Re: [w3c/ServiceWorker] Improve service worker script caching and update (#1283)

jungkees commented on this pull request.



> -            1. Else, return a <a>network error</a>.
+        1. If |serviceWorker|'s [=service worker/script resource map=][|request|'s [=request/url=]] [=map/exists=], return [=service worker/script resource map=][|request|'s [=request/url=]].
+        1. If |serviceWorker|'s [=state=] is *installed*, *activating*, *activated*, or *redundant*, return a [=network error=].
+        1. Let |registration| be |serviceWorker|'s [=containing service worker registration=].
+        1. Set |request|'s [=service-workers mode=] to "`none`".
+        1. Set |request|'s [=request/cache mode=] to "<code>no-cache</code>" if any of the following are true:
+            * |registration|'s [=service worker registration/update via cache mode=] is "`none`".
+            * The [=current global object=]'s [=force bypass cache for importscripts flag=] is set.
+            * |registration|'s [=last update check time=] is not null and the time difference in seconds calculated by the current time minus |registration|’s [=last update check time=] is greater than 86400.
+        1. Let |response| be the result of <a lt="fetch">fetching</a> |request|.
+        1. If |response|’s <a for="response" href="https://github.com/whatwg/fetch/issues/376">cache state</a> is not "<code>local</code>", set |registration|’s [=service worker registration/last update check time=] to the current time.
+        1. [=Extract a MIME type=] from the |response|'s [=unsafe response=]'s [=response/header list=]. If this MIME type (ignoring parameters) is not a [=JavaScript MIME type=], return a [=network error=].
+        1. If |response|'s <a>unsafe response</a>'s [=response/type=] is not "<code>error</code>", and |response|'s [=response/status=] is an <a>ok status</a>, then:
+            1. Let |newestWorker| be the result of running [=Get Newest Worker=] with |registration|.
+            1. Let |resource| be null.
+            1. If |newestWorker| is not null, set |resource| to |newestWorker|'s [=service worker/script resource map=][|request|'s [=request/url=]], or null if it does not [=map/exist=].

This is a case where `serviceWorker` doesn't have any stored response and hasn't gone to the installed state. (Cases other than that return early in the step 2 and 3.)

My intention here is to compare the response retrieved from the network (or HTTP cache depending on the cache mode) with the registration's newest worker's stored response, if any. I think we'd want to make it continue with Install only when importScripts() for `serviceWorker` has byte-differnce against `newestWorker`'s stored resources. The service worker's *include updated resources flag* is used to mark this condition that is later checked in Update.

-- 
You are receiving this because you are subscribed to this thread.
Reply to this email directly or view it on GitHub:
https://github.com/w3c/ServiceWorker/pull/1283#discussion_r172722598