Merge pull request #6821 from Tribler/fix/6802

Replace `get` by `select.limit` in BandwidthDatabase.get_latest_transaction

src/tribler/core/components/bandwidth_accounting/db/database.py

@@ -1,7 +1,7 @@
 from pathlib import Path
 from typing import List, Optional, Union
 
-from pony.orm import Database, count, db_session, select, sum
+from pony.orm import Database, count, db_session, desc, select
 
 from tribler.core.components.bandwidth_accounting.db import history, misc, transaction as db_transaction
 from tribler.core.components.bandwidth_accounting.db.transaction import BandwidthTransactionData
@@ -28,6 +28,7 @@ def __init__(self, db_path: Union[Path, type(MEMORY_DB)], my_pub_key: bytes,
         self.store_all_transactions = store_all_transactions
 
         self.database = Database()
+
         # This attribute is internally called by Pony on startup, though pylint cannot detect it
         # with the static analysis.
         # pylint: disable=unused-variable
@@ -77,7 +78,7 @@ def get_my_latest_transactions(self, limit: Optional[int] = None) -> List[Bandwi
         """
         results = []
         db_txs = select(tx for tx in self.BandwidthTransaction
-                        if tx.public_key_a == self.my_pub_key or tx.public_key_b == self.my_pub_key)\
+                        if tx.public_key_a == self.my_pub_key or tx.public_key_b == self.my_pub_key) \
             .limit(limit)
         for db_tx in db_txs:
             results.append(BandwidthTransactionData.from_db(db_tx))
@@ -91,8 +92,12 @@ def get_latest_transaction(self, public_key_a: bytes, public_key_b: bytes) -> Ba
         :param public_key_b: The public key of the party receiving the bandwidth.
         :return The latest transaction between the two specified parties, or None if no such transaction exists.
         """
-        db_obj = self.BandwidthTransaction.get(public_key_a=public_key_a, public_key_b=public_key_b)
-        return BandwidthTransactionData.from_db(db_obj) if db_obj else None
+        db_tx = select(tx for tx in self.BandwidthTransaction
+                       if public_key_a == tx.public_key_a and public_key_b == tx.public_key_b) \
+            .order_by(lambda tx: desc(tx.sequence_number)) \
+            .first()
+
+        return BandwidthTransactionData.from_db(db_tx) if db_tx else None
 
     @db_session
     def get_latest_transactions(self, public_key: bytes, limit: Optional[int] = 100) -> List[BandwidthTransactionData]:
@@ -103,7 +108,7 @@ def get_latest_transactions(self, public_key: bytes, limit: Optional[int] = 100)
         :return The latest transactions of the specified public key, or an empty list if no transactions exist.
         """
         db_txs = select(tx for tx in self.BandwidthTransaction
-                        if public_key in (tx.public_key_a, tx.public_key_b))\
+                        if public_key in (tx.public_key_a, tx.public_key_b)) \
             .limit(limit)
         return [BandwidthTransactionData.from_db(db_txn) for db_txn in db_txs]
 
@@ -114,8 +119,8 @@ def get_total_taken(self, public_key: bytes) -> int:
         :param public_key: The public key of the peer of which we want to determine the total taken.
         :return The total amount of bandwidth taken by the specified peer, in bytes.
         """
-        return sum(transaction.amount for transaction in self.BandwidthTransaction
-                   if transaction.public_key_a == public_key)
+        return select(transaction.amount for transaction in self.BandwidthTransaction
+                      if transaction.public_key_a == public_key).sum()
 
     @db_session
     def get_total_given(self, public_key: bytes) -> int:
@@ -124,8 +129,8 @@ def get_total_given(self, public_key: bytes) -> int:
         :param public_key: The public key of the peer of which we want to determine the total given.
         :return The total amount of bandwidth given by the specified peer, in bytes.
         """
-        return sum(transaction.amount for transaction in self.BandwidthTransaction
-                   if transaction.public_key_b == public_key)
+        return select(transaction.amount for transaction in self.BandwidthTransaction
+                      if transaction.public_key_b == public_key).sum()
 
     @db_session
     def get_balance(self, public_key: bytes) -> int: