Truncate excessively long output from tests in test.dart.

Truncate excessively long output from tests in test.dart.

BUG=dartbug.com/18084
R=kustermann@google.com

Committed: https://code.google.com/p/dart/source/detail?r=34867

[kustermann, 2014-04-08 15:23:47]

lgtm with comments

https://codereview.chromium.org/227113010/diff/1/tools/testing/dart/test_runn...
File tools/testing/dart/test_runner.dart (right):

https://codereview.chromium.org/227113010/diff/1/tools/testing/dart/test_runn...
tools/testing/dart/test_runner.dart:1674: static const int TAIL_LENGTH = 20000;
I would make the limit lower and use 20 * 1024, so it is easy to read.

https://codereview.chromium.org/227113010/diff/1/tools/testing/dart/test_runn...
tools/testing/dart/test_runner.dart:1717: return head;
This will get confusing if you call toList() several times.

Either guard against multiple calls to it, or create a instance instead of
modifying [head].

[Bill Hesse, 2014-04-09 10:38:34]

Committed patchset #1 manually as r34867 (presubmit successful).

[Bill Hesse, 2014-04-09 10:40:27]

https://codereview.chromium.org/227113010/diff/1/tools/testing/dart/test_runn...
File tools/testing/dart/test_runner.dart (right):

https://codereview.chromium.org/227113010/diff/1/tools/testing/dart/test_runn...
tools/testing/dart/test_runner.dart:1674: static const int TAIL_LENGTH = 20000;
On 2014/04/08 15:23:47, kustermann wrote:
> I would make the limit lower and use 20 * 1024, so it is easy to read.

Done.

https://codereview.chromium.org/227113010/diff/1/tools/testing/dart/test_runn...
tools/testing/dart/test_runner.dart:1717: return head;
On 2014/04/08 15:23:47, kustermann wrote:
> This will get confusing if you call toList() several times.
> 
> Either guard against multiple calls to it, or create a instance instead of
> modifying [head].

Done.

[Ivan Posva, 2014-04-10 00:10:44]

-Ivan

https://codereview.chromium.org/227113010/diff/10001/tools/testing/dart/test_...
File tools/testing/dart/test_runner.dart (right):

https://codereview.chromium.org/227113010/diff/10001/tools/testing/dart/test_...
tools/testing/dart/test_runner.dart:1700: head.length = MAX_HEAD;
This is making matters actually worse, ending up using more memory. Now you
have:
- A tail list containing everything after the cutoff, which is the result of the
sublist call.
- A head list of the original capacity, but the length having been reset with
the call to length. Also you did have to go through the whole overhang and set
all elements to null.

[Bill Hesse, 2014-04-11 07:39:48]

https://codereview.chromium.org/227113010/diff/10001/tools/testing/dart/test_...
File tools/testing/dart/test_runner.dart (right):

https://codereview.chromium.org/227113010/diff/10001/tools/testing/dart/test_...
tools/testing/dart/test_runner.dart:1700: head.length = MAX_HEAD;
On 2014/04/10 00:10:44, Ivan Posva wrote:
> This is making matters actually worse, ending up using more memory. Now you
> have:
> - A tail list containing everything after the cutoff, which is the result of
the
> sublist call.
> - A head list of the original capacity, but the length having been reset with
> the call to length. Also you did have to go through the whole overhang and set
> all elements to null.

These variables are only live while the test is running.  As soon as the test
completes, both head and tail are dropped, and can be GCd, because toList has
been called.

Tail is also truncated on an ongoing basis.  I don't see any major improvements
that could be made - using head = head.sublist would not be better than
head.length, unless head was much longer than MAX_HEAD.


According to tests, this does reduce memory use by about 25%, or 40 MB.  It may
not save 25% when running 10 configurations though.