Speedup the snapshot serialization.

Speedup the snapshot serialization.

Replaced multiple calls to AddNumber with a single AddString.
AddNumber may now print the value directly into the output buffer.

BUG=none
TEST=none

Committed: https://code.google.com/p/v8/source/detail?r=10784

[alexeif, 2012-02-21 12:33:54]

Hi Mike,

Thanks for your comments! Could you please take another look.

[yurys, 2012-02-21 12:53:26]

https://chromiumcodereview.appspot.com/9395087/diff/1/src/profile-generator.cc
File src/profile-generator.cc (right):

https://chromiumcodereview.appspot.com/9395087/diff/1/src/profile-generator.c...
src/profile-generator.cc:3564: static const int kBufferSize = 3 * 20 + 3 + 1;
Can we use kMaxNumberSize here instead of 20?

[mnaganov (inactive), 2012-02-21 13:31:17]

On 2012/02/21 12:53:26, Yury Semikhatsky wrote:
> https://chromiumcodereview.appspot.com/9395087/diff/1/src/profile-generator.cc
> File src/profile-generator.cc (right):
> 
>
https://chromiumcodereview.appspot.com/9395087/diff/1/src/profile-generator.c...
> src/profile-generator.cc:3564: static const int kBufferSize = 3 * 20 + 3 + 1;
> Can we use kMaxNumberSize here instead of 20?

I think, it might be a good idea to put kMaxUint64DecimalDigits from strtod.cc
into .h file and re-use it.

[alexeif, 2012-02-21 13:49:54]

On 2012/02/21 13:31:17, Mikhail Naganov (Chromium) wrote:
> On 2012/02/21 12:53:26, Yury Semikhatsky wrote:
> >
https://chromiumcodereview.appspot.com/9395087/diff/1/src/profile-generator.cc
> > File src/profile-generator.cc (right):
> > 
> >
>
https://chromiumcodereview.appspot.com/9395087/diff/1/src/profile-generator.c...
> > src/profile-generator.cc:3564: static const int kBufferSize = 3 * 20 + 3 +
1;
> > Can we use kMaxNumberSize here instead of 20?
> 
> I think, it might be a good idea to put kMaxUint64DecimalDigits from strtod.cc
> into .h file and re-use it.

I can't use this particular constant because it's defined as 19, while the max
number of digits in int64 is 20. I'm not sure if it's a bug.

[alexeif, 2012-02-21 13:50:00]

https://chromiumcodereview.appspot.com/9395087/diff/1/src/profile-generator.cc
File src/profile-generator.cc (right):

https://chromiumcodereview.appspot.com/9395087/diff/1/src/profile-generator.c...
src/profile-generator.cc:3564: static const int kBufferSize = 3 * 20 + 3 + 1;
On 2012/02/21 12:53:27, Yury Semikhatsky wrote:
> Can we use kMaxNumberSize here instead of 20?

Done.

[mnaganov (inactive), 2012-02-21 14:21:53]

LGTM with a comment

https://chromiumcodereview.appspot.com/9395087/diff/6001/src/profile-generato...
File src/profile-generator.cc (right):

https://chromiumcodereview.appspot.com/9395087/diff/6001/src/profile-generato...
src/profile-generator.cc:3432: MaxDecimalDigitsIn<sizeof(long long)>::kUnsigned
+ 1;  // NOLINT
I will change "long long" to "T" (and update the comment), because "long long"
isn't the part of ISO 1998 C++ standard and hence doesn't compile in a
standalone V8.

If you are OK with this, I'll submit your change.

[alexeif, 2012-02-21 14:33:16]

On 2012/02/21 14:21:53, Mikhail Naganov (Chromium) wrote:
> LGTM with a comment
> 
>
https://chromiumcodereview.appspot.com/9395087/diff/6001/src/profile-generato...
> File src/profile-generator.cc (right):
> 
>
https://chromiumcodereview.appspot.com/9395087/diff/6001/src/profile-generato...
> src/profile-generator.cc:3432: MaxDecimalDigitsIn<sizeof(long
long)>::kUnsigned
> + 1;  // NOLINT
> I will change "long long" to "T" (and update the comment), because "long long"
> isn't the part of ISO 1998 C++ standard and hence doesn't compile in a
> standalone V8.
> 
> If you are OK with this, I'll submit your change.

I'm ok. Thanks a lot!