Revert commits about evaluating the queryset at the end.

This reverts commit a0a17c3630985fe960211708f5b90acf449f76b3.
This reverts commit 92122270e5815cbbf301a6e247c682a05717b19d.
This reverts commit c5d4c4d347e99be00258d55ec6338e3749084bbe.
This reverts commit c78876087d29511b6126132a213f4267249a869f.

src/c3nav/editor/wrappers.py

@@ -1,6 +1,5 @@
 import typing
-from collections import Iterable, deque
-from functools import wraps
+from collections import deque
 from itertools import chain
 
 from django.db import models
@@ -10,8 +9,7 @@ from django.db.models.query_utils import DeferredAttribute
 
 
 class BaseWrapper:
-    _not_wrapped = ('_changeset', '_author', '_obj', '_commands', '_with_commands_executed', '_wrap_instances',
-                    '_initial_values')
+    _not_wrapped = ('_changeset', '_author', '_obj', '_changes_qs', '_initial_values', '_wrap_instances')
     _allowed_callables = ('', )
 
     def __init__(self, changeset, obj, author=None):
@@ -208,72 +206,47 @@ class ModelInstanceWrapper(BaseWrapper):
         self._changeset.add_delete(self, author=author)
 
 
-def modifies_query(f):
-    @wraps(f)
-    def wrapper(self, *args, execute=False, **kwargs):
-        if execute:
-            return f(self, *args, **kwargs)
-        if f.__name__ in ('filter', 'exclude'):
-            kwargs = {name: (tuple(value) if name.endswith('__in') and isinstance(value, Iterable) else value)
-                      for name, value in kwargs.items()}
-        qs = self._wrap_queryset(self.get_queryset(), add_command=(f.__name__, args, kwargs))
-        qs.execute_commands()
-        return qs
-    return wrapper
-
-
-def executes_query(f):
-    @wraps(f)
-    def wrapper(self, *args, **kwargs):
-        return f(self._with_commands_executed, *args, **kwargs)
-    return wrapper
+class ChangesQuerySet:
+    def __init__(self, changeset, model, author):
+        self._changeset = changeset
+        self._model = model
+        self._author = author
 
 
 class BaseQueryWrapper(BaseWrapper):
     _allowed_callables = ('_add_hints', '_next_is_sticky', 'get_prefetch_queryset')
 
-    def __init__(self, changeset, obj, author=None, commands=(), wrap_instances=True):
+    def __init__(self, changeset, obj, author=None, changes_qs=None, wrap_instances=True):
         super().__init__(changeset, obj, author)
+        if changes_qs is None:
+            changes_qs = ChangesQuerySet(changeset, obj.model, author)
+        self._changes_qs = changes_qs
         self._wrap_instances = wrap_instances
-        self._commands = commands
-        self._with_commands_executed = self
 
     def get_queryset(self):
         return self._obj
 
-    def execute_commands(self):
-        result = self
-        for name, args, kwargs in self._commands:
-            result = getattr(result, name)(*args, execute=True, **kwargs)
-        result._commands = ()
-        self._with_commands_executed = result
-
     def _wrap_instance(self, instance):
         if self._wrap_instances:
             return super()._wrap_instance(instance)
         return instance
 
-    def _wrap_queryset(self, queryset, add_command=None, wrap_instances=None):
+    def _wrap_queryset(self, queryset, changes_qs=None, wrap_instances=None):
+        if changes_qs is None:
+            changes_qs = self._changes_qs
         if wrap_instances is None:
             wrap_instances = self._wrap_instances
-        commands = self._commands
-        if add_command is not None:
-            commands += (add_command, )
-        return QuerySetWrapper(self._changeset, queryset, self._author, commands, wrap_instances)
+        return QuerySetWrapper(self._changeset, queryset, self._author, changes_qs, wrap_instances)
 
-    @modifies_query
     def all(self):
         return self._wrap_queryset(self.get_queryset().all())
 
-    @modifies_query
     def none(self):
         return self._wrap_queryset(self.get_queryset().none())
 
-    @modifies_query
     def select_related(self, *args, **kwargs):
         return self._wrap_queryset(self.get_queryset().select_related(*args, **kwargs))
 
-    @modifies_query
     def prefetch_related(self, *lookups):
         new_lookups = deque()
         for lookup in lookups:
@@ -288,7 +261,6 @@ class BaseQueryWrapper(BaseWrapper):
             new_lookups.append(Prefetch(lookup, qs))
         return self._wrap_queryset(self.get_queryset().prefetch_related(*new_lookups))
 
-    @executes_query
     def get(self, *args, **kwargs):
         results = tuple(self.filter(*args, **kwargs))
         if len(results) == 1:
@@ -297,7 +269,6 @@ class BaseQueryWrapper(BaseWrapper):
             raise self._obj.model.DoesNotExist
         raise self._obj.model.MultipleObjectsReturned
 
-    @modifies_query
     def order_by(self, *args):
         return self._wrap_queryset(self.get_queryset().order_by(*args))
 
@@ -413,42 +384,33 @@ class BaseQueryWrapper(BaseWrapper):
             tuple(self._filter_kwarg(name, value) for name, value in kwargs.items())
         )
 
-    @modifies_query
     def filter(self, *args, **kwargs):
         return self._wrap_queryset(self.get_queryset().filter(*self._filter(*args, **kwargs)))
 
-    @modifies_query
     def exclude(self, *args, **kwargs):
         return self._wrap_queryset(self.get_queryset().exclude(*self._filter(*args, **kwargs)))
 
-    @executes_query
     def count(self):
         return self.get_queryset().count()
 
-    @executes_query
     def values_list(self, *args, flat=False):
         return self.get_queryset().values_list(*args, flat=flat)
 
-    @executes_query
     def first(self):
         first = self.get_queryset().first()
         if first is not None:
             first = self._wrap_instance(first)
         return first
 
-    @modifies_query
     def using(self, alias):
         return self._wrap_queryset(self.get_queryset().using(alias))
 
-    @executes_query
     def __iter__(self):
         return iter((self._wrap_instance(instance) for instance in self.get_queryset()))
 
-    @executes_query
     def iterator(self):
         return iter((self._wrap_instance(instance) for instance in self.get_queryset().iterator()))
 
-    @executes_query
     def __len__(self):
         return len(self.get_queryset())