Extract common django-orm-backed-cache functionality
This commit is contained in:
Calen Pennington
@@ -3,6 +3,7 @@ Classes to provide the LMS runtime data storage to XBlocks
|
||||
"""
|
||||
|
||||
import json
|
||||
from abc import abstractmethod, ABCMeta
|
||||
from collections import defaultdict
|
||||
from itertools import chain
|
||||
from .models import (
|
||||
@@ -98,137 +99,238 @@ def _all_block_types(descriptors, aside_types):
|
||||
return block_types
|
||||
|
||||
|
||||
class UserStateCache(object):
|
||||
class DjangoOrmFieldCache(object):
|
||||
"""
|
||||
Baseclass for Scope-specific field cache objects that are based on
|
||||
single-row-per-field Django ORM objects.
|
||||
"""
|
||||
__metaclass__ = ABCMeta
|
||||
|
||||
def __init__(self):
|
||||
self._cache = {}
|
||||
|
||||
def cache_fields(self, fields, xblocks, aside_types):
|
||||
"""
|
||||
Load all fields specified by ``fields`` for the supplied ``xblocks``
|
||||
and ``aside_types`` into this cache.
|
||||
|
||||
Arguments:
|
||||
fields (list of str): Field names to cache.
|
||||
xblocks (list of :class:`XBlock`): XBlocks to cache fields for.
|
||||
aside_types (list of str): Aside types to cache fields for.
|
||||
"""
|
||||
for field_object in self._read_objects(fields, xblocks, aside_types):
|
||||
self._cache[self._cache_key_for_field_object(field_object)] = field_object
|
||||
|
||||
def get(self, cache_key):
|
||||
return self._cache.get(cache_key)
|
||||
|
||||
def set(self, cache_key, value):
|
||||
self._cache[cache_key] = value
|
||||
|
||||
def __len__(self):
|
||||
return len(self._cache)
|
||||
|
||||
@abstractmethod
|
||||
def _create_object(self, kvs_key, value):
|
||||
"""
|
||||
Create a new object to add to the cache (which should record
|
||||
the specified field ``value`` for the field identified by
|
||||
``kvs_key``).
|
||||
|
||||
Arguments:
|
||||
kvs_key (:class:`DjangoKeyValueStore.Key`): Which field to create an entry for
|
||||
value: What value to record in the field
|
||||
"""
|
||||
raise NotImplementedError()
|
||||
|
||||
@abstractmethod
|
||||
def _read_objects(self, fields, xblocks, aside_types):
|
||||
"""
|
||||
Return an iterator for all objects stored in the underlying datastore
|
||||
for the ``fields`` on the ``xblocks`` and the ``aside_types`` associated
|
||||
with them.
|
||||
|
||||
Arguments:
|
||||
fields (list of str): Field names to return values for
|
||||
xblocks (list of :class:`~XBlock`): XBlocks to load fields for
|
||||
aside_types (list of str): Asides to load field for (which annotate the supplied
|
||||
xblocks).
|
||||
"""
|
||||
raise NotImplementedError()
|
||||
|
||||
@abstractmethod
|
||||
def _cache_key_for_field_object(self, field_object):
|
||||
"""
|
||||
Return the key used in this DjangoOrmFieldCache to store the specified field_object.
|
||||
|
||||
Arguments:
|
||||
field_object: A Django model instance that stores the data for fields in this cache
|
||||
"""
|
||||
raise NotImplementedError()
|
||||
|
||||
@abstractmethod
|
||||
def _cache_key_for_kvs_key(self, key):
|
||||
"""
|
||||
Return the key used in this DjangoOrmFieldCache for the specified KeyValueStore key.
|
||||
|
||||
Arguments:
|
||||
key (:class:`~DjangoKeyValueStore.Key`): The key representing the cached field
|
||||
"""
|
||||
raise NotImplementedError()
|
||||
|
||||
|
||||
class UserStateCache(DjangoOrmFieldCache):
|
||||
"""
|
||||
Cache for Scope.user_state xblock field data.
|
||||
"""
|
||||
def __init__(self, user, course_id, select_for_update=False):
|
||||
super(UserStateCache, self).__init__()
|
||||
self.course_id = course_id
|
||||
self._cache = {}
|
||||
self.user = user
|
||||
self.select_for_update = select_for_update
|
||||
|
||||
def cache_fields(self, fields, descriptors, aside_types):
|
||||
data = _chunked_query(
|
||||
def _read_objects(self, fields, xblocks, aside_types):
|
||||
"""
|
||||
Return an iterator for all objects stored in the underlying datastore
|
||||
for the ``fields`` on the ``xblocks`` and the ``aside_types`` associated
|
||||
with them.
|
||||
|
||||
Arguments:
|
||||
fields (list of str): Field names to return values for
|
||||
xblocks (list of :class:`~XBlock`): XBlocks to load fields for
|
||||
aside_types (list of str): Asides to load field for (which annotate the supplied
|
||||
xblocks).
|
||||
"""
|
||||
return _chunked_query(
|
||||
StudentModule,
|
||||
self.select_for_update,
|
||||
'module_state_key__in',
|
||||
_all_usage_keys(descriptors, aside_types),
|
||||
_all_usage_keys(xblocks, aside_types),
|
||||
course_id=self.course_id,
|
||||
student=self.user.pk,
|
||||
)
|
||||
for field_object in data:
|
||||
self._cache[self.cache_key_for_field_object(field_object)] = field_object
|
||||
|
||||
def cache_key_for_field_object(self, field_object):
|
||||
def _cache_key_for_field_object(self, field_object):
|
||||
return field_object.module_state_key.map_into_course(self.course_id)
|
||||
|
||||
def get(self, cache_key):
|
||||
return self._cache.get(cache_key)
|
||||
|
||||
def set(self, cache_key, value):
|
||||
self._cache[cache_key] = value
|
||||
|
||||
def __len__(self):
|
||||
return len(self._cache)
|
||||
|
||||
class UserStateSummaryCache(object):
|
||||
class UserStateSummaryCache(DjangoOrmFieldCache):
|
||||
"""
|
||||
Cache for Scope.user_state_summary xblock field data.
|
||||
"""
|
||||
def __init__(self, course_id, select_for_update=False):
|
||||
super(UserStateSummaryCache, self).__init__()
|
||||
self.course_id = course_id
|
||||
self._cache = {}
|
||||
self.select_for_update = select_for_update
|
||||
|
||||
def cache_fields(self, fields, descriptors, aside_types):
|
||||
data = _chunked_query(
|
||||
def _read_objects(self, fields, xblocks, aside_types):
|
||||
"""
|
||||
Return an iterator for all objects stored in the underlying datastore
|
||||
for the ``fields`` on the ``xblocks`` and the ``aside_types`` associated
|
||||
with them.
|
||||
|
||||
Arguments:
|
||||
fields (list of str): Field names to return values for
|
||||
xblocks (list of :class:`~XBlock`): XBlocks to load fields for
|
||||
aside_types (list of str): Asides to load field for (which annotate the supplied
|
||||
xblocks).
|
||||
"""
|
||||
return _chunked_query(
|
||||
XModuleUserStateSummaryField,
|
||||
self.select_for_update,
|
||||
'usage_id__in',
|
||||
_all_usage_keys(descriptors, aside_types),
|
||||
_all_usage_keys(xblocks, aside_types),
|
||||
field_name__in=set(field.name for field in fields),
|
||||
)
|
||||
for field_object in data:
|
||||
self._cache[self.cache_key_for_field_object(field_object)] = field_object
|
||||
|
||||
def cache_key_for_field_object(self, field_object):
|
||||
def _cache_key_for_field_object(self, field_object):
|
||||
"""
|
||||
Return the key used in this DjangoOrmFieldCache to store the specified field_object.
|
||||
|
||||
Arguments:
|
||||
field_object: A Django model instance that stores the data for fields in this cache
|
||||
"""
|
||||
return (field_object.usage_id.map_into_course(self.course_id), field_object.field_name)
|
||||
|
||||
def get(self, cache_key):
|
||||
return self._cache.get(cache_key)
|
||||
|
||||
def set(self, cache_key, value):
|
||||
self._cache[cache_key] = value
|
||||
|
||||
def __len__(self):
|
||||
return len(self._cache)
|
||||
|
||||
|
||||
class PreferencesCache(object):
|
||||
class PreferencesCache(DjangoOrmFieldCache):
|
||||
"""
|
||||
Cache for Scope.preferences xblock field data.
|
||||
"""
|
||||
def __init__(self, user, select_for_update=False):
|
||||
super(PreferencesCache, self).__init__()
|
||||
self.user = user
|
||||
self.select_for_update = select_for_update
|
||||
self._cache = {}
|
||||
|
||||
def cache_fields(self, fields, descriptors, aside_types):
|
||||
data = _chunked_query(
|
||||
def _read_objects(self, fields, xblocks, aside_types):
|
||||
"""
|
||||
Return an iterator for all objects stored in the underlying datastore
|
||||
for the ``fields`` on the ``xblocks`` and the ``aside_types`` associated
|
||||
with them.
|
||||
|
||||
Arguments:
|
||||
fields (list of str): Field names to return values for
|
||||
xblocks (list of :class:`~XBlock`): XBlocks to load fields for
|
||||
aside_types (list of str): Asides to load field for (which annotate the supplied
|
||||
xblocks).
|
||||
"""
|
||||
return _chunked_query(
|
||||
XModuleStudentPrefsField,
|
||||
self.select_for_update,
|
||||
'module_type__in',
|
||||
_all_block_types(descriptors, aside_types),
|
||||
_all_block_types(xblocks, aside_types),
|
||||
student=self.user.pk,
|
||||
field_name__in=set(field.name for field in fields),
|
||||
)
|
||||
for field_object in data:
|
||||
self._cache[self.cache_key_for_field_object(field_object)] = field_object
|
||||
|
||||
def cache_key_for_field_object(self, field_object):
|
||||
def _cache_key_for_field_object(self, field_object):
|
||||
"""
|
||||
Return the key used in this DjangoOrmFieldCache to store the specified field_object.
|
||||
|
||||
Arguments:
|
||||
field_object: A Django model instance that stores the data for fields in this cache
|
||||
"""
|
||||
return (field_object.module_type, field_object.field_name)
|
||||
|
||||
def get(self, cache_key):
|
||||
return self._cache.get(cache_key)
|
||||
|
||||
def set(self, cache_key, value):
|
||||
self._cache[cache_key] = value
|
||||
|
||||
def __len__(self):
|
||||
return len(self._cache)
|
||||
|
||||
|
||||
class UserInfoCache(object):
|
||||
class UserInfoCache(DjangoOrmFieldCache):
|
||||
"""
|
||||
Cache for Scope.user_info xblock field data
|
||||
"""
|
||||
def __init__(self, user, select_for_update=False):
|
||||
self._cache = {}
|
||||
super(UserInfoCache, self).__init__()
|
||||
self.user = user
|
||||
self.select_for_update = select_for_update
|
||||
|
||||
def cache_fields(self, fields, descriptors, aside_types):
|
||||
data = _query(
|
||||
def _read_objects(self, fields, xblocks, aside_types):
|
||||
"""
|
||||
Return an iterator for all objects stored in the underlying datastore
|
||||
for the ``fields`` on the ``xblocks`` and the ``aside_types`` associated
|
||||
with them.
|
||||
|
||||
Arguments:
|
||||
fields (list of str): Field names to return values for
|
||||
xblocks (list of :class:`~XBlock`): XBlocks to load fields for
|
||||
aside_types (list of str): Asides to load field for (which annotate the supplied
|
||||
xblocks).
|
||||
"""
|
||||
return _query(
|
||||
XModuleStudentInfoField,
|
||||
self.select_for_update,
|
||||
student=self.user.pk,
|
||||
field_name__in=set(field.name for field in fields),
|
||||
)
|
||||
for field_object in data:
|
||||
self._cache[self.cache_key_for_field_object(field_object)] = field_object
|
||||
|
||||
def cache_key_for_field_object(self, field_object):
|
||||
def _cache_key_for_field_object(self, field_object):
|
||||
"""
|
||||
Return the key used in this DjangoOrmFieldCache to store the specified field_object.
|
||||
|
||||
Arguments:
|
||||
field_object: A Django model instance that stores the data for fields in this cache
|
||||
"""
|
||||
return field_object.field_name
|
||||
|
||||
def get(self, cache_key):
|
||||
return self._cache.get(cache_key)
|
||||
|
||||
def set(self, cache_key, value):
|
||||
self._cache[cache_key] = value
|
||||
|
||||
def __len__(self):
|
||||
return len(self._cache)
|
||||
|
||||
|
||||
class FieldDataCache(object):
|
||||
|
||||
Reference in New Issue
Block a user