1515194 - slim down nsLoadGroup

Status: RESOLVED FIXED

(Core :: Networking, enhancement, P2)

Description

[Nathan Froyd [:froydnj]]

The upcoming changes remove unused fields, rearrange fields for better packing,
and de-aggregate nsLoadGroup, all in the name of making it smaller.

Comment 1

[Nathan Froyd [:froydnj]]

Attachment: part 1 - assert if we create an aggregate load group

This was in my patch stack for test purposes, but later patches wind up
removing the assert.  I'm happy to fold it away if you like.

Comment 2

[Nathan Froyd [:froydnj]]

Attachment: part 2 - remove nsLoadGroup::mTimedNonCachedRequestsUntilOnEndPageLoad

We only write to this variable and never read it.  The whole
nsPILoadGroupInternal interface looks like it could go away, actually;
we'll do that in a subsequent patch.

Comment 3

[Nathan Froyd [:froydnj]]

Attachment: part 3 - remove nsPILoadGroupInternal

We apparently had this for internal extension hooks that couldn't be
depended on externally...but now that interfaces aren't exposed to
addons, we can remove this no-op interface entirely.

Comment 4

[Nathan Froyd [:froydnj]]

Attachment: part 4 - pack holes in nsLoadGroup better on 64-bit platforms

Due to member alignment rules on 64-bit platforms, nsLoadGroup has more
unused space than it should.  Shuffling members around a little to fill
in holes should make nsLoadGroup somewhat smaller.

Comment 5

[Nathan Froyd [:froydnj]]

Attachment: part 5 - un-aggregate nsLoadGroup

We no longer use the aggregation facility for nsLoadGroup, and removing
it saves approximately 10% of the space consumed by nsLoadGroup.

Comment 6

[Nathan Froyd [:froydnj]]

Worth noting that we have a clean try run (well, modulo a few HTTP 500 errors) with the release assert in place:

https://treeherder.mozilla.org/#/jobs?repo=try&revision=7d34d7ee014cf578287e6c60e7dd03ec23aaf242

I think I am just going to drop that first part.

Comment 7

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/mozilla-inbound/rev/83a64c5eb4fc
part 1 - remove nsLoadGroup::mTimedNonCachedRequestsUntilOnEndPageLoad; r=valentin
https://hg.mozilla.org/integration/mozilla-inbound/rev/7caeaeed08f0
part 2 - remove nsPILoadGroupInternal; r=valentin
https://hg.mozilla.org/integration/mozilla-inbound/rev/2c961fec66d8
part 3 - pack holes in nsLoadGroup better on 64-bit platforms; r=valentin
https://hg.mozilla.org/integration/mozilla-inbound/rev/e5a00beb701e
part 4 - un-aggregate nsLoadGroup; r=valentin

Comment 8

[Razvan Maries]

https://hg.mozilla.org/mozilla-central/rev/83a64c5eb4fc
https://hg.mozilla.org/mozilla-central/rev/7caeaeed08f0
https://hg.mozilla.org/mozilla-central/rev/2c961fec66d8
https://hg.mozilla.org/mozilla-central/rev/e5a00beb701e