class Model:
def __init__(self, clsobj=XParcel):
self.__db = DB()
self.__cache = Cache()
self.__clsobj = clsobj
self.maxCount = 4096
def open(self, filepath, mode='w'):
self.mode = mode
intMode = {'r':DB_RDONLY, 'w':DB_CREATE|DB_TRUNCATE, 'a':DB_CREATE}[mode]
self.__db.setcache(256*1024*1024, 0)
return self.__db.open(filepath, intMode)
def close(self):
self.sync()
self.__db.close()
def put(self, key, data):
self.__cache.put(key, data)
self.__measure()
def get(self, key):
value = self.__cache.get(key)
if not value:
value = self.db_get(key)
if value:
self.__cache.put(key, value)
self.__measure()
return value
def keys(self):
self.sync()
cursor = self.__db.cursor()
result = cursor.get(None, DB_FIRST|XDB_NOT_RETRIEVE_VAL)
while result:
if not result[0].startswith('__'):
yield result[0]
result = cursor.get(None, DB_NEXT|XDB_NOT_RETRIEVE_VAL)
cursor.close()
def values(self):
self.sync()
cursor = self.__db.cursor()
result = cursor.get(None, DB_FIRST)
while result:
if not result[0].startswith('__'):
obj = self.__clsobj()
obj.unpack(result[1])
yield obj
result = cursor.get(None, DB_NEXT)
cursor.close()
def sync(self):
for key, value in self.__cache.items():
self.db_put(key, value)
def items(self):
self.__cache.cache_sync()
cursor = self.__db.cursor()
result = cursor.get(None, DB_FIRST)
while result:
if not result[0].startswith('__'):
obj = self.__clsobj()
obj.unpack(result[1])
yield result[0], obj
result = cursor.get(None, DB_NEXT)
cursor.close()
def __measure(self):
while len(self.__cache) > self.maxCount:
#print len(self.__cache), self.__cache.__dict__
key, value = self.__cache.top()
self.db_put(key, value)
self.__cache.pop()
def db_get(self, key):
result = self.__db.get(key, 0)
if result:
obj = self.__clsobj()
obj.unpack(result[1])
return obj
return None
def db_put(self, key, data):
if self.mode != 'r':
return self.__db.put(key, data.pack(), 0)
