[AIRFLOW-3950] Improve AirflowSecurityManager.update_admin_perm_view

[XD-DENG]

Jira

• https://issues.apache.org/jira/browse/AIRFLOW-3950

Description

• Here are some details about my PR, including screenshots of any UI changes:

This PR helps improve AirflowSecurityManager.update_admin_perm_view by

• Simplifying the implementation: avoid unnecessary for-loop by using set.
• Improving the performance (especially when there are many DAGs)

Regarding performance improvement, please refer to this simple toy benchmarking:

def fun1(a, b):
    a=set(a)

    for i in b:
        if i not in a:
            a.add(i)

    list(a)

def fun2(a, b):
    list(set(a) | set(b))


if __name__ == '__main__':
    import timeit
    print("-Test.1-")
    print(timeit.timeit("fun1([1,2,3], range(100))", setup="from __main__ import fun1"))
    print(timeit.timeit("fun2([1,2,3], range(100))", setup="from __main__ import fun2"))
    print("-Test.2-")
    print(timeit.timeit("fun1([1,2,3], range(500))", setup="from __main__ import fun1"))
    print(timeit.timeit("fun2([1,2,3], range(500))", setup="from __main__ import fun2"))

Result:

-Test.1-
12.912254190000112
5.487735479000094
-Test.2-
62.42928877399936
21.93449944399981

[XD-DENG]

One test failed, likely due to transient/flaky error.

[XD-DENG]

@ashb @feng-tao PTAL. A low-hanging improvement.