SkImage method for detecting lazy decoding

SkImage method for detecting lazy decoding

BUG=skia:4224
R=reed@google.com

Committed: https://skia.googlesource.com/skia/+/ddbbddabefe865cc52e4b89a9d45455b987129bd

[f(malita), 2015-08-20 08:46:13]

The CQ bit was checked by fmalita@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2015-08-20 08:46:27]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1305453007/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1305453007/1

[commit-bot: I haz the power, 2015-08-20 08:47:19]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2015-08-20 08:47:20]

Dry run: Try jobs failed on following builders:
  Build-Ubuntu-Clang-x86_64-Debug-Trybot on client.skia.compile (JOB_FAILED,
http://build.chromium.org/p/client.skia.compile/builders/Build-Ubuntu-Clang-x...)
  Build-Ubuntu-GCC-Arm64-Debug-Android-Trybot on client.skia.compile
(JOB_FAILED,
http://build.chromium.org/p/client.skia.compile/builders/Build-Ubuntu-GCC-Arm...)
  Build-Ubuntu-GCC-Mips-Debug-Android-Trybot on client.skia.compile (JOB_FAILED,
http://build.chromium.org/p/client.skia.compile/builders/Build-Ubuntu-GCC-Mip...)

[f(malita), 2015-08-20 08:50:29]

The CQ bit was checked by fmalita@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2015-08-20 08:50:38]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1305453007/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1305453007/20001

[f(malita), 2015-08-20 08:56:17]

Any suggestions for a better method name?

[commit-bot: I haz the power, 2015-08-20 08:57:10]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2015-08-20 08:57:10]

Dry run: This issue passed the CQ dry run.

[f(malita), 2015-08-20 15:08:50]

fmalita@chromium.org changed reviewers:
+ scroggo@google.com

[reed1, 2015-08-20 15:27:50]

I guess we'll want to update blink's subclass after this lands.

lgtm

https://codereview.chromium.org/1305453007/diff/20001/include/core/SkImage.h
File include/core/SkImage.h (right):

https://codereview.chromium.org/1305453007/diff/20001/include/core/SkImage.h#...
include/core/SkImage.h:292: *  Returns true if the image is backed by a pixel
ref which generates pixels on-the-fly
... backed by an image-generator or other src that creates (and caches) its
pixels / texture on-demand.

[f(malita), 2015-08-20 15:38:37]

On 2015/08/20 15:27:50, reed1 wrote:
> I guess we'll want to update blink's subclass after this lands.

Which subclass do you have in mind?  AFAIK Blink doesn't subclass SkPixelRef. 
Deferred decoding is implemented using a SkImageGenerator subclass +
SkImage::NewFromGenerator => which ends up installing a SkDiscardablePixelRef. 
So I think the new method would just work for Blink.

https://codereview.chromium.org/1305453007/diff/20001/include/core/SkImage.h
File include/core/SkImage.h (right):

https://codereview.chromium.org/1305453007/diff/20001/include/core/SkImage.h#...
include/core/SkImage.h:292: *  Returns true if the image is backed by a pixel
ref which generates pixels on-the-fly
On 2015/08/20 15:27:50, reed1 wrote:
> ... backed by an image-generator or other src that creates (and caches) its
> pixels / texture on-demand.

Done.

[f(malita), 2015-08-20 15:39:18]

The CQ bit was checked by fmalita@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2015-08-20 15:39:30]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1305453007/40001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1305453007/40001

[reed1, 2015-08-20 15:44:20]

On 2015/08/20 15:38:37, f(malita) wrote:
> On 2015/08/20 15:27:50, reed1 wrote:
> > I guess we'll want to update blink's subclass after this lands.
> 
> Which subclass do you have in mind?  AFAIK Blink doesn't subclass SkPixelRef. 
> Deferred decoding is implemented using a SkImageGenerator subclass +
> SkImage::NewFromGenerator => which ends up installing a SkDiscardablePixelRef.

> So I think the new method would just work for Blink.

Ah, right. Groovy.

> 
> https://codereview.chromium.org/1305453007/diff/20001/include/core/SkImage.h
> File include/core/SkImage.h (right):
> 
>
https://codereview.chromium.org/1305453007/diff/20001/include/core/SkImage.h#...
> include/core/SkImage.h:292: *  Returns true if the image is backed by a pixel
> ref which generates pixels on-the-fly
> On 2015/08/20 15:27:50, reed1 wrote:
> > ... backed by an image-generator or other src that creates (and caches) its
> > pixels / texture on-demand.
> 
> Done.

[commit-bot: I haz the power, 2015-08-20 15:46:10]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2015-08-20 15:46:11]

Dry run: This issue passed the CQ dry run.

[f(malita), 2015-08-20 15:46:38]

The CQ bit was checked by fmalita@chromium.org

[f(malita), 2015-08-20 15:46:39]

The patchset sent to the CQ was uploaded after l-g-t-m from reed@google.com
Link to the patchset: https://codereview.chromium.org/1305453007/#ps40001
(title: "review comments")

[commit-bot: I haz the power, 2015-08-20 15:46:49]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1305453007/40001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1305453007/40001

[commit-bot: I haz the power, 2015-08-20 15:47:29]

Committed patchset #3 (id:40001) as
https://skia.googlesource.com/skia/+/ddbbddabefe865cc52e4b89a9d45455b987129bd

[Noel Gordon, 2015-08-21 05:49:35]

On 2015/08/20 15:38:37, f(malita) wrote:
> On 2015/08/20 15:27:50, reed1 wrote:
> > I guess we'll want to update blink's subclass after this lands.
> 
> Which subclass do you have in mind?  AFAIK Blink doesn't subclass SkPixelRef. 
> Deferred decoding is implemented using a SkImageGenerator subclass +
> SkImage::NewFromGenerator => which ends up installing a SkDiscardablePixelRef.

> So I think the new method would just work for Blink.

Looks like it will.

> https://codereview.chromium.org/1305453007/diff/20001/include/core/SkImage.h
> File include/core/SkImage.h (right):
> 
>
https://codereview.chromium.org/1305453007/diff/20001/include/core/SkImage.h#...
> include/core/SkImage.h:292: *  Returns true if the image is backed by a pixel
> ref which generates pixels on-the-fly
> On 2015/08/20 15:27:50, reed1 wrote:
> > ... backed by an image-generator or other src that creates (and caches) its
> > pixels / texture on-demand.
> 
> Done.

"caches"?

[f(malita), 2015-08-21 08:56:41]

On 2015/08/21 05:49:35, noel gordon wrote:
> On 2015/08/20 15:38:37, f(malita) wrote:
> > On 2015/08/20 15:27:50, reed1 wrote:
> > > I guess we'll want to update blink's subclass after this lands.
> > 
> > Which subclass do you have in mind?  AFAIK Blink doesn't subclass
SkPixelRef. 
> > Deferred decoding is implemented using a SkImageGenerator subclass +
> > SkImage::NewFromGenerator => which ends up installing a
SkDiscardablePixelRef.
> 
> > So I think the new method would just work for Blink.
> 
> Looks like it will.

It should also allow us to simplify lazy-decoding tracking in Blink (remove the
explicit mechanism I introduced when we switched from SkImage). 


> > https://codereview.chromium.org/1305453007/diff/20001/include/core/SkImage.h
> > File include/core/SkImage.h (right):
> > 
> >
>
https://codereview.chromium.org/1305453007/diff/20001/include/core/SkImage.h#...
> > include/core/SkImage.h:292: *  Returns true if the image is backed by a
pixel
> > ref which generates pixels on-the-fly
> > On 2015/08/20 15:27:50, reed1 wrote:
> > > ... backed by an image-generator or other src that creates (and caches)
its
> > > pixels / texture on-demand.
> > 
> > Done.
> 
> "caches"?

Skia has a bitmap cache sitting in front of generated images, and the generators
themselves can implement internal caching as needed.

I assume the cache verbiage is intended to clarify that isLazyGenerated() ==
true doesn't necessarily mean that the generator has to perform heavy lifting
every time we draw the image.

[scroggo, 2015-08-26 16:46:12]

Late to the party (back from vacation) LGTM