Fixed problem with enum internal functions removed in Python 3.11

Author: pcisar

docs/changelog.txt

@@ -2,6 +2,14 @@
 Changelog
 #########
 
+Version 1.4.3
+=============
+
+* `~firebird.base.types` module:
+
+  - Added internal functions `_decompose` and `_power_of_two` from stdlib `.enum` module,
+    because they were removed in Python 3.11.
+
 Version 1.4.2
 =============
 

firebird/base/config.py

@@ -55,10 +55,10 @@
 from decimal import Decimal, DecimalException
 from configparser import ConfigParser, DEFAULTSECT
 from inspect import signature, Signature, Parameter
-from enum import Enum, Flag, _decompose
+from enum import Enum, Flag
 import os
 from .config_pb2 import ConfigProto
-from .types import Error, MIME, ZMQAddress, PyExpr, PyCode, PyCallable
+from .types import Error, MIME, ZMQAddress, PyExpr, PyCode, PyCallable, _decompose
 from .strconv import get_convertor, convert_to_str, Convertor
 
 PROTO_CONFIG = 'firebird.base.ConfigProto'

firebird/base/types.py

@@ -475,3 +475,47 @@ def load(spec: str) -> Any:
     for item in name.split('.'):
         result = getattr(result, item)
     return result
+
+# Next two functions are copied from stdlib enum module, as they were removed in Python 3.11
+
+def _decompose(flag, value):
+    """
+    Extract all members from the value.
+    """
+    # _decompose is only called if the value is not named
+    not_covered = value
+    negative = value < 0
+    # issue29167: wrap accesses to _value2member_map_ in a list to avoid race
+    #             conditions between iterating over it and having more pseudo-
+    #             members added to it
+    if negative:
+        # only check for named flags
+        flags_to_check = [
+                (m, v)
+                for v, m in list(flag._value2member_map_.items())
+                if m.name is not None
+                ]
+    else:
+        # check for named flags and powers-of-two flags
+        flags_to_check = [
+                (m, v)
+                for v, m in list(flag._value2member_map_.items())
+                if m.name is not None or _power_of_two(v)
+                ]
+    members = []
+    for member, member_value in flags_to_check:
+        if member_value and member_value & value == member_value:
+            members.append(member)
+            not_covered &= ~member_value
+    if not members and value in flag._value2member_map_:
+        members.append(flag._value2member_map_[value])
+    members.sort(key=lambda m: m._value_, reverse=True)
+    if len(members) > 1 and members[0].value == value:
+        # we have the breakdown, don't need the value member itself
+        members.pop(0)
+    return members, not_covered
+
+def _power_of_two(value):
+    if value < 1:
+        return False
+    return value == 2 ** (value.bit_length() - 1)