09edab5027
Add keyword arguments. Sort imports. Move settings and test literals to their own module. Signed-off-by: Roberto Rosario <Roberto.Rosario@mayan-edms.com>
126 lines
3.7 KiB
Python
126 lines
3.7 KiB
Python
from __future__ import unicode_literals
|
|
|
|
import hashlib
|
|
import json
|
|
import logging
|
|
import os
|
|
import threading
|
|
import time
|
|
import uuid
|
|
|
|
from django.conf import settings
|
|
from django.core.files import locks
|
|
from django.utils.encoding import force_bytes, force_text
|
|
|
|
from mayan.apps.common.settings import setting_temporary_directory
|
|
|
|
from ..exceptions import LockError
|
|
from ..settings import setting_default_lock_timeout
|
|
|
|
from .base import LockingBackend
|
|
|
|
lock = threading.Lock()
|
|
logger = logging.getLogger(__name__)
|
|
|
|
lock_file = os.path.join(
|
|
setting_temporary_directory.value, hashlib.sha256(
|
|
force_bytes(settings.SECRET_KEY)
|
|
).hexdigest()
|
|
)
|
|
open(lock_file, 'a').close()
|
|
logger.debug('lock_file: %s', lock_file)
|
|
|
|
|
|
class FileLock(LockingBackend):
|
|
lock_file = lock_file
|
|
|
|
@classmethod
|
|
def acquire_lock(cls, name, timeout=None):
|
|
super(FileLock, cls).acquire_lock(name=name, timeout=timeout)
|
|
instance = FileLock(
|
|
name=name, timeout=timeout or setting_default_lock_timeout.value
|
|
)
|
|
return instance
|
|
|
|
@classmethod
|
|
def purge_locks(cls):
|
|
super(FileLock, cls).purge_locks()
|
|
lock.acquire()
|
|
with open(cls.lock_file, 'r+') as file_object:
|
|
locks.lock(f=file_object, flags=locks.LOCK_EX)
|
|
file_object.seek(0)
|
|
file_object.truncate()
|
|
lock.release()
|
|
|
|
def _get_lock_dictionary(self):
|
|
if self.timeout:
|
|
result = {
|
|
'expiration': time.time() + self.timeout,
|
|
'uuid': self.uuid
|
|
}
|
|
else:
|
|
result = {
|
|
'expiration': 0,
|
|
'uuid': self.uuid
|
|
}
|
|
|
|
return result
|
|
|
|
def __init__(self, name, timeout=None):
|
|
self.name = name
|
|
self.timeout = timeout or setting_default_lock_timeout.value
|
|
self.uuid = force_text(uuid.uuid4())
|
|
|
|
lock.acquire()
|
|
with open(self.__class__.lock_file, 'r+') as file_object:
|
|
locks.lock(f=file_object, flags=locks.LOCK_EX)
|
|
|
|
data = file_object.read()
|
|
|
|
if data:
|
|
file_locks = json.loads(s=data)
|
|
else:
|
|
file_locks = {}
|
|
|
|
if name in file_locks:
|
|
# Someone already got this lock, check to see if it is expired
|
|
if file_locks[name]['expiration'] and time.time() > file_locks[name]['expiration']:
|
|
# It expires and has expired, we re-acquired it
|
|
file_locks[name] = self._get_lock_dictionary()
|
|
else:
|
|
lock.release()
|
|
raise LockError
|
|
else:
|
|
file_locks[name] = self._get_lock_dictionary()
|
|
|
|
file_object.seek(0)
|
|
file_object.truncate()
|
|
file_object.write(json.dumps(file_locks))
|
|
lock.release()
|
|
|
|
def release(self):
|
|
super(FileLock, self).release()
|
|
|
|
lock.acquire()
|
|
with open(self.__class__.lock_file, 'r+') as file_object:
|
|
locks.lock(f=file_object, flags=locks.LOCK_EX)
|
|
try:
|
|
file_locks = json.loads(s=file_object.read())
|
|
except EOFError:
|
|
file_locks = {}
|
|
|
|
if self.name in file_locks:
|
|
if file_locks[self.name]['uuid'] == self.uuid:
|
|
file_locks.pop(self.name)
|
|
else:
|
|
# Lock expired and someone else acquired it
|
|
pass
|
|
else:
|
|
# Lock expired and someone else released it
|
|
pass
|
|
|
|
file_object.seek(0)
|
|
file_object.truncate()
|
|
file_object.write(json.dumps(file_locks))
|
|
lock.release()
|