Class GraphStore

code_review_graph/graph.py:143–1335

SQLite-backed code knowledge graph.

class GraphStore:
    """SQLite-backed code knowledge graph."""

    def __init__(self, db_path: str | Path) -> None:
        self.db_path = Path(db_path)
        self.db_path.parent.mkdir(parents=True, exist_ok=True)
        self._conn = sqlite3.connect(
            str(self.db_path), timeout=30, check_same_thread=False,
            isolation_level=None,  # Disable implicit transactions (#135)
        )
        self._conn.row_factory = sqlite3.Row
        self._conn.execute("PRAGMA journal_mode=WAL")
        self._conn.execute("PRAGMA busy_timeout=5000")
        self._init_schema()
        # Ensure schema_version is set, then run pending migrations
        if get_schema_version(self._conn) < 1:
            # Fresh DB — metadata table just created by _init_schema
            self._conn.execute(
                "INSERT OR IGNORE INTO metadata (key, value) "
                "VALUES ('schema_version', '1')"
            )
            self._conn.commit()
        run_migrations(self._conn)
        self._nxg_cache: nx.DiGraph | None = None
        self._cache_lock = threading.Lock()

    def __enter__(self) -> "GraphStore":
        return self

    def __exit__(self, exc_type, exc_val, exc_tb) -> None:
        self.close()

    def _init_schema(self) -> None:
        self._conn.executescript(_SCHEMA_SQL)
        self._conn.commit()

    def _invalidate_cache(self) -> None:
        """Invalidate the cached NetworkX graph after write operations."""
        with self._cache_lock:
            self._nxg_cache = None

    def close(self) -> None:
        self._conn.close()

    # --- Write operations ---

    def upsert_node(self, node: NodeInfo, file_hash: str = "") -> int:
        """Insert or update a node. Returns the node ID."""
        now = time.time()
        qualified = self._make_qualified(node)
        extra = json.dumps(node.extra) if node.extra else "{}"

        self._conn.execute(
            """INSERT INTO nodes
               (kind, name, qualified_name, file_path, line_start, line_end,
                language, parent_name, params, return_type, modifiers, is_test,
                file_hash, extra, updated_at)
               VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)