[tor-bugs] #29120 [Applications/Tor Browser]: Default value of media.cache_size (0) causes some media to load extremely slowly or become unplayable

[Tor Bug Tracker & Wiki]

#29120: Default value of media.cache_size (0) causes some media to load extremely
slowly or become unplayable
-------------------------------------------------+-------------------------
 Reporter:  QZw2aBQoPyuEVXYVlBps                 |          Owner:  tbb-
                                                 |  team
     Type:  defect                               |         Status:
                                                 |  needs_revision
 Priority:  High                                 |      Milestone:
Component:  Applications/Tor Browser             |        Version:
 Severity:  Normal                               |     Resolution:
 Keywords:  tbb-disk-leak, tbb-usability-        |  Actual Points:
  website, TorBrowserTeam201902                  |
Parent ID:                                       |         Points:
 Reviewer:                                       |        Sponsor:
-------------------------------------------------+-------------------------

Comment (by QZw2aBQoPyuEVXYVlBps):

 Replying to [comment:19 gk]:
 > You have
 > {{{
 >  if (aContentLength < 0) {
 > }}}
 > in your patch but looking at the original code I think we should take
 care of the case here as well that `aContentLength` is `0`.
 If you look here: https://hg.mozilla.org/releases/mozilla-
 esr60/file/256453759958ed9c2eb17a0764d2fcfd7f8e3323/dom/media/MediaCache.cpp#l153
 You'll see that `aContentLength` is `-1` if it is unknown, so an
 `aContentLength` of `0` means that's what the server actually sent.
 I can test whether this plays nicely with the current code or not, but if
 not, what do you suggest we do here?

 > Additionally, I think we should go back to the default size for
 `media.cache_size` so that users outside of private browsing mode get the
 usual behavior (right now they would still be affected by this bug without
 resetting the pref). (https://gitweb.torproject.org/tor-
 browser.git/tree/browser/app/profile/000-tor-browser.js?h=tor-
 browser-60.5.0esr-8.5-1 is the file to look at)
 I agree with this, I was going to mention it but it slipped my mind. I
 also suggested above that the default of `media.memory_cache_max_size`
 should be increased to handle buffering longer media content in memory,
 what do you think about this?
 > QZw2aBQoPyuEVXYVlBps: Thanks for this find and a patch, really
 appreciated. We are close here. Do you want to fix the remaining things up
 or should we? How should we credit you? (I am fine crediting
 QZw2aBQoPyuEVXYVlBps in the commit message :) )
 It's a little time consuming for me to test my code since compiling takes
 awhile, but since there's only a few changes, I think I should be fine
 completing it.
 You can credit either "QZw2aBQoPyuEVXYVlBps" or "anonymous", this is
 simply a throwaway account because I wasn't able to get the cypherpunks
 account to work.

--
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/29120#comment:20>
Tor Bug Tracker & Wiki <https://trac.torproject.org/>
The Tor Project: anonymity online