Problem: get_asset_tokens_for_public_key query complicated

Solution: Simply the query by removing the operation and allowing only one
public key as argument

bigchaindb/backend/localmongodb/query.py

@@ -310,11 +310,9 @@ def get_validator_set(conn, height=None):
 
 
 @register_query(LocalMongoDBConnection)
-def get_asset_tokens_for_public_keys(conn, asset_id, public_keys, operation=None):
-    query = {'outputs.public_keys': public_keys,
+def get_asset_tokens_for_public_key(conn, asset_id, public_key):
+    query = {'outputs.public_keys': [public_key],
              'asset.id': asset_id}
-    if operation:
-        query['operation'] = operation
 
     cursor = conn.run(
         conn.collection('transactions').aggregate([

bigchaindb/backend/query.py

@@ -375,12 +375,12 @@ def get_validator_set(conn, height):
 
 
 @singledispatch
-def get_asset_tokens_for_public_keys(connection, asset_id,
-                                     public_keys, operation):
-    """Retrieve a list of tokens of type `asset_id` that are owned by `public_keys`.
+def get_asset_tokens_for_public_key(connection, asset_id,
+                                    public_key, operation):
+    """Retrieve a list of tokens of type `asset_id` that are owned by the `public_key`.
     Args:
         asset_id (str): Id of the token.
-        public_keys (str): list of public keys
+        public_key (str): base58 encoded public key
         operation: filter transaction based on `operation`
     Returns:
         Iterator of transaction that list given owner in conditions.

bigchaindb/upsert_validator/validator_election.py

@@ -156,9 +156,9 @@ class ValidatorElection(Transaction):
         return base58.b58encode(bytes.fromhex(election_id))
 
     @classmethod
-    def count_votes(cls, election_pk, txns, getter=getattr):
+    def count_votes(cls, election_pk, transactions, getter=getattr):
         votes = 0
-        for txn in txns:
+        for txn in transactions:
             if getter(txn, 'operation') == 'VALIDATOR_ELECTION_VOTE':
                 for output in getter(txn, 'outputs'):
                     # NOTE: We enforce that a valid vote to election id will have only
@@ -171,10 +171,9 @@ class ValidatorElection(Transaction):
     def get_commited_votes(self, bigchain, election_pk=None):
         if election_pk is None:
             election_pk = self.to_public_key(self.id)
-        txns = list(backend.query.get_asset_tokens_for_public_keys(bigchain.connection,
-                                                                   self.id,
-                                                                   [election_pk],
-                                                                   'VALIDATOR_ELECTION_VOTE'))
+        txns = list(backend.query.get_asset_tokens_for_public_key(bigchain.connection,
+                                                                  self.id,
+                                                                  election_pk))
         return self.count_votes(election_pk, txns, dict.get)
 
     @classmethod