Add DartWorkManager to manage Dart-specific results computation scheduling.

Add DartWorkManager to manage Dart-specific results computation scheduling.

R=brianwilkerson@google.com
BUG=

Committed: https://code.google.com/p/dart/source/detail?r=45677

[Brian Wilkerson, 2015-05-09 17:22:00]

LGTM

https://codereview.chromium.org/1132893003/diff/1/pkg/analyzer/lib/src/task/d...
File pkg/analyzer/lib/src/task/dart_work_manager.dart (right):

https://codereview.chromium.org/1132893003/diff/1/pkg/analyzer/lib/src/task/d...
pkg/analyzer/lib/src/task/dart_work_manager.dart:27: final HashSet<Source>
explicitSources = new HashSet<Source>();
The sets of 'explicitSources', 'librarySources' and 'partSources' are being
maintained (added to and removed from), but are not being used (accessed) here.
I don't understand their purpose.

https://codereview.chromium.org/1132893003/diff/1/pkg/analyzer/lib/src/task/d...
pkg/analyzer/lib/src/task/dart_work_manager.dart:109: return null;
The old work manager also maintained a queue of part sources (removing them when
a library was found that contained them). I don't think I got it implemented,
but the plan was always to add an analysis error for parts that remained in the
queue after all libraries had been processed because they would be parts that
were not included in any library. Perhaps a TODO comment to remind us to add
this.

[scheglov, 2015-05-09 23:20:17]

https://codereview.chromium.org/1132893003/diff/1/pkg/analyzer/lib/src/task/d...
File pkg/analyzer/lib/src/task/dart_work_manager.dart (right):

https://codereview.chromium.org/1132893003/diff/1/pkg/analyzer/lib/src/task/d...
pkg/analyzer/lib/src/task/dart_work_manager.dart:27: final HashSet<Source>
explicitSources = new HashSet<Source>();
On 2015/05/09 17:22:00, Brian Wilkerson wrote:
> The sets of 'explicitSources', 'librarySources' and 'partSources' are being
> maintained (added to and removed from), but are not being used (accessed)
here.
> I don't understand their purpose.

Well, you're right that they're not used now.
But:

1. There is AnalysisContext.librarySources, which can be implemented using
DartWorkManager.
2. "partSources" can be repurposed to Map<Part, List<Library>> and be used for
implementing AnalysisContext.getLibrariesContaining() later.

I cannot think out a good use of "explicitSources" right now :-)
Removing it for now.

https://codereview.chromium.org/1132893003/diff/1/pkg/analyzer/lib/src/task/d...
pkg/analyzer/lib/src/task/dart_work_manager.dart:109: return null;
On 2015/05/09 17:22:00, Brian Wilkerson wrote:
> The old work manager also maintained a queue of part sources (removing them
when
> a library was found that contained them). I don't think I got it implemented,
> but the plan was always to add an analysis error for parts that remained in
the
> queue after all libraries had been processed because they would be parts that
> were not included in any library. Perhaps a TODO comment to remind us to add
> this.

Good idea.
I've added a TODO comment.

[scheglov, 2015-05-09 23:22:31]

Committed patchset #1 (id:1) manually as 45677 (presubmit successful).