Transcation API extension: last_tx parameter (#2667)

* added last_tx switch to the TX get query to only get the latest TX for a given asset.
* extended test case to contain last_tx field
* Add last_tx option in query module
* Fix natural descending cursor sort argument

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):
+def get_txids_filtered(conn, asset_id, operation=None, last_tx=None):
-    match_create = {
-        'operation': 'CREATE',
-        'id': asset_id
-    }
-    match_transfer = {
-        'operation': 'TRANSFER',
-        'asset.id': asset_id
-    }
 
-    if operation == Transaction.CREATE:
+    match = {
-        match = match_create
+        Transaction.CREATE: {'operation': 'CREATE', 'id': asset_id},
-    elif operation == Transaction.TRANSFER:
+        Transaction.TRANSFER: {'operation': 'TRANSFER', 'asset.id': asset_id},
-        match = match_transfer
+        None: {'$or': [{'asset.id': asset_id}, {'id': asset_id}]},
-    else:
+    }[operation]
-        match = {'$or': [match_create, match_transfer]}
+
+    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

@@ -261,11 +261,11 @@ class BigchainDB(object):
     def get_transactions(self, txn_ids):
         return backend.query.get_transactions(self.connection, txn_ids)
 
-    def get_transactions_filtered(self, asset_id, operation=None):
+    def get_transactions_filtered(self, asset_id, operation=None, last_tx=None):
         """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/version.py

@@ -2,8 +2,8 @@
 # SPDX-License-Identifier: (Apache-2.0 AND CC-BY-4.0)
 # Code is Apache-2.0 and docs are CC-BY-4.0
 
-__version__ = '2.0.0'
+__version__ = '2.1.0'
-__short_version__ = '2.0'
+__short_version__ = '2.1'
 
 # Supported Tendermint versions
 __tm_supported_versions__ = ["0.31.5"]

bigchaindb/web/views/transactions.py

@@ -48,8 +48,9 @@ class TransactionListApi(Resource):
         parser.add_argument('operation', type=parameters.valid_operation)
         parser.add_argument('asset_id', type=parameters.valid_txid,
                             required=True)
+        parser.add_argument('last_tx', type=parameters.valid_bool,
+                            required=False)
         args = parser.parse_args()
-
         with current_app.config['bigchain_pool']() as bigchain:
             txs = bigchain.get_transactions_filtered(**args)
 

docs/server/source/http-client-server-api.rst

@@ -91,7 +91,7 @@ Transactions
    Requests to the ``/api/v1/transactions`` endpoint
    without any query parameters will get a response status code ``400 Bad Request``.
 
-.. http:get:: /api/v1/transactions?asset_id={asset_id}&operation={CREATE|TRANSFER}
+.. http:get:: /api/v1/transactions?asset_id={asset_id}&operation={CREATE|TRANSFER}&last_tx={true|false}
 
    Get a list of transactions that use an asset with the ID ``asset_id``.
 
@@ -106,12 +106,18 @@ Transactions
    If ``operation`` is not included, then *every* transaction involving
    the asset with ID ``asset_id`` will be returned.
 
+   if ``last_tx`` is set to ``true``, only the last transaction is returned
+   instead of all transactions with the given ``asset_id``.
+
    This endpoint returns transactions only if they are in committed blocks.
 
    :query string operation: (Optional) ``CREATE`` or ``TRANSFER``.
 
    :query string asset_id: asset ID.
 
+   :query string last_tx: (Optional) ``true`` or ``false``.
+
+
    **Example request**:
 
    .. literalinclude:: http-samples/get-tx-by-asset-request.http

tests/web/test_transactions.py

@@ -382,13 +382,21 @@ def test_transactions_get_list_good(client):
         url = TX_ENDPOINT + '?asset_id=' + asset_id
         assert client.get(url).json == [
             ['asset_id', asset_id],
+            ['last_tx', None],
             ['operation', None]
         ]
         url = TX_ENDPOINT + '?asset_id=' + asset_id + '&operation=CREATE'
         assert client.get(url).json == [
             ['asset_id', asset_id],
+            ['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):