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
import logging
+if not hasattr(cache, 'get_many'):
+ #put django 1.2 code here
+ pass
+
class LazyQueryList(object):
def __init__(self, model, items):
- self.model = model
self.items = items
+ self.model = model
def __getitem__(self, k):
- return self.model.objects.get(id=self.items[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)
+ yield self.model.objects.get(id=id[0])
def __len__(self):
return len(self.items)
+class ToFetch(str):
+ pass
+
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)))
+ 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)
obj = cache.get(key)
if obj is None:
- obj = super(CachedQuerySet, self).get(*args, **kwargs)
+ obj = self._base_clone().get(*args, **kwargs)
obj.cache()
else:
obj = self.obj_from_datadict(obj)
return obj
- return super(CachedQuerySet, self).get(*args, **kwargs)
+ 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 = {}
+
+ key_list = self._fetch_from_query_cache(cache_key)
+
+ if key_list is None:
+ if not len(self.query.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] for row in to_return])
+
+ 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(key_list[i]) for i, ck in enumerate(row_keys)
+ ]
+
+ if len(cached) != len(row_keys):
+ to_fetch = [str(tr) for tr in to_return if isinstance(tr, ToFetch)]
+
+ fetched = dict([(str(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[str(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 len(to_cache):
+ cache.set_many(to_cache, 60 * 60)
+
+ if to_return:
+ for row in to_return:
+ if hasattr(row, 'leaf'):
+ yield row.leaf
+ else:
+ yield row
+
+ def _get_query_hash(self):
+ return md5(str(self.query)).hexdigest()
+
+
class CachedManager(models.Manager):
use_for_related_fields = True
(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, *args, **kwargs):
+ 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 self.id:
+ 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()
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:
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:
def delete(self):
self.uncache()
+ self._set_query_cache_invalidation_timestamp()
super(BaseModel, self).delete()
projects / osqa.git / blobdiff