I wrote a test using fetch() that seems to suggest we don't re-use in-progress requests at the http cache level.
(Note, this downloads about 200MB... don't click on your mobile.) https://people.mozilla.org/~bkelly/fetch/http-cache/ On Wed, Sep 7, 2016 at 1:45 PM, Andrew Sutherland < [email protected]> wrote: > There's a proposal at https://github.com/jakearchibald/background-cache > for enabling persistently-tracked uploads/downloads in the background. It > might change names to background-fetch. > > I'm interested in getting some informed feedback about the following > use-case on https://github.com/jakearchibald/background-cache/issues/3 > > A motivating use-case is for a site that wants to download movies/podcasts > in the background and keep them around for offline purposes. Once the file > is downloaded, it seems clear that the (ServiceWorker [DOM]) Cache API[1] > is a great place to store the result. What's less clear is how best to > handle allowing the user to begin watching the movie when the download is > still in-progress. A potential straw-man is: > > * Start the download with background-fetch > * Use the background-fetch API to track the status of the download. When > there's "enough" downloaded, start playing the video via its online URL > with the confidence that the netwerk cache2 can unify the two requests as > much as possible. > * When the download completes, stick the movie in the DOM Cache API and > use Cache-furnished Responses for all future playback requests. > > The greatest concern right now is around range requests and redundantly > downloaded data. We've seen interest in the Service Worker repo issues for > the ability to track/match in-flight fetch requests[2] that I hope should > be entirely mooted by the HTTP cache. Depending on the HTTP cache until > the download is complete ideally avoids redundant downloads, but it would > be great to have reassurance and an understanding of how a background-fetch > download mechanism might interact with the HTTP cache. Could the download > entirely use the HTTP cache for storage with the cache entries pinned to > avoid eviction until the download notification extendable event completes? > > Andrew > > 1: https://w3c.github.io/ServiceWorker/spec/service_worker/ > index.html#cache-objects > 2: https://github.com/w3c/ServiceWorker/issues/959 > > _______________________________________________ > dev-platform mailing list > [email protected] > https://lists.mozilla.org/listinfo/dev-platform > _______________________________________________ dev-platform mailing list [email protected] https://lists.mozilla.org/listinfo/dev-platform
