"""Result caching for web_search / web_extract; both caches TTL-bounded (default 20 min, ``web.cache_ttl_minutes``; disable with ``web.cache_enabled: false``), only successful responses cache. * **Search memo** — in-memory, per-process, single-flighted: concurrent identical queries share one paid request. Limits bucket to 10/20/50/100 so near-identical requests share an entry. * **Extract cache** — disk-backed under ``cache/web`` (cross-process) with a JSON sidecar index: URL digest → (file, fetched_at, title). Hits re-run the normal truncate pipeline. Lives here, not in tool dispatch, so hits sit *after* every safety check and skip only the vendor call. """ import hashlib import json import logging import re import threading import time from contextlib import suppress from pathlib import Path from typing import Dict, Optional, Tuple from urllib.parse import urlparse from utils import atomic_json_write logger = logging.getLogger(__name__) # Requested limits round UP to a bucket so cache keys collide on purpose. _LIMIT_BUCKETS = (10, 20, 50, 100) DEFAULT_TTL_MINUTES = 20 _INDEX_FILENAME = "extract-index.json" _INDEX_MAX_ENTRIES = 500 # oldest entries evicted past this def _web_config() -> dict: try: from tools.web_tools import _load_web_config return _load_web_config() except Exception: # noqa: BLE001 — config problems must never break tools return {} def cache_enabled() -> bool: """Both caches honor ``web.cache_enabled`` (default: on).""" return True if (val := _web_config().get("cache_enabled")) is None else bool(val) def ttl_seconds() -> float: """TTL from ``web.cache_ttl_minutes`` (default 20, clamped 1–1440).""" raw = _web_config().get("cache_ttl_minutes") try: minutes = float(raw) if raw is not None else DEFAULT_TTL_MINUTES except (TypeError, ValueError): minutes = DEFAULT_TTL_MINUTES return max(1.0, min(minutes, 1440.0)) * 60.0 def bucket_limit(limit: int) -> int: """Round a requested result count up to the nearest bucket.""" return next((b for b in _LIMIT_BUCKETS if limit <= b), _LIMIT_BUCKETS[-1]) def normalize_query(query: str) -> str: """Case-fold and collapse whitespace so trivial variants share an entry.""" return re.sub(r"\s+", " ", (query or "").strip().lower()) def _host_slug(url: str) -> str: """Filesystem-safe hostname slug for cache filenames (``"page"`` when hostless). Shared with tools.web_tools_truncate.""" host = (urlparse(url).hostname or "page").replace(":", "_") return re.sub(r"[^A-Za-z0-9._-]", "-", host)[:60].strip("-") or "page" def _deep_copy(response: dict) -> dict: """Defensive copy so callers mutating a hit never corrupt the cached entry.""" return json.loads(json.dumps(response)) # ─── Search memo (in-memory, single-flight) ─────────────────────────────────── class SearchMemo: """TTL memo + single-flight coalescer for search responses. Thread-safe: the parallel tool-dispatch pool and subagents share this process, so identical queries genuinely race; per-key locks make the losers wait for (and share) the winner's response.""" def __init__(self) -> None: self._store: Dict[tuple, Tuple[float, dict]] = {} # key -> (expires_at, response) self._store_lock = threading.Lock() self._key_locks: Dict[tuple, threading.Lock] = {} @staticmethod def _key(provider: str, query: str, limit: int) -> tuple: return (provider, normalize_query(query), bucket_limit(limit)) def lookup(self, provider: str, query: str, limit: int) -> Optional[dict]: if not cache_enabled(): return None key = self._key(provider, query, limit) with self._store_lock: hit = self._store.get(key) if hit is None or time.monotonic() >= hit[0]: self._store.pop(key, None) return None logger.info("web_search cache hit: %r via %s", query, provider) return _deep_copy(hit[1]) def store(self, provider: str, query: str, limit: int, response: dict) -> None: """Cache a SUCCESSFUL response for the bucketed key.""" if not cache_enabled() or not isinstance(response, dict) or not response.get("success"): return key = self._key(provider, query, limit) with self._store_lock: now = time.monotonic() # opportunistic expiry sweep bounds memory for k in [k for k, (exp, _) in self._store.items() if now >= exp]: del self._store[k] self._store[key] = (now + ttl_seconds(), _deep_copy(response)) def flight_lock(self, provider: str, query: str, limit: int) -> threading.Lock: """Per-key lock held around lookup-miss → paid request → store.""" key = self._key(provider, query, limit) with self._store_lock: lock = self._key_locks.get(key) if lock is None: # Bound the lock table, but never evict a HELD lock: dropping one lets a concurrent # identical request mint a fresh lock and issue a duplicate paid call. locked() is a # safe snapshot under _store_lock because holders already have their reference. # See #94618. if len(self._key_locks) > 256: self._key_locks = {k: v for k, v in self._key_locks.items() if v.locked()} lock = self._key_locks[key] = threading.Lock() return lock def clear(self) -> None: """Drop all cached entries (tests; config changes).""" with self._store_lock: self._store.clear() self._key_locks.clear() search_memo = SearchMemo() def slice_search_response(response: dict, limit: int) -> dict: """Trim a bucketed response's result list down to the caller's limit.""" try: web = response.get("data", {}).get("web") if isinstance(web, list) and len(web) > limit: out = _deep_copy(response) out["data"]["web"] = out["data"]["web"][:limit] return out except Exception: # noqa: BLE001 pass return response # ─── Extract cache (disk-backed, reuses cache/web) ──────────────────────────── _index_lock = threading.Lock() def _cache_dir() -> Optional[Path]: try: from hermes_constants import get_hermes_dir d = get_hermes_dir("cache/web", "web_cache") d.mkdir(parents=True, exist_ok=True) return d except Exception: # noqa: BLE001 return None def _load_index() -> dict: try: data = json.loads((_cache_dir() / _INDEX_FILENAME).read_text(encoding="utf-8-sig")) return data if isinstance(data, dict) else {} except Exception: # noqa: BLE001 — missing/corrupt index == empty cache return {} def _save_index(index: dict) -> None: if (d := _cache_dir()) is None: return path = d / _INDEX_FILENAME try: if len(index) > _INDEX_MAX_ENTRIES: newest = sorted(index.items(), key=lambda kv: kv[1].get("fetched_at", 0), reverse=True) index = dict(newest[:_INDEX_MAX_ENTRIES]) # CLI, gateway, cron, and subagents all write this index; the replace is atomic, so the worst case # under concurrent writers is a lost insert, never a truncated index. atomic_json_write(path, index, indent=None) except Exception as exc: # noqa: BLE001 logger.debug("Failed to save web extract cache index: %s", exc) def _url_digest(url: str, format: Optional[str], provider: str = "") -> str: # format AND provider are part of the key: html != markdown, and one backend's rendering is not another's. raw = f"{url}\n{format or 'markdown'}\n{provider or ''}" return hashlib.sha256(raw.encode("utf-8")).hexdigest()[:16] def _entry_file_path(url: str, format: Optional[str], provider: str) -> Optional[Path]: """Dedicated cache file per (url, format, provider) — deliberately NOT the truncate-store file (keyed on URL alone), which html/markdown or two providers' copies of one URL would overwrite. The truncate-store file keeps its role for read_file paging; these files exist only for cache reuse and carry the full key in their name. See #94618. """ if (d := _cache_dir()) is None: return None slug = "page" with suppress(Exception): slug = _host_slug(url) return d / f"{slug}-{_url_digest(url, format, provider)}.cache.md" def _host_matches_pattern(host: str, pattern: str) -> bool: """Case-insensitive: exact, ``*.wildcard``, or bare-domain suffix (``mysite.dev`` also matches ``preview.mysite.dev``).""" host = host.lower().strip(".") pattern = (pattern or "").lower().strip().strip(".").removeprefix("*.") return bool(pattern) and (host == pattern or host.endswith("." + pattern)) def _is_cache_exempt_host(url: str) -> bool: """True when the host matches ``web.cache_exempt_hosts`` — sites the user develops over public DNS (staging, tunnels, previews) that must fetch live.""" try: patterns = _web_config().get("cache_exempt_hosts") or [] host = (urlparse(url).hostname or "").strip("[]") if not isinstance(patterns, (list, tuple)) or not host: return False return any(_host_matches_pattern(host, str(p)) for p in patterns) except Exception: # noqa: BLE001 — config problems never break tools return False def _is_local_dev_url(url: str) -> bool: """True for loopback/private/LAN URLs — never cached: they are the user's own fast-changing dev servers. Hostname heuristics only, no DNS: this is a freshness decision, not a security boundary (SSRF enforcement lives in tools/url_safety.py, which blocks these by default anyway).""" try: host = (urlparse(url).hostname or "").strip("[]").lower() # Unparseable → don't cache; single-label (no "." / ":") == LAN name, not public DNS. if not host or host == "localhost" or host.endswith((".localhost", ".local")): return True if "." not in host and ":" not in host: return True import ipaddress try: ip = ipaddress.ip_address(host) except ValueError: return False # public DNS name return ip.is_private or ip.is_loopback or ip.is_link_local or ip.is_reserved or ip.is_unspecified except Exception: # noqa: BLE001 — on doubt, don't cache return True def _cacheable(url: str) -> bool: """Extract-cache gate: enabled, not a local-dev host, not user-exempted.""" return cache_enabled() and not (_is_local_dev_url(url) or _is_cache_exempt_host(url)) def extract_cache_get(url: str, format: Optional[str] = None, provider: str = "") -> Optional[dict]: """Return {'url','title','content'} for a fresh cached page, else None.""" if not _cacheable(url): return None with _index_lock: entry = _load_index().get(_url_digest(url, format, provider)) if not entry or (time.time() - float(entry.get("fetched_at", 0))) >= ttl_seconds(): return None try: file_path, cache_root = Path(entry["file"]), _cache_dir() # The index is plain JSON on disk; never let a tampered entry read outside cache/web. if cache_root.resolve() not in file_path.resolve().parents: return None content = file_path.read_text(encoding="utf-8-sig") except Exception: # noqa: BLE001 — evicted/pruned file == miss (or no cache dir) return None logger.info("web_extract cache hit: %s", url) return {"url": url, "title": entry.get("title", ""), "content": content, "error": None, "cached": True} def extract_cache_put( url: str, content: str, title: str = "", format: Optional[str] = None, provider: str = "" ) -> None: """Store one successful extraction's full clean text for TTL reuse; pages over the truncate-store ceiling are not cached (serving a capped copy back as if whole would silently lose the tail).""" if not content or not _cacheable(url): return try: from tools.web_tools_truncate import MAX_STORED_TEXT_CHARS file_path = _entry_file_path(url, format, provider) if len(content) > MAX_STORED_TEXT_CHARS or file_path is None: return from tools.spill_safety import write_text_exclusive write_text_exclusive(file_path, content, private=False, overwrite=True) with _index_lock: index = _load_index() index[_url_digest(url, format, provider)] = { "url": url, "file": str(file_path), "title": title or "", "fetched_at": time.time(), } _save_index(index) except Exception as exc: # noqa: BLE001 — cache writes are best-effort logger.debug("Failed to cache web extract for %s: %s", url, exc)