def __init__(self, name='Demo Storage', base=None, quota=None):
BaseStorage.__init__(self, name, base)
# We use a BTree because the items are sorted!
self._data = OOBTree.OOBTree()
self._index = {}
self._vindex = {}
self._base = base
self._size = 0
self._quota = quota
self._ltid = None
self._clear_temp()
if base is not None and base.versions():
raise POSException.StorageError(
"Demo base storage has version data")
def store(self, oid, serial, data, version, transaction):
if transaction is not self._transaction:
raise POSException.StorageTransactionError(self, transaction)
self._lock_acquire()
try:
old = self._index.get(oid, None)
if old is None:
# Hm, nothing here, check the base version:
if self._base:
try:
p, tid = self._base.load(oid, '')
except KeyError:
pass
else:
old = oid, None, None, p, tid
nv=None
if old:
oid, pre, vdata, p, tid = old
if vdata:
if vdata[0] != version:
raise POSException.VersionLockError(oid)
nv=vdata[1]
else:
nv=old
if serial != tid:
raise POSException.ConflictError(
oid=oid, serials=(tid, serial), data=data)
r = [oid, old, version and (version, nv) or None, data, self._tid]
self._tindex.append(r)
s=self._tsize
s=s+72+(data and (16+len(data)) or 4)
if version: s=s+32+len(version)
if self._quota is not None and s > self._quota:
raise POSException.StorageError(
'''<b>Quota Exceeded</b><br>
The maximum quota for this demonstration storage
has been exceeded.<br>Have a nice day.''')
finally: self._lock_release()
return self._tid
