tweaks

dbutil.py

@@ -0,0 +1,31 @@
+import sqlite3
+import time
+
+
+LOCKED_MSGS = ("database is locked", "database is busy")
+
+
+def connect(db_path, timeout=30):
+    """Open a SQLite connection hardened against cross-process contention.
+
+    Enables WAL mode and a busy timeout so that the multiple bot processes
+    sharing a database file wait for each other instead of raising
+    ``OperationalError: database is locked`` immediately.
+    """
+    conn = sqlite3.connect(db_path, timeout=timeout)
+    conn.execute("PRAGMA busy_timeout=%d" % (timeout * 1000))
+    conn.execute("PRAGMA journal_mode=WAL")
+    return conn
+
+
+def commit(conn, retries=5, backoff=0.2):
+    """Commit, retrying briefly when the database is locked by another writer."""
+    for attempt in range(retries):
+        try:
+            conn.commit()
+            return
+        except sqlite3.OperationalError as e:
+            if str(e).lower() in LOCKED_MSGS and attempt < retries - 1:
+                time.sleep(backoff * (attempt + 1))
+                continue
+            raise