Emit assets in serial, use Stream.pipe to write to output files

Emit assets in serial, use Stream.pipe to write to output files

BUG= https://code.google.com/p/dart/issues/detail?id=13752
R=sigmund@google.com

Committed: https://code.google.com/p/dart/source/detail?r=28314

[kevmoo-old, 2013-10-07 15:18:06]

I replaced the usage of Future.wait w/ a Future.forEach

This ensures that we don't get overlapping file.open for every asset passed in.

Speed also seems fine.

Also included Soren's suggestion of using read().pipe

[Siggi Cherem (dart-lang), 2013-10-07 16:29:35]

lgtm with comment below?

https://codereview.chromium.org/26268002/diff/1/pkg/polymer/lib/src/build/run...
File pkg/polymer/lib/src/build/runner.dart (right):

https://codereview.chromium.org/26268002/diff/1/pkg/polymer/lib/src/build/run...
pkg/polymer/lib/src/build/runner.dart:283: return Future.wait(futures);
change here also to use forEach?

[kevmoo-old, 2013-10-07 17:08:04]

https://codereview.chromium.org/26268002/diff/1/pkg/polymer/lib/src/build/run...
File pkg/polymer/lib/src/build/runner.dart (right):

https://codereview.chromium.org/26268002/diff/1/pkg/polymer/lib/src/build/run...
pkg/polymer/lib/src/build/runner.dart:283: return Future.wait(futures);
On 2013/10/07 16:29:35, Siggi Cherem (dart-lang) wrote:
> change here also to use forEach?

Done.

[kevmoo-old, 2013-10-07 17:08:41]

Committed patchset #2 manually as r28314 (presubmit successful).

[Jennifer Messerly, 2013-10-07 18:04:32]

On 2013/10/07 17:08:41, kevmoo wrote:
> Committed patchset #2 manually as r28314 (presubmit successful).

Can we add a comment about why we are doing async IO but serializing all the
operations?

[Siggi Cherem (dart-lang), 2013-10-07 18:31:50]

On 2013/10/07 18:04:32, John Messerly wrote:
> On 2013/10/07 17:08:41, kevmoo wrote:
> > Committed patchset #2 manually as r28314 (presubmit successful).
> 
> Can we add a comment about why we are doing async IO but serializing all the
> operations?

oops, forgot to mention that, yes +1. I think for asset makes sense because all
the 'read' APIs are async in the first place. For copy we should either switch
to a sync API or mention this is either because we hope this will be fixed in
dart:io.