Add last_tx option in query module

Signed-off-by: David Dashyan <mail@davie.li>

bigchaindb/backend/localmongodb/query.py

@@ -120,29 +120,19 @@ def store_block(conn, block):
 
 
 @register_query(LocalMongoDBConnection)
-def get_txids_filtered(conn, asset_id, operation=None):
-    match_create = {
-        'operation': 'CREATE',
-        'id': asset_id
-    }
-    match_transfer = {
-        'operation': 'TRANSFER',
-        'asset.id': asset_id
-    }
+def get_txids_filtered(conn, asset_id, operation=None, last_tx=None):
 
-    if operation == Transaction.CREATE:
-        match = match_create
-    elif operation == Transaction.TRANSFER:
-        match = match_transfer
-    else:
-        match = {'$or': [match_create, match_transfer]}
+    match = {
+        Transaction.CREATE: {'operation': 'CREATE', 'id': asset_id},
+        Transaction.TRANSFER: {'operation': 'TRANSFER', 'asset.id': asset_id},
+        None: {'$or': [{'asset.id': asset_id}, {'id': asset_id}]},
+    }[operation]
+
+    cursor = conn.run(conn.collection('transactions').find(match))
+
+    if last_tx:
+        cursor = cursor.sort({'$natural': DESCENDING}).limit(1)
 
-    pipeline = [
-        {'$match': match}
-    ]
-    cursor = conn.run(
-        conn.collection('transactions')
-        .aggregate(pipeline))
     return (elem['id'] for elem in cursor)
 
 

bigchaindb/lib.py

@@ -265,7 +265,7 @@ class BigchainDB(object):
         """Get a list of transactions filtered on some criteria
         """
         txids = backend.query.get_txids_filtered(self.connection, asset_id,
-                                                 operation)
+                                                 operation, last_tx)
         for txid in txids:
             yield self.get_transaction(txid)
 

bigchaindb/web/views/transactions.py

@@ -53,17 +53,8 @@ class TransactionListApi(Resource):
         args = parser.parse_args()
         with current_app.config['bigchain_pool']() as bigchain:
             txs = bigchain.get_transactions_filtered(**args)
-            if args['last_tx'] and args['last_tx'] is True:
-                lastTX = None
 
-                for x in txs:
-                    lastTX = x
-                if lastTX:
-                    return [lastTX.to_dict()]
-                else:
-                    return []
-            else:
-                return [tx.to_dict() for tx in txs]
+        return [tx.to_dict() for tx in txs]
 
     def post(self):
         """API endpoint to push transactions to the Federation.

tests/web/test_transactions.py

@@ -391,6 +391,12 @@ def test_transactions_get_list_good(client):
             ['last_tx', None],
             ['operation', 'CREATE']
         ]
+        url = TX_ENDPOINT + '?asset_id=' + asset_id + '&last_tx=true'
+        assert client.get(url).json == [
+            ['asset_id', asset_id],
+            ['last_tx', True],
+            ['operation', None]
+        ]
 
 
 def test_transactions_get_list_bad(client):