # We don't need to call the register_models method. Importing the + # models.py file will suffice. This is done in the load_app function + # The ModelBase will call the register_models method + cache.load_app('model_app') + app = cache.app_instances[0] + self.assertEqual(len(cache.app_instances), 1) + self.assertEqual(app.models[0].__name__, 'Person') + + def test_new_instance(self): + """ + Test a new app instance is created if one doesn't exist, and the + models are attached to it. + """ + from model_app.models import Person + app = cache.app_instances[0] + self.assertEqual(len(cache.app_instances), 1) + self.assertEqual(app.name, 'model_app') + self.assertEqual(app.models[0].__name__, 'Person') + + def test_multiple_apps_with_same_label(self): + """ + Test that an exception is raised when the function gets passed an + app label but there are multiple app instances with that label + """ + cache.load_app('model_app') + self.assertRaises(MultipleInstancesReturned, cache.load_app, + 'same_label.model_app') if __name__ == '__main__': unittest.main() diff --git a/tests/appcachetests/same_label/__init__.py b/tests/appcachetests/same_label/__init__.py new file mode 100644 index 0000000000..e69de29bb2 --- /dev/null +++ b/tests/appcachetests/same_label/__init__.py diff --git a/tests/appcachetests/same_label/model_app/__init__.py b/tests/appcachetests/same_label/model_app/__init__.py new file mode 100644 index 0000000000..e69de29bb2 --- /dev/null +++ b/tests/appcachetests/same_label/model_app/__init__.py diff --git a/tests/appcachetests/same_label/model_app/models.py b/tests/appcachetests/same_label/model_app/models.py new file mode 100644 index 0000000000..94f391537f --- /dev/null +++ b/tests/appcachetests/same_label/model_app/models.py @@ -0,0 +1,5 @@ +from django.db import models + +class User(models.Model): + first_name = models.CharField(max_length=30) + last_name = models.CharField(max_length=30) diff --git a/tests/appcachetests/same_label/nomodel_app/__init__.py b/tests/appcachetests/same_label/nomodel_app/__init__.py new file mode 100644 index 0000000000..8e455462ad --- /dev/null +++ b/tests/appcachetests/same_label/nomodel_app/__init__.py @@ -0,0 +1,6 @@ +from django.core.apps import App + +class MyApp(App): + + def __repr__(self): + return '<MyApp: %s>' % self.name |