908962 - Investigate using bypass-history and -cache load flags in background thumbnail browser

Status: RESOLVED WORKSFORME

(Toolkit :: General, defect)

Description

[Drew Willcoxon :adw]

nsIWebNavigation.LOAD_FLAGS_BYPASS_HISTORY
nsIRequest.INHIBIT_PERSISTENT_CACHING

There may be others that are useful.  If these flags do what they say they do, then combined with LOAD_ANONYMOUS (bug 902439), the bg thumbnail browser may be able to stop using private browsing mode.

Comment 1

[Mark Hammond [:markh] [:mhammond]]

Why would we care about nsIRequest.INHIBIT_PERSISTENT_CACHING?  It seems as though this flag is designed to prevent "private" info from ending up in the cache, but background thumbnails are intended to *never* actually grab private data.  The docs for these flags imply that data already in the cache can still be used to satisfy the request, which sounds like what we are trying to avoid - so maybe LOAD_BYPASS_CACHE is what we want?

Comment 2

[Drew Willcoxon :adw]

Yeah, I know nothing about these flags.  I just noticed them on various interfaces and their names make them sound potentially useful.

Gavin and I have been talking like we want to prevent most if not all disk I/O done by backgrounds thumbs in the course of fetching pages.  (There's that bug about minimizing resource use.)  Preventing cache writes would support that goal, but maybe it turns out we don't actually want to prevent that, I don't know.

Comment 3

[Mark Hammond [:markh] [:mhammond]]

Bug 875986 landed with the following flags:

 Ci.nsIRequest.LOAD_ANONYMOUS |
 Ci.nsIRequest.LOAD_BYPASS_CACHE |
 Ci.nsIRequest.INHIBIT_CACHING |
 Ci.nsIWebNavigation.LOAD_FLAGS_BYPASS_HISTORY;

So I think we can mark this WFM?

Comment 4

[Drew Willcoxon :adw]

Sure, thanks, Mark.