feat(consensus): Use DAG of funds to set first_block

hathor/consensus/block_consensus.py

@@ -432,7 +432,7 @@ def remove_first_block_markers(self, block: Block) -> None:
         storage = block.storage
 
         from hathor.transaction.storage.traversal import BFSTimestampWalk
-        bfs = BFSTimestampWalk(storage, is_dag_verifications=True, is_left_to_right=False)
+        bfs = BFSTimestampWalk(storage, is_dag_verifications=True, is_dag_funds=True, is_left_to_right=False)
         for tx in bfs.run(block, skip_root=True):
             if tx.is_block:
                 bfs.skip_neighbors(tx)
@@ -469,9 +469,12 @@ def _score_block_dfs(self, block: BaseTransaction, used: set[bytes],
 
             else:
                 from hathor.transaction.storage.traversal import BFSTimestampWalk
-                bfs = BFSTimestampWalk(storage, is_dag_verifications=True, is_left_to_right=False)
+                bfs = BFSTimestampWalk(storage, is_dag_verifications=True, is_dag_funds=True, is_left_to_right=False)
                 for tx in bfs.run(parent, skip_root=False):
-                    assert not tx.is_block
+                    assert tx.hash is not None
+                    if tx.is_block:
+                        bfs.skip_neighbors(tx)
+                        continue
 
                     if tx.hash in used:
                         bfs.skip_neighbors(tx)

hathor/transaction/storage/migrations/include_funds_for_first_block.py

@@ -0,0 +1,37 @@
+#  Copyright 2023 Hathor Labs
+#
+#  Licensed under the Apache License, Version 2.0 (the "License");
+#  you may not use this file except in compliance with the License.
+#  You may obtain a copy of the License at
+#
+#  http://www.apache.org/licenses/LICENSE-2.0
+#
+#  Unless required by applicable law or agreed to in writing, software
+#  distributed under the License is distributed on an "AS IS" BASIS,
+#  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#  See the License for the specific language governing permissions and
+#  limitations under the License.
+
+from typing import TYPE_CHECKING
+
+from structlog import get_logger
+
+from hathor.transaction.storage.migrations import BaseMigration
+
+if TYPE_CHECKING:
+    from hathor.transaction.storage import TransactionStorage
+
+logger = get_logger()
+
+
+class Migration(BaseMigration):
+    def skip_empty_db(self) -> bool:
+        return True
+
+    def get_db_name(self) -> str:
+        return 'include_funds_for_first_block'
+
+    def run(self, storage: 'TransactionStorage') -> None:
+        raise Exception('Cannot migrate your database due to an incompatible change in the metadata. '
+                        'Please, delete your data folder and use the latest available snapshot or sync '
+                        'from beginning.')

hathor/transaction/storage/transaction_storage.py

@@ -37,7 +37,13 @@
     TransactionIsNotABlock,
     TransactionNotInAllowedScopeError,
 )
-from hathor.transaction.storage.migrations import BaseMigration, MigrationState, change_score_acc_weight_metadata
+from hathor.transaction.storage.migrations import (
+    BaseMigration,
+    MigrationState,
+    add_closest_ancestor_block,
+    change_score_acc_weight_metadata,
+    include_funds_for_first_block,
+)
 from hathor.transaction.storage.tx_allow_scope import TxAllowScope, tx_allow_context
 from hathor.transaction.transaction import Transaction
 from hathor.transaction.transaction_metadata import TransactionMetadata
@@ -88,6 +94,8 @@ class TransactionStorage(ABC):
     # history of migrations that have to be applied in the order defined here
     _migration_factories: list[type[BaseMigration]] = [
         change_score_acc_weight_metadata.Migration,
+        add_closest_ancestor_block.Migration,
+        include_funds_for_first_block.Migration,
     ]
 
     _migrations: list[BaseMigration]

tests/consensus/test_first_block.py

@@ -0,0 +1,71 @@
+from tests import unittest
+
+
+class FirstBlockTestCase(unittest.TestCase):
+    _enable_sync_v1 = True
+    _enable_sync_v2 = True
+
+    def setUp(self) -> None:
+        super().setUp()
+
+        from hathor.simulator.patches import SimulatorCpuMiningService
+        from hathor.simulator.simulator import _build_vertex_verifiers
+
+        cpu_mining_service = SimulatorCpuMiningService()
+
+        builder = self.get_builder() \
+            .set_vertex_verifiers_builder(_build_vertex_verifiers) \
+            .set_cpu_mining_service(cpu_mining_service)
+
+        self.manager = self.create_peer_from_builder(builder)
+        self.dag_builder = self.get_dag_builder(self.manager)
+
+    def test_first_block(self) -> None:
+        artifacts = self.dag_builder.build_from_str("""
+            blockchain genesis b[1..50]
+
+            b30 < dummy
+
+            tx10.out[0] <<< tx50
+            tx20.out[0] <<< tx50
+            tx30 <-- tx50
+            tx40 <-- tx50
+
+            tx41.out[0] <<< tx40
+            tx42 <-- tx40
+            tx43 <-- tx40
+
+            b31 --> tx10
+
+            b32 --> tx30
+            b32 --> tx43
+
+            b33 --> tx50
+        """)
+
+        for node, vertex in artifacts.list:
+            self.manager.on_new_tx(vertex, fails_silently=False)
+
+        b31 = artifacts.by_name['b31'].vertex
+        b32 = artifacts.by_name['b32'].vertex
+        b33 = artifacts.by_name['b33'].vertex
+
+        tx10 = artifacts.by_name['tx10'].vertex
+        tx20 = artifacts.by_name['tx20'].vertex
+        tx30 = artifacts.by_name['tx30'].vertex
+        tx40 = artifacts.by_name['tx40'].vertex
+        tx41 = artifacts.by_name['tx41'].vertex
+        tx42 = artifacts.by_name['tx42'].vertex
+        tx43 = artifacts.by_name['tx43'].vertex
+        tx50 = artifacts.by_name['tx50'].vertex
+
+        self.assertEqual(tx10.get_metadata().first_block, b31.hash)
+
+        self.assertEqual(tx30.get_metadata().first_block, b32.hash)
+        self.assertEqual(tx43.get_metadata().first_block, b32.hash)
+
+        self.assertEqual(tx50.get_metadata().first_block, b33.hash)
+        self.assertEqual(tx20.get_metadata().first_block, b33.hash)
+        self.assertEqual(tx40.get_metadata().first_block, b33.hash)
+        self.assertEqual(tx41.get_metadata().first_block, b33.hash)
+        self.assertEqual(tx42.get_metadata().first_block, b33.hash)