[Android] Provide a logging suppressing context manager

[Android] Provide a logging suppressing context manager

Using this we will be able to write:

  with logging_utils.SuppressLogging():
    # all but CRITICAL logging messages are suppressed
    logging.info('just doing some thing') # not shown
    logging.critical('something really bad happened') # still shown

BUG=

Committed: https://crrev.com/4bf260f81b3909da9099e5bcac948cbc0ca5e295
Cr-Commit-Position: refs/heads/master@{#313083}

[perezju, 2015-01-26 16:03:37]

perezju@chromium.org changed reviewers:
+ jbudorick@chromium.org

[jbudorick, 2015-01-26 16:07:32]

https://codereview.chromium.org/875083002/diff/1/build/android/pylib/utils/lo...
File build/android/pylib/utils/logging_utils.py (right):

https://codereview.chromium.org/875083002/diff/1/build/android/pylib/utils/lo...
build/android/pylib/utils/logging_utils.py:9: def
SuppressLogging(level=logging.ERROR):
My only comment on this is that handling levels as "x and below" feels ...
weird. Logging levels are typically dealt with as "x and above", so having a
default here of logging.ERROR "feels" like it should only print anything at or
above ERROR level. wdyt?

[perezju, 2015-01-26 16:23:49]

On 2015/01/26 16:07:32, jbudorick wrote:
>
https://codereview.chromium.org/875083002/diff/1/build/android/pylib/utils/lo...
> File build/android/pylib/utils/logging_utils.py (right):
> 
>
https://codereview.chromium.org/875083002/diff/1/build/android/pylib/utils/lo...
> build/android/pylib/utils/logging_utils.py:9: def
> SuppressLogging(level=logging.ERROR):
> My only comment on this is that handling levels as "x and below" feels ...
> weird. Logging levels are typically dealt with as "x and above", so having a
> default here of logging.ERROR "feels" like it should only print anything at or
> above ERROR level. wdyt?

I agree, slightly. When I read the documentation of logging.disable I was also
confused for a while, but I think it makes sense and the confusing bit is just
the duality between showing (above) vs suppressing/disabling (below). And,
surely, when I say "suppress ... ERROR" I expect ERROR messages to be
suppressed. Hopefully the example in the doc string also makes it very clear
what to expect from the default behaviour.

[jbudorick, 2015-01-26 16:29:24]

On 2015/01/26 16:23:49, perezju wrote:
> On 2015/01/26 16:07:32, jbudorick wrote:
> >
>
https://codereview.chromium.org/875083002/diff/1/build/android/pylib/utils/lo...
> > File build/android/pylib/utils/logging_utils.py (right):
> > 
> >
>
https://codereview.chromium.org/875083002/diff/1/build/android/pylib/utils/lo...
> > build/android/pylib/utils/logging_utils.py:9: def
> > SuppressLogging(level=logging.ERROR):
> > My only comment on this is that handling levels as "x and below" feels ...
> > weird. Logging levels are typically dealt with as "x and above", so having a
> > default here of logging.ERROR "feels" like it should only print anything at
or
> > above ERROR level. wdyt?
> 
> I agree, slightly. When I read the documentation of logging.disable I was also
> confused for a while, but I think it makes sense and the confusing bit is just
> the duality between showing (above) vs suppressing/disabling (below). And,
> surely, when I say "suppress ... ERROR" I expect ERROR messages to be
> suppressed. Hopefully the example in the doc string also makes it very clear
> what to expect from the default behaviour.

Ah, yeah, I suppose that makes sense, and we shouldn't deviate from
logging.disable here. lgtm.

[perezju, 2015-01-26 16:34:58]

The CQ bit was checked by perezju@chromium.org

[commit-bot: I haz the power, 2015-01-26 16:35:53]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/875083002/1

[commit-bot: I haz the power, 2015-01-26 17:34:34]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-01-26 17:35:27]

Patchset 1 (id:??) landed as
https://crrev.com/4bf260f81b3909da9099e5bcac948cbc0ca5e295
Cr-Commit-Position: refs/heads/master@{#313083}