merge: testing → main (reconcile 2-week divergence)

decnet/asn/iptoasn/provider.py

@@ -0,0 +1,83 @@
+"""iptoasn provider — orchestrates fetch + parse into an :class:`AsnLookup`.
+
+Mirrors :class:`decnet.geoip.rir.provider.RirProvider` exactly: fetch,
+build a pickled cache, invalidate when raw files are newer than the
+cache.
+"""
+from __future__ import annotations
+
+import logging
+from pathlib import Path
+from typing import Sequence
+
+from decnet.asn.base import Provider
+from decnet.asn.iptoasn.fetch import IPTOASN_SOURCES, fetch_all
+from decnet.asn.iptoasn.parse import parse_file
+from decnet.asn.lookup import AsnLookup
+from decnet.asn.paths import ensure_root
+
+logger = logging.getLogger("decnet.asn.iptoasn.provider")
+
+# Pickled lookup cache — skips re-parsing the ~580k-row gz dump on every
+# profiler restart. Rebuilt whenever any raw file is newer than the
+# cache, see ``_cache_fresh``.
+_CACHE_NAME = ".iptoasn_index.pkl"
+
+
+class IptoasnProvider(Provider):
+    name = "iptoasn"
+
+    def __init__(self) -> None:
+        self._root = ensure_root()
+
+    # ---------- Provider interface ----------
+
+    def refresh(self) -> None:
+        logger.info("asn.iptoasn: refreshing dump into %s", self._root)
+        fetch_all(self._root)
+        cache = self._root / _CACHE_NAME
+        if cache.exists():
+            cache.unlink(missing_ok=True)
+
+    def build_lookup(self) -> AsnLookup:
+        cache = self._root / _CACHE_NAME
+        if self._cache_fresh(cache):
+            try:
+                lookup = AsnLookup.load(cache)
+                logger.debug(
+                    "asn.iptoasn: loaded cached index (%d ranges)",
+                    len(lookup),
+                )
+                return lookup
+            except Exception as exc:
+                logger.warning(
+                    "asn.iptoasn: cache load failed, rebuilding: %s", exc
+                )
+
+        ranges = []
+        for path in self.data_paths():
+            if not path.exists():
+                continue
+            ranges.extend(parse_file(path))
+        lookup = AsnLookup.from_ranges(ranges)
+        try:
+            lookup.save(cache)
+        except Exception as exc:
+            logger.warning("asn.iptoasn: cache save failed: %s", exc)
+        logger.info("asn.iptoasn: built index with %d ranges", len(lookup))
+        return lookup
+
+    def data_paths(self) -> Sequence[Path]:
+        return [self._root / f"{name}.tsv.gz" for name, _url in IPTOASN_SOURCES]
+
+    # ---------- internals ----------
+
+    def _cache_fresh(self, cache: Path) -> bool:
+        """True when the pickle exists and is at least as new as every raw file."""
+        if not cache.exists():
+            return False
+        cache_mtime = cache.stat().st_mtime
+        for path in self.data_paths():
+            if path.exists() and path.stat().st_mtime > cache_mtime:
+                return False
+        return True