mint start

mint/app.py

@@ -21,6 +21,8 @@ class MyFlaskApp(Flask):
     def __init__(self, *args, **kwargs):
         async def create_tasks_func():
             await asyncio.wait([m001_initial(ledger.db)])
+            await ledger.load_used_proofs()
+            print("Mint started.")
 
         loop = asyncio.get_event_loop()
         loop.run_until_complete(create_tasks_func())

mint/crud.py

@@ -29,6 +29,19 @@ async def store_promise(
     )
 
 
+async def get_proofs_used(
+    db: Database,
+    conn: Optional[Connection] = None,
+):
+
+    rows = await (conn or db).fetchall(
+        """
+        SELECT secret from proofs_used
+        """
+    )
+    return [row[0] for row in rows]
+
+
 async def invalidate_proof(
     proof: dict,
     db: Database,

mint/ledger.py

@@ -11,16 +11,19 @@ import core.b_dhke as b_dhke
 from core.db import Database
 from core.split import amount_split
 from core.settings import MAX_ORDER
-from mint.crud import store_promise, invalidate_proof
+from mint.crud import store_promise, invalidate_proof, get_proofs_used
 
 
 class Ledger:
     def __init__(self, secret_key: str, db: str):
         self.master_key = secret_key
-        self.proofs_used = set()  # no promise proofs have been used
+        self.proofs_used = set()
         self.keys = self._derive_keys(self.master_key)
         self.db = Database("mint", db)
 
+    async def load_used_proofs(self):
+        self.proofs_used = await get_proofs_used(db=self.db)
+
     @staticmethod
     def _derive_keys(master_key):
         """Deterministic derivation of keys for 2^n values."""