configure sqlite w/ best settings (#51)

bmds_ui/analysis/apps.py

@@ -3,6 +3,3 @@
 
 class Config(AppConfig):
     name = "bmds_ui.analysis"
-
-    def ready(self):
-        from .signals import init_command  # noqa: F401

bmds_ui/desktop/sqlite3/base.py

@@ -0,0 +1,31 @@
+from sqlite3 import dbapi2 as Database
+
+from django.db.backends.sqlite3 import base
+from django.db.backends.sqlite3._functions import register as register_functions
+from django.utils.asyncio import async_unsafe
+
+
+class DatabaseWrapper(base.DatabaseWrapper):
+    # TODO - remove w/ django 5.1 release
+    # adapted from https://blog.pecar.me/sqlite-django-config
+    # https://gcollazo.com/optimal-sqlite-settings-for-django/
+    def _start_transaction_under_autocommit(self):
+        # Acquire a write lock immediately for transactions
+        self.cursor().execute("BEGIN IMMEDIATE")
+
+    @async_unsafe
+    def get_new_connection(self, conn_params):
+        conn = Database.connect(**conn_params)
+        register_functions(conn)
+
+        conn.execute("PRAGMA foreign_keys=ON")
+        conn.execute("PRAGMA legacy_alter_table = OFF")
+        conn.execute("PRAGMA journal_mode = WAL")
+        conn.execute("PRAGMA synchronous = NORMAL")
+        conn.execute("PRAGMA busy_timeout = 5000")
+        conn.execute("PRAGMA temp_store = MEMORY")
+        conn.execute("PRAGMA mmap_size = 134217728")
+        conn.execute("PRAGMA journal_size_limit = 67108864")
+        conn.execute("PRAGMA cache_size = 2000")
+
+        return conn

bmds_ui/main/settings/desktop.py

@@ -32,9 +32,8 @@
 
 DATABASES = {
     "default": {
-        "ENGINE": "django.db.backends.sqlite3",
-        "NAME": os.getenv("BMDS_DB", APP_HOME / "pybmds.sqlite3"),
-        "STARTUP_OPTIONS": {"init_command": "PRAGMA journal_mode=wal;"},
+        "ENGINE": "bmds_ui.desktop.sqlite3",
+        "NAME": os.getenv("BMDS_DB", APP_HOME / "bmds-desktop.db"),
     }
 }