Use m̶u̶l̶t̶i̶p̶r̶o̶c̶e̶s̶s̶i̶n̶g̶ asyncio locks instead of db locks (#256)

* use mp locks instead of db locks

* replace mp.Lock with asyncio.Lock

* make format

* push

* remove db connection (and lock) and delete asyncio locks

cashu/mint/ledger.py

@@ -1,3 +1,4 @@
+import asyncio
 import math
 from typing import Dict, List, Literal, Optional, Set, Union
 
@@ -15,7 +16,7 @@ from ..core.base import (
 from ..core.crypto import b_dhke
 from ..core.crypto.keys import derive_pubkey, random_hash
 from ..core.crypto.secp import PublicKey
-from ..core.db import Connection, Database, lock_table
+from ..core.db import Connection, Database
 from ..core.helpers import fee_reserve, sum_proofs
 from ..core.script import verify_script
 from ..core.settings import settings
@@ -25,6 +26,11 @@ from ..mint.crud import LedgerCrud
 
 
 class Ledger:
+    locks: Dict[str, asyncio.Lock] = {}  # holds multiprocessing locks
+    proofs_pending_lock: asyncio.Lock = (
+        asyncio.Lock()
+    )  # holds locks for proofs_pending database
+
     def __init__(
         self,
         db: Database,
@@ -433,6 +439,7 @@ class Ledger:
             Exception: At least one proof already in pending table.
         """
         # first we check whether these proofs are pending aready
+        async with self.proofs_pending_lock:
             await self._validate_proofs_pending(proofs, conn)
             for p in proofs:
                 try:
@@ -456,6 +463,7 @@ class Ledger:
         """
         # we try: except: this block in order to avoid that any errors here
         # could block the _invalidate_proofs() call that happens afterwards.
+        async with self.proofs_pending_lock:
             try:
                 for p in proofs:
                     logger.trace(
@@ -469,7 +477,9 @@ class Ledger:
                 print(e)
                 pass
 
-    async def _validate_proofs_pending(self, proofs: List[Proof], conn):
+    async def _validate_proofs_pending(
+        self, proofs: List[Proof], conn: Optional[Connection] = None
+    ):
         """Checks if any of the provided proofs is in the pending proofs table.
 
         Args:
@@ -633,8 +643,9 @@ class Ledger:
             keyset (Optional[MintKeyset], optional): Keyset to use. If not provided, uses active keyset. Defaults to None.
 
         Raises:
+            Exception: Lightning invvoice is not paid.
             Exception: Lightning is turned on but no payment hash is provided.
-            e: Something went wrong with the invoice check.
+            Exception: Something went wrong with the invoice check.
             Exception: Amount too large.
 
         Returns:
@@ -643,20 +654,17 @@ class Ledger:
         logger.trace("called mint")
         amounts = [b.amount for b in B_s]
         amount = sum(amounts)
-        async with self.db.connect() as conn:
+
-            logger.trace("attempting lock table invoice")
-            await conn.execute(lock_table(self.db, "invoices"))
-            logger.trace("locked table invoice")
-            # check if lightning invoice was paid
         if settings.lightning:
             if not hash:
                 raise Exception("no hash provided.")
-                try:
+            self.locks[hash] = (
-                    logger.trace("checking lightning invoice")
+                self.locks.get(hash) or asyncio.Lock()
-                    paid = await self._check_lightning_invoice(amount, hash, conn)
+            )  # create a new lock if it doesn't exist
-                    logger.trace(f"invoice paid: {paid}")
+            async with self.locks[hash]:
-                except Exception as e:
+                # will raise an exception if the invoice is not paid or tokens are already issued
-                    raise e
+                await self._check_lightning_invoice(amount, hash)
+            del self.locks[hash]
 
         for amount in amounts:
             if amount not in [2**i for i in range(settings.max_order)]:
@@ -687,15 +695,7 @@ class Ledger:
 
         logger.trace("melt called")
 
-        async with self.db.connect() as conn:
+        await self._set_proofs_pending(proofs)
-            logger.trace("attempting lock table proofs_pending")
-            await conn.execute(lock_table(self.db, "proofs_pending"))
-            logger.trace("locked table proofs_pending")
-            # validate and set proofs as pending
-            logger.trace("setting proofs pending")
-            await self._set_proofs_pending(proofs, conn)
-            logger.trace(f"set proofs as pending")
-        logger.trace("unlocked table proofs_pending")
 
         try:
             await self._verify_proofs(proofs)
@@ -751,14 +751,7 @@ class Ledger:
             raise e
         finally:
             # delete proofs from pending list
-            async with self.db.connect() as conn:
+            await self._unset_proofs_pending(proofs)
-                logger.trace("attempting lock table proofs_pending")
-                await conn.execute(lock_table(self.db, "proofs_pending"))
-                logger.trace("locked table proofs_pending")
-                logger.trace("unsetting proofs as pending")
-                await self._unset_proofs_pending(proofs, conn)
-                logger.trace(f"unset proofs as pending")
-            logger.trace("unlocked table proofs_pending")
 
         return status, preimage, return_promises
 
@@ -829,15 +822,9 @@ class Ledger:
             Tuple[List[BlindSignature],List[BlindSignature]]: Promises on both sides of the split.
         """
         logger.trace(f"split called")
-        # set proofs as pending
+
-        async with self.db.connect() as conn:
+        await self._set_proofs_pending(proofs)
-            logger.trace("attempting lock table proofs_pending")
+
-            await conn.execute(lock_table(self.db, "proofs_pending"))
-            logger.trace("locked table proofs_pending")
-            # validate and set proofs as pending
-            logger.trace("setting proofs pending")
-            await self._set_proofs_pending(proofs, conn)
-            logger.trace(f"set proofs as pending")
         total = sum_proofs(proofs)
 
         try:
@@ -863,13 +850,7 @@ class Ledger:
             raise e
         finally:
             # delete proofs from pending list
-            async with self.db.connect() as conn:
+            await self._unset_proofs_pending(proofs)
-                logger.trace("attempting lock table proofs_pending")
-                await conn.execute(lock_table(self.db, "proofs_pending"))
-                logger.trace("locked table proofs_pending")
-                logger.trace("unsetting proofs as pending")
-                await self._unset_proofs_pending(proofs, conn)
-                logger.trace(f"unset proofs as pending")
 
         # Mark proofs as used and prepare new promises
         logger.trace(f"invalidating proofs")

cashu/wallet/cli/cli.py

@@ -453,6 +453,7 @@ async def pending(ctx: Context, legacy, number: int, offset: int):
             tokenObj = deserialize_token_from_string(token)
             mint = [t.mint for t in tokenObj.token][0]
             # token_hidden_secret = await wallet.serialize_proofs(grouped_proofs)
+            assert grouped_proofs[0].time_reserved
             reserved_date = datetime.utcfromtimestamp(
                 int(grouped_proofs[0].time_reserved)
             ).strftime("%Y-%m-%d %H:%M:%S")