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import datetime
import re
try:
from hashlib import md5
except:
from md5 import new as md5
from urllib import quote_plus, urlencode
from django.db import models, IntegrityError, connection, transaction
from django.utils.http import urlquote as django_urlquote
from django.utils.html import strip_tags
from django.conf import settings as django_settings
from django.core.urlresolvers import reverse
from django.contrib.contenttypes import generic
from django.contrib.contenttypes.models import ContentType
from django.core.cache import cache
from django.template.defaultfilters import slugify
from django.db.models.signals import post_delete, post_save, pre_save, pre_delete
from django.utils.translation import ugettext as _
from django.utils.safestring import mark_safe
from django.utils.encoding import force_unicode
from django.contrib.sitemaps import ping_google
import django.dispatch
from forum import settings
import logging
if not hasattr(cache, 'get_many'):
#put django 1.2 code here
pass
class LazyQueryList(object):
def __init__(self, model, items):
self.items = items
self.model = model
def __getitem__(self, k):
return self.model.objects.get(id=self.items[k][0])
def __iter__(self):
for id in self.items:
yield self.model.objects.get(id=id[0])
def __len__(self):
return len(self.items)
class ToFetch(unicode):
pass
class CachedQuerySet(models.query.QuerySet):
def lazy(self):
if not len(self.query.aggregates):
values_list = ['id']
if len(self.query.extra):
extra_keys = self.query.extra.keys()
values_list += extra_keys
return LazyQueryList(self.model, list(self.values_list(*values_list)))
else:
return self
def obj_from_datadict(self, datadict):
obj = self.model()
obj.__dict__.update(datadict)
if hasattr(obj, '_state'):
obj._state.db = 'default'
return obj
def _base_clone(self):
return self._clone(klass=models.query.QuerySet)
def get(self, *args, **kwargs):
key = self.model.infer_cache_key(kwargs)
if key is not None:
obj = cache.get(key)
if obj is None:
obj = self._base_clone().get(*args, **kwargs)
obj.cache()
else:
obj = self.obj_from_datadict(obj)
obj.reset_original_state()
return obj
return self._base_clone().get(*args, **kwargs)
def _fetch_from_query_cache(self, key):
invalidation_key = self.model._get_cache_query_invalidation_key()
cached_result = cache.get_many([invalidation_key, key])
if not invalidation_key in cached_result:
self.model._set_query_cache_invalidation_timestamp()
return None
if (key in cached_result) and(cached_result[invalidation_key] < cached_result[key][0]):
return cached_result[key][1]
return None
def count(self):
cache_key = self.model._generate_cache_key("CNT:%s" % self._get_query_hash())
result = self._fetch_from_query_cache(cache_key)
if result is not None:
return result
result = super(CachedQuerySet, self).count()
cache.set(cache_key, (datetime.datetime.now(), result), 60 * 60)
return result
def iterator(self):
cache_key = self.model._generate_cache_key("QUERY:%s" % self._get_query_hash())
on_cache_query_attr = self.model.value_to_list_on_cache_query()
to_return = None
to_cache = {}
with_aggregates = len(self.query.aggregates) > 0
key_list = self._fetch_from_query_cache(cache_key)
if key_list is None:
if not with_aggregates:
values_list = [on_cache_query_attr]
if len(self.query.extra):
values_list += self.query.extra.keys()
key_list = [v[0] for v in self.values_list(*values_list)]
to_cache[cache_key] = (datetime.datetime.now(), key_list)
else:
to_return = list(super(CachedQuerySet, self).iterator())
to_cache[cache_key] = (datetime.datetime.now(), [
(row.__dict__[on_cache_query_attr], dict([(k, row.__dict__[k]) for k in self.query.aggregates.keys()]))
for row in to_return])
elif with_aggregates:
tmp = key_list
key_list = [k[0] for k in tmp]
with_aggregates = [k[1] for k in tmp]
del tmp
if (not to_return) and key_list:
row_keys = [self.model.infer_cache_key({on_cache_query_attr: attr}) for attr in key_list]
cached = cache.get_many(row_keys)
to_return = [
(ck in cached) and self.obj_from_datadict(cached[ck]) or ToFetch(force_unicode(key_list[i])) for i, ck in enumerate(row_keys)
]
if len(cached) != len(row_keys):
to_fetch = [unicode(tr) for tr in to_return if isinstance(tr, ToFetch)]
fetched = dict([(force_unicode(r.__dict__[on_cache_query_attr]), r) for r in
models.query.QuerySet(self.model).filter(**{"%s__in" % on_cache_query_attr: to_fetch})])
to_return = [(isinstance(tr, ToFetch) and fetched[unicode(tr)] or tr) for tr in to_return]
to_cache.update(dict([(self.model.infer_cache_key({on_cache_query_attr: attr}), r._as_dict()) for attr, r in fetched.items()]))
if with_aggregates:
for i, r in enumerate(to_return):
r.__dict__.update(with_aggregates[i])
if len(to_cache):
cache.set_many(to_cache, 60 * 60)
if to_return:
for row in to_return:
if hasattr(row, 'leaf'):
row = row.leaf
row.reset_original_state()
yield row
def _get_query_hash(self):
return md5(unicode(self.query).encode("utf-8")).hexdigest()
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:
return self.get(*args, **kwargs)
except:
return super(CachedManager, self).get_or_create(*args, **kwargs)
class DenormalizedField(object):
def __init__(self, manager, *args, **kwargs):
self.manager = manager
self.filter = (args, kwargs)
def setup_class(self, cls, name):
dict_name = '_%s_dencache_' % name
def getter(inst):
val = inst.__dict__.get(dict_name, None)
if val is None:
val = getattr(inst, self.manager).filter(*self.filter[0], **self.filter[1]).count()
inst.__dict__[dict_name] = val
inst.cache()
return val
def reset_cache(inst):
inst.__dict__.pop(dict_name, None)
inst.uncache()
cls.add_to_class(name, property(getter))
cls.add_to_class("reset_%s_cache" % name, reset_cache)
class BaseMetaClass(models.Model.__metaclass__):
to_denormalize = []
def __new__(cls, *args, **kwargs):
new_cls = super(BaseMetaClass, cls).__new__(cls, *args, **kwargs)
BaseMetaClass.to_denormalize.extend(
[(new_cls, name, field) for name, field in new_cls.__dict__.items() if isinstance(field, DenormalizedField)]
)
return new_cls
@classmethod
def setup_denormalizes(cls):
for new_cls, name, field in BaseMetaClass.to_denormalize:
field.setup_class(new_cls, name)
class BaseModel(models.Model):
__metaclass__ = BaseMetaClass
objects = CachedManager()
class Meta:
abstract = True
app_label = 'forum'
def __init__(self, *args, **kwargs):
super(BaseModel, self).__init__(*args, **kwargs)
self.reset_original_state(kwargs.keys())
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]))
def get_dirty_fields(self):
return [f.name for f in self._meta.fields if self._original_state[f.attname] != self.__dict__[f.attname]]
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]
])
def save(self, full_save=False, *args, **kwargs):
put_back = [k for k, v in self.__dict__.items() if isinstance(v, models.expressions.ExpressionNode)]
if hasattr(self, '_state'):
self._state.db = 'default'
if self.id and not full_save:
self.__class__.objects.filter(id=self.id).update(**self._get_update_kwargs())
else:
super(BaseModel, self).save()
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()
self.reset_original_state()
self._set_query_cache_invalidation_timestamp()
self.cache()
@classmethod
def _get_cache_query_invalidation_key(cls):
return cls._generate_cache_key("INV_TS")
@classmethod
def _set_query_cache_invalidation_timestamp(cls):
cache.set(cls._get_cache_query_invalidation_key(), datetime.datetime.now(), 60 * 60 * 24)
for base in filter(lambda c: issubclass(c, BaseModel) and (not c is BaseModel), cls.__bases__):
base._set_query_cache_invalidation_timestamp()
@classmethod
def _generate_cache_key(cls, key, group=None):
if group is None:
group = cls.__name__
return '%s:%s:%s' % (settings.APP_URL, group, key)
def cache_key(self):
return self._generate_cache_key(self.id)
@classmethod
def value_to_list_on_cache_query(cls):
return 'id'
@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]
cache_key = cls._generate_cache_key(pk)
if len(cache_key) > django_settings.CACHE_MAX_KEY_LENGTH:
cache_key = cache_key[:django_settings.CACHE_MAX_KEY_LENGTH]
return cache_key
except:
return None
def cache(self):
cache.set(self.cache_key(), self._as_dict(), 60 * 60)
def uncache(self):
cache.delete(self.cache_key())
def delete(self):
self.uncache()
self._set_query_cache_invalidation_timestamp()
super(BaseModel, self).delete()
from user import User
from node import Node, NodeRevision, NodeManager
from action import Action