]> git.openstreetmap.org Git - osqa.git/blobdiff - forum/models/base.py
Prevents questions on which the slug comes out empty to enter a redirect loop.
[osqa.git] / forum / models / base.py
index 43668d9bcb0c0065818307572a93f48cab400344..3d54d75e95d8025efee2a6af8c97ebf3b47e60a8 100644 (file)
@@ -14,44 +14,59 @@ from django.utils.translation import ugettext as _
 from django.utils.safestring import mark_safe
 from django.contrib.sitemaps import ping_google
 import django.dispatch
-from django.conf import settings
-from forum import const
+from forum import settings
 import logging
 
-from forum.const import *
 
-class CachedManager(models.Manager):
-    use_for_related_fields = True
-    int_cache_re = re.compile('^_[\w_]+cache$')
+class LazyQueryList(object):
+    def __init__(self, model, items):
+        self.model = model
+        self.items = items
+
+    def __getitem__(self, k):
+        return self.model.objects.get(id=self.items[k])
 
-    def cache_obj(self, obj):
-        int_cache_keys = [k for k in obj.__dict__.keys() if self.int_cache_re.match(k)]
+    def __iter__(self):
+        for id in self.items:
+            yield self.model.objects.get(id=id)
 
-        for k in int_cache_keys:
-            del obj.__dict__[k]
+    def __len__(self):
+        return len(self.items)
+
+class CachedQuerySet(models.query.QuerySet):
+    def lazy(self):
+        if len(self.query.extra) == 0:
+            return LazyQueryList(self.model, list(self.values_list('id', flat=True)))
+        else:
+            return self
 
-        cache.set(self.model.cache_key(obj.id), obj, 60 * 60)
+    def obj_from_datadict(self, datadict):
+        obj = self.model()
+        obj.__dict__.update(datadict)
+        return obj
 
     def get(self, *args, **kwargs):
-        try:
-            pk = [v for (k,v) in kwargs.items() if k in ('pk', 'pk__exact', 'id', 'id__exact'
-                            ) or k.endswith('_ptr__pk') or k.endswith('_ptr__id')][0]
-        except:
-            pk = None
+        key = self.model.infer_cache_key(kwargs)
 
-        if pk is not None:
-            key = self.model.cache_key(pk)
+        if key is not None:
             obj = cache.get(key)
 
             if obj is None:
-                obj = super(CachedManager, self).get(*args, **kwargs)
-                self.cache_obj(obj)
+                obj = super(CachedQuerySet, self).get(*args, **kwargs)
+                obj.cache()
             else:
-                d = obj.__dict__
+                obj = self.obj_from_datadict(obj)
+                obj.reset_original_state()
 
             return obj
-        
-        return super(CachedManager, self).get(*args, **kwargs)
+
+        return super(CachedQuerySet, self).get(*args, **kwargs) 
+
+class CachedManager(models.Manager):
+    use_for_related_fields = True
+
+    def get_query_set(self):
+        return CachedQuerySet(self.model)
 
     def get_or_create(self, *args, **kwargs):
         try:
@@ -59,183 +74,138 @@ class CachedManager(models.Manager):
         except:
             return super(CachedManager, self).get_or_create(*args, **kwargs)
 
-denorm_update = django.dispatch.Signal(providing_args=["instance", "field", "old", "new"])
 
-class DenormalizedField(models.IntegerField):
-    __metaclass__ = models.SubfieldBase
-
-    def contribute_to_class(self, cls, name):
-        super (DenormalizedField, self).contribute_to_class(cls, name)
-        if not hasattr(cls, '_denormalizad_fields'):
-            cls._denormalizad_fields = []
-
-        cls._denormalizad_fields.append(name)
-
-class BaseModel(models.Model):
-    objects = CachedManager()
+class DenormalizedField(object):
+    def __init__(self, manager, *args, **kwargs):
+        self.manager = manager
+        self.filter = (args, kwargs)
 
-    class Meta:
-        abstract = True
-        app_label = 'forum'
+    def setup_class(self, cls, name):
+        dict_name = '_%s_dencache_' % name
 
-    def __init__(self, *args, **kwargs):
-        super(BaseModel, self).__init__(*args, **kwargs)
-        self._original_state = dict([(k, v) for k,v in self.__dict__.items() if not k in kwargs])
+        def getter(inst):
+            val = inst.__dict__.get(dict_name, None)
 
-    @classmethod
-    def cache_key(cls, pk):
-        return '%s.%s:%s' % (settings.APP_URL, cls.__name__, pk)
+            if val is None:
+                val = getattr(inst, self.manager).filter(*self.filter[0], **self.filter[1]).count()
+                inst.__dict__[dict_name] = val
+                inst.cache()
 
-    def get_dirty_fields(self):
-        missing = object()
-        return dict([(k, self._original_state.get(k, None)) for k,v in self.__dict__.items()
-                 if self._original_state.get(k, missing) == missing or self._original_state[k] != v])
+            return val
 
-    def save(self, *args, **kwargs):
-        put_back = None
+        def reset_cache(inst):
+            inst.__dict__.pop(dict_name, None)
+            inst.uncache()
 
-        if hasattr(self.__class__, '_denormalizad_fields'):
-            dirty = self.get_dirty_fields()
-            put_back = [f for f in self.__class__._denormalizad_fields if f in dirty]
+        cls.add_to_class(name, property(getter))
+        cls.add_to_class("reset_%s_cache" % name, reset_cache)
 
-            if put_back:
-                for n in put_back:
-                    self.__dict__[n] = models.F(n) + (self.__dict__[n] - dirty[n])
 
-        super(BaseModel, self).save(*args, **kwargs)
+class BaseMetaClass(models.Model.__metaclass__):
+    to_denormalize = []
 
-        if put_back:
-            try:
-                self.__dict__.update(
-                    self.__class__.objects.filter(id=self.id).values(*put_back)[0]
-                )
-                for f in put_back:
-                    denorm_update.send(sender=self.__class__, instance=self, field=f,
-                                       old=self._original_state[f], new=self.__dict__[f])
-            except:
-                #todo: log this properly
-                pass
+    def __new__(cls, *args, **kwargs):
+        new_cls = super(BaseMetaClass, cls).__new__(cls, *args, **kwargs)
 
-        self._original_state = dict(self.__dict__)
-        self.__class__.objects.cache_obj(self)
+        BaseMetaClass.to_denormalize.extend(
+            [(new_cls, name, field) for name, field in new_cls.__dict__.items() if isinstance(field, DenormalizedField)]
+        )
 
-    def delete(self):
-        cache.delete(self.cache_key(self.pk))
-        super(BaseModel, self).delete()
+        return new_cls
 
+    @classmethod
+    def setup_denormalizes(cls):
+        for new_cls, name, field in BaseMetaClass.to_denormalize:
+            field.setup_class(new_cls, name)
 
-class ActiveObjectManager(models.Manager):
-    use_for_related_fields = True
-    def get_query_set(self):
-        return super(ActiveObjectManager, self).get_query_set().filter(canceled=False)
 
-class UndeletedObjectManager(models.Manager):
-    def get_query_set(self):
-        return super(UndeletedObjectManager, self).get_query_set().filter(deleted=False)
+class BaseModel(models.Model):
+    __metaclass__ = BaseMetaClass
 
-class GenericContent(models.Model):
-    content_type   = models.ForeignKey(ContentType)
-    object_id      = models.PositiveIntegerField()
-    content_object = generic.GenericForeignKey('content_type', 'object_id')
+    objects = CachedManager()
 
     class Meta:
         abstract = True
         app_label = 'forum'
 
-class MetaContent(BaseModel):
-    node = models.ForeignKey('Node', null=True, related_name='%(class)ss')
-
     def __init__(self, *args, **kwargs):
-        if 'content_object' in kwargs:
-            kwargs['node'] = kwargs['content_object']
-            del kwargs['content_object']
-
-        super (MetaContent, self).__init__(*args, **kwargs)
-    
-    @property
-    def content_object(self):
-        return self.node.leaf
-
-    class Meta:
-        abstract = True
-        app_label = 'forum'
+        super(BaseModel, self).__init__(*args, **kwargs)
+        self.reset_original_state(kwargs.keys())
 
-from user import User
+    def reset_original_state(self, reset_fields=None):
+        self._original_state = self._as_dict()
+        
+        if reset_fields:
+            self._original_state.update(dict([(f, None) for f in reset_fields]))
 
-class UserContent(models.Model):
-    user = models.ForeignKey(User, related_name='%(class)ss')
+    def get_dirty_fields(self):
+        return [f.name for f in self._meta.fields if self._original_state[f.attname] != self.__dict__[f.attname]]
 
-    class Meta:
-        abstract = True
-        app_label = 'forum'
+    def _as_dict(self):
+        return dict([(name, getattr(self, name)) for name in
+                     ([f.attname for f in self._meta.fields] + [k for k in self.__dict__.keys() if k.endswith('_dencache_')])
+        ])
 
+    def _get_update_kwargs(self):
+        return dict([
+            (f.name, getattr(self, f.name)) for f in self._meta.fields if self._original_state[f.attname] != self.__dict__[f.attname]
+        ])
 
-marked_deleted = django.dispatch.Signal(providing_args=["instance", "deleted_by"])
+    def save(self, full_save=False, *args, **kwargs):
+        put_back = [k for k, v in self.__dict__.items() if isinstance(v, models.expressions.ExpressionNode)]
 
-class DeletableContent(models.Model):
-    deleted     = models.BooleanField(default=False)
-    deleted_at  = models.DateTimeField(null=True, blank=True)
-    deleted_by  = models.ForeignKey(User, null=True, blank=True, related_name='deleted_%(class)ss')
+        if self.id and not full_save:
+            self.__class__.objects.filter(id=self.id).update(**self._get_update_kwargs())
+        else:
+            super(BaseModel, self).save()
 
-    active = UndeletedObjectManager()
+        if put_back:
+            try:
+                self.__dict__.update(
+                    self.__class__.objects.filter(id=self.id).values(*put_back)[0]
+                )
+            except:
+                logging.error("Unable to read %s from %s" % (", ".join(put_back), self.__class__.__name__))
+                self.uncache()
 
-    class Meta:
-        abstract = True
-        app_label = 'forum'
+        self.reset_original_state()
+        self.cache()
 
-    def mark_deleted(self, user):
-        if not self.deleted:
-            self.deleted = True
-            self.deleted_at = datetime.datetime.now()
-            self.deleted_by = user
-            self.save()
-            marked_deleted.send(sender=self.__class__, instance=self, deleted_by=user)
-            return True
-        else:
-            return False
+    @classmethod
+    def _generate_cache_key(cls, key, group=None):
+        if group is None:
+            group = cls.__name__
 
-    def unmark_deleted(self):
-        if self.deleted:
-            self.deleted = False
-            self.save()
-            return True
-        else:
-            return False
+        return '%s:%s:%s' % (settings.APP_URL, group, key)
 
-mark_canceled = django.dispatch.Signal(providing_args=['instance'])
+    def cache_key(self):
+        return self._generate_cache_key(self.id)
 
-class CancelableContent(models.Model):
-    canceled = models.BooleanField(default=False)
+    @classmethod
+    def infer_cache_key(cls, querydict):
+        try:
+            pk = [v for (k,v) in querydict.items() if k in ('pk', 'pk__exact', 'id', 'id__exact'
+                            ) or k.endswith('_ptr__pk') or k.endswith('_ptr__id')][0]
 
-    def cancel(self):
-        if not self.canceled:
-            self.canceled = True
-            self.save()
-            mark_canceled.send(sender=self.__class__, instance=self)
-            return True
-            
-        return False
+            return cls._generate_cache_key(pk)
+        except:
+            return None
 
-    class Meta:
-        abstract = True
-        app_label = 'forum'
+    def cache(self):
+        cache.set(self.cache_key(), self._as_dict(), 60 * 60)
 
+    def uncache(self):
+        cache.delete(self.cache_key())
 
-from node import Node, NodeRevision
+    def delete(self):
+        self.uncache()
+        super(BaseModel, self).delete()
 
-class QandA(Node):
-    wiki                 = models.BooleanField(default=False)
-    wikified_at          = models.DateTimeField(null=True, blank=True)
 
-    class Meta:
-        abstract = True
-        app_label = 'forum'
+from user import User
+from node import Node, NodeRevision, NodeManager
+from action import Action
 
-    def wikify(self):
-        if not self.wiki:
-            self.wiki = True
-            self.wikified_at = datetime.datetime.now()
-            self.save()