Better transaction control

Use context manager to handle commit/rollback.
Use `sqlite3.Connection.in_transaction` property instead of rolling our own.
Read-only methods don't need the transaction wrapper and we never read-update-write.

sbysrc/sby_status.py

@@ -17,61 +17,52 @@ Fn = TypeVar("Fn", bound=Callable[..., Any])
 def transaction(method: Fn) -> Fn:
     @wraps(method)
     def wrapper(self: SbyStatusDb, *args: Any, **kwargs: Any) -> Any:
-        if self._transaction_active:
+        if self.con.in_transaction:
             return method(self, *args, **kwargs)
 
         try:
-            self.log_debug(f"begin {method.__name__!r} transaction")
-            self.db.execute("begin")
-            self._transaction_active = True
-            result = method(self, *args, **kwargs)
-            self.db.execute("commit")
-            self._transaction_active = False
-            self.log_debug(f"comitted {method.__name__!r} transaction")
-            return result
-        except sqlite3.OperationalError as err:
-            self.log_debug(f"failed {method.__name__!r} transaction {err}")
-            self.db.rollback()
-            self._transaction_active = False
+            with self.con:
+                self.log_debug(f"begin {method.__name__!r} transaction")
+                self.db.execute("begin")
+                result = method(self, *args, **kwargs)
         except Exception as err:
             self.log_debug(f"failed {method.__name__!r} transaction {err}")
-            self.db.rollback()
-            self._transaction_active = False
-            raise
+            if not isinstance(err, sqlite3.OperationalError):
+                raise
+        else:
+            self.log_debug(f"comitted {method.__name__!r} transaction")
+            return result
+
         try:
-            self.log_debug(
-                f"retrying {method.__name__!r} transaction once in immediate mode"
-            )
-            self.db.execute("begin immediate")
-            self._transaction_active = True
-            result = method(self, *args, **kwargs)
-            self.db.execute("commit")
-            self._transaction_active = False
-            self.log_debug(f"comitted {method.__name__!r} transaction")
-            return result
+            with self.con:
+                self.log_debug(
+                    f"retrying {method.__name__!r} transaction once in immediate mode"
+                )
+                self.db.execute("begin immediate")
+                result = method(self, *args, **kwargs)
         except Exception as err:
             self.log_debug(f"failed {method.__name__!r} transaction {err}")
-            self.db.rollback()
-            self._transaction_active = False
             raise
+        else:
+            self.log_debug(f"comitted {method.__name__!r} transaction")
+            return result
 
     return wrapper  # type: ignore
 
 
 class SbyStatusDb:
     def __init__(self, path: Path, task, timeout: float = 5.0):
-        self.debug = False
+        self.debug = True
         self.task = task
-        self._transaction_active = False
 
         setup = not os.path.exists(path)
 
-        self.db = sqlite3.connect(path, isolation_level=None, timeout=timeout)
+        self.con = sqlite3.connect(path, isolation_level=None, timeout=timeout)
+        self.db = self.con.cursor()
         self.db.row_factory = sqlite3.Row
-        cur = self.db.cursor()
-        cur.execute("PRAGMA journal_mode=WAL")
-        cur.execute("PRAGMA synchronous=0")
-        self.db.commit()
+        with self.con:
+            self.db.execute("PRAGMA journal_mode=WAL")
+            self.db.execute("PRAGMA synchronous=0")
 
         if setup:
             self._setup()
@@ -245,7 +236,6 @@ class SbyStatusDb:
             ),
         )
 
-    @transaction
     def all_tasks(self):
         rows = self.db.execute(
             """
@@ -255,7 +245,6 @@ class SbyStatusDb:
 
         return {row["id"]: dict(row) for row in rows}
 
-    @transaction
     def all_task_properties(self):
         rows = self.db.execute(
             """
@@ -271,7 +260,6 @@ class SbyStatusDb:
 
         return {row["id"]: get_result(row) for row in rows}
 
-    @transaction
     def all_task_property_statuses(self):
         rows = self.db.execute(
             """
@@ -287,7 +275,6 @@ class SbyStatusDb:
 
         return {row["id"]: get_result(row) for row in rows}
 
-    @transaction
     def all_status_data(self):
         return (
             self.all_tasks(),