[PATCH] kunit: tool: simplify kconfig is_subset_of() logic

[PATCH] kunit: tool: simplify kconfig is_subset_of() logic

[Daniel Latypov]

Don't use an O(nm) algorithm* and make it more readable by using a dict.

*Most obviously, it does a nested for-loop over the entire other config.
A bit more subtle, it calls .entries(), which constructs a set from the
list for _every_ outer iteration.

Signed-off-by: Daniel Latypov <dlatypov@google.com>
---
 tools/testing/kunit/kunit_config.py | 13 ++++++-------
 1 file changed, 6 insertions(+), 7 deletions(-)

diff --git a/tools/testing/kunit/kunit_config.py b/tools/testing/kunit/kunit_config.py
index 02ffc3a3e5dc..f1101075d458 100644
--- a/tools/testing/kunit/kunit_config.py
+++ b/tools/testing/kunit/kunit_config.py
@@ -40,15 +40,14 @@ class Kconfig(object):
 		self._entries.append(entry)
 
 	def is_subset_of(self, other: 'Kconfig') -> bool:
+		other_dict = {e.name: e.value for e in other.entries()}
 		for a in self.entries():
-			found = False
-			for b in other.entries():
-				if a.name != b.name:
+			b = other_dict.get(a.name)
+			if b is None:
+				if a.value == 'n':
 					continue
-				if a.value != b.value:
-					return False
-				found = True
-			if a.value != 'n' and found == False:
+				return False
+			elif a.value != b:
 				return False
 		return True
 

base-commit: c6f7e1510b872c281ff603a3108c084b6548d35c
-- 
2.29.2.576.ga3fc446d84-goog

Re: [PATCH] kunit: tool: simplify kconfig is_subset_of() logic

[David Gow]

On Wed, Dec 9, 2020 at 7:21 AM Daniel Latypov <dlatypov@google.com> wrote:
>
> Don't use an O(nm) algorithm* and make it more readable by using a dict.
>
> *Most obviously, it does a nested for-loop over the entire other config.
> A bit more subtle, it calls .entries(), which constructs a set from the
> list for _every_ outer iteration.
>
> Signed-off-by: Daniel Latypov <dlatypov@google.com>
> ---
Thanks! This works great here: I didn't time it to see how much faster
it is, but it's clearly an improvement.

Reviewed-by: David Gow <davidgow@google.com>

Cheers,
-- David

Re: [PATCH] kunit: tool: simplify kconfig is_subset_of() logic

[Brendan Higgins]

On Tue, Dec 8, 2020 at 3:21 PM Daniel Latypov <dlatypov@google.com> wrote:
>
> Don't use an O(nm) algorithm* and make it more readable by using a dict.
>
> *Most obviously, it does a nested for-loop over the entire other config.
> A bit more subtle, it calls .entries(), which constructs a set from the
> list for _every_ outer iteration.
>
> Signed-off-by: Daniel Latypov <dlatypov@google.com>

Tested-by: Brendan Higgins <brendanhiggins@google.com>
Acked-by: Brendan Higgins <brendanhiggins@google.com>