InWork/ar_lock

= ArLock for Rails3
{<img src="https://codeclimate.com/github/InWork/ar_lock.png" />}[https://codeclimate.com/github/InWork/ar_lock]

This Rails3 Gem implements an atomic locking model based on ActiveRecord.

== Install

Inside your Gemfile:

  gem "ar_lock"

and then run:

* bundle install

=== Inside your Application:

Geting a lock is always an atomic operation. If you try to get more than one lock (by specifying an array), this is also executed atomic.

==== Get lock(s):
Get one lock:
  Lock.get :lock_name

Get multiple locks as one atomic operation:
  Lock.get [:lock_name1, :lock_name2]

optional you can specify a value (for example the user, which acquired the lock):
  Lock.get :lock_name, value: 'value'

You can let Lock.get block, until the lock was acquired:
  Lock.get :lock_name, blocking: true

If you do not want a lock which was already acquired will block your code:
  Lock.get :lock_name, blocking: true, successful_if: :value_matches

It is possible to force a lock. Values of already acquired locks will be overwriten by the given value.
  Lock.get :lock_name, value: 'value', force: true

==== Release lock(s):
Release one Lock:
  Lock.release :lock_name

Release multiple locks:
  Lock.release [:lock_name1, :lock_name2]

Only release a lock, if the value matches:
  Lock.release :lock_name, value: 'value'

You can also release all locks at once:
  Lock.release_all

==== Get the value of a lock:
To read the value of a lock:
  Lock.get_value :lock_name

== Generators

* rails generate ar_lock:migration

=== Database Setup

Use

  rails g ar_lock:migration

This will create a database migration:

  TIMESTAMP_add_ar_lock_table.rb

== License
This project is licenced under the MIT license.

== Author
Philip Kurmann (philip (at) kman.ch)