Files
DECNET/decnet/asn/factory.py
anti f2b3393669 chore: relicense to AGPL-3.0-or-later and add SPDX headers
Replaces LICENSE (GPLv3 -> AGPLv3) and prepends
`SPDX-License-Identifier: AGPL-3.0-or-later` to every source file
across decnet/, decnet_web/, tests/, scripts/, and tools/.

Rationale: closes the GPLv3 ASP loophole so any party operating a
modified DECNET as a network service must offer their modified
source. Personal copyright (Samuel Paschuan) + inbound=outbound
contributions make a future unilateral relicense infeasible.

- LICENSE: full AGPL-3.0 text (gnu.org/licenses/agpl-3.0.txt)
- COPYRIGHT: project copyright notice
- tools/add_spdx_headers.py: idempotent header injector
  (shebang- and PEP 263-aware)

Touches 1565 source files (.py, .ts, .tsx, .js, .jsx, .css, .sh).
No behavior change; comments only.
2026-05-22 21:04:16 -04:00

41 lines
1.1 KiB
Python

# SPDX-License-Identifier: AGPL-3.0-or-later
"""ASN provider factory — mirror of :mod:`decnet.geoip.factory`.
Dispatch key: ``DECNET_ASN_PROVIDER`` (default ``iptoasn``). Lazy
singleton.
"""
from __future__ import annotations
import os
from typing import Optional
from decnet.asn.base import Provider
_cached: Optional[Provider] = None
_cached_key: Optional[str] = None
def get_provider() -> Provider:
"""Return the configured :class:`Provider` singleton."""
global _cached, _cached_key
key = os.environ.get("DECNET_ASN_PROVIDER", "iptoasn").lower()
if _cached is not None and _cached_key == key:
return _cached
if key == "iptoasn":
from decnet.asn.iptoasn.provider import IptoasnProvider
provider: Provider = IptoasnProvider()
else:
raise ValueError(f"Unsupported ASN provider: {key!r}")
_cached = provider
_cached_key = key
return provider
def reset_cache() -> None:
"""Forget the singleton — tests swap providers via the env var."""
global _cached, _cached_key
_cached = None
_cached_key = None