initial: blog-app snapshot

extensions.py

@@ -0,0 +1,43 @@
+"""Flask-bound extensions: per-request DB connections and teardown.
+
+These helpers depend on Flask's `g` and must only be used inside an
+application/request context. Pure (Flask-free) helpers live in
+services/ and repositories/.
+"""
+
+import logging
+import sqlite3
+
+from flask import g
+
+import config
+
+logger = logging.getLogger(__name__)
+
+
+def get_db():
+    """Return a per-request SQLite connection (row access by name)."""
+    if "db" not in g:
+        conn = sqlite3.connect(config.DB_PATH)
+        conn.row_factory = sqlite3.Row
+        g.db = conn
+    return g.db
+
+
+def get_watchdog_db():
+    """Return a per-request SQLite connection to the watchdog db (read-only)."""
+    if "watchdog_db" not in g:
+        conn = sqlite3.connect(f"file:{config.WATCHDOG_DB}?mode=ro", uri=True)
+        conn.row_factory = sqlite3.Row
+        g.watchdog_db = conn
+    return g.watchdog_db
+
+
+def close_db(exception=None):
+    """Teardown handler registered via app.teardown_appcontext."""
+    conn = g.pop("db", None)
+    if conn is not None:
+        conn.close()
+    wconn = g.pop("watchdog_db", None)
+    if wconn is not None:
+        wconn.close()