Files
mcp-nextcloud/nextcloud_mcp_server/capabilities.py
T
Chris CoutinhoandClaude Opus 4.8 7067c5fff1 test(vector-sync): close round-8 coverage gaps (500 path, non-string list)
- route test for purge_doc_types raising on total failure -> 500
- route test for doc_types list containing non-strings -> 400
- reword the capabilities move_to_end comment (no-op on new keys; needed only
  for the expired-key in-place update)

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
2026-06-16 02:10:54 +02:00

124 lines
4.9 KiB
Python

"""Reads admin-approved searchable sources from the Astrolabe capability.
The Astrolabe Nextcloud app advertises, per user, which content sources an
admin has approved for semantic search, under
``capabilities.astrolabe.semantic_search.enabled_doc_types`` on the OCS
capabilities endpoint (``/ocs/v2.php/cloud/capabilities``). This is the single
source of truth for admin consent: the search layer filters results to these
doc types, and the indexing layer (scanner + webhook ingest) skips everything
else (the hard data-at-rest guarantee is the eager purge Astrolabe triggers on
disable; see ``vector.purge``).
Fail-open for *availability*: if the capability block is absent (an older
Astrolabe that predates this feature) or the OCS call fails, ``allowed_doc_types``
returns ``None`` meaning "no restriction", so search keeps working. ``None`` is
distinct from an empty set, which means "the admin disabled every source".
"""
from __future__ import annotations
import logging
import time
from collections import OrderedDict
from typing import Any, Protocol
logger = logging.getLogger(__name__)
# Short-lived per-user cache for the OCS capabilities lookup. Admin consent
# changes rarely, but search/scan paths consult it frequently, so trade a little
# staleness for keeping the OCS round-trip off the hot path. Mirrors the
# list_accessible_owners cache in search/access_filter.py.
#
# Keyed by user_id even though enabled_doc_types is an admin-wide value: the OCS
# call is authenticated per-user (and ``installed`` resolves per-user on the
# Astrolabe side), so we cache per-user for correctness. The redundancy is
# bounded by _CACHE_MAXSIZE; on an admin change all entries reconverge within
# one TTL window.
_CACHE_TTL_SECONDS = 30.0
_CACHE_MAXSIZE = 1024
# user_id -> (monotonic_ts, frozenset[doc_type] | None). None = no restriction.
_cache: OrderedDict[str, tuple[float, frozenset[str] | None]] = OrderedDict()
class _CapabilitiesClientProtocol(Protocol):
async def capabilities(self) -> Any: ...
def _parse_enabled_doc_types(payload: Any) -> frozenset[str] | None:
"""Extract ``enabled_doc_types`` from an OCS capabilities payload.
Returns ``None`` when the ``astrolabe.semantic_search`` block is absent or
malformed (treated as "no restriction"). Returns a frozenset (possibly
empty) when the block is present and well-formed; an empty set means the
admin disabled every source.
"""
if not isinstance(payload, dict):
return None
try:
caps = payload["ocs"]["data"]["capabilities"]
except (KeyError, TypeError):
return None
if not isinstance(caps, dict):
return None
block = caps.get("astrolabe")
if not isinstance(block, dict):
return None
semantic = block.get("semantic_search")
if not isinstance(semantic, dict):
return None
raw = semantic.get("enabled_doc_types")
if not isinstance(raw, list):
return None
return frozenset(dt for dt in raw if isinstance(dt, str) and dt)
async def allowed_doc_types(
client: _CapabilitiesClientProtocol, user_id: str
) -> frozenset[str] | None:
"""Admin-approved doc types for ``user_id``, or ``None`` for "no restriction".
Cached per user with a short TTL (+ LRU eviction). Failures are not cached so
a transient OCS hiccup retries on the next call. Fail-open: a missing
capability block or an error yields ``None`` so search remains available.
"""
now = time.monotonic()
cached = _cache.get(user_id)
if cached is not None and now - cached[0] < _CACHE_TTL_SECONDS:
_cache.move_to_end(user_id) # mark recently used (LRU)
return cached[1]
try:
payload = await client.capabilities()
except Exception as exc: # noqa: BLE001 — degrade gracefully (fail-open)
logger.warning(
"Astrolabe capabilities unavailable for user %s (%s); "
"not restricting doc types this cycle",
user_id,
exc,
)
return None # don't cache failures — retry next call
result = _parse_enabled_doc_types(payload)
_cache[user_id] = (now, result)
# Needed only for an existing (expired) key: __setitem__ updates it in place,
# keeping its old position, so move it to the end to preserve LRU order. For
# a brand-new key __setitem__ already appends, so this is a harmless no-op.
_cache.move_to_end(user_id)
while len(_cache) > _CACHE_MAXSIZE:
_cache.popitem(last=False) # evict least-recently-used
return result
def is_doc_type_allowed(doc_type: str, allowed: frozenset[str] | None) -> bool:
"""Whether ``doc_type`` may be indexed/searched given an allow-set.
``allowed=None`` means "no restriction" (fail-open / older Astrolabe), so
everything is permitted.
"""
return allowed is None or doc_type in allowed
def clear_cache() -> None:
"""Test hook: drop all cached entries."""
_cache.clear()