fix sqlite database locked issues by using an async lock on the database and requiring explicit transaction control (or each command will be its own transaction).

lnbits/extensions/bleskomat/lnurl_api.py

@@ -1,6 +1,6 @@
 import json
 import math
-from quart import g, jsonify, request
+from quart import jsonify, request
 from http import HTTPStatus
 import traceback
 
@@ -29,7 +29,6 @@ from .helpers import (
 # Handles signed URL from Bleskomat ATMs and "action" callback of auto-generated LNURLs.
 @bleskomat_ext.route("/u", methods=["GET"])
 async def api_bleskomat_lnurl():
-
     try:
         query = request.args.to_dict()
 
@@ -125,7 +124,7 @@ async def api_bleskomat_lnurl():
 
     except LnurlHttpError as e:
         return jsonify({"status": "ERROR", "reason": str(e)}), e.http_status
-    except Exception as e:
+    except Exception:
         traceback.print_exc()
         return (
             jsonify({"status": "ERROR", "reason": "Unexpected error"}),

lnbits/extensions/bleskomat/models.py

@@ -61,7 +61,7 @@ class BleskomatLnurl(NamedTuple):
                 raise LnurlValidationError("Multiple payment requests not supported")
             try:
                 invoice = bolt11.decode(pr)
-            except ValueError as e:
+            except ValueError:
                 raise LnurlValidationError(
                     'Invalid parameter ("pr"): Lightning payment request expected'
                 )
@@ -79,14 +79,11 @@ class BleskomatLnurl(NamedTuple):
     async def execute_action(self, query: Dict[str, str]):
         self.validate_action(query)
         used = False
-        if self.initial_uses > 0:
-            await db.commit()
-            await db.begin()
-            used = await self.use()
-            if not used:
-                await db.rollback()
-                raise LnurlValidationError("Maximum number of uses already reached")
-        try:
+        async with db.connect() as conn:
+            if self.initial_uses > 0:
+                used = await self.use(conn)
+                if not used:
+                    raise LnurlValidationError("Maximum number of uses already reached")
             tag = self.tag
             if tag == "withdrawRequest":
                 payment_hash = await pay_invoice(
@@ -95,16 +92,10 @@ class BleskomatLnurl(NamedTuple):
                 )
                 if not payment_hash:
                     raise LnurlValidationError("Failed to pay invoice")
-        except Exception as e:
-            if used:
-                await db.rollback()
-            raise e
-        if used:
-            await db.commit()
 
-    async def use(self) -> bool:
+    async def use(self, conn) -> bool:
         now = int(time.time())
-        result = await db.execute(
+        result = await conn.execute(
             """
             UPDATE bleskomat_lnurls
             SET remaining_uses = remaining_uses - 1, updated_time = ?

lnbits/extensions/bleskomat/views_api.py

@@ -70,11 +70,10 @@ async def api_bleskomat_retrieve(bleskomat_id):
     }
 )
 async def api_bleskomat_create_or_update(bleskomat_id=None):
-
     try:
         fiat_currency = g.data["fiat_currency"]
         exchange_rate_provider = g.data["exchange_rate_provider"]
-        rate = await fetch_fiat_exchange_rate(
+        await fetch_fiat_exchange_rate(
             currency=fiat_currency, provider=exchange_rate_provider
         )
     except Exception as e: