kafka.util 32 bit field helpers for authorized operations

Author: dpkp

kafka/util.py

@@ -138,3 +138,21 @@ def wrapper(self, *args, **kwargs):
             return func(self, *args, **kwargs)
     functools.update_wrapper(wrapper, func)
     return wrapper
+
+
+def to_32_bit_field(vals):
+    value = 0
+    for b in vals:
+        assert 0 <= b < 32
+        value |= 1 << b
+    return value
+
+def from_32_bit_field(value):
+    result = set()
+    count = 0
+    while value != 0:
+        if (value & 1) != 0:
+            result.add(count)
+        count += 1
+        value = (value & 0xFFFFFFFF) >> 1
+    return result

test/test_util.py

@@ -3,7 +3,7 @@
 
 import pytest
 
-from kafka.util import ensure_valid_topic_name
+from kafka.util import ensure_valid_topic_name, from_32_bit_field, to_32_bit_field
 
 @pytest.mark.parametrize(('topic_name', 'expectation'), [
     (0, pytest.raises(TypeError)),
@@ -22,3 +22,11 @@
 def test_topic_name_validation(topic_name, expectation):
     with expectation:
         ensure_valid_topic_name(topic_name)
+
+
+@pytest.mark.parametrize(('test_set',), [
+    (set([0, 1, 5, 10, 31]),),
+    (set(range(32)),),
+])
+def test_32_bit_field(test_set):
+    assert from_32_bit_field(to_32_bit_field(test_set)) == test_set