Javascript-取消的请求会影响性能吗？

Question

Our application is using angular and get a lot of requests. There is a group of request (Request BCD) has dependency on watching data returned by another request.(Please see attachment) So when first load the page, it will send BCD requests and A request was sent at same time. When A request returned data, BCD request will send again and the earlier BCD request will be abort(Canceled).

My question is: since the request was canceled anyway, will this affect my page loading time? Should I implement something like a promise to let BCD request wait for A request finish then watch data returned from A request?

Screen shoot 1

Answer 1

There will be additional work as engine will have to perform certain actions to cancel request. You can find steps here

As you see engine will have to fire following events:

• readystatechange
• progress
• abort
• loadend

Along with updating some flags. But these work will take very less time and delay in performance would be negligible.

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Edit 1:

If you refer concept-event-fire-progress , mentioned events will be fired anyways except abort . It would be error or load or timeout based on status. But cancelling a request would make engine fire these events right away and this might add some time. But again, the total time will be negligible.