hermes-agent/plugins/memory/holographic/store.py
Adam Biggs b5226caff8 fix(memory): share one SQLite connection per holographic store database
Every MemoryStore instance opened its own SQLite connection guarded by
its own RLock. Several providers coexist in one process (the main agent
plus every delegate_task subagent), so instances pointing at the same
memory_store.db raced as independent WAL writers. Combined with writes
that were not rolled back on error, one connection could leave an open
write transaction that pinned the write lock and made every other
connection's writes fail with "database is locked" for the full busy
timeout.

Instances for the same database now share ONE process-wide connection
and ONE re-entrant lock, so access is fully serialized and
cross-connection contention is impossible. The shared connection is
refcounted: closing one instance never tears it out from under a live
sibling, and the last close releases it. The connection runs in
autocommit (isolation_level=None) so a write that raises mid-method can
never leave a dangling transaction holding the write lock; the existing
explicit commit() calls become harmless no-ops.

The provider's shutdown() now calls the refcount-guarded close() instead
of just dropping the reference: leaving finalization to GC kept the
connection (and its write lock) alive indefinitely on long-running
gateways, prolonging the exact contention this fix removes. The last
provider now releases the connection deterministically while siblings
stay live; regression tests fail without the wiring.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
2026-07-09 18:17:40 -07:00

638 lines
23 KiB
Python

"""
SQLite-backed fact store with entity resolution and trust scoring.
Single-user Hermes memory store plugin.
"""
import re
import sqlite3
import threading
from pathlib import Path
try:
from . import holographic as hrr
except ImportError:
import holographic as hrr # type: ignore[no-redef]
_SCHEMA = """
CREATE TABLE IF NOT EXISTS facts (
fact_id INTEGER PRIMARY KEY AUTOINCREMENT,
content TEXT NOT NULL UNIQUE,
category TEXT DEFAULT 'general',
tags TEXT DEFAULT '',
trust_score REAL DEFAULT 0.5,
retrieval_count INTEGER DEFAULT 0,
helpful_count INTEGER DEFAULT 0,
created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
hrr_vector BLOB
);
CREATE TABLE IF NOT EXISTS entities (
entity_id INTEGER PRIMARY KEY AUTOINCREMENT,
name TEXT NOT NULL,
entity_type TEXT DEFAULT 'unknown',
aliases TEXT DEFAULT '',
created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
);
CREATE TABLE IF NOT EXISTS fact_entities (
fact_id INTEGER REFERENCES facts(fact_id),
entity_id INTEGER REFERENCES entities(entity_id),
PRIMARY KEY (fact_id, entity_id)
);
CREATE INDEX IF NOT EXISTS idx_facts_trust ON facts(trust_score DESC);
CREATE INDEX IF NOT EXISTS idx_facts_category ON facts(category);
CREATE INDEX IF NOT EXISTS idx_entities_name ON entities(name);
CREATE VIRTUAL TABLE IF NOT EXISTS facts_fts
USING fts5(content, tags, content=facts, content_rowid=fact_id);
CREATE TRIGGER IF NOT EXISTS facts_ai AFTER INSERT ON facts BEGIN
INSERT INTO facts_fts(rowid, content, tags)
VALUES (new.fact_id, new.content, new.tags);
END;
CREATE TRIGGER IF NOT EXISTS facts_ad AFTER DELETE ON facts BEGIN
INSERT INTO facts_fts(facts_fts, rowid, content, tags)
VALUES ('delete', old.fact_id, old.content, old.tags);
END;
CREATE TRIGGER IF NOT EXISTS facts_au AFTER UPDATE ON facts BEGIN
INSERT INTO facts_fts(facts_fts, rowid, content, tags)
VALUES ('delete', old.fact_id, old.content, old.tags);
INSERT INTO facts_fts(rowid, content, tags)
VALUES (new.fact_id, new.content, new.tags);
END;
CREATE TABLE IF NOT EXISTS memory_banks (
bank_id INTEGER PRIMARY KEY AUTOINCREMENT,
bank_name TEXT NOT NULL UNIQUE,
vector BLOB NOT NULL,
dim INTEGER NOT NULL,
fact_count INTEGER DEFAULT 0,
updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
);
"""
# Trust adjustment constants
_HELPFUL_DELTA = 0.05
_UNHELPFUL_DELTA = -0.10
_TRUST_MIN = 0.0
_TRUST_MAX = 1.0
# Entity extraction patterns
_RE_CAPITALIZED = re.compile(r'\b([A-Z][a-z]+(?:\s+[A-Z][a-z]+)+)\b')
_RE_DOUBLE_QUOTE = re.compile(r'"([^"]+)"')
_RE_SINGLE_QUOTE = re.compile(r"'([^']+)'")
_RE_AKA = re.compile(
r'(\w+(?:\s+\w+)*)\s+(?:aka|also known as)\s+(\w+(?:\s+\w+)*)',
re.IGNORECASE,
)
def _clamp_trust(value: float) -> float:
return max(_TRUST_MIN, min(_TRUST_MAX, value))
class MemoryStore:
"""SQLite-backed fact store with entity resolution and trust scoring."""
# --- Process-wide shared connection registry -------------------------
# SQLite permits only one writer at a time. Each MemoryStore instance used
# to open its own connection guarded by its own RLock, so the several
# providers that coexist in one process (the main agent plus every
# delegate_task subagent) raced as independent WAL writers. Combined with
# writes that were not rolled back on error, one connection could leave an
# open write transaction that pinned the write lock and made every other
# connection's write fail with "database is locked" for the full busy
# timeout. All instances for the same database now share ONE connection and
# ONE re-entrant lock, so access is fully serialized and cross-connection
# contention is impossible. The shared connection is refcounted, so closing
# one instance never tears the connection out from under a live sibling.
_shared: dict = {}
_shared_guard = threading.Lock()
def __init__(
self,
db_path: "str | Path | None" = None,
default_trust: float = 0.5,
hrr_dim: int = 1024,
) -> None:
if db_path is None:
from hermes_constants import get_hermes_home
db_path = str(get_hermes_home() / "memory_store.db")
self.db_path = Path(db_path).expanduser()
self.db_path.parent.mkdir(parents=True, exist_ok=True)
self.default_trust = _clamp_trust(default_trust)
self.hrr_dim = hrr_dim
self._hrr_available = hrr._HAS_NUMPY
# Acquire (or open) the process-wide shared connection for this DB.
self._key = str(self.db_path)
with MemoryStore._shared_guard:
entry = MemoryStore._shared.get(self._key)
if entry is None:
conn = sqlite3.connect(
self._key,
check_same_thread=False,
timeout=10.0,
# Autocommit: every statement is its own transaction, so a
# write that raises mid-method can never leave a dangling
# transaction (and its write lock) open. The explicit
# commit() calls below become harmless no-ops.
isolation_level=None,
)
conn.row_factory = sqlite3.Row
entry = {"conn": conn, "lock": threading.RLock(), "refs": 0, "ready": False}
MemoryStore._shared[self._key] = entry
entry["refs"] += 1
self._entry = entry
self._conn = entry["conn"]
self._lock = entry["lock"]
# Initialise the schema once per shared connection.
with self._lock:
if not self._entry["ready"]:
self._init_db()
self._entry["ready"] = True
# ------------------------------------------------------------------
# Initialisation
# ------------------------------------------------------------------
def _init_db(self) -> None:
"""Create tables, indexes, and triggers if they do not exist. Enable WAL mode."""
# Use the shared WAL-fallback helper so memory_store.db degrades
# gracefully on NFS/SMB/FUSE-mounted HERMES_HOME (same issue as
# state.db / kanban.db — see hermes_state._WAL_INCOMPAT_MARKERS).
from hermes_state import apply_wal_with_fallback
apply_wal_with_fallback(self._conn, db_label="memory_store.db (holographic)")
self._conn.executescript(_SCHEMA)
# Migrate: add hrr_vector column if missing (safe for existing databases)
columns = {row[1] for row in self._conn.execute("PRAGMA table_info(facts)").fetchall()}
if "hrr_vector" not in columns:
self._conn.execute("ALTER TABLE facts ADD COLUMN hrr_vector BLOB")
self._conn.commit()
# ------------------------------------------------------------------
# Public API
# ------------------------------------------------------------------
def add_fact(
self,
content: str,
category: str = "general",
tags: str = "",
) -> int:
"""Insert a fact and return its fact_id.
Deduplicates by content (UNIQUE constraint). On duplicate, returns
the existing fact_id without modifying the row. Extracts entities from
the content and links them to the fact.
"""
with self._lock:
content = content.strip()
if not content:
raise ValueError("content must not be empty")
try:
cur = self._conn.execute(
"""
INSERT INTO facts (content, category, tags, trust_score)
VALUES (?, ?, ?, ?)
""",
(content, category, tags, self.default_trust),
)
self._conn.commit()
fact_id: int = cur.lastrowid # type: ignore[assignment]
except sqlite3.IntegrityError:
# Duplicate content — return existing id
row = self._conn.execute(
"SELECT fact_id FROM facts WHERE content = ?", (content,)
).fetchone()
return int(row["fact_id"])
# Entity extraction and linking
for name in self._extract_entities(content):
entity_id = self._resolve_entity(name)
self._link_fact_entity(fact_id, entity_id)
# Compute HRR vector after entity linking
self._compute_hrr_vector(fact_id, content)
self._rebuild_bank(category)
return fact_id
def search_facts(
self,
query: str,
category: str | None = None,
min_trust: float = 0.3,
limit: int = 10,
) -> list[dict]:
"""Full-text search over facts using FTS5.
Returns a list of fact dicts ordered by FTS5 rank, then trust_score
descending. Also increments retrieval_count for matched facts.
"""
with self._lock:
query = query.strip()
if not query:
return []
# FTS5 AND-joins tokens by default, which zeroes out recall on
# natural-language queries. Reuse the retriever's sanitizer
# (stopword drop + OR-join content tokens). Imported lazily to
# avoid a store->retrieval import cycle.
from plugins.memory.holographic.retrieval import FactRetriever
match_query = FactRetriever._sanitize_fts_query(query)
params: list = [match_query, min_trust]
category_clause = ""
if category is not None:
category_clause = "AND f.category = ?"
params.append(category)
params.append(limit)
sql = f"""
SELECT f.fact_id, f.content, f.category, f.tags,
f.trust_score, f.retrieval_count, f.helpful_count,
f.created_at, f.updated_at
FROM facts f
JOIN facts_fts fts ON fts.rowid = f.fact_id
WHERE facts_fts MATCH ?
AND f.trust_score >= ?
{category_clause}
ORDER BY fts.rank, f.trust_score DESC
LIMIT ?
"""
rows = self._conn.execute(sql, params).fetchall()
results = [self._row_to_dict(r) for r in rows]
if results:
ids = [r["fact_id"] for r in results]
placeholders = ",".join("?" * len(ids))
self._conn.execute(
f"UPDATE facts SET retrieval_count = retrieval_count + 1 WHERE fact_id IN ({placeholders})",
ids,
)
self._conn.commit()
return results
def update_fact(
self,
fact_id: int,
content: str | None = None,
trust_delta: float | None = None,
tags: str | None = None,
category: str | None = None,
) -> bool:
"""Partially update a fact. Trust is clamped to [0, 1].
Returns True if the row existed, False otherwise.
"""
with self._lock:
row = self._conn.execute(
"SELECT fact_id, trust_score FROM facts WHERE fact_id = ?", (fact_id,)
).fetchone()
if row is None:
return False
assignments: list[str] = ["updated_at = CURRENT_TIMESTAMP"]
params: list = []
if content is not None:
assignments.append("content = ?")
params.append(content.strip())
if tags is not None:
assignments.append("tags = ?")
params.append(tags)
if category is not None:
assignments.append("category = ?")
params.append(category)
if trust_delta is not None:
new_trust = _clamp_trust(row["trust_score"] + trust_delta)
assignments.append("trust_score = ?")
params.append(new_trust)
params.append(fact_id)
self._conn.execute(
f"UPDATE facts SET {', '.join(assignments)} WHERE fact_id = ?",
params,
)
self._conn.commit()
# If content changed, re-extract entities
if content is not None:
self._conn.execute(
"DELETE FROM fact_entities WHERE fact_id = ?", (fact_id,)
)
for name in self._extract_entities(content):
entity_id = self._resolve_entity(name)
self._link_fact_entity(fact_id, entity_id)
self._conn.commit()
# Recompute HRR vector if content changed
if content is not None:
self._compute_hrr_vector(fact_id, content)
# Rebuild bank for relevant category
cat = category or self._conn.execute(
"SELECT category FROM facts WHERE fact_id = ?", (fact_id,)
).fetchone()["category"]
self._rebuild_bank(cat)
return True
def remove_fact(self, fact_id: int) -> bool:
"""Delete a fact and its entity links. Returns True if the row existed."""
with self._lock:
row = self._conn.execute(
"SELECT fact_id, category FROM facts WHERE fact_id = ?", (fact_id,)
).fetchone()
if row is None:
return False
self._conn.execute(
"DELETE FROM fact_entities WHERE fact_id = ?", (fact_id,)
)
self._conn.execute("DELETE FROM facts WHERE fact_id = ?", (fact_id,))
self._conn.commit()
self._rebuild_bank(row["category"])
return True
def list_facts(
self,
category: str | None = None,
min_trust: float = 0.0,
limit: int = 50,
) -> list[dict]:
"""Browse facts ordered by trust_score descending.
Optionally filter by category and minimum trust score.
"""
with self._lock:
params: list = [min_trust]
category_clause = ""
if category is not None:
category_clause = "AND category = ?"
params.append(category)
params.append(limit)
sql = f"""
SELECT fact_id, content, category, tags, trust_score,
retrieval_count, helpful_count, created_at, updated_at
FROM facts
WHERE trust_score >= ?
{category_clause}
ORDER BY trust_score DESC
LIMIT ?
"""
rows = self._conn.execute(sql, params).fetchall()
return [self._row_to_dict(r) for r in rows]
def record_feedback(self, fact_id: int, helpful: bool) -> dict:
"""Record user feedback and adjust trust asymmetrically.
helpful=True -> trust += 0.05, helpful_count += 1
helpful=False -> trust -= 0.10
Returns a dict with fact_id, old_trust, new_trust, helpful_count.
Raises KeyError if fact_id does not exist.
"""
with self._lock:
row = self._conn.execute(
"SELECT fact_id, trust_score, helpful_count FROM facts WHERE fact_id = ?",
(fact_id,),
).fetchone()
if row is None:
raise KeyError(f"fact_id {fact_id} not found")
old_trust: float = row["trust_score"]
delta = _HELPFUL_DELTA if helpful else _UNHELPFUL_DELTA
new_trust = _clamp_trust(old_trust + delta)
helpful_increment = 1 if helpful else 0
self._conn.execute(
"""
UPDATE facts
SET trust_score = ?,
helpful_count = helpful_count + ?,
updated_at = CURRENT_TIMESTAMP
WHERE fact_id = ?
""",
(new_trust, helpful_increment, fact_id),
)
self._conn.commit()
return {
"fact_id": fact_id,
"old_trust": old_trust,
"new_trust": new_trust,
"helpful_count": row["helpful_count"] + helpful_increment,
}
# ------------------------------------------------------------------
# Entity helpers
# ------------------------------------------------------------------
def _extract_entities(self, text: str) -> list[str]:
"""Extract entity candidates from text using simple regex rules.
Rules applied (in order):
1. Capitalized multi-word phrases e.g. "John Doe"
2. Double-quoted terms e.g. "Python"
3. Single-quoted terms e.g. 'pytest'
4. AKA patterns e.g. "Guido aka BDFL" -> two entities
Returns a deduplicated list preserving first-seen order.
"""
seen: set[str] = set()
candidates: list[str] = []
def _add(name: str) -> None:
stripped = name.strip()
if stripped and stripped.lower() not in seen:
seen.add(stripped.lower())
candidates.append(stripped)
for m in _RE_CAPITALIZED.finditer(text):
_add(m.group(1))
for m in _RE_DOUBLE_QUOTE.finditer(text):
_add(m.group(1))
for m in _RE_SINGLE_QUOTE.finditer(text):
_add(m.group(1))
for m in _RE_AKA.finditer(text):
_add(m.group(1))
_add(m.group(2))
return candidates
def _resolve_entity(self, name: str) -> int:
"""Find an existing entity by name or alias (case-insensitive) or create one.
Returns the entity_id.
"""
# Exact name match
row = self._conn.execute(
"SELECT entity_id FROM entities WHERE name LIKE ?", (name,)
).fetchone()
if row is not None:
return int(row["entity_id"])
# Search aliases — aliases stored as comma-separated; use LIKE with % boundaries
alias_row = self._conn.execute(
"""
SELECT entity_id FROM entities
WHERE ',' || aliases || ',' LIKE '%,' || ? || ',%'
""",
(name,),
).fetchone()
if alias_row is not None:
return int(alias_row["entity_id"])
# Create new entity
cur = self._conn.execute(
"INSERT INTO entities (name) VALUES (?)", (name,)
)
self._conn.commit()
return int(cur.lastrowid) # type: ignore[return-value]
def _link_fact_entity(self, fact_id: int, entity_id: int) -> None:
"""Insert into fact_entities, silently ignore if the link already exists."""
self._conn.execute(
"""
INSERT OR IGNORE INTO fact_entities (fact_id, entity_id)
VALUES (?, ?)
""",
(fact_id, entity_id),
)
self._conn.commit()
def _compute_hrr_vector(self, fact_id: int, content: str) -> None:
"""Compute and store HRR vector for a fact. No-op if numpy unavailable."""
with self._lock:
if not self._hrr_available:
return
# Get entities linked to this fact
rows = self._conn.execute(
"""
SELECT e.name FROM entities e
JOIN fact_entities fe ON fe.entity_id = e.entity_id
WHERE fe.fact_id = ?
""",
(fact_id,),
).fetchall()
entities = [row["name"] for row in rows]
vector = hrr.encode_fact(content, entities, self.hrr_dim)
self._conn.execute(
"UPDATE facts SET hrr_vector = ? WHERE fact_id = ?",
(hrr.phases_to_bytes(vector), fact_id),
)
self._conn.commit()
def _rebuild_bank(self, category: str) -> None:
"""Full rebuild of a category's memory bank from all its fact vectors."""
with self._lock:
if not self._hrr_available:
return
bank_name = f"cat:{category}"
rows = self._conn.execute(
"SELECT hrr_vector FROM facts WHERE category = ? AND hrr_vector IS NOT NULL",
(category,),
).fetchall()
if not rows:
self._conn.execute("DELETE FROM memory_banks WHERE bank_name = ?", (bank_name,))
self._conn.commit()
return
vectors = [hrr.bytes_to_phases(row["hrr_vector"]) for row in rows]
bank_vector = hrr.bundle(*vectors)
fact_count = len(vectors)
# Check SNR
hrr.snr_estimate(self.hrr_dim, fact_count)
self._conn.execute(
"""
INSERT INTO memory_banks (bank_name, vector, dim, fact_count, updated_at)
VALUES (?, ?, ?, ?, CURRENT_TIMESTAMP)
ON CONFLICT(bank_name) DO UPDATE SET
vector = excluded.vector,
dim = excluded.dim,
fact_count = excluded.fact_count,
updated_at = excluded.updated_at
""",
(bank_name, hrr.phases_to_bytes(bank_vector), self.hrr_dim, fact_count),
)
self._conn.commit()
def rebuild_all_vectors(self, dim: int | None = None) -> int:
"""Recompute all HRR vectors + banks from text. For recovery/migration.
Returns the number of facts processed.
"""
with self._lock:
if not self._hrr_available:
return 0
if dim is not None:
self.hrr_dim = dim
rows = self._conn.execute(
"SELECT fact_id, content, category FROM facts"
).fetchall()
categories: set[str] = set()
for row in rows:
self._compute_hrr_vector(row["fact_id"], row["content"])
categories.add(row["category"])
for category in categories:
self._rebuild_bank(category)
return len(rows)
# ------------------------------------------------------------------
# Utilities
# ------------------------------------------------------------------
def _row_to_dict(self, row: sqlite3.Row) -> dict:
"""Convert a sqlite3.Row to a plain dict."""
return dict(row)
def close(self) -> None:
"""Release this instance's reference to the shared connection.
The underlying connection is closed only when the last MemoryStore
referencing the same database is closed, so closing one instance can
never break sibling instances that still hold it. Idempotent.
"""
if getattr(self, "_entry", None) is None:
return
with MemoryStore._shared_guard:
entry = self._entry
if entry is None:
return
entry["refs"] -= 1
if entry["refs"] <= 0:
try:
entry["conn"].close()
finally:
MemoryStore._shared.pop(self._key, None)
self._entry = None
def __enter__(self) -> "MemoryStore":
return self
def __exit__(self, *_: object) -> None:
self.close()