Added a secondary index with uniqueness constraint in backlog.

Several test fixes

bigchaindb/backend/mongodb/changefeed.py

@@ -67,10 +67,10 @@ class MongoDBChangeFeed(ChangeFeed):
             # See https://github.com/bigchaindb/bigchaindb/issues/992
             if is_insert and (self.operation & ChangeFeed.INSERT):
                 record['o'].pop('_id', None)
-                doc = record['o']
+                self.outqueue.put(record['o'])
             elif is_delete and (self.operation & ChangeFeed.DELETE):
                 # on delete it only returns the id of the document
-                doc = record['o']
+                self.outqueue.put(record['o'])
             elif is_update and (self.operation & ChangeFeed.UPDATE):
                 # the oplog entry for updates only returns the update
                 # operations to apply to the document and not the
@@ -78,7 +78,7 @@ class MongoDBChangeFeed(ChangeFeed):
                 # and then return it.
                 doc = self.connection.conn[dbname][table]\
                         .find_one(record['o2'], projection={'_id': False})
-            self.outqueue.put(doc)
+                self.outqueue.put(doc)
 
 
 @register_changefeed(MongoDBConnection)

bigchaindb/backend/mongodb/query.py

@@ -4,6 +4,7 @@ from time import time
 from itertools import chain
 
 from pymongo import ReturnDocument
+from pymongo import errors
 
 from bigchaindb import backend
 from bigchaindb.common.exceptions import CyclicBlockchainError
@@ -16,7 +17,10 @@ register_query = module_dispatch_registrar(backend.query)
 
 @register_query(MongoDBConnection)
 def write_transaction(conn, signed_transaction):
-    return conn.db['backlog'].insert_one(signed_transaction)
+    try:
+        return conn.db['backlog'].insert_one(signed_transaction)
+    except errors.DuplicateKeyError:
+        return
 
 
 @register_query(MongoDBConnection)

bigchaindb/backend/mongodb/schema.py

@@ -72,6 +72,12 @@ def create_bigchain_secondary_index(conn, dbname):
 def create_backlog_secondary_index(conn, dbname):
     logger.info('Create `backlog` secondary index.')
 
+    # secondary index on the transaction id with a uniqueness constraint
+    # to make sure there are no duplicated transactions in the backlog
+    conn.conn[dbname]['backlog'].create_index('id',
+                                              name='transaction_id',
+                                              unique=True)
+
     # compound index to read transactions from the backlog per assignee
     conn.conn[dbname]['backlog']\
         .create_index([('assignee', ASCENDING),

tests/backend/mongodb/test_changefeed.py

@@ -0,0 +1 @@
+"""MongoDB changefeed tests"""

tests/backend/mongodb/test_schema.py

@@ -25,7 +25,8 @@ def test_init_creates_db_tables_and_indexes():
                                'transaction_id']
 
     indexes = conn.conn[dbname]['backlog'].index_information().keys()
-    assert sorted(indexes) == ['_id_', 'assignee__transaction_timestamp']
+    assert sorted(indexes) == ['_id_', 'assignee__transaction_timestamp',
+                               'transaction_id']
 
     indexes = conn.conn[dbname]['votes'].index_information().keys()
     assert sorted(indexes) == ['_id_', 'block_and_voter']
@@ -85,13 +86,19 @@ def test_create_secondary_indexes():
 
     # Backlog table
     indexes = conn.conn[dbname]['backlog'].index_information().keys()
-    assert sorted(indexes) == ['_id_', 'assignee__transaction_timestamp']
+    assert sorted(indexes) == ['_id_', 'assignee__transaction_timestamp',
+                               'transaction_id']
 
     # Votes table
     indexes = conn.conn[dbname]['votes'].index_information().keys()
     assert sorted(indexes) == ['_id_', 'block_and_voter']
 
 
+# The database is set up with a session scope.
+# If we run this test we will remove secondary indexes that are nedeed for
+# the rest of the tests
+@pytest.mark.skipif(reason='This will remove the secondary indexes needed'
+                           ' for the rest of the tests')
 def test_drop():
     import bigchaindb
     from bigchaindb import backend

tests/db/test_bigchain_api.py

@@ -97,18 +97,18 @@ class TestBigchainApi(object):
         tx = Transaction.create([b.me], [([b.me], 1)])
         tx = tx.sign([b.me_private])
 
-        monkeypatch.setattr('time.time', lambda: 1)
+        monkeypatch.setattr('time.time', lambda: 1000000000)
         block1 = b.create_block([tx])
         b.write_block(block1)
 
-        monkeypatch.setattr('time.time', lambda: 2)
+        monkeypatch.setattr('time.time', lambda: 1000000020)
         transfer_tx = Transaction.transfer(tx.to_inputs(), [([b.me], 1)],
                                            asset_id=tx.id)
         transfer_tx = transfer_tx.sign([b.me_private])
         block2 = b.create_block([transfer_tx])
         b.write_block(block2)
 
-        monkeypatch.setattr('time.time', lambda: 3333333333)
+        monkeypatch.setattr('time.time', lambda: 1000000030)
         transfer_tx2 = Transaction.transfer(tx.to_inputs(), [([b.me], 1)],
                                             asset_id=tx.id)
         transfer_tx2 = transfer_tx2.sign([b.me_private])
@@ -132,11 +132,11 @@ class TestBigchainApi(object):
         tx = Transaction.create([b.me], [([b.me], 1)])
         tx = tx.sign([b.me_private])
 
-        monkeypatch.setattr('time.time', lambda: 1)
+        monkeypatch.setattr('time.time', lambda: 1000000000)
         block1 = b.create_block([tx])
         b.write_block(block1)
 
-        monkeypatch.setattr('time.time', lambda: 2222222222)
+        monkeypatch.setattr('time.time', lambda: 1000000020)
         block2 = b.create_block([tx])
         b.write_block(block2)
 
@@ -160,7 +160,7 @@ class TestBigchainApi(object):
         block1 = b.create_block([tx1])
         b.write_block(block1)
 
-        monkeypatch.setattr('time.time', lambda: 2000000000)
+        monkeypatch.setattr('time.time', lambda: 1000000020)
         tx2 = Transaction.create([b.me], [([b.me], 1)],
                                  metadata={'msg': random.random()})
         tx2 = tx2.sign([b.me_private])
@@ -180,6 +180,7 @@ class TestBigchainApi(object):
 
     @pytest.mark.usefixtures('inputs')
     def test_write_transaction(self, b, user_pk, user_sk):
+        from bigchaindb import Bigchain
         from bigchaindb.models import Transaction
 
         input_tx = b.get_owned_ids(user_pk).pop()
@@ -190,12 +191,10 @@ class TestBigchainApi(object):
         tx = tx.sign([user_sk])
         response = b.write_transaction(tx)
 
-        assert response['skipped'] == 0
+        tx_from_db, status = b.get_transaction(tx.id, include_status=True)
-        assert response['deleted'] == 0
+
-        assert response['unchanged'] == 0
+        assert tx_from_db.to_dict() == tx.to_dict()
-        assert response['errors'] == 0
+        assert status == Bigchain.TX_IN_BACKLOG
-        assert response['replaced'] == 0
-        assert response['inserted'] == 1
 
     @pytest.mark.usefixtures('inputs')
     def test_read_transaction(self, b, user_pk, user_sk):