Initial timing framework and test for server

Initial timing framework and test for server

R=paulberry@google.com, scheglov@google.com

Committed: https://code.google.com/p/dart/source/detail?r=40902

[Brian Wilkerson, 2014-10-03 16:35:56]

brianwilkerson@google.com changed reviewers:
+ paulberry@google.com, scheglov@google.com

[Brian Wilkerson, 2014-10-03 16:35:56]

The test runs and prints out timing information. I didn't run any existing tests
because I didn't change any non-test code (let me know if there are tests I
should run anyway).

[scheglov, 2014-10-03 16:46:14]

LGTM

https://codereview.chromium.org/625973002/diff/1/pkg/analysis_server/test/tim...
File pkg/analysis_server/test/timing/completion/completion_simple.dart (right):

https://codereview.chromium.org/625973002/diff/1/pkg/analysis_server/test/tim...
pkg/analysis_server/test/timing/completion/completion_simple.dart:12: * Perform
the timing test, printing the minimum time to the output.
Not only the minimum time.

https://codereview.chromium.org/625973002/diff/1/pkg/analysis_server/test/tim...
pkg/analysis_server/test/timing/completion/completion_simple.dart:85: String
mainDirectory = mainFilePath.substring(0, separatorIndex);
We could use package:path for this.

https://codereview.chromium.org/625973002/diff/1/pkg/analysis_server/test/tim...
File pkg/analysis_server/test/timing/timing_framework.dart (right):

https://codereview.chromium.org/625973002/diff/1/pkg/analysis_server/test/tim...
pkg/analysis_server/test/timing/timing_framework.dart:180:
stopwatch..reset..start();
..reset() ?

[Paul Berry, 2014-10-03 16:58:35]

lgtm with comments addressed.

https://codereview.chromium.org/625973002/diff/1/pkg/analysis_server/test/tim...
File pkg/analysis_server/test/timing/completion/completion_simple.dart (right):

https://codereview.chromium.org/625973002/diff/1/pkg/analysis_server/test/tim...
pkg/analysis_server/test/timing/completion/completion_simple.dart:84: int
separatorIndex = mainFilePath.lastIndexOf('/');
I think this will be wrong on Windows.  Instead use

  String mainDirectory = path.dirname(mainFilePath);

https://codereview.chromium.org/625973002/diff/1/pkg/analysis_server/test/tim...
File pkg/analysis_server/test/timing/timing_framework.dart (right):

https://codereview.chromium.org/625973002/diff/1/pkg/analysis_server/test/tim...
pkg/analysis_server/test/timing/timing_framework.dart:260: int minTime =
0xFFFFFFFF;
0xFFFFFFFF nanoseconds ~= 4 seconds.  I don't think this is long enough.

How about just:

int minTime = times[0];
for (int i = 1; i < count; i++) {
  minTime = min(minTime, times[i]);
}

https://codereview.chromium.org/625973002/diff/1/pkg/analysis_server/test/tim...
pkg/analysis_server/test/timing/timing_framework.dart:303: return
sqrt((sumOfDiffSquared / count));
Using (count - 1) is correct in this circumstance.

Using count would be correct if the true mean were known.  Using (count - 1) is
correct when the true mean isn't known, and we have to estimate the mean using
the same sample points that we are using to estimate the standard deviation. 
Which is the situation we're in here.

[Brian Wilkerson, 2014-10-03 17:17:37]

https://codereview.chromium.org/625973002/diff/1/pkg/analysis_server/test/tim...
File pkg/analysis_server/test/timing/completion/completion_simple.dart (right):

https://codereview.chromium.org/625973002/diff/1/pkg/analysis_server/test/tim...
pkg/analysis_server/test/timing/completion/completion_simple.dart:12: * Perform
the timing test, printing the minimum time to the output.
Done

https://codereview.chromium.org/625973002/diff/1/pkg/analysis_server/test/tim...
pkg/analysis_server/test/timing/completion/completion_simple.dart:84: int
separatorIndex = mainFilePath.lastIndexOf('/');
Done

https://codereview.chromium.org/625973002/diff/1/pkg/analysis_server/test/tim...
pkg/analysis_server/test/timing/completion/completion_simple.dart:85: String
mainDirectory = mainFilePath.substring(0, separatorIndex);
Done

https://codereview.chromium.org/625973002/diff/1/pkg/analysis_server/test/tim...
File pkg/analysis_server/test/timing/timing_framework.dart (right):

https://codereview.chromium.org/625973002/diff/1/pkg/analysis_server/test/tim...
pkg/analysis_server/test/timing/timing_framework.dart:180:
stopwatch..reset..start();
Left over from an earlier timing framework that I started from. Removed.

https://codereview.chromium.org/625973002/diff/1/pkg/analysis_server/test/tim...
pkg/analysis_server/test/timing/timing_framework.dart:260: int minTime =
0xFFFFFFFF;
Done

https://codereview.chromium.org/625973002/diff/1/pkg/analysis_server/test/tim...
pkg/analysis_server/test/timing/timing_framework.dart:303: return
sqrt((sumOfDiffSquared / count));
Done

[Brian Wilkerson, 2014-10-03 17:18:49]

Committed patchset #1 (id:1) manually as 40902 (presubmit successful).