838223 - lazy load gallery features to improve startup speed

Status: VERIFIED FIXED

(Firefox OS Graveyard :: Gaia::Gallery, defect)

Description

[David Flanagan [:djf]]

Gallery doesn't need to load all of its scripts at startup. The photo editing features, for example, could be loaded after initialization.

Comment 1

[David Flanagan [:djf]]

Marking this as blocking meta bug 817113, taking it, and requesting tef+ since we can't mark the parent bug tef+, but gallery performance is blocking tef.

Comment 2

[Dylan Oliver [:doliver]]

tef+ to clear the way for gallery work.

Comment 3

[David Flanagan [:djf]]

This should be relatively straightforward to do. My work on bug 838219 has turned into a big enough refactoring, however, that I'll probably end up addressing this bug as part of that one.

On its own, I could get this landed by 2/12. But as part of the larger 838219 it is more at risk of not making it.

Comment 4

[David Flanagan [:djf]]

I'm not going to be able to land bug 838219 by 2/12, so I'm going to try to do this bug independently of that one.

Comment 5

[David Flanagan [:djf]]

Attachment: link to patch on github

The linked patch is a big one, but most of the changes just move code from gallery.js to other files where it can be loaded lazily.

To summarize what this patch is doing, here are the original commit messages for the various pieces of it:

pick d0892ba only load edit mode code when needed
pick 42406e0 load photo/video view scripts on demand
pick b7076ad don't load gesture detector until we need it
pick e7e23bc don't load metadata parsing code unless needed
pick b7563fb get rid of spinner on startup
pick aefb63e move WebGL shaders from html file to ImageEditor.js
pick 71e4d3b change the db enumeration algorithm for faster startup

Note the creation of a Makefile to concatenate scripts that are going to be loaded lazily. This seems to work correctly with the build system.  Also I've added a local .gitignore directory so git will ignore the concatenated files.

The enumeration change in initThumbnails() in gallery.js is an important one, but most of it just reverts to an older algorithm that has already been tried and tested.

The new loadScript() function at the end of gallery.js is they dynamic loading mechanism.

I know you're busy with your own tef+ bugs, Dale, but my other usual reviewers, James and Dominic are both on vacation.

Comment 6

[Dale Harvey (:daleharvey)]

Comment on attachment 712799 [details]
link to patch on github

rather large change but havent found any issues so far, its mostly restructuring. and it does have a noticeable effect on startup. 

I do see a big issue with images flashing the previous version when selected from the grid view, but that was visible in previous versions as well

Comment 7

[Dale Harvey (:daleharvey)]

Merged in: https://github.com/mozilla-b2g/gaia/commit/f365915392d28ec111589883a2883b3682579340

Comment 8

[Lukas Blakk [:lsblakk] use ?needinfo]

Batch edit: Bugs still affected on b2g18 after 2/13 merge to v1.0.1 branch are affected on v1.0.1 branch.

Comment 9

[John Ford [:jhford] CET/CEST Berlin Time]

v1-train: f029bdf67fd37c0463111f634208e171324c1e4d
v1.0.1: ff0e3a141eb8b8f1f93a4d5e3a380a76aa9e482e

Comment 10

[amiller]

does not make sense to create a regression issue.

Comment 11

[Natalya Kot [:nkot]]

Verifying fix - gallery load time improved significantly, 
loading time is now 680-770 comparing to 1400-1600 on 2013-02-10-070201 build 

results are taken from:
settings => device info => more info => developer => show time to load => launch gallery

tested on Unagis running with the following builds:

V1.0.1
Build  2013-03-22-07-02-03
Gecko  http://hg.mozilla.org/releases/mozilla-b2g18_v1_0_1/rev/4931ec89ebbe
Gaia   85fd164691bb852f1cfaf82405df4380629ced6e

V1.1.0
Build  2013-03-22-07-02-02
Gecko  http://hg.mozilla.org/releases/mozilla-b2g18/rev/5aacf880400b
Gaia   5a31a56b96a8fc559232d35dabf20411b9c2ca1d