diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml index 761a6dd..f45a707 100644 --- a/.github/workflows/test.yml +++ b/.github/workflows/test.yml @@ -20,10 +20,10 @@ jobs: python-version: "3.10" - name: Install danix + shell: bash run: | - sudo apt update -y - sudo apt install make -y cd danix - make install - make aliases + sudo apt install make -y + sudo make install + sudo python /usr/share/danix/main.py --help diff --git a/danix/makefile b/danix/makefile index 282af67..0a410e3 100644 --- a/danix/makefile +++ b/danix/makefile @@ -14,7 +14,7 @@ ENV_STARTED=Environment started successfully! ENV_STOPPED=Environment stopped successfully! ENV_STOPPED_ERROR=Error! The environment is stopped! ENV_PATTERN_ERROR=Environment name pattern contains in multiples environments - +PYTHON_PATH := $(shell python -c "import sysconfig; print(sysconfig.get_paths()['purelib'])") install: @@ -45,8 +45,11 @@ else @echo ENV_STARTED=$(ENV_STARTED) >> $(DANIX_PATH)/.env @echo ENV_STOPPED=$(ENV_STOPPED) >> $(DANIX_PATH)/.env - @touch $(DANIX_PATH)/db/$(DB_NAME) > /dev/null 2>&1 - @$(PIP) install -r $(DANIX_PATH)/requirements.txt > /dev/null 2>&1 + @touch $(DANIX_PATH)/db/$(DB_NAME) + @$(PIP) install -r $(DANIX_PATH)/requirements.txt + + @rm -r $(PYTHON_PATH)/django/apps/registry.py + @mv $(DANIX_PATH)/registry.py $(PYTHON_PATH)/django/apps/ @$(PYTHON) $(DANIX_PATH)/manage.py migrate @@ -105,4 +108,4 @@ clean: @rm -r $(MAIN_REPO) > /dev/null 2>&1 @rm -r $(DANIX_PATH) > /dev/null 2>&1 - @echo Danix cleaned! \ No newline at end of file + @echo Danix cleaned! diff --git a/danix/registry.py b/danix/registry.py new file mode 100644 index 0000000..dd9ee90 --- /dev/null +++ b/danix/registry.py @@ -0,0 +1,437 @@ +import functools +import sys +import threading +import warnings +from collections import Counter, defaultdict +from functools import partial + +from django.core.exceptions import AppRegistryNotReady, ImproperlyConfigured + +from .config import AppConfig + + +class Apps: + """ + A registry that stores the configuration of installed applications. + + It also keeps track of models, e.g. to provide reverse relations. + """ + + def __init__(self, installed_apps=()): + # installed_apps is set to None when creating the main registry + # because it cannot be populated at that point. Other registries must + # provide a list of installed apps and are populated immediately. + if installed_apps is None and hasattr(sys.modules[__name__], "apps"): + raise RuntimeError("You must supply an installed_apps argument.") + + # Mapping of app labels => model names => model classes. Every time a + # model is imported, ModelBase.__new__ calls apps.register_model which + # creates an entry in all_models. All imported models are registered, + # regardless of whether they're defined in an installed application + # and whether the registry has been populated. Since it isn't possible + # to reimport a module safely (it could reexecute initialization code) + # all_models is never overridden or reset. + self.all_models = defaultdict(dict) + + # Mapping of labels to AppConfig instances for installed apps. + self.app_configs = {} + + # Stack of app_configs. Used to store the current state in + # set_available_apps and set_installed_apps. + self.stored_app_configs = [] + + # Whether the registry is populated. + self.apps_ready = self.models_ready = self.ready = False + # For the autoreloader. + self.ready_event = threading.Event() + + # Lock for thread-safe population. + self._lock = threading.RLock() + self.loading = False + + # Maps ("app_label", "modelname") tuples to lists of functions to be + # called when the corresponding model is ready. Used by this class's + # `lazy_model_operation()` and `do_pending_operations()` methods. + self._pending_operations = defaultdict(list) + + # Populate apps and models, unless it's the main registry. + if installed_apps is not None: + self.populate(installed_apps) + + def populate(self, installed_apps=None): + """ + Load application configurations and models. + + Import each application module and then each model module. + + It is thread-safe and idempotent, but not reentrant. + """ + if self.ready: + return + + # populate() might be called by two threads in parallel on servers + # that create threads before initializing the WSGI callable. + with self._lock: + if self.ready: + return + + # An RLock prevents other threads from entering this section. The + # compare and set operation below is atomic. + if self.loading: + # Prevent reentrant calls to avoid running AppConfig.ready() + # methods twice. + self.app_configs = {} + #raise RuntimeError("populate() isn't reentrant") + self.loading = True + + # Phase 1: initialize app configs and import app modules. + for entry in installed_apps: + if isinstance(entry, AppConfig): + app_config = entry + else: + app_config = AppConfig.create(entry) + if app_config.label in self.app_configs: + raise ImproperlyConfigured( + "Application labels aren't unique, " + "duplicates: %s" % app_config.label + ) + + self.app_configs[app_config.label] = app_config + app_config.apps = self + + # Check for duplicate app names. + counts = Counter( + app_config.name for app_config in self.app_configs.values() + ) + duplicates = [name for name, count in counts.most_common() if count > 1] + if duplicates: + raise ImproperlyConfigured( + "Application names aren't unique, " + "duplicates: %s" % ", ".join(duplicates) + ) + + self.apps_ready = True + + # Phase 2: import models modules. + for app_config in self.app_configs.values(): + app_config.import_models() + + self.clear_cache() + + self.models_ready = True + + # Phase 3: run ready() methods of app configs. + for app_config in self.get_app_configs(): + app_config.ready() + + self.ready = True + self.ready_event.set() + + def check_apps_ready(self): + """Raise an exception if all apps haven't been imported yet.""" + if not self.apps_ready: + from django.conf import settings + + # If "not ready" is due to unconfigured settings, accessing + # INSTALLED_APPS raises a more helpful ImproperlyConfigured + # exception. + settings.INSTALLED_APPS + raise AppRegistryNotReady("Apps aren't loaded yet.") + + def check_models_ready(self): + """Raise an exception if all models haven't been imported yet.""" + if not self.models_ready: + raise AppRegistryNotReady("Models aren't loaded yet.") + + def get_app_configs(self): + """Import applications and return an iterable of app configs.""" + self.check_apps_ready() + return self.app_configs.values() + + def get_app_config(self, app_label): + """ + Import applications and returns an app config for the given label. + + Raise LookupError if no application exists with this label. + """ + self.check_apps_ready() + try: + return self.app_configs[app_label] + except KeyError: + message = "No installed app with label '%s'." % app_label + for app_config in self.get_app_configs(): + if app_config.name == app_label: + message += " Did you mean '%s'?" % app_config.label + break + raise LookupError(message) + + # This method is performance-critical at least for Django's test suite. + @functools.lru_cache(maxsize=None) + def get_models(self, include_auto_created=False, include_swapped=False): + """ + Return a list of all installed models. + + By default, the following models aren't included: + + - auto-created models for many-to-many relations without + an explicit intermediate table, + - models that have been swapped out. + + Set the corresponding keyword argument to True to include such models. + """ + self.check_models_ready() + + result = [] + for app_config in self.app_configs.values(): + result.extend(app_config.get_models(include_auto_created, include_swapped)) + return result + + def get_model(self, app_label, model_name=None, require_ready=True): + """ + Return the model matching the given app_label and model_name. + + As a shortcut, app_label may be in the form .. + + model_name is case-insensitive. + + Raise LookupError if no application exists with this label, or no + model exists with this name in the application. Raise ValueError if + called with a single argument that doesn't contain exactly one dot. + """ + if require_ready: + self.check_models_ready() + else: + self.check_apps_ready() + + if model_name is None: + app_label, model_name = app_label.split(".") + + app_config = self.get_app_config(app_label) + + if not require_ready and app_config.models is None: + app_config.import_models() + + return app_config.get_model(model_name, require_ready=require_ready) + + def register_model(self, app_label, model): + # Since this method is called when models are imported, it cannot + # perform imports because of the risk of import loops. It mustn't + # call get_app_config(). + model_name = model._meta.model_name + app_models = self.all_models[app_label] + if model_name in app_models: + if ( + model.__name__ == app_models[model_name].__name__ + and model.__module__ == app_models[model_name].__module__ + ): + warnings.warn( + "Model '%s.%s' was already registered. Reloading models is not " + "advised as it can lead to inconsistencies, most notably with " + "related models." % (app_label, model_name), + RuntimeWarning, + stacklevel=2, + ) + else: + raise RuntimeError( + "Conflicting '%s' models in application '%s': %s and %s." + % (model_name, app_label, app_models[model_name], model) + ) + app_models[model_name] = model + self.do_pending_operations(model) + self.clear_cache() + + def is_installed(self, app_name): + """ + Check whether an application with this name exists in the registry. + + app_name is the full name of the app e.g. 'django.contrib.admin'. + """ + self.check_apps_ready() + return any(ac.name == app_name for ac in self.app_configs.values()) + + def get_containing_app_config(self, object_name): + """ + Look for an app config containing a given object. + + object_name is the dotted Python path to the object. + + Return the app config for the inner application in case of nesting. + Return None if the object isn't in any registered app config. + """ + self.check_apps_ready() + candidates = [] + for app_config in self.app_configs.values(): + if object_name.startswith(app_config.name): + subpath = object_name[len(app_config.name) :] + if subpath == "" or subpath[0] == ".": + candidates.append(app_config) + if candidates: + return sorted(candidates, key=lambda ac: -len(ac.name))[0] + + def get_registered_model(self, app_label, model_name): + """ + Similar to get_model(), but doesn't require that an app exists with + the given app_label. + + It's safe to call this method at import time, even while the registry + is being populated. + """ + model = self.all_models[app_label].get(model_name.lower()) + if model is None: + raise LookupError("Model '%s.%s' not registered." % (app_label, model_name)) + return model + + @functools.lru_cache(maxsize=None) + def get_swappable_settings_name(self, to_string): + """ + For a given model string (e.g. "auth.User"), return the name of the + corresponding settings name if it refers to a swappable model. If the + referred model is not swappable, return None. + + This method is decorated with lru_cache because it's performance + critical when it comes to migrations. Since the swappable settings don't + change after Django has loaded the settings, there is no reason to get + the respective settings attribute over and over again. + """ + to_string = to_string.lower() + for model in self.get_models(include_swapped=True): + swapped = model._meta.swapped + # Is this model swapped out for the model given by to_string? + if swapped and swapped.lower() == to_string: + return model._meta.swappable + # Is this model swappable and the one given by to_string? + if model._meta.swappable and model._meta.label_lower == to_string: + return model._meta.swappable + return None + + def set_available_apps(self, available): + """ + Restrict the set of installed apps used by get_app_config[s]. + + available must be an iterable of application names. + + set_available_apps() must be balanced with unset_available_apps(). + + Primarily used for performance optimization in TransactionTestCase. + + This method is safe in the sense that it doesn't trigger any imports. + """ + available = set(available) + installed = {app_config.name for app_config in self.get_app_configs()} + if not available.issubset(installed): + raise ValueError( + "Available apps isn't a subset of installed apps, extra apps: %s" + % ", ".join(available - installed) + ) + + self.stored_app_configs.append(self.app_configs) + self.app_configs = { + label: app_config + for label, app_config in self.app_configs.items() + if app_config.name in available + } + self.clear_cache() + + def unset_available_apps(self): + """Cancel a previous call to set_available_apps().""" + self.app_configs = self.stored_app_configs.pop() + self.clear_cache() + + def set_installed_apps(self, installed): + """ + Enable a different set of installed apps for get_app_config[s]. + + installed must be an iterable in the same format as INSTALLED_APPS. + + set_installed_apps() must be balanced with unset_installed_apps(), + even if it exits with an exception. + + Primarily used as a receiver of the setting_changed signal in tests. + + This method may trigger new imports, which may add new models to the + registry of all imported models. They will stay in the registry even + after unset_installed_apps(). Since it isn't possible to replay + imports safely (e.g. that could lead to registering listeners twice), + models are registered when they're imported and never removed. + """ + if not self.ready: + raise AppRegistryNotReady("App registry isn't ready yet.") + self.stored_app_configs.append(self.app_configs) + self.app_configs = {} + self.apps_ready = self.models_ready = self.loading = self.ready = False + self.clear_cache() + self.populate(installed) + + def unset_installed_apps(self): + """Cancel a previous call to set_installed_apps().""" + self.app_configs = self.stored_app_configs.pop() + self.apps_ready = self.models_ready = self.ready = True + self.clear_cache() + + def clear_cache(self): + """ + Clear all internal caches, for methods that alter the app registry. + + This is mostly used in tests. + """ + # Call expire cache on each model. This will purge + # the relation tree and the fields cache. + self.get_models.cache_clear() + if self.ready: + # Circumvent self.get_models() to prevent that the cache is refilled. + # This particularly prevents that an empty value is cached while cloning. + for app_config in self.app_configs.values(): + for model in app_config.get_models(include_auto_created=True): + model._meta._expire_cache() + + def lazy_model_operation(self, function, *model_keys): + """ + Take a function and a number of ("app_label", "modelname") tuples, and + when all the corresponding models have been imported and registered, + call the function with the model classes as its arguments. + + The function passed to this method must accept exactly n models as + arguments, where n=len(model_keys). + """ + # Base case: no arguments, just execute the function. + if not model_keys: + function() + # Recursive case: take the head of model_keys, wait for the + # corresponding model class to be imported and registered, then apply + # that argument to the supplied function. Pass the resulting partial + # to lazy_model_operation() along with the remaining model args and + # repeat until all models are loaded and all arguments are applied. + else: + next_model, *more_models = model_keys + + # This will be executed after the class corresponding to next_model + # has been imported and registered. The `func` attribute provides + # duck-type compatibility with partials. + def apply_next_model(model): + next_function = partial(apply_next_model.func, model) + self.lazy_model_operation(next_function, *more_models) + + apply_next_model.func = function + + # If the model has already been imported and registered, partially + # apply it to the function now. If not, add it to the list of + # pending operations for the model, where it will be executed with + # the model class as its sole argument once the model is ready. + try: + model_class = self.get_registered_model(*next_model) + except LookupError: + self._pending_operations[next_model].append(apply_next_model) + else: + apply_next_model(model_class) + + def do_pending_operations(self, model): + """ + Take a newly-prepared model and pass it to each function waiting for + it. This is called at the very end of Apps.register_model(). + """ + key = model._meta.app_label, model._meta.model_name + for function in self._pending_operations.pop(key, []): + function(model) + + +apps = Apps(installed_apps=None)