django-cache-lock

A simple lock extension for django's cache to prevent concurrent editing.

Installation

Install django-cache-lock by using pip

pip install django-cache-lock

Quick Start

You can work with django-cache-lock by using with-statement or decorator.

from django_lock import lock

with lock("global"):
    pass

@lock("global")
def foo():
    pass

A shortcut to lock model instance

from django.db import models
from django_lock import model_lock

class Foo(models.Model):
    bar = models.CharField(max_length=8)

    @lock_model
    def lock_pk(self):
        pass

    @lock_model("bar", blocking=False)
    def lock_bar(self):
        pass

    def nolock(self):
        pass

foo = Foo()
with lock_model(foo, blocking=False):
    nolock()

Configurations

key	default	desc
DJANGOLOCK_PREFIX	"lock:"	lock's key prefix stored in cache
DJANGOLOCK_SLEEP	0.1	default interval time to acquire a lock if a lock is holded by others
DJANGOLOCK_RELEASEONDEL	True	release lock when `__del__` is called if True

Advanced usage

For more usages, please read the code.

Supported backends

django.core.cache.backends.db
django.core.cache.backends.file
django.core.cache.backends.locmem
django.core.cache.backends.memcached
django-redis
django-redis-cache

ATTENTIONS

locmem backend

DO NOT USE locmem backend in a product environment.

memcached backend

Memcached does not support milliseconds expire time, and its' expire time is not very exact. So memcached lock's timeout time is not as exact as other backends.

redis backend

We didn't test distributed redis lock.

TODOS:

use memcached's cas to release lock
reacquire and extend lock
database backend cache support

Xavier-Lam / django-cache-lock

readme