PubSub: correctly decrement the byte counter in drop()

[aongko]

I'm looking at this 2 files:

• https://github.com/GoogleCloudPlatform/google-cloud-python/blob/5c010e3790c9067e6d7bf8ba37724ee5121eadb7/pubsub/google/cloud/pubsub_v1/subscriber/policy/base.py#L215
• https://github.com/GoogleCloudPlatform/google-cloud-python/blob/5c010e3790c9067e6d7bf8ba37724ee5121eadb7/pubsub/tests/unit/pubsub_v1/subscriber/test_policy_base.py

Should the code in base.py line 215 be max instead of min?

self._bytes = min([self._bytes, 0])

Current code:

1. current state self._bytes = 50
2. then we call self._bytes -= 20
3. now self._bytes == 30
4. but then we do self._bytes = min([30, 0]) -> self._bytes = 0

Should be:

1. current state self._bytes = 50
2. then we call self._bytes -= 20
3. now self._bytes == 30
4. but then we do self._bytes = max([30, 0]) -> self._bytes = 30

even if we drop it below 0, we should use max:

1. self._bytes = 10
2. self._bytes -= 20
3. self._bytes == -10
4. min([-10, 0]) == -10 should be max([-10, 0]) == 0

Or is there something I miss?

[aongko]

Then I found #4514.
Hope it gets merged and released soon