[Piglit] [PATCH 3/7] framework/status.py: Convert from NotImplementedError to ABCMeta

[Ilia Mirkin]

On Thu, Mar 6, 2014 at 4:54 PM, Dylan Baker <baker.dylan.c at gmail.com> wrote:
> Using pythons __metaclass__ = abc.ABCMeta allows us to set the abstract
> Status class's __init__ to pass instead of raise NotImplementedError,

I haven't investigated the reason for this, but can't come up with
anything sane off-hand... why are Pass/etc subclasses of Status, and
not just instances of it? i.e. why not make a constructor that takes
the name/value/fraction, and then just say

Fail = Status('fail', 35)

and be done with it? Then you also avoid having the tons of little
identical objects (the cost of which is minimized by using slots, but
still). And you could probably do some sort of cleverness to make it
immutable too.

But like I said, I haven't actually looked that carefully, so perhaps
there's a good reason why they're separate objects.

  -ilia

> but still raise an exception if there is an attempt initialize it. This
> reduces boilerplate by removing the need for each subclass to override
> the __init__ method.
>
> Signed-off-by: Dylan Baker <baker.dylan.c at gmail.com>
> ---
>  framework/status.py | 32 +++++++-------------------------
>  1 file changed, 7 insertions(+), 25 deletions(-)
>
> diff --git a/framework/status.py b/framework/status.py
> index 2c6b692..d682531 100644
> --- a/framework/status.py
> +++ b/framework/status.py
> @@ -62,6 +62,8 @@ The formula for determining fixes is:
>
>  """
>
> +import abc
> +
>
>  def status_lookup(status):
>      """ Provided a string return a status object instance
> @@ -115,12 +117,16 @@ class Status(object):
>      # the memory consumed for creating tens of thousands of these objects.
>      __slots__ = ['name', 'value', 'fraction']
>
> +    # setting the __metaclass__ allows Status to be an abstract class, and
> +    # doesn't require children to overwrite __init__ reducing boilerplate
> +    __metaclass__ = abc.ABCMeta
> +
>      name = None
>      value = None
>      fraction = (0, 1)
>
>      def __init__(self):
> -        raise NotImplementedError
> +        pass
>
>      def __repr__(self):
>          return self.name
> @@ -158,63 +164,39 @@ class NotRun(Status):
>      value = 0
>      fraction = (0, 0)
>
> -    def __init__(self):
> -        pass
> -
>
>  class Skip(Status):
>      name = 'skip'
>      value = 5
>      fraction = (0, 0)
>
> -    def __init__(self):
> -        pass
> -
>
>  class Pass(Status):
>      name = 'pass'
>      value = 10
>      fraction = (1, 1)
>
> -    def __init__(self):
> -        pass
> -
>
>  class DmesgWarn(Status):
>      name = 'dmesg-warn'
>      value = 20
>
> -    def __init__(self):
> -        pass
> -
>
>  class Warn(Status):
>      name = 'warn'
>      value = 25
>
> -    def __init__(self):
> -        pass
> -
>
>  class DmesgFail(Status):
>      name = 'dmesg-fail'
>      value = 30
>
> -    def __init__(self):
> -        pass
> -
>
>  class Fail(Status):
>      name = 'fail'
>      value = 35
>
> -    def __init__(self):
> -        pass
> -
>
>  class Crash(Status):
>      name = 'crash'
>      value = 40
> -
> -    def __init__(self):
> -        pass
> --
> 1.9.0
>
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