remove discussion cache, which isn't used

cms/one_time_startup.py

 from dogapi import dog_http_api, dog_stats_api
 from django.conf import settings
 from xmodule.modulestore.django import modulestore
-from cache_toolbox.discussion_cache import discussion_cache_register_for_updates
 from django.dispatch import Signal
 from request_cache.middleware import RequestCache
 
-from django.core.cache import get_cache, InvalidCacheBackendError
+from django.core.cache import get_cache
 
 cache = get_cache('mongo_metadata_inheritance')
 for store_name in settings.MODULESTORE:
@@ -13,12 +12,8 @@ for store_name in settings.MODULESTORE:
     store.metadata_inheritance_cache_subsystem = cache
     store.request_cache = RequestCache.get_request_cache()
 
-    modulestore_update_signal = Signal(
-                            providing_args=['modulestore', 'course_id', 'location']
-                        )
+    modulestore_update_signal = Signal(providing_args=['modulestore', 'course_id', 'location'])
     store.modulestore_update_signal = modulestore_update_signal
-    discussion_cache_register_for_updates(store)
-
 if hasattr(settings, 'DATADOG_API'):
     dog_http_api.api_key = settings.DATADOG_API
     dog_stats_api.start(api_key=settings.DATADOG_API, statsd=True)

common/djangoapps/cache_toolbox/discussion_cache.py

-import logging
-from django.core.cache import cache, get_cache
-from datetime import datetime
-
-def _get_discussion_cache():
-    return get_cache('mongo_metadata_inheritance')
-
-
-def get_discussion_cache_key(course_id):
-    return 'discussion_items_{0}'.format(course_id)
-
-
-def get_discussion_cache_entry(modulestore, course_id):
-    cache_entry = None
-    cache = _get_discussion_cache()
-    
-    if cache is not None:
-        cache_entry = cache.get(get_discussion_cache_key(course_id), None)
-        # @todo: add expiry here
-    
-    if cache_entry is None:
-        cache_entry = generate_discussion_cache_entry(modulestore, course_id)
-
-    return cache_entry.get('modules',[])
-
-
-def generate_discussion_cache_entry(modulestore, course_id):
-    # make this a NOP for now. We have to figure out how to pickle the result set
-    return
-    
-    components = course_id.split('/')
-    all_discussion_modules = modulestore.get_items(['i4x', components[0], components[1], 'discussion', None], 
-        course_id=course_id)
-
-    cache = _get_discussion_cache()
-    entry = {'modules': all_discussion_modules, 'timestamp': datetime.now()}
-    if cache is not None:
-        cache.set(get_discussion_cache_key(course_id), entry)
-    return entry
-
-
-def modulestore_update_signal_handler(modulestore = None, course_id = None, location = None, **kwargs):
-    """called when there is an write event in our modulestore
-    """
-    return
-    if location.category == 'discussion':
-        logging.debug('******* got modulestore update signal. Regenerating discussion cache for {0}'.format(course_id))
-        # refresh the cache entry if we've changed a discussion module
-        generate_discussion_cache_entry(modulestore, course_id)
-
-
-def discussion_cache_register_for_updates(modulestore):
-    if modulestore.modulestore_update_signal is not None:
-        modulestore.modulestore_update_signal.connect(modulestore_update_signal_handler)
\ No newline at end of file

common/lib/xmodule/xmodule/editing_module.py

@@ -40,10 +40,11 @@ class XMLEditingDescriptor(EditingDescriptor):
     js = {'coffee': [resource_string(__name__, 'js/src/raw/edit/xml.coffee')]}
     js_module_name = "XMLEditingDescriptor"
 
+
 class MetadataOnlyEditingDescriptor(EditingDescriptor):
     """
-    Module that provides a raw editing view of its data as XML. It does not perform
-    any validation of its definition
+    Module which only provides an editing interface for the metadata, it does
+    not expose a UI for editing the module data
     """
 
     js = {'coffee': [resource_string(__name__, 'js/src/raw/edit/metadata-only.coffee')]}
@@ -51,6 +52,7 @@ class MetadataOnlyEditingDescriptor(EditingDescriptor):
 
     mako_template = "widgets/metadata-only-edit.html"
 
+
 class JSONEditingDescriptor(EditingDescriptor):
     """
     Module that provides a raw editing view of its data as XML. It does not perform

common/lib/xmodule/xmodule/modulestore/mongo.py

@@ -329,7 +329,7 @@ class MongoModuleStore(ModuleStoreBase):
         '''
         key = metadata_cache_key(location)
         tree = {}
-        
+
         if not force_refresh:
             # see if we are first in the request cache (if present)
             if self.request_cache is not None and key in self.request_cache.data.get('metadata_inheritance', {}):
@@ -344,7 +344,7 @@ class MongoModuleStore(ModuleStoreBase):
         if not tree:
             # if not in subsystem, or we are on force refresh, then we have to compute
             tree = self.compute_metadata_inheritance_tree(location)
-            
+
             # now write out computed tree to caching subsystem (e.g. memcached), if available
             if self.metadata_inheritance_cache_subsystem is not None:
                 self.metadata_inheritance_cache_subsystem.set(key, tree)
@@ -578,11 +578,8 @@ class MongoModuleStore(ModuleStoreBase):
 
     def fire_updated_modulestore_signal(self, course_id, location):
         if self.modulestore_update_signal is not None:
-            self.modulestore_update_signal.send(None,
-                modulestore = self,
-                course_id = course_id,
-                location = location
-            )
+            self.modulestore_update_signal.send(self, modulestore=self, course_id=course_id,
+                                                location=location)
 
     def get_course_for_item(self, location, depth=0):
         '''
@@ -682,8 +679,7 @@ class MongoModuleStore(ModuleStoreBase):
         self._update_single_item(location, {'metadata': metadata})
         # recompute (and update) the metadata inheritance tree which is cached
         self.refresh_cached_metadata_inheritance_tree(loc)
-        self.fire_updated_modulestore_signal(get_course_id_no_run(Location(location)), Location(location))   
-
+        self.fire_updated_modulestore_signal(get_course_id_no_run(Location(location)), Location(location))
 
     def delete_item(self, location):
         """
@@ -707,7 +703,7 @@ class MongoModuleStore(ModuleStoreBase):
             safe=self.collection.safe)
         # recompute (and update) the metadata inheritance tree which is cached
         self.refresh_cached_metadata_inheritance_tree(Location(location))
-        self.fire_updated_modulestore_signal(get_course_id_no_run(Location(location)), Location(location))   
+        self.fire_updated_modulestore_signal(get_course_id_no_run(Location(location)), Location(location))
 
     def get_parent_locations(self, location, course_id):
         '''Find all locations that are the parents of this location in this

lms/djangoapps/django_comment_client/utils.py

@@ -16,7 +16,6 @@ from django.utils import simplejson
 from django_comment_client.models import Role
 from django_comment_client.permissions import check_permissions_by_view
 from xmodule.modulestore.exceptions import NoPathToItem
-from cache_toolbox.discussion_cache import get_discussion_cache_entry
 
 from mitxmako import middleware
 import pystache_custom as pystache