milesrichardson / ParsePy

A relatively up-to-date fork of ParsePy, the Python wrapper for the Parse.com API. Originally maintained by @dgrtwo
MIT License
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RFC: locks and queues #110

Open dankrause opened 9 years ago

dankrause commented 9 years ago

It seems to me that it's possible to implement atomic exclusive locking by slightly abusing the ACL features of Parse. Also, given the ability to lock like this, a queue should also be possible.

Here's a first pass at an implementation: https://gist.github.com/dankrause/a58161d3f4a7db904b57

You'll see that a lock is held by a user, so we assume that each client has a different user. To claim the lock, you simply alter the ACLs in such a way that no other user can write. To release it, you revert the ACLs.

My class handles a collection of locks, where you can fetch locks using normal queries, and then claim and release them.

A subclass of this handles a queue, which is basically just an ordered collection of locks.

Any interest in including something like this in ParsePy?