[PATCH 4 of 7 V2] profiling: add a context manager that no-ops if profiling isn't enabled

[Yuya Nishihara]

On Sun, 14 Aug 2016 18:37:41 -0700, Gregory Szorc wrote:
> # HG changeset patch
> # User Gregory Szorc <gregory.szorc at gmail.com>
> # Date 1471222272 25200
> #      Sun Aug 14 17:51:12 2016 -0700
> # Node ID fd7b55561853e9d5532f3a9265433a7b614f2687
> # Parent  3338d4536f490fca055881b4e3884b28e4e25d22
> profiling: add a context manager that no-ops if profiling isn't enabled

> --- a/mercurial/help/config.txt
> +++ b/mercurial/help/config.txt
> @@ -1388,16 +1388,22 @@ Specifies profiling type, format, and fi
>  supported: an instrumenting profiler (named ``ls``), and a sampling
>  profiler (named ``stat``).
>  
>  In this section description, 'profiling data' stands for the raw data
>  collected during profiling, while 'profiling report' stands for a
>  statistical text report generated from the profiling data. The
>  profiling is done using lsprof.
>  
> +``enabled``
> +    Enable the profiler.
> +    (default: false)
> +
> +    This is equivalent to passing ``--profile`` on the command line.
> +

> +def maybeprofile(ui):
> +    """Profile if enabled, else do nothing.
> +
> +    This context manager can be used to optionally profile if profiling
> +    is enabled. Otherwise, it does nothing.
> +
> +    The purpose of this context manager is to make calling code simpler:
> +    just use a single code path for calling into code you may want to profile
> +    and this function determines whether to start profiling.
> +    """
> +    # internal config profiling.enabled

Removed this line because profiling.enabled is now documented.