Initial commit: snapshot of spesmilo/electrumx 2.0.0

Unmodified source tree of upstream commit 280cb339aa158e099eb936033eecd15719770651
("Merge pull request #389 from SomberNight/202607_release_2_0",
https://github.com/spesmilo/electrumx, release 2.0.0, 3 July 2026).

All Palladium-specific changes are in the commits that follow.

src/electrumx/lib/env_base.py

@@ -0,0 +1,79 @@
+# Copyright (c) 2017, Neil Booth
+#
+# All rights reserved.
+#
+# See the file "LICENCE" for information about the copyright
+# and warranty status of this software.
+
+'''Class for server environment configuration and defaults.'''
+
+
+from os import environ
+
+from electrumx.lib.util import class_logger
+
+
+class EnvBase:
+    '''Wraps environment configuration.'''
+
+    class Error(Exception):
+        pass
+
+    def __init__(self):
+        self.logger = class_logger(__name__, self.__class__.__name__)
+        self.allow_root = self.boolean('ALLOW_ROOT', False)
+        self.loop_policy = self.event_loop_policy()
+
+    @classmethod
+    def default(cls, envvar, default):
+        return environ.get(envvar, default)
+
+    @classmethod
+    def boolean(cls, envvar, default):
+        default = 'Yes' if default else ''
+        return bool(cls.default(envvar, default).strip())
+
+    @classmethod
+    def required(cls, envvar):
+        value = environ.get(envvar)
+        if value is None:
+            raise cls.Error(f'required envvar {envvar} not set')
+        return value
+
+    @classmethod
+    def integer(cls, envvar, default):
+        value = environ.get(envvar)
+        if value is None:
+            return default
+        try:
+            return int(value)
+        except Exception:
+            raise cls.Error(f'cannot convert envvar {envvar} value {value} to '
+                            f'an integer')
+
+    @classmethod
+    def custom(cls, envvar, default, parse):
+        value = environ.get(envvar)
+        if value is None:
+            return default
+        try:
+            return parse(value)
+        except Exception as e:
+            raise cls.Error(
+                f'cannot parse envvar {envvar} value {value}'
+            ) from e
+
+    @classmethod
+    def obsolete(cls, envvars):
+        bad = [envvar for envvar in envvars if environ.get(envvar)]
+        if bad:
+            raise cls.Error(f'remove obsolete environment variables {bad}')
+
+    def event_loop_policy(self):
+        policy = self.default('EVENT_LOOP_POLICY', None)
+        if policy is None:
+            return None
+        if policy == 'uvloop':
+            import uvloop
+            return uvloop.EventLoopPolicy()
+        raise self.Error(f'unknown event loop policy "{policy}"')