Merge pull request #195 from thenewboston-developers/BC-272-add-block-to-blockchain-once-it-gets-enough-confirmations

Starting process_block_confirmations_task

Author: dmugtasimov

node/blockchain/facade.py

@@ -1,4 +1,5 @@
 import logging
+import math
 from typing import TYPE_CHECKING, Optional, Type, TypeVar  # noqa: I101
 
 from node.blockchain.constants import BLOCK_LOCK
@@ -263,8 +264,12 @@ def yield_nodes(roles=None):
 
     @staticmethod
     def get_confirmation_validator_identifiers():
-        return ORMNode.objects.filter_by_roles((NodeRole.CONFIRMATION_VALIDATOR,)).values_list('_id', flat=True)
+        return ORMNode.objects.filter_confirmation_validators().values_list('_id', flat=True)
 
     @staticmethod
     def is_confirmation_validator(identifier):
         return ORMNode.objects.is_confirmation_validator(identifier)
+
+    @staticmethod
+    def get_minimum_consensus():
+        return int(math.ceil(ORMNode.objects.filter_confirmation_validators().count() * 2 / 3))

node/blockchain/models/node.py

@@ -52,6 +52,9 @@ def filter_by_roles(self, roles: Collection[NodeRole]):
 
         raise AssertionError('Should have exited on previous shortcut guard condition')
 
+    def filter_confirmation_validators(self):
+        return self.filter_by_roles((NodeRole.CONFIRMATION_VALIDATOR,))
+
 
 class NodeManager(DjongoManager.from_queryset(NodeQuerySet)):  # type: ignore
 

node/blockchain/tasks/process_block_confirmations.py

@@ -17,7 +17,7 @@ def process_next_block():
     cv_identifiers = facade.get_confirmation_validator_identifiers()
     confirmations = BlockConfirmation.objects.filter(number=next_block_number, signer__in=cv_identifiers)
     grouped_confirmations = groupby(confirmations.order_by('hash'), key=attrgetter('hash'))
-    minimum_consensus = len(cv_identifiers) * 2 / 3
+    minimum_consensus = facade.get_minimum_consensus()
 
     finalizable_hashes = [
         hash_ for hash_, _confirmations in grouped_confirmations if len(list(_confirmations)) >= minimum_consensus

node/blockchain/tests/fixtures/mocks.py

@@ -13,3 +13,9 @@ def mock_get_primary_validator(primary_validator_node):
 def start_send_new_block_task_mock():
     with patch('node.blockchain.views.signed_change_request.start_send_new_block_task') as mock:
         yield mock
+
+
+@pytest.fixture(autouse=True)
+def start_process_block_confirmations_task_mock():
+    with patch('node.blockchain.views.block_confirmation.start_process_block_confirmations_task') as mock:
+        yield mock

node/blockchain/views/block_confirmation.py

@@ -5,6 +5,8 @@
 from node.blockchain.facade import BlockchainFacade
 from node.blockchain.models.block_confirmation import BlockConfirmation as ORMBlockConfirmation
 from node.blockchain.serializers.block_confirmation import BlockConfirmationSerializer
+from node.blockchain.tasks.process_block_confirmations import start_process_block_confirmations_task
+from node.core.utils.misc import apply_on_commit
 
 
 class BlockConfirmationViewSet(GenericViewSet):
@@ -16,8 +18,12 @@ def create(self, request, *args, **kwargs):
         block_confirmation = serializer.save()
 
         facade = BlockchainFacade.get_instance()
-        if facade.get_next_block_number() == block_confirmation.get_number():
+        next_block_number = facade.get_next_block_number()
+        is_next_block_number = block_confirmation.get_number() == next_block_number
+        if is_next_block_number:
             block_confirmation.validate_all(facade)
+        else:
+            block_confirmation.validate_business_logic()
 
         ORMBlockConfirmation.objects.update_or_create(
             number=block_confirmation.get_number(),
@@ -28,8 +34,9 @@ def create(self, request, *args, **kwargs):
             },
         )
 
-        # TODO(dmu) CRITICAL: https://thenewboston.atlassian.net/browse/BC-272
-        # if next block number and we have enough confirmations then run a celery task
-        # to add the block to the blockchain
+        if is_next_block_number and (
+            ORMBlockConfirmation.objects.filter(number=next_block_number).count() >= facade.get_minimum_consensus()
+        ):
+            apply_on_commit(start_process_block_confirmations_task)
 
         return Response(serializer.data, status=status.HTTP_201_CREATED)

node/blockchain/views/signed_change_request.py

@@ -30,7 +30,7 @@ def create(self, request, *args, **kwargs):
             #                 of validators instead of the list existed before the block (fix it)
             #                 https://thenewboston.atlassian.net/browse/BC-268
             block_number = block.get_block_number()  # it is important to put block number to a variable first
-            apply_on_commit(lambda: start_send_new_block_task(block_number))
+            apply_on_commit(lambda block_number_=block_number: start_send_new_block_task(block_number_))
             return Response(serializer.data, status=status.HTTP_201_CREATED)
 
         pv_node = blockchain_facade.get_primary_validator()