Functionality that is in edx-platform/common/lib/xmodule/xmodule/modulestore:

• mongo/* ("old mongo")
  • Stores xmodules as a single document along with definitions and children
  • Has draft/published functionality
  • Implements a KVS
  • Implements a caching descriptor system
  • Implements bulk ops to prevent the cache from being cleared repeatedly during a publish
  • Implements a modulestore which:
    • Implements inheritance at the Mongo level
    • Implements draft / publish at the Mongo level
    • Allows CRUD access to courses, asset metadata, module data, etc.
  • Implements some Mongo management
• split_mongo/* ("split mongo")
  
  • All of the same things as old mongo, but in the split methodology. Plus:
  • Implements a lazy loader for xblocks
  • Implements a cached id manager for split mongo
  • Implements a "write only dirty" pattern
  • Stores library data as well
• xml.py / xml_importer.py / xml_exporter.py
  • Handles importing / exporting courses from OLX on disk
• A handful of other utilities / helpers:
  • Django signals helper
  • Versioning helper for draft modulestores
  • edit_info mixin
  • custom exceptions
  • additional inheritance code
  • MixedModuleStore for aggregating across different modulestore, including across old and split instances
  • Helper functions for dealing with settings
  • Cusom field types for mongoengine
  • Search helpers
  • Helper for migrating xml or old mongo modulestore instances to split
  • A handful of other utils

That functionality is what I would deem "modulestore", personally. A pretty flexible way of storing off module data for course trees.

Other things that live in edx-platform/common/lib/xmodule/ and edx-platform/common/lib/xmodule/xmodule:

• assetstore
• contentstore
• bunches of test files
• templates, css, and js for xmodules / xblocks in those dirs
• user partitioning code
• some random util methods
• many things called "modules", only some of which are xmodules:
  • video_module
  • many things dealing with annotation
  • backcompat_module
    • Smooths transition from old xml modulestore formats to newer
  • capa stuff
  • XModuleMixin and CourseOverview shared util code
  • conditional_module
  • course_metadata_utils
  • course_module
  • editing_module
  • edx_notes
  • error_module
  • 38 more files....

Places where modulestore (edx-platform/common/lib/xmodule/xmodule/modulestore) calls up to "higher level" code:

• mongo/base.py

  • from xmodule.assetstore import AssetMetadata, CourseAssetsFromStorage
    from xmodule.course_module import CourseSummary
    from xmodule.error_module import ErrorDescriptor
    from xmodule.errortracker import null_error_tracker, exc_info_to_str
    from xmodule.exceptions import HeartbeatFailure
    from xmodule.mako_module import MakoDescriptorSystem
    from xmodule.mongo_utils import connect_to_mongodb, create_collection_index
    from xmodule.partitions.partitions_service import PartitionService
    from xmodule.services import SettingsService

• split_mongo/caching_descriptor_system.py

  • from xmodule.library_tools import LibraryToolsService
    from xmodule.mako_module import MakoDescriptorSystem
    from xmodule.error_module import ErrorDescriptor
    from xmodule.errortracker import exc_info_to_str
    from xmodule.x_module import XModuleMixin

• split_mongo/mongo_connection.py

  • from xmodule.exceptions import HeartbeatFailure
    from xmodule.mongo_utils import connect_to_mongodb, create_collection_index

• split_mongo/split.py

  • from xmodule.course_module import CourseSummary
    from xmodule.errortracker import null_error_tracker
    from ..exceptions import ItemNotFoundError
    from xmodule.partitions.partitions_service import PartitionService
    from xmodule.error_module import ErrorDescriptor
    from xmodule.assetstore import AssetMetadata

• split_mongo/split_draft.py

  • from xmodule.exceptions import InvalidVersionError

• __init__.py