VM [KERNEL] Fix performance issue in KernelReader

VM [KERNEL] Fix performance issue in KernelReader

Original code is constructing Class fields
and functions incrementally going through
poorly scalable AddFunction and AddField
reallocating the whole array on each call.

Instead accumulate things in GrowableArrays
and insert in one go.

BUG= https://github.com/dart-lang/sdk/issues/28312
R=vegorov@google.com

Committed: https://github.com/dart-lang/sdk/commit/a8bc1de524f778c940c0171aaaea980f78819705

[Dmitry Olshansky, 2017-03-27 16:23:45]

dmitryolsh@google.com changed reviewers:
+ kustermann@google.com, vegorov@chromium.org

[Vyacheslav Egorov (Google), 2017-03-27 17:25:04]

Description was changed from

==========
VM [KERNEL] Fix performance issue in KernelReader

Original code is constructing Class fields
and functions incrementally going through
poorly scalable AddFunction and AddField
reallocating the whole array on each call.

Instead accumulate things in GrowableArrays
and insert in one go.

BUG= https://github.com/dart-lang/sdk/issues/28312
==========

to

==========
VM [KERNEL] Fix performance issue in KernelReader

Original code is constructing Class fields
and functions incrementally going through
poorly scalable AddFunction and AddField
reallocating the whole array on each call.

Instead accumulate things in GrowableArrays
and insert in one go.

BUG= https://github.com/dart-lang/sdk/issues/28312
==========

[Vyacheslav Egorov (Google), 2017-03-27 17:31:54]

vegorov@google.com changed reviewers:
+ vegorov@google.com

[Vyacheslav Egorov (Google), 2017-03-27 17:31:55]

https://codereview.chromium.org/2777963002/diff/1/runtime/vm/kernel_reader.cc
File runtime/vm/kernel_reader.cc (right):

https://codereview.chromium.org/2777963002/diff/1/runtime/vm/kernel_reader.cc...
runtime/vm/kernel_reader.cc:183: GrowableArray<const dart::Function*> functions;
Maybe make 

functions_ and fields_ members of the Kernel reader?

that would decrease Zone memory usage because then you can reuse these arrays
and also that would remove the need to explicitly pass them around.

[Dmitry Olshansky, 2017-03-27 18:08:47]

https://codereview.chromium.org/2777963002/diff/1/runtime/vm/kernel_reader.cc
File runtime/vm/kernel_reader.cc (right):

https://codereview.chromium.org/2777963002/diff/1/runtime/vm/kernel_reader.cc...
runtime/vm/kernel_reader.cc:183: GrowableArray<const dart::Function*> functions;
On 2017/03/27 17:31:55, Vyacheslav Egorov (Google) wrote:
> Maybe make 
> 
> functions_ and fields_ members of the Kernel reader?
> 
> that would decrease Zone memory usage because then you can reuse these arrays
> and also that would remove the need to explicitly pass them around.

Done.

[Vyacheslav Egorov (Google), 2017-03-27 18:19:09]

lgtm

https://codereview.chromium.org/2777963002/diff/20001/runtime/vm/kernel_reade...
File runtime/vm/kernel_reader.cc (right):

https://codereview.chromium.org/2777963002/diff/20001/runtime/vm/kernel_reade...
runtime/vm/kernel_reader.cc:210: ReadProcedure(library, toplevel_class,
kernel_procedure, NULL);
NULL is a default value. You can remove this change here.

[Dmitry Olshansky, 2017-03-27 18:24:26]

Description was changed from

==========
VM [KERNEL] Fix performance issue in KernelReader

Original code is constructing Class fields
and functions incrementally going through
poorly scalable AddFunction and AddField
reallocating the whole array on each call.

Instead accumulate things in GrowableArrays
and insert in one go.

BUG= https://github.com/dart-lang/sdk/issues/28312
==========

to

==========
VM [KERNEL] Fix performance issue in KernelReader

Original code is constructing Class fields
and functions incrementally going through
poorly scalable AddFunction and AddField
reallocating the whole array on each call.

Instead accumulate things in GrowableArrays
and insert in one go.

BUG= https://github.com/dart-lang/sdk/issues/28312
R=vegorov@google.com

Committed:
https://github.com/dart-lang/sdk/commit/a8bc1de524f778c940c0171aaaea980f78819705
==========

[Dmitry Olshansky, 2017-03-27 18:24:27]

Committed patchset #2 (id:20001) manually as
a8bc1de524f778c940c0171aaaea980f78819705 (presubmit successful).