1366975 - Expose the MediaCache statistics to DevTools Media

Status: NEW

(Core :: Audio/Video: Playback, enhancement, P3)

Description

[Benjamin Chen [:bechen]]

The idea comes from JW says: our MediaCache download the same data and drop it again and again due to the MediaCache readahead and drop mechanism.

So I think we can record the operations about the MediaCache then output to about:media page.

We might need a new class for recording.
class MediaCacheRecorder {
  nsTArray<MediaCacheOperation> array;
}

class MediaCacheOperation {
  ResourceID // unique id to identify the download source
  time // timestamp
  action // read/write/drop
  actionByteRange
}

Then we can render a timeline graph to the about:media page.

Comment 1

[Anthony Jones (:ajones, :kentuckyfriedtakahe, :k17e)]

about:media is dead. Long live DevTools Media Panel https://addons.mozilla.org/en-US/firefox/addon/devtools-media-panel/

Comment 2

[Benjamin Chen [:bechen]]

Attachment: Bug 1366975 - MediaCacheStatus webidl.

Review commit: https://reviewboard.mozilla.org/r/148436/diff/#index_header
See other reviews: https://reviewboard.mozilla.org/r/148436/

Comment 3

[Benjamin Chen [:bechen]]

Attachment: Bug 1366975 - MediaCacheStatusImpl.

Review commit: https://reviewboard.mozilla.org/r/148438/diff/#index_header
See other reviews: https://reviewboard.mozilla.org/r/148438/

Comment 4

[Benjamin Chen [:bechen]]

Attachment: Bug 1366975 - MediaElementWebidl.

Review commit: https://reviewboard.mozilla.org/r/148440/diff/#index_header
See other reviews: https://reviewboard.mozilla.org/r/148440/

Comment 5

[Benjamin Chen [:bechen]]

Attachment: Bug 1366975 - MediaElement

Review commit: https://reviewboard.mozilla.org/r/148442/diff/#index_header
See other reviews: https://reviewboard.mozilla.org/r/148442/

Comment 6

[Benjamin Chen [:bechen]]

Attachment: Bug 1366975 - testMediaCache.

Review commit: https://reviewboard.mozilla.org/r/148444/diff/#index_header
See other reviews: https://reviewboard.mozilla.org/r/148444/

Comment 7

[Benjamin Chen [:bechen]]

Comment on attachment 8877102 [details]
Bug 1366975 - MediaCacheStatus webidl.

https://reviewboard.mozilla.org/r/148434/#review152882

It is a simple code to access how many blocks store in the MediaCache.

Comment 8

[Gerald Squelart (he/him) (not at Mozilla since 2022-09-15)]

FYI, I'm working on bug 1371882, which will introduce multiple instances of MediaCache.
But looking at your patches, I think we won't have troubles working together, as you're counting cached blocks from each resource, it should work fine! (Maybe just a bit of merge pain for whoever lands second!) :-)

Comment 9

[BugBot [:suhaib / :marco/ :calixte]]

The bug assignee is inactive on Bugzilla, so the assignee is being reset.