Make http-imports faster to load, by hinting persistent connection on request.

Make http-imports faster to load, by hinting persistent connection on request.

Also avoids a BytesBuilder, if only one chunk is received. This speeds
up e.g. 'pub build' notably (4x speedup).

BUG=
R=sgjesse@google.com

Committed: https://code.google.com/p/dart/source/detail?r=33798

[Anders Johnsen, 2014-03-18 08:53:05]

Bob, Nathan:

Note that you can speed it up further, by disabling gzip in barback:

      // Disable gzip-compression.
      request.response.headers.set('content-encoding', '');

at line 201 in pub/lib/src/barback/server.dart should do it.

[Søren Gjesse, 2014-03-18 08:55:26]

LGTM!

[Anders Johnsen, 2014-03-18 08:57:07]

Committed patchset #1 manually as r33798 (presubmit successful).

[Anders Johnsen, 2014-03-18 12:05:43]

I meant NOT persistent. Sorry.

[Ivan Posva, 2014-03-18 12:13:43]

DBC -ip

https://codereview.chromium.org/203213002/diff/1/runtime/bin/builtin.dart
File runtime/bin/builtin.dart (left):

https://codereview.chromium.org/203213002/diff/1/runtime/bin/builtin.dart#old...
runtime/bin/builtin.dart:89: // it now otherwise we wait around until it times
out.
This comment was crucial in understanding why the client had to be closed.
Please restore it.

[Anders Johnsen, 2014-03-18 12:22:33]

https://codereview.chromium.org/203213002/diff/1/runtime/bin/builtin.dart
File runtime/bin/builtin.dart (left):

https://codereview.chromium.org/203213002/diff/1/runtime/bin/builtin.dart#old...
runtime/bin/builtin.dart:89: // it now otherwise we wait around until it times
out.
On 2014/03/18 12:13:43, Ivan Posva wrote:
> This comment was crucial in understanding why the client had to be closed.
> Please restore it.

No, it was crucial to why we were using `force: true`.

The comment now could be:

  Close the client to stop any timers currently held alive.

[floitsch, 2014-03-18 12:26:24]

dbc.

https://codereview.chromium.org/203213002/diff/1/runtime/bin/builtin.dart
File runtime/bin/builtin.dart (right):

https://codereview.chromium.org/203213002/diff/1/runtime/bin/builtin.dart#new...
runtime/bin/builtin.dart:87: // Only create a ByteBuilder, if multiple chunks is
received.
are received.

[Anders Johnsen, 2014-03-18 12:33:24]

https://codereview.chromium.org/200793006

https://codereview.chromium.org/203213002/diff/1/runtime/bin/builtin.dart
File runtime/bin/builtin.dart (right):

https://codereview.chromium.org/203213002/diff/1/runtime/bin/builtin.dart#new...
runtime/bin/builtin.dart:87: // Only create a ByteBuilder, if multiple chunks is
received.
On 2014/03/18 12:26:24, floitsch wrote:
> are received.

Done.