Mongoose Document Lock

Easy to use document lock plugin for mongoose. Both in-memory lock and Redis lock.

If you are implementing this lock, it is usually a good idea to remove the versionKey field in your schema, since you don't need an optimistic lock if you are using this library.

Install

$ npm install mongoose-schema-lock

Unfortunately mongoose-document-lock is taken :(

Then in your code

mongoose.plugin(require('mongoose-schema-lock'));

By default, locks will be stored in-memory, if you wish to use Redis, you can pass an node_redis client instance in config (more on this later).

Basic Usage

To lock a document, simply call document.lock(callback).

User.findOne({name: "Jun"}, function(err, user) {
    user.lock(function(release) {
        // Do you stuff here
        release();
    })
})

Once you lock a document, no other .lock calls will be able to obtain the lock for that specific document until you call release().

You can find some demos within /demo folder.

Use Promises

You can choose to use promises instead of callbacks, to do this, simply pass promise: true in configurations.

mongoose.plugin(require('mongoose-schema-lock'), {promise: true});

User.findOne({name: "Jun"}, function(err, user) {
    user.lock().then(lock => {
        // Do your sutff
        lock.release();
    })
})

Use Redis

If you have multiple servers load-balanced, or wish to share locks across applications, you might want to use Redis.

To use Redis, simply pass a Redis client in configurations.

const redis = require("redis"),
      client = redis.createClient();

mongoose.plugin(require('../index'), {redis: client});

Configurations

{
    redis: node_redis.client, // If this is set, locks will use Redis instead of in-memory
    promise: Boolean // If true, lock() will return a promise instead
}