Viewing file:  BaseDB.py (3.43 KB) -rw-r--r--
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"""Base class for SharedKeyDB and VerifierDB."""
import anydbm
import thread
class BaseDB:
def __init__(self, filename, type):
self.type = type
self.filename = filename
if self.filename:
self.db = None
else:
self.db = {}
self.lock = thread.allocate_lock()
def create(self):
"""Create a new on-disk database.
@raise anydbm.error: If there's a problem creating the database.
"""
if self.filename:
self.db = anydbm.open(self.filename, "n") #raises anydbm.error
self.db["--Reserved--type"] = self.type
self.db.sync()
else:
self.db = {}
def open(self):
"""Open a pre-existing on-disk database.
@raise anydbm.error: If there's a problem opening the database.
@raise ValueError: If the database is not of the right type.
"""
if not self.filename:
raise ValueError("Can only open on-disk databases")
self.db = anydbm.open(self.filename, "w") #raises anydbm.error
try:
if self.db["--Reserved--type"] != self.type:
raise ValueError("Not a %s database" % self.type)
except KeyError:
raise ValueError("Not a recognized database")
def __getitem__(self, username):
if self.db == None:
raise AssertionError("DB not open")
self.lock.acquire()
try:
valueStr = self.db[username]
finally:
self.lock.release()
return self._getItem(username, valueStr)
def __setitem__(self, username, value):
if self.db == None:
raise AssertionError("DB not open")
valueStr = self._setItem(username, value)
self.lock.acquire()
try:
self.db[username] = valueStr
if self.filename:
self.db.sync()
finally:
self.lock.release()
def __delitem__(self, username):
if self.db == None:
raise AssertionError("DB not open")
self.lock.acquire()
try:
del(self.db[username])
if self.filename:
self.db.sync()
finally:
self.lock.release()
def __contains__(self, username):
"""Check if the database contains the specified username.
@type username: str
@param username: The username to check for.
@rtype: bool
@return: True if the database contains the username, False
otherwise.
"""
if self.db == None:
raise AssertionError("DB not open")
self.lock.acquire()
try:
return self.db.has_key(username)
finally:
self.lock.release()
def check(self, username, param):
value = self.__getitem__(username)
return self._checkItem(value, username, param)
def keys(self):
"""Return a list of usernames in the database.
@rtype: list
@return: The usernames in the database.
"""
if self.db == None:
raise AssertionError("DB not open")
self.lock.acquire()
try:
usernames = self.db.keys()
finally:
self.lock.release()
usernames = [u for u in usernames if not u.startswith("--Reserved--")]
return usernames
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