Download the PHP package reshadman/laravel-optimistic-locking without Composer
On this page you can find all versions of the php package reshadman/laravel-optimistic-locking. It is possible to download/install these versions without Composer. Possible dependencies are resolved automatically.
Download reshadman/laravel-optimistic-locking
More information about reshadman/laravel-optimistic-locking
Files in reshadman/laravel-optimistic-locking
Package laravel-optimistic-locking
Short Description Adds optimistic locking feature to eloquent models.
License MIT
Informations about the package laravel-optimistic-locking
Laravel Optimistic Locking
Adds optimistic locking feature to Eloquent models.
Installation
This package supports Laravel 5.5., 5.6., 5.7., 5.8., and 6.* .
Usage
Basic usage
use the \Reshadman\OptimisticLocking\OptimisticLocking
trait
in your model:
and add the integer lock_version
field to the table of the model:
Then you are ready to go, if the same resource is edited by two different processes CONCURRENTLY then the following exception will be raised:
You should catch the above exception and act properly based on your business logic.
Maintaining lock_version during business transactions
You can keep track of a lock version during a business transaction by informing your API or HTML client about the current version:
and in controller:
So if two authors are editing the same content concurrently, you can keep track of your Read State, and ask the second author to rewrite his changes.
Disabling and enabling optimistic locking
You can disable and enable optimistic locking for a specific instance:
By default optimistic locking is enabled when you use
OptimisticLocking
trait in your model, to alter the default
behaviour you can set the lock strictly to false
:
and then you may enable it: $blogPost->enableLocking();
Use a different column for tracking version
By default the lock_version
column is used for tracking
version, you can alter that by overriding the following method
of the trait:
What is optimistic locking?
For detailed explanation read the concurrency section of Patterns of Enterprise Application Architecture by Martin Fowler.
There are two way to approach generic concurrency race conditions:
- Do not allow other processes (or users) to read and update the same resource (Pessimistic Locking)
- Allow other processes to read the same resource concurrently, but do not allow further update, if one of the processes updated the resource before the others (Optimistic locking).
Laravel allows Pessimistic locking as described in the documentation, this package allows you to have Optimistic locking in a rails like way.
What happens during an optimistic lock?
Every time you perform an upsert action to your resource(model),
the lock_version
counter field in the table is incremented by 1
,
If you read a resource and another process updates the resource
after you read it, the true version counter is incremented by one,
If the current process attempts to update the model, simply a
StaleModelLockingException
will be thrown, and you should
handle the race condition (merge, retry, ignore) based on your
business logic. That is simply via adding the following criteria
to the update query of a optimistically lockable model:
If the resource has been updated before your update attempt, then the above will simply update no records and it means that the model has been updated before current attempt or it has been deleted.
Why don't we use updated_at
for tracking changes?
Because they may remain the same during two concurrent updates.
Running tests
Clone the repo, perform a composer install and run:
License
The MIT License (MIT). Please see License File for more information. ense (MIT). Please see License File for more information.
All versions of laravel-optimistic-locking with dependencies
illuminate/database Version ~5.5.0|~5.6.0|~5.7.0
illuminate/support Version ~5.5.0|~5.6.0|~5.7.0