Adust the as_table tag to render a pick link if appropriate
The templates are adjusted to pass on a 'reference' value, which
is the url_name of the view from which the entity should be picked.
The as_table (and related) function(s) construct and then pass on
this argument and enable takes_contex so that we have access to the
context of the enclosing template.
We only extract ReferenceProperties that end with '_link_id' since
that is how all RP's are currently named. It is not possible to
create a field with the same name as the RP, as GAE will try to
interpret it's contents as the key of an entity before even calling
any function we can override.
Patch by: Sverre Rabbelier
"Thread-safe in-memory cache backend."
import time
try:
import cPickle as pickle
except ImportError:
import pickle
from django.core.cache.backends.base import BaseCache
from django.utils.synch import RWLock
class CacheClass(BaseCache):
def __init__(self, _, params):
BaseCache.__init__(self, params)
self._cache = {}
self._expire_info = {}
max_entries = params.get('max_entries', 300)
try:
self._max_entries = int(max_entries)
except (ValueError, TypeError):
self._max_entries = 300
cull_frequency = params.get('cull_frequency', 3)
try:
self._cull_frequency = int(cull_frequency)
except (ValueError, TypeError):
self._cull_frequency = 3
self._lock = RWLock()
def add(self, key, value, timeout=None):
self._lock.writer_enters()
try:
exp = self._expire_info.get(key)
if exp is None or exp <= time.time():
try:
self._set(key, pickle.dumps(value), timeout)
return True
except pickle.PickleError:
pass
return False
finally:
self._lock.writer_leaves()
def get(self, key, default=None):
self._lock.reader_enters()
try:
exp = self._expire_info.get(key)
if exp is None:
return default
elif exp > time.time():
try:
return pickle.loads(self._cache[key])
except pickle.PickleError:
return default
finally:
self._lock.reader_leaves()
self._lock.writer_enters()
try:
del self._cache[key]
del self._expire_info[key]
return default
finally:
self._lock.writer_leaves()
def _set(self, key, value, timeout=None):
if len(self._cache) >= self._max_entries:
self._cull()
if timeout is None:
timeout = self.default_timeout
self._cache[key] = value
self._expire_info[key] = time.time() + timeout
def set(self, key, value, timeout=None):
self._lock.writer_enters()
# Python 2.3 and 2.4 don't allow combined try-except-finally blocks.
try:
try:
self._set(key, pickle.dumps(value), timeout)
except pickle.PickleError:
pass
finally:
self._lock.writer_leaves()
def has_key(self, key):
self._lock.reader_enters()
try:
exp = self._expire_info.get(key)
if exp is None:
return False
elif exp > time.time():
return True
finally:
self._lock.reader_leaves()
self._lock.writer_enters()
try:
del self._cache[key]
del self._expire_info[key]
return False
finally:
self._lock.writer_leaves()
def _cull(self):
if self._cull_frequency == 0:
self._cache.clear()
self._expire_info.clear()
else:
doomed = [k for (i, k) in enumerate(self._cache) if i % self._cull_frequency == 0]
for k in doomed:
self._delete(k)
def _delete(self, key):
try:
del self._cache[key]
except KeyError:
pass
try:
del self._expire_info[key]
except KeyError:
pass
def delete(self, key):
self._lock.writer_enters()
try:
self._delete(key)
finally:
self._lock.writer_leaves()