django 文件锁

当我们的需求场景满足：

　　进程之间的

　　对同一个文件的排他操作时

我们可以尝试对文件进行加锁。后续扩展锁时，只需要创建锁类，然后在锁管理里面添加即可。import fcntl

import os
from abc import ABCMeta, abstractmethod


class Lock(metaclass=ABCMeta):
    __doc__ = """抽象锁鸡肋, 用于定义锁"""
    
    @abstractmethod
    def acquire(self):
        """获取锁"""
        ...
    
    @abstractmethod
    def release(slef):
        """释放锁"""
        ...

    @abstractmethod
    def __enter__(self):
　　　　"""实现上下文操作"""
        ...
    
    @abstractmethod
    def __exit__(self, exc_type, exc_value, traceback):
        ...

class FileLock(Lock):
    __doc__ = """文件锁"""
    def init (self, lockfile_path):
        self.lockfile_path = lockfile_path
        self.file = None
    def acquire(self):
        lock_dir = os.path.dirname(self.lockfile_path)
        if lock_dir:
            os.makedirs(lock_dir, exist_ok=True)
        self. file = open(self.lockfile path,
        try:
            fcntl.flock(self, file, fcntl.LOCK_Ex | fcntl.LOCK_NB)
        except BlockingIoError:
            raise RuntimeError(f"Lock is already held for: {self,lockfile path}")
    def __enter__(self):
        self.acquire()
        return self
    def __exit__(self,exc_type,exc_value,traceback):
        self.release()

class LockManager(object):
    __doc__ = """创建锁管理"""
    def __init__(self,lock_type='file', **kwa):
        self.lock_type=lock_type
        self.kwa = kwa
    def create_lock(self):
        if self.lock_type == 'file':
            return Filelock(**self.kwa)
        raise ValueError(f"不支持的锁类型:{self.lock_type}")