Merge pull request #1770 from MITx/fix/brian/remove-input_state

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, CommandError
+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).
+
+    This filtering is done on the production database replica, so that the larger select queries don't lock
+    the real production database.  The list of id values for Student Modules is written to a file, and the
+    file is passed into this command.  The sql file passed to mysql contains:
+
+        select sm.id from courseware_studentmodule sm
+            where sm.modified > "2013-03-28 22:00:00"
+                and sm.created < "2013-03-29 16:30:00"
+                and sm.state like "%input_state%"
+                and sm.module_type = 'problem';
+
+    '''
+
+    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_in_list(self, save_changes, idlist_path):
+        '''Read in the list of StudentModule objects that might need fixing, and then fix each one'''
+
+        # open file and read id values from it:
+        for line in open(idlist_path, 'r'):
+            student_module_id = line.strip()
+            # skip the header, if present:
+            if student_module_id == 'id':
+                continue
+            try:
+                module = StudentModule.objects.get(id=student_module_id)
+            except StudentModule.DoesNotExist:
+                LOG.error("Unable to find student module with id = {0}: skipping... ".format(student_module_id))
+                continue
+            self.remove_studentmodule_input_state(module, save_changes)
+
+            hist_modules = StudentModuleHistory.objects.filter(student_module_id=student_module_id)
+            for hist_module in hist_modules:
+                self.remove_studentmodulehistory_input_state(hist_module, save_changes)
+
+    @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, *args, **options):
+        '''Handle management command request'''
+        if len(args) != 1:
+            raise CommandError("missing idlist file")
+        idlist_path = args[0]
+        save_changes = options['save_changes']
+        LOG.info("Starting run:  reading from idlist file {0}; save_changes = {1}".format(idlist_path, save_changes))
+
+        self.fix_studentmodules_in_list(save_changes, idlist_path)
+
+        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))