1255104 - Use SurfacePipe in the Icon decoder

Status: RESOLVED FIXED

(Core :: Graphics: ImageLib, defect)

Description

[Seth Fowler [:seth] [:s2h]]

SurfacePipe is intended to eliminate the possibility of output buffer overflows in ImageLib, so we want to use it for all decoders. That includes Icon.

This is a good opportunity to introduce downscale-during-decode support for the Icon format, since it's trivial with SurfacePipe.

Comment 1

[Seth Fowler [:seth] [:s2h]]

Silly me - of course we already introduced downscale-during-decode for Icon. I went ahead and did this one because the patch is so simple, and I figured it'd be nice to have this as a simple example for both SurfacePipe and StreamingLexer.

Comment 2

[Seth Fowler [:seth] [:s2h]]

Attachment: Use SurfacePipe in nsIconDecoder.

Here's the patch. nsIconDecoder is truly minimal at this point. We could even
get rid of mBytesPerRow but I think it makes things a bit clearer.

I preferred WritePixels to WriteRows here. Unlike in the GIF decoder, there's
probably not enough work per pixel to make this effectively free (i.e. memcpy
with WriteRows would undoubtedly be faster) but I would prefer the additional
memory safety unless we run into an issue.

Comment 3

[Seth Fowler [:seth] [:s2h]]

Attachment: Use SurfacePipe in nsIconDecoder.

Whoops, forgot to commit before attaching.

Comment 4

[Seth Fowler [:seth] [:s2h]]

Thanks for the review!

Comment 5

[Seth Fowler [:seth] [:s2h]]

https://treeherder.mozilla.org/#/jobs?repo=try&revision=64d6ff8bb94e

Comment 6

[Seth Fowler [:seth] [:s2h]]

https://hg.mozilla.org/integration/mozilla-inbound/rev/033d603cd91d2a6ec256c23cb26f7aa4310e47b0
Bug 1255104 - Use SurfacePipe in nsIconDecoder. r=njn

Comment 7

[Carsten Book [:Tomcat]]

https://hg.mozilla.org/mozilla-central/rev/033d603cd91d