ABANDONED. Use gclient_utils instead.

Add a way to stream && capture subprocess output.

Motivation:
  When pushing to Gerrit, it may take some time, during which
  "git push" is printing useful things for both user and our tooling.

  Until now, the only way our tooling can capture this data was by
  making user stare a the blank {default_background} terminal.

  This patch allows to show progress to user and gives data to tooling.

R=maruel@chromium.org,phajdan.jr@chromium.org
BUG=580136

[tandrii(chromium), 2016-03-08 16:59:01]

PTAL

FTR: subprocess2 module didn't fail me as there is no such functionality in
subprocess :)

[Paweł Hajdan Jr., 2016-03-08 23:52:24]

LGTM w/nits

https://codereview.chromium.org/1773183002/diff/40001/subprocess2.py
File subprocess2.py (right):

https://codereview.chromium.org/1773183002/diff/40001/subprocess2.py#newcode480
subprocess2.py:480: # Aslo, because callbacks are called in asynchroneous
thread, we can stream
nit: Aslo -> Also ; asynchroneous -> asynchronous

https://codereview.chromium.org/1773183002/diff/40001/subprocess2.py#newcode491
subprocess2.py:491: # Don't stream/capture streams that user specified
explicitely.
nit: explicitely -> explicitly

[M-A Ruel, 2016-03-08 23:54:08]

https://codereview.chromium.org/1773183002/diff/40001/subprocess2.py
File subprocess2.py (right):

https://codereview.chromium.org/1773183002/diff/40001/subprocess2.py#newcode465
subprocess2.py:465: def communicate_and_stream(args, **kwargs):
There's a function to do something similar in gclient_utils.py. In practice,
subprocess42 does it much better with a for loop.

[tandrii(chromium), 2016-03-14 13:44:54]

On 2016/03/08 23:54:08, M-A Ruel wrote:
> https://codereview.chromium.org/1773183002/diff/40001/subprocess2.py
> File subprocess2.py (right):
> 
>
https://codereview.chromium.org/1773183002/diff/40001/subprocess2.py#newcode465
> subprocess2.py:465: def communicate_and_stream(args, **kwargs):
> There's a function to do something similar in gclient_utils.py. In practice,
> subprocess42 does it much better with a for loop.
Ah, i knew there is certainly such a function. Thanks! Any reason against moving
v42 to depot_tools?
Shouldn't it be a general win for depot_tools?

[tandrii(chromium), 2016-03-14 13:45:15]

Description was changed from

==========
Add a way to stream && capture subprocess output.

Motivation:
  When pushing to Gerrit, it may take some time, during which
  "git push" is printing useful things for both user and our tooling.

  Until now, the only way our tooling can capture this data was by
  making user stare a the blank {default_background} terminal.

  This patch allows to show progress to user and gives data to tooling.

R=maruel@chromium.org,phajdan.jr@chromium.org
BUG=580136
==========

to

==========
Add a way to stream && capture subprocess output.

Motivation:
  When pushing to Gerrit, it may take some time, during which
  "git push" is printing useful things for both user and our tooling.

  Until now, the only way our tooling can capture this data was by
  making user stare a the blank {default_background} terminal.

  This patch allows to show progress to user and gives data to tooling.

R=maruel@chromium.org,phajdan.jr@chromium.org
BUG=580136
==========

[M-A Ruel, 2016-03-14 13:52:18]

On 2016/03/14 13:44:54, tandrii(chromium) wrote:
> On 2016/03/08 23:54:08, M-A Ruel wrote:
> > There's a function to do something similar in gclient_utils.py. In practice,
> > subprocess42 does it much better with a for loop.
> Ah, i knew there is certainly such a function. Thanks! Any reason against
moving
> v42 to depot_tools?
> Shouldn't it be a general win for depot_tools?

I'm fine with that. The reason it wasn't done before was that I actually wanted
to remove subprocess2 at the same time, but this was some work.