class Persistent(object):
def __init__(self, name, **kw):
super(Persistent, self).__init__()
self.name = name
self.storage = None
self.synclock = RLock()
self.path = kw.get('path', PDODIR)
self.encode = kw.get('encode', repr)
self.decode = kw.get('decode', eval)
self.extension = kw.get('extension', 'dat')
self.autopersist = kw.get('autopersist', True)
if self.autopersist:
self.load()
def open(self):
self.synclock.acquire()
try:
self.storage = FileStorage(self.path, self.name, self.extension)
self.storage.open()
finally:
self.synclock.release()
def close(self):
self.synclock.acquire()
try:
self.storage.close()
self.storage = None
finally:
self.synclock.release()
def closed(self):
storage = self.storage
if storage is None:
return True
elif storage.closed():
return True
return False
def update_storage(self):
"""
Serialize and data associated with object and
update storage record to match serialization.
"""
self.synclock.acquire()
try:
data = self.getencoded()
self.storage.set(data)
finally:
self.synclock.release()
def update_data(self):
self.synclock.acquire()
try:
data = self.storage.getdata()
self.setencoded(data)
finally:
self.synclock.release()
def commit(self):
"""
Update storage with most recent data, then
commit changes.
"""
self.synclock.acquire()
try:
self.update_storage()
self.storage.commit()
self.notify_committed()
finally:
self.synclock.release()
def load(self):
"""
Load most recently stored data, then update
current data with loaded content.
"""
self.synclock.acquire()
try:
if self.storage is None:
self.open()
self.storage.load()
self.update_data()
self.notify_loaded()
finally:
self.synclock.release()
def serialize(self, data):
if self.encode is not None:
data = self.encode(data)
return data
def unserialize(self, data):
if self.decode is not None:
data = self.decode(data)
return data
def getencoded(self):
"""
Return encoded representation of current data object.
This method must be overridden in type-specific
subclasses.
"""
raise TypeError("Method must be overridden")
def setencoded(self, data):
"""
Use encoded representation of persisted data object
to update current data object.
This method must be overridden in type-specific
subclasses.
"""
raise TypeError("Method must be overridden")
def notify_committed(self):
pass
def notify_loaded(self):
pass
class Persistent(object):
def __init__(self, name, **kw):
super(Persistent, self).__init__()
self.name = name
self.storage = None
self.synclock = RLock()
self.path = kw.get('path', PDODIR)
self.encode = kw.get('encode', repr)
self.decode = kw.get('decode', eval)
self.extension = kw.get('extension', 'dat')
self.autopersist = kw.get('autopersist', True)
if self.autopersist:
self.load()
def open(self):
self.synclock.acquire()
try:
self.storage = FileStorage(self.path, self.name, self.extension)
self.storage.open()
finally:
self.synclock.release()
def close(self):
self.synclock.acquire()
try:
self.storage.close()
self.storage = None
finally:
self.synclock.release()
def closed(self):
storage = self.storage
if storage is None:
return True
elif storage.closed():
return True
return False
def update_storage(self):
"""
Serialize and data associated with object and
update storage record to match serialization.
"""
self.synclock.acquire()
try:
data = self.getencoded()
self.storage.set(data)
finally:
self.synclock.release()
def update_data(self):
self.synclock.acquire()
try:
data = self.storage.getdata()
self.setencoded(data)
finally:
self.synclock.release()
def commit(self):
"""
Update storage with most recent data, then
commit changes.
"""
self.synclock.acquire()
try:
self.update_storage()
self.storage.commit()
self.notify_committed()
finally:
self.synclock.release()
def load(self):
"""
Load most recently stored data, then update
current data with loaded content.
"""
self.synclock.acquire()
try:
if self.storage is None:
self.open()
self.storage.load()
self.update_data()
self.notify_loaded()
finally:
self.synclock.release()
def serialize(self, data):
if self.encode is not None:
data = self.encode(data)
return data
def unserialize(self, data):
if self.decode is not None:
data = self.decode(data)
return data
def getencoded(self):
"""
Return encoded representation of current data object.
This method must be overridden in type-specific
subclasses.
"""
raise TypeError("Method must be overridden")
def setencoded(self, data):
"""
Use encoded representation of persisted data object
to update current data object.
This method must be overridden in type-specific
subclasses.
"""
raise TypeError("Method must be overridden")
def notify_committed(self):
pass
def notify_loaded(self):
pass
