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fix: address PR #813 review round 4 (log leak, cross-user chunk ctx, algo, overlap)

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1. Don't log unverified result titles: both search algorithms logged top-5
   titles at DEBUG before verify-on-read; with owner-level share expansion the
   unverified set can contain other users' docs. Algorithms now log a count
   only; the verifying callers (server/semantic, viz_routes, api/visualization)
   log verified titles after verify-on-read.

2. Cross-user FILE chunk context: get_chunk_with_context + the Qdrant chunk
   helpers now take accessible_owners and use build_ownership_filter. For files
   the expanded scope is honoured only after a per-file file_accessible_by_id
   check (accessible_owners is owner-level, so the gate prevents a one-file
   share recipient from reading any of the owner's cached chunks). note/deck/
   news stay self-only (per-user APIs) — a documented gap. Both chunk endpoints
   pass accessible_owners.

3. Algorithm usage: SemanticSearchAlgorithm is not dead (it backs the dense-only
   option on the viz/API surfaces); added a clarifying comment in server/
   semantic.py. Additionally wired accessible_owners + verify-on-read into the
   /api/v1 search routes (unified_search, vector_search) so the astrolabe
   surface is ACL-aware too — degrading gracefully to self-only/unverified for
   non-provisioned callers instead of 401.

4. Overlapping conditions: build_ownership_filter no longer lists self in the
   owner_id MatchAny branch (self is already covered by the user_id branch);
   the owner_id branch carries only the OTHER owners.

Tests: build_ownership_filter dedup + chunk-bbox filter-shape updates; new
ACL-aware get_indexed_doc_types, cached-chunk lookup, and end-to-end cross-user
file chunk-context (recipient gets the chunk, non-recipient denied) tests.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
This commit is contained in:
Chris Coutinho
2026-05-29 16:55:00 +02:00
co-authored by Claude Opus 4.8
parent ac041d5c97
commit 8deb48e6fa
11 changed files with 393 additions and 87 deletions
Download Patch File Download Diff File Expand all files Collapse all files
nextcloud_mcp_server/search/context.py
+90 -13
View File
@@ -7,10 +7,12 @@ position markers for better visualization and understanding of search results.
import logging
from dataclasses import dataclass
from httpx import HTTPStatusError
from qdrant_client.models import FieldCondition, Filter, MatchValue
from nextcloud_mcp_server.client import NextcloudClient
from nextcloud_mcp_server.config import get_settings
from nextcloud_mcp_server.search.access_filter import build_ownership_filter
from nextcloud_mcp_server.utils.validation import is_valid_nextcloud_doc_id
from nextcloud_mcp_server.vector.html_processor import html_to_markdown
from nextcloud_mcp_server.vector.placeholder import get_placeholder_filter
@@ -20,7 +22,12 @@ logger = logging.getLogger(__name__)
async def _get_chunk_from_qdrant(
user_id: str, doc_id: str, doc_type: str, chunk_start: int, chunk_end: int
user_id: str,
doc_id: str,
doc_type: str,
chunk_start: int,
chunk_end: int,
accessible_owners: list[str] | None = None,
) -> str | None:
"""Retrieve full chunk text from Qdrant payload.
@@ -28,11 +35,15 @@ async def _get_chunk_from_qdrant(
chunk content already stored in Qdrant.
Args:
user_id: User ID who owns the document
user_id: Querying user.
doc_id: Document ID
doc_type: Document type (e.g., "note", "file")
chunk_start: Character offset where chunk starts
chunk_end: Character offset where chunk ends
accessible_owners: Owner UIDs the caller may read (self + share senders).
When None, the lookup is self-only. Callers must only pass an
expanded set after confirming the caller can access the document
(see ``get_chunk_with_context``) — the filter is owner-level.
Returns:
Full chunk text from Qdrant excerpt field, or None if not found
@@ -46,7 +57,7 @@ async def _get_chunk_from_qdrant(
collection_name=settings.get_collection_name(),
scroll_filter=Filter(
must=[
FieldCondition(key="user_id", match=MatchValue(value=user_id)),
build_ownership_filter(user_id, accessible_owners),
FieldCondition(key="doc_id", match=MatchValue(value=doc_id)),
FieldCondition(key="doc_type", match=MatchValue(value=doc_type)),
FieldCondition(
@@ -93,17 +104,24 @@ async def _get_chunk_from_qdrant(
async def _get_chunk_by_index_from_qdrant(
user_id: str, doc_id: str, doc_type: str, chunk_index: int
user_id: str,
doc_id: str,
doc_type: str,
chunk_index: int,
accessible_owners: list[str] | None = None,
) -> str | None:
"""Retrieve chunk text by chunk_index from Qdrant payload.
Used to fetch adjacent chunks for context expansion.
Args:
user_id: User ID who owns the document
user_id: Querying user.
doc_id: Document ID
doc_type: Document type (e.g., "note", "file")
chunk_index: Zero-based chunk index in document
accessible_owners: Owner UIDs the caller may read; None ⇒ self-only.
Only pass an expanded set after a per-document access check (see
``get_chunk_with_context``).
Returns:
Full chunk text from Qdrant excerpt field, or None if not found
@@ -117,7 +135,7 @@ async def _get_chunk_by_index_from_qdrant(
collection_name=settings.get_collection_name(),
scroll_filter=Filter(
must=[
FieldCondition(key="user_id", match=MatchValue(value=user_id)),
build_ownership_filter(user_id, accessible_owners),
FieldCondition(key="doc_id", match=MatchValue(value=doc_id)),
FieldCondition(key="doc_type", match=MatchValue(value=doc_type)),
FieldCondition(
@@ -217,6 +235,7 @@ async def get_chunk_bbox_and_page_from_qdrant(
chunk_index: int | None,
chunk_start: int,
chunk_end: int,
accessible_owners: list[str] | None = None,
) -> tuple[list | None, int | None]:
"""Fetch chunk_bbox and page_number for a chunk from Qdrant payload.
@@ -256,7 +275,7 @@ async def get_chunk_bbox_and_page_from_qdrant(
must=[
get_placeholder_filter(),
FieldCondition(key="doc_id", match=MatchValue(value=doc_id)),
FieldCondition(key="user_id", match=MatchValue(value=user_id)),
build_ownership_filter(user_id, accessible_owners),
FieldCondition(
key="chunk_index", match=MatchValue(value=chunk_index)
),
@@ -273,7 +292,7 @@ async def get_chunk_bbox_and_page_from_qdrant(
must=[
get_placeholder_filter(),
FieldCondition(key="doc_id", match=MatchValue(value=doc_id)),
FieldCondition(key="user_id", match=MatchValue(value=user_id)),
build_ownership_filter(user_id, accessible_owners),
FieldCondition(
key="chunk_start_offset",
match=MatchValue(value=chunk_start),
@@ -352,6 +371,7 @@ async def get_chunk_with_context(
chunk_index: int | None = None,
total_chunks: int = 1,
context_chars: int = 300,
accessible_owners: list[str] | None = None,
) -> ChunkContext | None:
"""Fetch chunk with surrounding context.
@@ -361,7 +381,7 @@ async def get_chunk_with_context(
Args:
nc_client: Authenticated Nextcloud client
user_id: User ID who owns the document
user_id: Querying user.
doc_id: Document ID (str — keyword-indexed in Qdrant payload)
doc_type: Type of document ("note", "file", etc.)
chunk_start: Character offset where chunk starts
@@ -372,6 +392,10 @@ async def get_chunk_with_context(
field). When None, falls back to the (chunk_start, chunk_end) lookup.
total_chunks: Total number of chunks in document
context_chars: Number of characters to include before/after chunk
accessible_owners: Owner UIDs the caller may read (self + share senders).
Used to support cross-user context for SHARED FILES only, and only
after a per-file access check (see ``lookup_owners`` below). For
non-file types the lookup stays self-only.
Returns:
ChunkContext with expanded context and markers, or None if document
@@ -380,13 +404,53 @@ async def get_chunk_with_context(
# doc_id is keyword-indexed in Qdrant as str — pass through verbatim
# (no int coercion; producers always stringify on write).
# Determine the ownership scope for the Qdrant cached-chunk lookups.
#
# ``accessible_owners`` is OWNER-level (every owner who shared anything with
# the caller), so widening the lookup to it unconditionally would let a
# recipient of a single shared file read ANY of that owner's cached chunks
# by guessing doc_ids. We therefore honour it only for FILES, and only after
# confirming the caller can access THIS file by id (``file_accessible_by_id``
# is cross-user-safe: a WebDAV SEARCH over the caller's whole tree incl.
# mounted shares). For per-user types (note/deck/news) there is no
# share-mounted by-id access via the caller's credentials, so the lookup
# stays self-only — cross-user context for those types is a known gap.
lookup_owners: list[str] | None = None # None ⇒ self-only
if doc_type == "file" and accessible_owners:
try:
if await nc_client.webdav.file_accessible_by_id(int(doc_id)):
lookup_owners = accessible_owners
else:
# Not owned and not shared with the caller → no access. Return
# early rather than falling back to a self-only lookup that
# would also miss (and so the result is the same None, but this
# is explicit and skips a pointless Qdrant round-trip).
logger.debug(
"File %s not accessible to %s; no cross-user chunk context",
doc_id,
user_id,
)
return None
except (ValueError, TypeError):
# Non-numeric doc_id: shouldn't happen (endpoints validate), but
# degrade to self-only rather than raising.
logger.warning("Non-numeric file doc_id %r; using self-only scope", doc_id)
except HTTPStatusError as exc:
# Transient transport/server error — treat as inconclusive and fall
# back to self-only so the caller's own files still resolve.
logger.warning(
"file_accessible_by_id(%s) failed (%s); using self-only scope",
doc_id,
exc,
)
# Try to get chunk from Qdrant (fast path).
# Prefer chunk_index lookup (always-indexed field) when caller supplied it;
# fall back to (chunk_start, chunk_end) lookup otherwise.
chunk_text: str | None = None
if chunk_index is not None:
chunk_text = await _get_chunk_by_index_from_qdrant(
user_id, doc_id, doc_type, chunk_index
user_id, doc_id, doc_type, chunk_index, accessible_owners=lookup_owners
)
# When chunk_index is supplied, the indexed lookup is canonical: both the
# index path and the offset path query the same Qdrant collection, so an
@@ -398,7 +462,12 @@ async def get_chunk_with_context(
skip_offset_lookup = chunk_index is not None
if chunk_text is None and not skip_offset_lookup:
chunk_text = await _get_chunk_from_qdrant(
user_id, doc_id, doc_type, chunk_start, chunk_end
user_id,
doc_id,
doc_type,
chunk_start,
chunk_end,
accessible_owners=lookup_owners,
)
if chunk_text:
@@ -422,7 +491,11 @@ async def get_chunk_with_context(
# Fetch previous chunk if not first chunk
if chunk_index > 0:
before_chunk = await _get_chunk_by_index_from_qdrant(
user_id, doc_id, doc_type, chunk_index - 1
user_id,
doc_id,
doc_type,
chunk_index - 1,
accessible_owners=lookup_owners,
)
if before_chunk:
# Remove overlap: the last chunk_overlap chars of previous chunk
@@ -443,7 +516,11 @@ async def get_chunk_with_context(
# Fetch next chunk if not last chunk
if chunk_index < total_chunks - 1:
after_chunk = await _get_chunk_by_index_from_qdrant(
user_id, doc_id, doc_type, chunk_index + 1
user_id,
doc_id,
doc_type,
chunk_index + 1,
accessible_owners=lookup_owners,
)
if after_chunk:
# Remove overlap: the first chunk_overlap chars of next chunk