management command to remove excess input_state entries

lms/djangoapps/courseware/management/commands/remove_input_state.py

+'''
+This is a one-off command aimed at fixing a temporary problem encountered where input_state was added to
+the same dict object in capa problems, so was accumulating.  The fix is simply to remove input_state entry
+from state for all problems in the affected date range.
+'''
+
+import json
+import logging
+from optparse import make_option
+
+from django.core.management.base import BaseCommand
+from django.db import transaction
+
+from courseware.models import StudentModule, StudentModuleHistory
+
+LOG = logging.getLogger(__name__)
+
+
+class Command(BaseCommand):
+    '''
+    The fix here is to remove the "input_state" entry in the StudentModule objects of any problems that
+    contain them.  No problem is yet making use of this, and the code should do the right thing if it's
+    missing (by recreating an empty dict for its value).
+    
+    To narrow down the set of problems that might need fixing, the StudentModule
+    objects to be checked is filtered down to those:
+
+        created < '2013-03-29 16:30:00' (the problem must have been answered before the buggy code was reverted,
+                                         on Prod and Edge)
+        modified > '2013-03-28 22:00:00' (the problem must have been visited after the bug was introduced
+                                          on Prod and Edge)
+        state like '%input_state%' (the problem must have "input_state" set).
+    '''
+
+    num_visited = 0
+    num_changed = 0
+    num_hist_visited = 0
+    num_hist_changed = 0
+
+    option_list = BaseCommand.option_list + (
+        make_option('--save',
+                    action='store_true',
+                    dest='save_changes',
+                    default=False,
+                    help='Persist the changes that were encountered.  If not set, no changes are saved.'), )
+
+    def fix_studentmodules(self, save_changes):
+        '''Identify the list of StudentModule objects that might need fixing, and then fix each one'''
+        modules = StudentModule.objects.filter(modified__gt='2013-03-28 22:00:00',
+                                               created__lt='2013-03-29 16:30:00',
+                                               state__contains='input_state')
+
+        for module in modules:
+            self.remove_studentmodule_input_state(module, save_changes)
+
+        LOG.info("Finished student modules:  updating {0} of {1} modules".format(self.num_changed, self.num_visited))
+
+        hist_modules = StudentModuleHistory.objects.filter(created__gt='2013-03-28 22:00:00',
+                                                           created__lt='2013-03-29 16:30:00',
+                                                           state__contains='input_state')
+
+        for hist_module in hist_modules:
+            self.remove_studentmodulehistory_input_state(hist_module, save_changes)
+
+        LOG.info("Finished student history modules:  updating {0} of {1} modules".format(self.num_hist_changed, self.num_hist_visited))
+    
+    @transaction.autocommit
+    def remove_studentmodule_input_state(self, module, save_changes):
+        ''' Fix the grade assigned to a StudentModule'''
+        module_state = module.state
+        if module_state is None:
+            # not likely, since we filter on it.  But in general...
+            LOG.info("No state found for {type} module {id} for student {student} in course {course_id}"
+                     .format(type=module.module_type, id=module.module_state_key,
+                             student=module.student.username, course_id=module.course_id))
+            return
+
+        state_dict = json.loads(module_state)
+        self.num_visited += 1
+
+        if 'input_state' not in state_dict:
+            pass
+        elif save_changes:
+            # make the change and persist
+            del state_dict['input_state']
+            module.state = json.dumps(state_dict)
+            module.save()
+            self.num_changed += 1
+        else:
+            # don't make the change, but increment the count indicating the change would be made
+            self.num_changed += 1
+
+    @transaction.autocommit
+    def remove_studentmodulehistory_input_state(self, module, save_changes):
+        ''' Fix the grade assigned to a StudentModule'''
+        module_state = module.state
+        if module_state is None:
+            # not likely, since we filter on it.  But in general...
+            LOG.info("No state found for {type} module {id} for student {student} in course {course_id}"
+                     .format(type=module.module_type, id=module.module_state_key,
+                             student=module.student.username, course_id=module.course_id))
+            return
+
+        state_dict = json.loads(module_state)
+        self.num_hist_visited += 1
+
+        if 'input_state' not in state_dict:
+            pass
+        elif save_changes:
+            # make the change and persist
+            del state_dict['input_state']
+            module.state = json.dumps(state_dict)
+            module.save()
+            self.num_hist_changed += 1
+        else:
+            # don't make the change, but increment the count indicating the change would be made
+            self.num_hist_changed += 1
+
+    def handle(self, **options):
+        '''Handle management command request'''
+
+        save_changes = options['save_changes']
+
+        LOG.info("Starting run: save_changes = {0}".format(save_changes))
+
+        self.fix_studentmodules(save_changes)
+
+        LOG.info("Finished run:  updating {0} of {1} student modules".format(self.num_changed, self.num_visited))
+        LOG.info("Finished run:  updating {0} of {1} student history modules".format(self.num_hist_changed, self.num_hist_visited))