Performance with AngularJS

[radarfox]

Hello Jason,

I think there is a big performance problem in part of this adapter when using with AngularJS.

If you are calling create or destroy on many items (thousands), you end up with $rootScope.$apply for every item, and huge lags!

Why?

1. In this adapter setTimeout is called for every injected item here https://github.com/js-data/js-data-localstorage/blob/master/src/index.js#L44
2. In each of timeout execution inject for that item is invoked
3. And then js-data-angular call $apply as reaction on that https://github.com/js-data/js-data-angular/blob/master/src/index.js#L199

I have replaced setTimeout for sync callback as hotfix, but I am not sure if thats good.

[jmdobry]

Thanks for bringing this up. There are a couple ways to deal with this at the moment:

• Don't use js-data-angular, but instead use js-data directly, as js-data is not coupled to Angular's $digest loop.
• Use destroyAll instead of destroy to delete many items at once.
• Keep your using hotfix, though I'm not sure about its implications
• Write a batch create method yourself, until one can be added to js-data-localstorage

I am planning to add a batch create method that can create many items at once.

[radarfox]

• Not using js-data-angular is kind of extreme solution. I would miss other usefull features as $http integration.
• destroyAll is not helping, as it simply calls destroy on each item with no performance optimalizations https://github.com/js-data/js-data-localstorage/blob/master/src/index.js#L386
• What do you mean by "batch create"? Something like implementating new function createAll (similar to deleteAll)? Wouldnt that required modifications to the core js-data module?

[jmdobry]

destroyAll is not helping, as it simply calls destroy on each item with no performance optimalizations

Oh yeah, I forgot. Other adapters that connect to actual databases are able to optimize this method. localStorage doesn't have any collection-based operations.

What do you mean by "batch create"? Something like implementating new function createAll (similar to deleteAll)?

Something like this: User.createMany([{ name: 'Bob' }, { name: 'John' }])

Wouldnt that required modifications to the core js-data module?

Yes, but only if you want to be able to call DS#createMany. Adapters can be used directly when necessary.