Optimizie the insertion of an iterable.

Optimizie the insertion of an iterable.

Avoids creating a list on the side, at the cost of an extra copying
inside the typed-data buffer to move the data into place.

R=floitsch@google.com, nweiz@google.com

Committed: https://github.com/dart-lang/typed_data/commit/2578718e9415987016bd5a44a29279c7d684a903

[Lasse Reichstein Nielsen, 2015-10-28 07:40:25]

lrn@google.com changed reviewers:
+ nweiz@google.com

[Lasse Reichstein Nielsen, 2015-10-28 07:40:26]

Well, it did annoy me enough to use a non-typed-data list as intermediate
storage that I rewrote it to use the existing buffer as the intermediate
storage. It puts the new data at the end (not changing _length until it has all
the data, to avoid leaking intermediate state) and then swaps the ranges
in-place.

[floitsch, 2015-10-28 18:20:51]

floitsch@google.com changed reviewers:
+ floitsch@google.com

[floitsch, 2015-10-28 18:20:51]

LGTM.

https://codereview.chromium.org/1408253004/diff/1/lib/typed_buffers.dart
File lib/typed_buffers.dart (right):

https://codereview.chromium.org/1408253004/diff/1/lib/typed_buffers.dart#newc...
lib/typed_buffers.dart:147: throw new RangeError.range(end, start, writeIndex,
"end");
Add comment, that throwing now leaves the array in an unchanged state, because
the _length hasn't been updated yet.

[nweiz, 2015-10-28 21:43:30]

lgtm

I released the previous change before I saw this one, so this should bump the
version to 1.1.1 and add a changelog entry.

https://codereview.chromium.org/1408253004/diff/1/lib/typed_buffers.dart
File lib/typed_buffers.dart (right):

https://codereview.chromium.org/1408253004/diff/1/lib/typed_buffers.dart#newc...
lib/typed_buffers.dart:107: if (start == end) return;
This has the same issue as calling [values.start]: it will fail to throw an
error if start = end > _length.

[Lasse Reichstein Nielsen, 2015-10-29 09:24:42]

Updated pubspec and changelog.

https://codereview.chromium.org/1408253004/diff/1/lib/typed_buffers.dart
File lib/typed_buffers.dart (right):

https://codereview.chromium.org/1408253004/diff/1/lib/typed_buffers.dart#newc...
lib/typed_buffers.dart:107: if (start == end) return;
I think that's acceptable - you are asking for zero values to be inserted. There
*are* zero values at position [start], so "too few elements" would be incorrect.

https://codereview.chromium.org/1408253004/diff/1/lib/typed_buffers.dart#newc...
lib/typed_buffers.dart:147: throw new RangeError.range(end, start, writeIndex,
"end");
On 2015/10/28 18:20:51, floitsch wrote:
> Add comment, that throwing now leaves the array in an unchanged state, because
> the _length hasn't been updated yet.

Done.

[Lasse Reichstein Nielsen, 2015-10-29 09:25:09]

Committed patchset #2 (id:20001) manually as
2578718e9415987016bd5a44a29279c7d684a903 (presubmit successful).