#!/usr/bin/python3
#
# Univention S4 Connector
# LockingDB
#
# SPDX-FileCopyrightText: 2014-2025 Univention GmbH
# SPDX-License-Identifier: AGPL-3.0-only
import sqlite3
from logging import getLogger
from univention.logging import Structured
log = Structured(getLogger("LDAP").getChild(__name__))
[docs]
class LockingDB:
"""
A local database which includes the list of objects
which are currently locked. That means the
synchronisation of these objects has not been finished.
https://forge.univention.org/bugzilla/show_bug.cgi?id=35391
"""
def __init__(self, filename):
self.filename = filename
self._dbcon = sqlite3.connect(self.filename)
self.s4cache = {}
self.__create_tables()
[docs]
def lock_ucs(self, uuid):
if not uuid:
return
# The SQLite Python module should do the escaping, that's
# the reason why we use the tuple ? syntax.
# I've chosen the str call because I want to make sure
# that we use the same SQL value as before switching
# to the tuple ? syntax
sql_commands = [
("INSERT INTO UCS_LOCK(uuid) VALUES(?);", (str(uuid),)),
]
self.__execute_sql_commands(sql_commands, fetch_result=False)
[docs]
def unlock_ucs(self, uuid):
if not uuid:
return
sql_commands = [
("DELETE FROM UCS_LOCK WHERE uuid = ?;", (str(uuid),)),
]
self.__execute_sql_commands(sql_commands, fetch_result=False)
[docs]
def lock_s4(self, guid):
if not guid:
return
sql_commands = [
("INSERT INTO S4_LOCK(guid) VALUES(?);", (str(guid),)),
]
self.__execute_sql_commands(sql_commands, fetch_result=False)
[docs]
def unlock_s4(self, guid):
if not guid:
return
sql_commands = [
("DELETE FROM S4_LOCK WHERE guid = ?;", (str(guid),)),
]
self.__execute_sql_commands(sql_commands, fetch_result=False)
[docs]
def is_ucs_locked(self, uuid):
if not uuid:
return False
sql_commands = [
("SELECT id FROM UCS_LOCK WHERE uuid=?;", (str(uuid),)),
]
rows = self.__execute_sql_commands(sql_commands, fetch_result=True)
return bool(rows)
[docs]
def is_s4_locked(self, guid):
if not guid:
return False
sql_commands = [
("SELECT id FROM S4_LOCK WHERE guid=?;", (str(guid),)),
]
rows = self.__execute_sql_commands(sql_commands, fetch_result=True)
return bool(rows)
def __create_tables(self):
sql_commands = [
"CREATE TABLE IF NOT EXISTS S4_LOCK (id INTEGER PRIMARY KEY, guid TEXT);",
"CREATE TABLE IF NOT EXISTS UCS_LOCK (id INTEGER PRIMARY KEY, uuid TEXT);",
"CREATE INDEX IF NOT EXISTS s4_lock_guid ON s4_lock(guid);",
"CREATE INDEX IF NOT EXISTS ucs_lock_uuid ON ucs_lock(uuid);",
]
self.__execute_sql_commands(sql_commands, fetch_result=False)
def __execute_sql_commands(self, sql_commands, fetch_result=False):
for _i in [1, 2]:
try:
cur = self._dbcon.cursor()
for sql_command in sql_commands:
if isinstance(sql_command, tuple):
log.trace("LockingDB: Execute SQL command: %r, %r", sql_command[0], sql_command[1])
cur.execute(sql_command[0], sql_command[1])
else:
log.trace("LockingDB: Execute SQL command: %r", sql_command)
cur.execute(sql_command)
self._dbcon.commit()
if fetch_result:
rows = cur.fetchall()
cur.close()
if fetch_result:
log.trace("LockingDB: Return SQL result: %r", rows)
return rows
return None
except sqlite3.Error as exp:
log.warning("LockingDB: sqlite: %r. SQL command was: %r", exp, sql_commands)
if self._dbcon:
self._dbcon.close()
self._dbcon = sqlite3.connect(self.filename)
if __name__ == '__main__':
import random
print('Starting LockingDB test example ')
lock = LockingDB('lock.sqlite')
uuid1 = random.random()
guid1 = random.random()
if lock.is_s4_locked(guid1):
print('E: guid1 is locked for S4')
if lock.is_s4_locked(uuid1):
print('E: uuid1 is locked for S4')
if lock.is_ucs_locked(guid1):
print('E: guid1 is locked for UCS')
if lock.is_ucs_locked(uuid1):
print('E: uuid1 is locked for UCS')
lock.lock_s4(guid1)
if not lock.is_s4_locked(guid1):
print('E: guid1 is not locked for S4')
if lock.is_s4_locked(uuid1):
print('E: uuid1 is locked for S4')
if lock.is_ucs_locked(guid1):
print('E: guid1 is locked for UCS')
if lock.is_ucs_locked(uuid1):
print('E: uuid1 is locked for UCS')
lock.unlock_s4(guid1)
if lock.is_s4_locked(guid1):
print('E: guid1 is locked for S4')
if lock.is_s4_locked(uuid1):
print('E: uuid1 is locked for S4')
if lock.is_ucs_locked(guid1):
print('E: guid1 is locked for UCS')
if lock.is_ucs_locked(uuid1):
print('E: uuid1 is locked for UCS')
lock.lock_ucs(uuid1)
lock.lock_ucs(uuid1)
lock.lock_ucs(uuid1)
lock.lock_ucs(uuid1)
lock.lock_ucs(uuid1)
if lock.is_s4_locked(guid1):
print('E: guid1 is locked for S4')
if lock.is_s4_locked(uuid1):
print('E: uuid1 is locked for S4')
if lock.is_ucs_locked(guid1):
print('E: guid1 is locked for UCS')
if not lock.is_ucs_locked(uuid1):
print('E: uuid1 is not locked for UCS')
lock.unlock_ucs(uuid1)
if lock.is_s4_locked(guid1):
print('E: guid1 is locked for S4')
if lock.is_s4_locked(uuid1):
print('E: uuid1 is locked for S4')
if lock.is_ucs_locked(guid1):
print('E: guid1 is locked for UCS')
if lock.is_ucs_locked(uuid1):
print('E: uuid1 is locked for UCS')
print('done')
