feat(14-02): add version-key, settings helpers and Phase 14 cache service functions

- cloud_analysis_versioning.py: compute_version_key with version>etag>fingerprint
  precedence (D-19); compute_fingerprint helper; content_hash is optional post-
  hydration only (D-20); raises ValueError only, no HTTPException
- cloud_analysis_settings.py: get_or_create_user_analysis_settings (upsert on
  first access), update_user_analysis_settings with enum validation and tier-capped
  cache limit, build_default_settings for API responses; raises ValueError only
- cloud_cache.py: Phase 14 durable cache functions added alongside existing Phase 12
  in-memory TTL cache — create_cache_entry, list_cache_entries (owner-scoped),
  evict_lru_entries (LRU, skips pin_count>0 and active_job_count>0), increment/
  decrement_quota_for_cache (atomic UPDATE pattern); re-exports compute_version_key
  from cloud_analysis_versioning so tests have one import site
This commit is contained in:
curo1305
2026-06-23 15:14:19 +02:00
parent fd76d06b3a
commit 1df61040c6
3 changed files with 546 additions and 2 deletions
+251 -2
View File
@@ -1,6 +1,7 @@
"""
Cloud folder listing cache for DocuVault.
Cloud cache service for DocuVault — Phase 12 in-memory layer + Phase 14 durable cache.
── Phase 12: in-memory folder listing cache ─────────────────────────────────────
Provides a module-level TTLCache singleton for caching cloud provider folder
listings with a 60-second TTL (D-16: live API calls with 60-second in-memory TTL).
@@ -17,13 +18,39 @@ Cache key scheme: "{user_id}:{provider}:{folder_id}"
References:
RESEARCH.md Pattern 8 — TTLCache thread safety + asyncio integration
D-16 — 60-second TTL, in-memory cache (not Redis)
── Phase 14: durable byte cache (cloud_byte_cache_entries) ─────────────────────
Exports create_cache_entry, evict_lru_entries, list_cache_entries,
increment_quota_for_cache, decrement_quota_for_cache for use by Celery tasks
and the analysis API.
Also re-exports compute_version_key from services.cloud_analysis_versioning so
tests and service callers have a single import location.
Rules:
- Raises ValueError or domain exceptions only — never HTTPException.
- Eviction never removes entries with pin_count > 0 or active_job_count > 0.
- Eviction is per-user LRU (oldest last_accessed_at first).
- quota.used_bytes is adjusted only via increment_quota_for_cache /
decrement_quota_for_cache which use the project's atomic UPDATE pattern.
- object_key is never returned in API responses (T-14-02).
"""
from __future__ import annotations
import threading
from typing import Any, Callable, Awaitable
import uuid
from datetime import datetime, timezone
from typing import Any, Callable, Awaitable, List, Optional, Sequence
from cachetools import TTLCache
from sqlalchemy import select, update, text
from sqlalchemy.ext.asyncio import AsyncSession
from db.models import CloudByteCacheEntry
from services.cloud_analysis_versioning import compute_version_key as _compute_version_key # noqa: F401
# Re-export so callers can do: from services.cloud_cache import compute_version_key
compute_version_key = _compute_version_key
# Module-level singleton: maxsize=1000 (sufficient for ~50 users × 20 folders),
@@ -77,6 +104,228 @@ async def get_cloud_folders_cached(
return result
# ══ Phase 14: durable byte cache operations ══════════════════════════════════
class CacheQuotaExceeded(ValueError):
"""User's quota cannot accommodate the requested cache entry size."""
async def create_cache_entry(
session: AsyncSession,
*,
user_id: uuid.UUID,
connection_id: uuid.UUID,
cloud_item_id: uuid.UUID,
provider_item_id: str,
version_key: str,
object_key: str,
content_type: Optional[str] = None,
size_bytes: int,
content_hash: Optional[str] = None,
pin_count: int = 0,
active_job_count: int = 0,
last_accessed_at: Optional[datetime] = None,
) -> CloudByteCacheEntry:
"""Create and flush a new cloud_byte_cache_entries row.
Does NOT update quota — call increment_quota_for_cache separately.
Does NOT enforce uniqueness beyond the DB constraint; callers must check
for an existing entry before calling this function.
Args:
session: Active async SQLAlchemy session.
user_id: Owner UUID.
connection_id: Cloud connection UUID.
cloud_item_id: CloudItem row UUID.
provider_item_id: Snapshot of the provider item id for audit/debug.
version_key: Idempotency key (from compute_version_key).
object_key: Private MinIO object key — UUID-based, never exposed.
content_type: Optional MIME type.
size_bytes: Actual byte count stored in MinIO.
content_hash: Optional post-hydration content hash.
pin_count: Active preview/download leases (default 0).
active_job_count: Active Celery jobs using these bytes (default 0).
last_accessed_at: Optional LRU timestamp; defaults to now().
Returns:
Flushed (but not committed) CloudByteCacheEntry row.
"""
now = datetime.now(timezone.utc)
entry = CloudByteCacheEntry(
user_id=user_id if isinstance(user_id, uuid.UUID) else uuid.UUID(str(user_id)),
connection_id=connection_id if isinstance(connection_id, uuid.UUID) else uuid.UUID(str(connection_id)),
cloud_item_id=cloud_item_id if isinstance(cloud_item_id, uuid.UUID) else uuid.UUID(str(cloud_item_id)),
provider_item_id=provider_item_id,
version_key=version_key,
object_key=object_key,
content_type=content_type,
size_bytes=size_bytes,
content_hash=content_hash,
pin_count=pin_count,
active_job_count=active_job_count,
last_accessed_at=last_accessed_at or now,
)
session.add(entry)
await session.flush()
return entry
async def list_cache_entries(
session: AsyncSession,
*,
user_id: uuid.UUID,
include_evicted: bool = False,
) -> Sequence[CloudByteCacheEntry]:
"""Return cache entries owned by user_id.
Ownership is strictly enforced — only rows where user_id matches are
returned. By default, evicted entries (evicted_at IS NOT NULL) are
excluded.
Args:
session: Active async SQLAlchemy session.
user_id: Owner UUID.
include_evicted: If True, include entries with evicted_at set.
Returns:
Sequence of CloudByteCacheEntry rows (may be empty).
"""
uid = user_id if isinstance(user_id, uuid.UUID) else uuid.UUID(str(user_id))
stmt = select(CloudByteCacheEntry).where(CloudByteCacheEntry.user_id == uid)
if not include_evicted:
stmt = stmt.where(CloudByteCacheEntry.evicted_at.is_(None))
result = await session.execute(stmt)
return result.scalars().all()
async def evict_lru_entries(
session: AsyncSession,
*,
user_id: uuid.UUID,
max_cache_bytes: int,
) -> List[uuid.UUID]:
"""Mark least-recently-used unpinned entries as evicted until total is within limit.
Eviction rules (D-14, D-16):
- Only entries with pin_count == 0 and active_job_count == 0 are eligible.
- Entries are evicted in ascending last_accessed_at order (oldest first).
- Eviction stops when the sum of retained entry size_bytes <= max_cache_bytes.
- evicted_at is stamped to now(); the caller is responsible for deleting
the MinIO objects and calling decrement_quota_for_cache per evicted entry.
Args:
session: Active async SQLAlchemy session.
user_id: Owner UUID.
max_cache_bytes: Target byte ceiling (entries evicted until we fit within).
Returns:
List of evicted CloudByteCacheEntry UUIDs (empty if nothing needed eviction).
"""
uid = user_id if isinstance(user_id, uuid.UUID) else uuid.UUID(str(user_id))
# Fetch all non-evicted entries for this user ordered by LRU ascending
stmt = (
select(CloudByteCacheEntry)
.where(
CloudByteCacheEntry.user_id == uid,
CloudByteCacheEntry.evicted_at.is_(None),
)
.order_by(CloudByteCacheEntry.last_accessed_at.asc().nulls_first())
)
result = await session.execute(stmt)
entries = result.scalars().all()
# Sum total retained bytes
total_bytes = sum(e.size_bytes for e in entries)
now = datetime.now(timezone.utc)
evicted_ids: List[uuid.UUID] = []
for entry in entries:
if total_bytes <= max_cache_bytes:
break
# Skip pinned or actively-used entries
if entry.pin_count > 0 or entry.active_job_count > 0:
continue
# Evict this entry
entry.evicted_at = now
entry.updated_at = now
total_bytes -= entry.size_bytes
evicted_ids.append(entry.id)
if evicted_ids:
await session.flush()
return evicted_ids
async def increment_quota_for_cache(
session: AsyncSession,
*,
user_id: uuid.UUID,
size_bytes: int,
) -> None:
"""Atomically increment quota.used_bytes for a cached byte entry.
Uses the project's atomic UPDATE pattern to prevent TOCTOU race conditions:
UPDATE quotas SET used_bytes = used_bytes + $delta
WHERE user_id = $user_id AND (used_bytes + $delta) <= limit_bytes
Raises:
CacheQuotaExceeded: The increment would exceed the user's quota limit.
Note:
Against SQLite (test environments) this runs as a non-atomic update;
the atomic guarantee is provided only by PostgreSQL in production.
"""
uid = user_id if isinstance(user_id, uuid.UUID) else uuid.UUID(str(user_id))
# Atomic UPDATE … RETURNING pattern (same as quota enforcement in upload flow)
result = await session.execute(
text(
"UPDATE quotas SET used_bytes = used_bytes + :delta "
"WHERE user_id = :uid AND (used_bytes + :delta) <= limit_bytes "
"RETURNING used_bytes"
),
{"delta": size_bytes, "uid": str(uid)},
)
row = result.fetchone()
if row is None:
raise CacheQuotaExceeded(
f"User {uid} quota exhausted — cannot cache {size_bytes} bytes"
)
async def decrement_quota_for_cache(
session: AsyncSession,
*,
user_id: uuid.UUID,
size_bytes: int,
) -> None:
"""Atomically decrement quota.used_bytes when a cached entry is evicted.
Clamps to 0 to prevent negative quota values (defensive — should not occur
in practice if increment/decrement are always called in pairs).
Args:
session: Active async SQLAlchemy session.
user_id: Owner UUID.
size_bytes: Byte count to release.
"""
uid = user_id if isinstance(user_id, uuid.UUID) else uuid.UUID(str(user_id))
await session.execute(
text(
"UPDATE quotas SET used_bytes = GREATEST(0, used_bytes - :delta) "
"WHERE user_id = :uid"
),
{"delta": size_bytes, "uid": str(uid)},
)
# ── Phase 12: in-memory folder listing cache ──────────────────────────────────
def invalidate_provider_cache(user_id: str, provider: str) -> None:
"""Invalidate all cached folder listings for a specific user + provider.