Don't load transformers that aren't going to be used for an executable.

Don't load transformers that aren't going to be used for an executable.

A package's executables may not use all of that package's transformers. This is
especially true for browser frameworks where there's a clear divide between
client-side and server-side code. This uses pub's existing dependency-sniffing
infrastructure to figure out which transformers can be omitted.

This takes "pub run polymer:new_element --help" from 1.52s to 0.96s.

R=rnystrom@google.com
BUG=20859
Committed: https://code.google.com/p/dart/source/detail?r=40659

[Bob Nystrom, 2014-09-24 23:42:47]

A couple of nits but otherwise LGTM. Nice!

https://codereview.chromium.org/599993004/diff/1/sdk/lib/_internal/pub/lib/sr...
File sdk/lib/_internal/pub/lib/src/barback/asset_environment.dart (right):

https://codereview.chromium.org/599993004/diff/1/sdk/lib/_internal/pub/lib/sr...
sdk/lib/_internal/pub/lib/src/barback/asset_environment.dart:60: /// entrypoints
will be loaded. Each entrypoint is expected to refer to a Dart
"will be" -> "are".

It took me a while to break my future tense habit, but I'm glad I did.

https://codereview.chromium.org/599993004/diff/1/sdk/lib/_internal/pub/lib/sr...
sdk/lib/_internal/pub/lib/src/barback/asset_environment.dart:517: .then((_) =>
transformerServer.close());
Whole lotta indentation here. How about using await?

https://codereview.chromium.org/599993004/diff/1/sdk/lib/_internal/pub/lib/sr...
File sdk/lib/_internal/pub/lib/src/barback/dependency_computer.dart (right):

https://codereview.chromium.org/599993004/diff/1/sdk/lib/_internal/pub/lib/sr...
sdk/lib/_internal/pub/lib/src/barback/dependency_computer.dart:19: /// A class
for determining which dependencies between transformers and from
You a grammar.

https://codereview.chromium.org/599993004/diff/1/sdk/lib/_internal/pub/lib/sr...
sdk/lib/_internal/pub/lib/src/barback/dependency_computer.dart:51: /// The
returned graph is transitively closed. That is, if there's an edge from
Long line.

https://codereview.chromium.org/599993004/diff/1/sdk/lib/_internal/pub/lib/sr...
File sdk/lib/_internal/pub/lib/src/entrypoint.dart (right):

https://codereview.chromium.org/599993004/diff/1/sdk/lib/_internal/pub/lib/sr...
sdk/lib/_internal/pub/lib/src/entrypoint.dart:268: var executableIds =
unionAll(executables.values.map((ids) => ids.toSet()));
Long line.

[nweiz, 2014-09-25 00:12:58]

Code review changes

[nweiz, 2014-09-25 00:13:15]

https://codereview.chromium.org/599993004/diff/1/sdk/lib/_internal/pub/lib/sr...
File sdk/lib/_internal/pub/lib/src/barback/asset_environment.dart (right):

https://codereview.chromium.org/599993004/diff/1/sdk/lib/_internal/pub/lib/sr...
sdk/lib/_internal/pub/lib/src/barback/asset_environment.dart:60: /// entrypoints
will be loaded. Each entrypoint is expected to refer to a Dart
On 2014/09/24 23:42:47, Bob Nystrom wrote:
> "will be" -> "are".
> 
> It took me a while to break my future tense habit, but I'm glad I did.

Done.

https://codereview.chromium.org/599993004/diff/1/sdk/lib/_internal/pub/lib/sr...
sdk/lib/_internal/pub/lib/src/barback/asset_environment.dart:517: .then((_) =>
transformerServer.close());
On 2014/09/24 23:42:47, Bob Nystrom wrote:
> Whole lotta indentation here. How about using await?

Done.

https://codereview.chromium.org/599993004/diff/1/sdk/lib/_internal/pub/lib/sr...
File sdk/lib/_internal/pub/lib/src/barback/dependency_computer.dart (right):

https://codereview.chromium.org/599993004/diff/1/sdk/lib/_internal/pub/lib/sr...
sdk/lib/_internal/pub/lib/src/barback/dependency_computer.dart:19: /// A class
for determining which dependencies between transformers and from
On 2014/09/24 23:42:47, Bob Nystrom wrote:
> You a grammar.

Done.

https://codereview.chromium.org/599993004/diff/1/sdk/lib/_internal/pub/lib/sr...
sdk/lib/_internal/pub/lib/src/barback/dependency_computer.dart:51: /// The
returned graph is transitively closed. That is, if there's an edge from
On 2014/09/24 23:42:47, Bob Nystrom wrote:
> Long line.

Done.

https://codereview.chromium.org/599993004/diff/1/sdk/lib/_internal/pub/lib/sr...
File sdk/lib/_internal/pub/lib/src/entrypoint.dart (right):

https://codereview.chromium.org/599993004/diff/1/sdk/lib/_internal/pub/lib/sr...
sdk/lib/_internal/pub/lib/src/entrypoint.dart:268: var executableIds =
unionAll(executables.values.map((ids) => ids.toSet()));
On 2014/09/24 23:42:47, Bob Nystrom wrote:
> Long line.

Done.

[nweiz, 2014-09-25 00:15:49]

Committed patchset #2 (id:20001) manually as 40659 (presubmit successful).