Privex's Django Database Lock Manager
======================================
[](https://travis-ci.com/Privex/django-lockmgr)
[](https://codecov.io/gh/Privex/django-lockmgr)
[](https://pypi.org/project/django-lockmgr/)
```
+===================================================+
| © 2019 Privex Inc. |
| https://www.privex.io |
+===================================================+
| |
| Django Database Lock Manager |
| License: X11/MIT |
| |
| Core Developer(s): |
| |
| (+) Chris (@someguy123) [Privex] |
| |
+===================================================+
Django Database Lock Manager - Easy to use lock system using your Django app's database
Copyright (c) 2019 Privex Inc. ( https://www.privex.io )
```
# Install with pip
We recommend at least Python 3.6 - we cannot guarantee compatibility with older versions.
```
pip3 install django-lockmgr
```
Add `lockmgr` to your `INSTALLED_APPS`
```python
INSTALLED_APPS = [
'django.contrib.admin.apps.SimpleAdminConfig',
'django.contrib.auth',
'django.contrib.contenttypes',
# ...
'lockmgr'
]
```
Run the migrations
```bash
./manage.py migrate lockmgr
```
# Usage
Use the `LockMgr` in your code like so:
```python
from lockmgr.lockmgr import LockMgr, Locked
try:
with LockMgr('mylock') as lck:
print('The lock "mylock" is now locked.')
lck.lock('otherlock')
print('The lock "otherlock" should also be locked.')
print('The locks "mylock" and "otherlock" should now both be cleared.')
except Locked as e:
print('Error! mylock is already locked: ', type(e), str(e))
```
If you want to wait for the lock to be released, rather than immediately excepting:
```python
from lockmgr.lockmgr import LockMgr, Locked
try:
# expires=60 means the lock will expire after 60 seconds if you don't renew it.
# wait=90 (must be in 5 second intervals) means: if the key is locked, retry every 5 seconds, if 90 seconds have
# passed and it's still locked, then give up and raise Locked.
with LockMgr('somelock', expires=60, wait=90) as lck:
print('The lock "somelock" is now locked.')
print('The lock "somelock" should now be cleared.')
except Locked as e:
print('Error! After retrying for 90 seconds, "somelock" is still locked: ', type(e), str(e))
```
Unit Tests
===========
To run the unit tests, clone the project and make a `.env` file containing details for a database:
```
DB_BACKEND=mysql
DB_NAME=lockmgr
DB_USER=someuser
DB_PASS=mypassword
```
Install all required dependencies:
```
pip3 install -r requirements.txt -U
```
Now run the tests (--verbose for more detailed testing output):
```
./manage.py test --verbose
```
