Avoid redownloading changes on Sync

[Natim]

Refs: mozilla-services/readinglist#68

Basically, when doing a Batch before syncing, in the next update you will get all the records you've just changed that are already up-to-date with your local version. (When using If-Match headers to handle races)

We've just landed something, that let you exclude a list of values when syncing: mozilla-services/cliquet#432

This is something we may want to use in kinto.js sync to optimize the second fetch.

[n1k0]

That would be basically adding an exclude query string parameter to the second fetch for changes request with the already processed record ids, right?

[leplatrem]

Using ?exclude_id=id1,id2,id3 it should work.

What is the limit of the URL length by the way ?

[leplatrem]

What is the limit of the URL length by the way ?

Staying under 2000 chars looks like the most reasonable approach (source)

We can fit around 50 uuids in the exclude querystring :)