refactor: deprecates ModuleSystem properties for code sandboxing and cache

* Deprecates ModuleSystem can_execute_unsafe_code, get_python_lib_zip and cache properties
* Adds a new CacheService and SandboxService to provide the deprecated property
* Adds tests for the added CacheService and SandboxService
* Updates the ModuleSystemShim tests in Lms and Studio

openedx/core/djangoapps/xblock/runtime/runtime.py

@@ -10,6 +10,7 @@ from completion.waffle import ENABLE_COMPLETION_TRACKING_SWITCH
 from completion.models import BlockCompletion
 from completion.services import CompletionService
 from django.contrib.auth import get_user_model
+from django.core.cache import cache
 from django.core.exceptions import PermissionDenied
 from functools import lru_cache  # lint-amnesty, pylint: disable=wrong-import-order
 from eventtracking import tracker
@@ -19,6 +20,10 @@ from xblock.field_data import SplitFieldData
 from xblock.fields import Scope
 from xblock.runtime import KvsFieldData, MemoryIdManager, Runtime
 
+from xmodule.errortracker import make_error_tracker
+from xmodule.contentstore.django import contentstore
+from xmodule.modulestore.django import ModuleI18nService
+from xmodule.util.sandboxing import SandboxService
 from common.djangoapps.edxmako.services import MakoService
 from common.djangoapps.track import contexts as track_contexts
 from common.djangoapps.track import views as track_views
@@ -30,10 +35,9 @@ from openedx.core.djangoapps.xblock.runtime.blockstore_field_data import Blockst
 from openedx.core.djangoapps.xblock.runtime.ephemeral_field_data import EphemeralKeyValueStore
 from openedx.core.djangoapps.xblock.runtime.mixin import LmsBlockMixin
 from openedx.core.djangoapps.xblock.utils import get_xblock_id_for_anonymous_user
+from openedx.core.lib.cache_utils import CacheService
 from openedx.core.lib.xblock_utils import wrap_fragment, xblock_local_resource_url
 from common.djangoapps.static_replace import process_static_urls
-from xmodule.errortracker import make_error_tracker  # lint-amnesty, pylint: disable=wrong-import-order
-from xmodule.modulestore.django import ModuleI18nService  # lint-amnesty, pylint: disable=wrong-import-order
 
 from .id_managers import OpaqueKeyReader
 from .shims import RuntimeShim, XBlockShim
@@ -240,6 +244,12 @@ class XBlockRuntime(RuntimeShim, Runtime):
             return MakoService()
         elif service_name == "i18n":
             return ModuleI18nService(block=block)
+        elif service_name == 'sandbox':
+            context_key = block.scope_ids.usage_id.context_key
+            return SandboxService(contentstore=contentstore, course_id=context_key)
+        elif service_name == 'cache':
+            return CacheService(cache)
+
         # Check if the XBlockRuntimeSystem wants to handle this:
         service = self.system.get_service(block, service_name)
         # Otherwise, fall back to the base implementation which loads services

openedx/core/lib/cache_utils.py

@@ -223,3 +223,27 @@ def get_cache(name):
     """
     assert name is not None
     return RequestCache(name).data
+
+
+class CacheService:
+    """
+    An XBlock service which provides a cache.
+
+    Args:
+        cache(object): provides get/set functions for retrieving/storing key/value pairs.
+    """
+    def __init__(self, cache, **kwargs):
+        super().__init__(**kwargs)
+        self._cache = cache
+
+    def get(self, key, *args, **kwargs):
+        """
+        Returns the value cached against the given key, or None.
+        """
+        return self._cache.get(key, *args, **kwargs)
+
+    def set(self, key, value, *args, **kwargs):
+        """
+        Caches the value against the given key.
+        """
+        return self._cache.set(key, value, *args, **kwargs)

openedx/core/lib/tests/test_cache_utils.py

@@ -1,14 +1,16 @@
 """
 Tests for cache_utils.py
 """
-
+from time import sleep
 from unittest import TestCase
 from unittest.mock import Mock
 
 import ddt
 from edx_django_utils.cache import RequestCache
+from django.core.cache import cache
+from django.test.utils import override_settings
 
-from openedx.core.lib.cache_utils import request_cached
+from openedx.core.lib.cache_utils import CacheService, request_cached
 
 
 @ddt.ddt
@@ -295,3 +297,26 @@ class TestRequestCachedDecorator(TestCase):
         result = wrapped(3)
         assert result == 2
         assert to_be_wrapped.call_count == 2
+
+
+class CacheServiceTest(TestCase):
+    """
+    Test CacheService methods.
+    """
+    @override_settings(CACHES={
+        'default': {
+            'BACKEND': 'django.core.cache.backends.locmem.LocMemCache',
+        }
+    })
+    def test_cache(self):
+        '''
+        Ensure the default cache works as expected.
+        '''
+        cache_service = CacheService(cache)
+        key = 'my_key'
+        value = 'some random value'
+        timeout = 1
+        cache_service.set(key, value, timeout=timeout)
+        assert cache_service.get(key) == value
+        sleep(timeout)
+        assert cache_service.get(key) is None