Refactor

app/authentication/auth.py

@@ -6,13 +6,10 @@ from notifications_python_client.errors import (
 from notifications_utils import request_helper
 from sqlalchemy.exc import DataError
 from sqlalchemy.orm.exc import NoResultFound
-from gds_metrics import Histogram
 
 from app import db
 from app.dao.services_dao import dao_fetch_service_by_id
-from app.dao.api_key_dao import get_model_api_keys
 from app.serialised_models import (
-    SerialisedAPIKey,
     SerialisedAPIKeyCollection,
     SerialisedService,
 )
@@ -20,11 +17,6 @@ from app.serialised_models import (
 
 GENERAL_TOKEN_ERROR_MESSAGE = 'Invalid token: make sure your API token matches the example at https://docs.notifications.service.gov.uk/rest-api.html#authorisation-header'  # noqa
 
-AUTH_DB_CONNECTION_DURATION_SECONDS = Histogram(
-    'auth_db_connection_duration_seconds',
-    'Time taken to get DB connection and fetch service from database',
-)
-
 
 class AuthError(Exception):
     def __init__(self, message, code, service_id=None, api_key_id=None):
@@ -93,30 +85,6 @@ def requires_admin_auth():
         raise AuthError('Unauthorized: admin authentication token required', 401)
 
 
-def get_service_dict(issuer):
-    from app.schemas import service_schema
-    with AUTH_DB_CONNECTION_DURATION_SECONDS.time():
-        fetched = dao_fetch_service_by_id(issuer)
-    return service_schema.dump(fetched).data
-
-
-@SerialisedService.cache
-def get_service_model(issuer):
-    return SerialisedService(get_service_dict(issuer))
-
-
-def get_api_keys_dict(issuer):
-    return [
-        {k: getattr(key, k) for k in SerialisedAPIKey.ALLOWED_PROPERTIES}
-        for key in get_model_api_keys(issuer)
-    ]
-
-
-@SerialisedAPIKeyCollection.cache
-def get_api_keys_models(issuer):
-    return SerialisedAPIKeyCollection(get_api_keys_dict(issuer))
-
-
 def requires_auth():
     request_helper.check_proxy_header_before_request()
 
@@ -124,8 +92,8 @@ def requires_auth():
     issuer = __get_token_issuer(auth_token)  # ie the `iss` claim which should be a service ID
 
     try:
-        service = get_service_model(issuer)
-        service.api_keys = get_api_keys_models(issuer)
+        service = SerialisedService.from_id(issuer)
+        service.api_keys = SerialisedAPIKeyCollection.from_service_id(issuer)
         db.session.commit()
     except DataError:
         raise AuthError("Invalid token: service id is not the right data type", 403)

app/notifications/validators.py

@@ -8,8 +8,7 @@ from notifications_utils.recipients import (
 )
 from notifications_utils.clients.redis import rate_limit_cache_key, daily_limit_cache_key
 
-from app import db
-from app.dao import services_dao, templates_dao
+from app.dao import services_dao
 from app.dao.service_sms_sender_dao import dao_get_service_sms_senders_by_id
 from app.models import (
     INTERNATIONAL_SMS_TYPE, SMS_TYPE, EMAIL_TYPE, LETTER_TYPE,
@@ -149,32 +148,15 @@ def check_notification_content_is_not_empty(template_with_content):
         raise BadRequestError(message=message)
 
 
-def get_template_dict(template_id, service_id):
-    from app.schemas import template_schema
+def validate_template(template_id, personalisation, service, notification_type):
+
     try:
-        fetched_template = templates_dao.dao_get_template_by_id_and_service_id(
-            template_id=template_id,
-            service_id=service_id
-        )
+        template = SerialisedTemplate.from_template_id_and_service_id(template_id, service.id)
     except NoResultFound:
         message = 'Template not found'
         raise BadRequestError(message=message,
                               fields=[{'template': message}])
 
-    template_dict = template_schema.dump(fetched_template).data
-
-    db.session.commit()
-    return template_dict
-
-
-@SerialisedTemplate.cache
-def get_template_model(template_id, service_id):
-    return SerialisedTemplate(get_template_dict(template_id, service_id))
-
-
-def validate_template(template_id, personalisation, service, notification_type):
-    template = get_template_model(template_id, service.id)
-
     check_template_is_for_notification_type(notification_type, template.template_type)
     check_template_is_active(template)
 

app/serialised_models.py

@@ -5,23 +5,34 @@ from threading import RLock
 
 import cachetools
 
+from gds_metrics import Histogram
+
+from app import db
+from app.dao.services_dao import dao_fetch_service_by_id
+from app.dao.api_key_dao import get_model_api_keys
+
 caches = defaultdict(partial(cachetools.TTLCache, maxsize=1024, ttl=2))
 locks = defaultdict(RLock)
 
 
-class CacheMixin:
-
-    @classmethod
-    def cache(cls, func):
-
-        @cachetools.cached(cache=caches[cls.__name__], lock=locks[cls.__name__])
-        def wrapper(*args, **kwargs):
-            return func(*args, **kwargs)
-
-        return wrapper
+AUTH_DB_CONNECTION_DURATION_SECONDS = Histogram(
+    'auth_db_connection_duration_seconds',
+    'Time taken to get DB connection and fetch service from database',
+)
 
 
-class SerialisedModel(ABC, CacheMixin):
+def cache(func):
+    @cachetools.cached(
+        cache=caches[func.__qualname__],
+        lock=locks[func.__qualname__],
+    )
+    def wrapper(*args, **kwargs):
+        return func(*args, **kwargs)
+
+    return wrapper
+
+
+class SerialisedModel(ABC):
 
     """
     A SerialisedModel takes a dictionary, typically created by
@@ -44,7 +55,7 @@ class SerialisedModel(ABC, CacheMixin):
         return super().__dir__() + list(sorted(self.ALLOWED_PROPERTIES))
 
 
-class SerialisedModelCollection(ABC, CacheMixin):
+class SerialisedModelCollection(ABC):
 
     """
     A SerialisedModelCollection takes a list of dictionaries, typically
@@ -68,6 +79,7 @@ class SerialisedModelCollection(ABC, CacheMixin):
 
 
 class SerialisedTemplate(SerialisedModel):
+
     ALLOWED_PROPERTIES = {
         'archived',
         'content',
@@ -80,6 +92,23 @@ class SerialisedTemplate(SerialisedModel):
         'version',
     }
 
+    @classmethod
+    @cache
+    def from_template_id_and_service_id(cls, template_id, service_id):
+
+        from app.dao.templates_dao import dao_get_template_by_id_and_service_id
+        from app.schemas import template_schema
+
+        fetched_template = dao_get_template_by_id_and_service_id(
+            template_id=template_id,
+            service_id=service_id
+        )
+
+        template_dict = template_schema.dump(fetched_template).data
+
+        db.session.commit()
+        return cls(template_dict)
+
 
 class SerialisedService(SerialisedModel):
     ALLOWED_PROPERTIES = {
@@ -92,6 +121,14 @@ class SerialisedService(SerialisedModel):
         'restricted',
     }
 
+    @classmethod
+    @cache
+    def from_id(cls, service_id):
+        from app.schemas import service_schema
+        with AUTH_DB_CONNECTION_DURATION_SECONDS.time():
+            fetched = dao_fetch_service_by_id(service_id)
+        return cls(service_schema.dump(fetched).data)
+
 
 class SerialisedAPIKey(SerialisedModel):
     ALLOWED_PROPERTIES = {
@@ -104,3 +141,11 @@ class SerialisedAPIKey(SerialisedModel):
 
 class SerialisedAPIKeyCollection(SerialisedModelCollection):
     model = SerialisedAPIKey
+
+    @classmethod
+    @cache
+    def from_service_id(cls, service_id):
+        return cls([
+            {k: getattr(key, k) for k in SerialisedAPIKey.ALLOWED_PROPERTIES}
+            for key in get_model_api_keys(service_id)
+        ])