Add 'skiapict' magic bytes to SkPicture format.

Add 'skiapict' magic bytes to SkPicture format.

Testing: out/Debug/tests && out/Release/gm --replay --serialize


BUG=

Committed: http://code.google.com/p/skia/source/detail?r=12391

[reed1, 2013-10-15 21:38:03]

is this technique any more or less endian-robust than

stream->write("skiapict", 8);

buffer sig[8];
stream->read(sig, 8);
memcmp(sig, "skiapict", 8);

?

If this CL is the same or safer, lgtm

[mtklein, 2013-10-16 15:25:20]

On 2013/10/15 21:38:03, reed1 wrote:
> is this technique any more or less endian-robust than
> 
> stream->write("skiapict", 8);
> 
> buffer sig[8];
> stream->read(sig, 8);
> memcmp(sig, "skiapict", 8);
> 
> ?
> 
> If this CL is the same or safer, lgtm

I think less endian robust.  Switched to your version.  PTAL.

[reed1, 2013-10-16 15:26:39]

https://codereview.chromium.org/27408002/diff/16001/src/core/SkPicture.cpp
File src/core/SkPicture.cpp (right):

https://codereview.chromium.org/27408002/diff/16001/src/core/SkPicture.cpp#ne...
src/core/SkPicture.cpp:277: uint8_t magic[SK_ARRAY_COUNT(kMagic)];
I think this returns 9...

[f(malita), 2013-10-16 15:26:47]

lgtm

[f(malita), 2013-10-16 15:29:43]

On 2013/10/16 15:26:39, reed1 wrote:
> https://codereview.chromium.org/27408002/diff/16001/src/core/SkPicture.cpp
> File src/core/SkPicture.cpp (right):
> 
>
https://codereview.chromium.org/27408002/diff/16001/src/core/SkPicture.cpp#ne...
> src/core/SkPicture.cpp:277: uint8_t magic[SK_ARRAY_COUNT(kMagic)];
> I think this returns 9...

Ah, nice catch. Though not necessarily broken (since it's used consistently),
we're wasting one byte.

I guess we should use an array initializer instead of string literal?

[mtklein, 2013-10-16 15:32:31]

On 2013/10/16 15:29:43, Florin Malita wrote:
> On 2013/10/16 15:26:39, reed1 wrote:
> > https://codereview.chromium.org/27408002/diff/16001/src/core/SkPicture.cpp
> > File src/core/SkPicture.cpp (right):
> > 
> >
>
https://codereview.chromium.org/27408002/diff/16001/src/core/SkPicture.cpp#ne...
> > src/core/SkPicture.cpp:277: uint8_t magic[SK_ARRAY_COUNT(kMagic)];
> > I think this returns 9...
> 
> Ah, nice catch. Though not necessarily broken (since it's used consistently),
> we're wasting one byte.
> 
> I guess we should use an array initializer instead of string literal?

Duh... fixed.

[reed1, 2013-10-16 15:34:41]

lgtm w/ half-nit

https://codereview.chromium.org/27408002/diff/25001/src/core/SkPicture.cpp
File src/core/SkPicture.cpp (right):

https://codereview.chromium.org/27408002/diff/25001/src/core/SkPicture.cpp#ne...
src/core/SkPicture.cpp:277: uint8_t magic[SK_ARRAY_COUNT(kMagic)];
could be sizeof or SK_ARRAY_COUNT. I find the former slightly clearer, but no
big pref.

[mtklein, 2013-10-16 15:37:20]

On 2013/10/16 15:34:41, reed1 wrote:
> lgtm w/ half-nit
> 
> https://codereview.chromium.org/27408002/diff/25001/src/core/SkPicture.cpp
> File src/core/SkPicture.cpp (right):
> 
>
https://codereview.chromium.org/27408002/diff/25001/src/core/SkPicture.cpp#ne...
> src/core/SkPicture.cpp:277: uint8_t magic[SK_ARRAY_COUNT(kMagic)];
> could be sizeof or SK_ARRAY_COUNT. I find the former slightly clearer, but no
> big pref.

A vague preference is enough for me.  sizeof it is.  I also noticed I was using
char in one place and uint8_t in the other, so I made them both char.

[tfarina, 2013-10-16 16:43:58]

https://codereview.chromium.org/27408002/diff/34001/src/core/SkPicture.cpp
File src/core/SkPicture.cpp (right):

https://codereview.chromium.org/27408002/diff/34001/src/core/SkPicture.cpp#ne...
src/core/SkPicture.cpp:269: static const char kMagic[] = { 's', 'k', 'i', 'a',
'p', 'i', 'c', 't' };
I assume the { 'f', 'o', 'o' }; syntax usage was intentional.

Otherwise, isn't this the same as of:

static const char kMagic[] = "skiapict";

?

[f(malita), 2013-10-16 16:48:37]

On 2013/10/16 16:43:58, tfarina wrote:
> I assume the { 'f', 'o', 'o' }; syntax usage was intentional.
> 
> Otherwise, isn't this the same as of:
> 
> static const char kMagic[] = "skiapict";
> 
> ?

See discussion above: sizeof("foo") == sizeof({'f', 'o', 'o'}) + 1

[commit-bot: I haz the power, 2013-11-26 12:34:30]

CQ is trying da patch. Follow status at
https://skia-tree-status.appspot.com/cq/mtklein@google.com/27408002/34001

[commit-bot: I haz the power, 2013-11-26 12:47:00]

Change committed as 12391