perf: keep planning reads available during writes (Closes #699)

src/later_store.py

@@ -22,10 +22,14 @@ class LaterStore:
         self.operation_limit = operation_limit
         self.operation_retention_seconds = operation_retention_seconds
         self.clock = clock
+        self._initialize()
 
-    def _connect(self) -> sqlite3.Connection:
+    def _initialize(self) -> None:
         self.path.parent.mkdir(parents=True, exist_ok=True)
         connection = sqlite3.connect(self.path, timeout=self.timeout)
+        if connection.execute("PRAGMA user_version").fetchone()[0] >= 1:
+            connection.close()
+            return
         connection.execute("PRAGMA journal_mode=WAL")
         connection.execute(
             """
@@ -63,8 +67,12 @@ class LaterStore:
             "UPDATE later_operations SET created_at = ? WHERE created_at IS NULL",
             (self.clock(),),
         )
+        connection.execute("PRAGMA user_version = 1")
         connection.commit()
-        return connection
+        connection.close()
+
+    def _connect(self) -> sqlite3.Connection:
+        return sqlite3.connect(self.path, timeout=self.timeout)
 
     def _record_operation(self, connection: sqlite3.Connection, login: str, operation_id: str) -> None:
         now = self.clock()

src/today_store.py

@@ -30,10 +30,14 @@ class TodayStore:
         self.operation_retention_seconds = operation_retention_seconds
         self.recap_limit = recap_limit
         self.clock = clock
+        self._initialize()
 
-    def _connect(self) -> sqlite3.Connection:
+    def _initialize(self) -> None:
         self.path.parent.mkdir(parents=True, exist_ok=True)
         connection = sqlite3.connect(self.path, timeout=self.timeout)
+        if connection.execute("PRAGMA user_version").fetchone()[0] >= 1:
+            connection.close()
+            return
         connection.execute("PRAGMA journal_mode=WAL")
         connection.execute(
             """
@@ -101,8 +105,12 @@ class TodayStore:
             )
             """
         )
+        connection.execute("PRAGMA user_version = 1")
         connection.commit()
-        return connection
+        connection.close()
+
+    def _connect(self) -> sqlite3.Connection:
+        return sqlite3.connect(self.path, timeout=self.timeout)
 
     def _record_operation(self, connection: sqlite3.Connection, login: str, operation_id: str) -> None:
         now = self.clock()