refactor(verification): externalize verification dependencies [part 1/2]

hathor/builder/builder.py

@@ -473,8 +473,13 @@ def _get_or_create_bit_signaling_service(self) -> BitSignalingService:
     def _get_or_create_verification_service(self) -> VerificationService:
         if self._verification_service is None:
             verifiers = self._get_or_create_vertex_verifiers()
+            daa = self._get_or_create_daa()
             feature_service = self._get_or_create_feature_service()
-            self._verification_service = VerificationService(verifiers=verifiers, feature_service=feature_service)
+            self._verification_service = VerificationService(
+                verifiers=verifiers,
+                daa=daa,
+                feature_service=feature_service
+            )
 
         return self._verification_service
 

hathor/builder/cli_builder.py

@@ -223,7 +223,11 @@ def create_manager(self, reactor: Reactor) -> HathorManager:
         daa = DifficultyAdjustmentAlgorithm(settings=settings, test_mode=test_mode)
 
         vertex_verifiers = VertexVerifiers.create_defaults(settings=settings, daa=daa)
-        verification_service = VerificationService(verifiers=vertex_verifiers, feature_service=self.feature_service)
+        verification_service = VerificationService(
+            verifiers=vertex_verifiers,
+            daa=daa,
+            feature_service=self.feature_service
+        )
 
         cpu_mining_service = CpuMiningService()
 

hathor/cli/mining.py

@@ -141,7 +141,7 @@ def execute(args: Namespace) -> None:
             settings = get_global_settings()
             daa = DifficultyAdjustmentAlgorithm(settings=settings)
             verifiers = VertexVerifiers.create_defaults(settings=settings, daa=daa)
-            verification_service = VerificationService(verifiers=verifiers)
+            verification_service = VerificationService(verifiers=verifiers, daa=daa)
             verification_service.verify_without_storage(block)
         except HathorError:
             print('[{}] ERROR: Block has not been pushed because it is not valid.'.format(datetime.datetime.now()))

hathor/transaction/resources/create_tx.py

@@ -22,6 +22,7 @@
 from hathor.transaction import Transaction, TxInput, TxOutput
 from hathor.transaction.scripts import create_output_script
 from hathor.util import api_catch_exceptions, json_dumpb, json_loadb
+from hathor.verification.verification_dependencies import TransactionDependencies
 
 
 def from_raw_output(raw_output: dict, tokens: list[bytes]) -> TxOutput:
@@ -109,15 +110,16 @@ def _verify_unsigned_skip_pow(self, tx: Transaction) -> None:
         """ Same as .verify but skipping pow and signature verification."""
         assert type(tx) is Transaction
         verifiers = self.manager.verification_service.verifiers
+        deps = TransactionDependencies.create(tx)
         verifiers.tx.verify_number_of_inputs(tx)
         verifiers.vertex.verify_number_of_outputs(tx)
         verifiers.vertex.verify_outputs(tx)
         verifiers.tx.verify_output_token_indexes(tx)
         verifiers.vertex.verify_sigops_output(tx)
-        verifiers.tx.verify_sigops_input(tx)
+        verifiers.tx.verify_sigops_input(tx, deps)
         # need to run verify_inputs first to check if all inputs exist
-        verifiers.tx.verify_inputs(tx, skip_script=True)
-        verifiers.vertex.verify_parents(tx)
+        verifiers.tx.verify_inputs(tx, deps, skip_script=True)
+        verifiers.vertex.verify_parents(tx, deps)
         verifiers.tx.verify_sum(tx.get_complete_token_info())
 
 

hathor/transaction/storage/simple_memory_storage.py

@@ -17,6 +17,7 @@
 from hathor.transaction.storage import TransactionStorage
 from hathor.transaction.storage.exceptions import TransactionDoesNotExist
 from hathor.types import VertexId
+from hathor.util import not_none
 
 
 class SimpleMemoryStorage:
@@ -47,6 +48,10 @@ def get_transaction(self, tx_id: VertexId) -> Transaction:
         assert isinstance(tx, Transaction)
         return tx
 
+    def get_vertex(self, vertex_id: VertexId) -> BaseTransaction:
+        """Return a vertex from the storage, raise if it's not found."""
+        return self._get_vertex(self._vertices, vertex_id)
+
     @staticmethod
     def _get_vertex(storage: dict[VertexId, BaseTransaction], vertex_id: VertexId) -> BaseTransaction:
         """Return a vertex from a storage, throw if it's not found."""
@@ -71,13 +76,19 @@ def add_vertices_from_storage(self, storage: TransactionStorage, ids: list[Verte
 
     def add_vertex_from_storage(self, storage: TransactionStorage, vertex_id: VertexId) -> None:
         """
-        Add a vertex to this storage. It automatically fetches data from the provided TransactionStorage and a list
-        of ids.
+        Add a vertex to this storage. It automatically fetches data from the provided TransactionStorage and vertex_id.
         """
+        vertex = storage.get_transaction(vertex_id)
+
+        self.add_vertex(vertex)
+
+    def add_vertex(self, vertex: BaseTransaction) -> None:
+        """Add a vertex to this storage."""
+        vertex_id = not_none(vertex.hash)
+
         if vertex_id in self._vertices:
             return
 
-        vertex = storage.get_transaction(vertex_id)
         clone = vertex.clone(include_metadata=True, include_storage=False)
 
         if isinstance(vertex, Block):
@@ -90,10 +101,6 @@ def add_vertex_from_storage(self, storage: TransactionStorage, vertex_id: Vertex
 
         raise NotImplementedError
 
-    def get_vertex(self, vertex_id: VertexId) -> BaseTransaction:
-        # TODO: Currently unused, will be implemented in a next PR.
-        raise NotImplementedError
-
     def get_best_block_tips(self) -> list[VertexId]:
         # TODO: Currently unused, will be implemented in a next PR.
         raise NotImplementedError

hathor/verification/block_verifier.py

@@ -16,7 +16,7 @@
 
 from hathor.conf.settings import HathorSettings
 from hathor.daa import DifficultyAdjustmentAlgorithm
-from hathor.feature_activation.feature_service import BlockIsMissingSignal, BlockIsSignaling, BlockSignalingState
+from hathor.feature_activation.feature_service import BlockIsMissingSignal, BlockIsSignaling
 from hathor.transaction import Block
 from hathor.transaction.exceptions import (
     BlockMustSignalError,
@@ -27,8 +27,7 @@
     TransactionDataError,
     WeightError,
 )
-from hathor.transaction.storage.simple_memory_storage import SimpleMemoryStorage
-from hathor.util import not_none
+from hathor.verification.verification_dependencies import BlockDependencies
 
 
 class BlockVerifier:
@@ -51,20 +50,16 @@ def verify_height(self, block: Block) -> None:
         if meta.height < meta.min_height:
             raise RewardLocked(f'Block needs {meta.min_height} height but has {meta.height}')
 
-    def verify_weight(self, block: Block) -> None:
+    def verify_weight(self, block: Block, block_deps: BlockDependencies) -> None:
         """Validate minimum block difficulty."""
-        memory_storage = SimpleMemoryStorage()
-        dependencies = self._daa.get_block_dependencies(block)
-        memory_storage.add_vertices_from_storage(not_none(block.storage), dependencies)
-
-        min_block_weight = self._daa.calculate_block_difficulty(block, memory_storage)
+        min_block_weight = self._daa.calculate_block_difficulty(block, block_deps.storage)
         if block.weight < min_block_weight - self._settings.WEIGHT_TOL:
             raise WeightError(f'Invalid new block {block.hash_hex}: weight ({block.weight}) is '
                               f'smaller than the minimum weight ({min_block_weight})')
 
-    def verify_reward(self, block: Block) -> None:
+    def verify_reward(self, block: Block, block_deps: BlockDependencies) -> None:
         """Validate reward amount."""
-        parent_block = block.get_block_parent()
+        parent_block = block_deps.storage.get_parent_block(block)
         tokens_issued_per_block = self._daa.get_tokens_issued_per_block(parent_block.get_height() + 1)
         if block.sum_outputs != tokens_issued_per_block:
             raise InvalidBlockReward(
@@ -86,14 +81,14 @@ def verify_data(self, block: Block) -> None:
         if len(block.data) > self._settings.BLOCK_DATA_MAX_SIZE:
             raise TransactionDataError('block data has {} bytes'.format(len(block.data)))
 
-    def verify_mandatory_signaling(self, signaling_state: BlockSignalingState) -> None:
+    def verify_mandatory_signaling(self, block_deps: BlockDependencies) -> None:
         """Verify whether this block is missing mandatory signaling for any feature."""
-        match signaling_state:
+        match block_deps.signaling_state:
             case BlockIsSignaling():
                 return
             case BlockIsMissingSignal(feature):
                 raise BlockMustSignalError(
                     f"Block must signal support for feature '{feature.value}' during MUST_SIGNAL phase."
                 )
             case _:
-                assert_never(signaling_state)
+                assert_never(block_deps.signaling_state)

hathor/verification/transaction_verifier.py

@@ -38,6 +38,7 @@
 from hathor.transaction.util import get_deposit_amount, get_withdraw_amount
 from hathor.types import TokenUid, VertexId
 from hathor.util import not_none
+from hathor.verification.verification_dependencies import TransactionDependencies
 
 cpu = get_cpu_profiler()
 
@@ -51,8 +52,6 @@ def __init__(self, *, settings: HathorSettings, daa: DifficultyAdjustmentAlgorit
 
     def verify_parents_basic(self, tx: Transaction) -> None:
         """Verify number and non-duplicity of parents."""
-        assert tx.storage is not None
-
         # check if parents are duplicated
         parents_set = set(tx.parents)
         if len(tx.parents) > len(parents_set):
@@ -72,15 +71,15 @@ def verify_weight(self, tx: Transaction) -> None:
             raise WeightError(f'Invalid new tx {tx.hash_hex}: weight ({tx.weight}) is '
                               f'greater than the maximum allowed ({max_tx_weight})')
 
-    def verify_sigops_input(self, tx: Transaction) -> None:
+    def verify_sigops_input(self, tx: Transaction, tx_deps: TransactionDependencies) -> None:
         """ Count sig operations on all inputs and verify that the total sum is below the limit
         """
         from hathor.transaction.scripts import get_sigops_count
         from hathor.transaction.storage.exceptions import TransactionDoesNotExist
         n_txops = 0
         for tx_input in tx.inputs:
             try:
-                spent_tx = tx.get_spent_tx(tx_input)
+                spent_tx = tx_deps.storage.get_vertex(tx_input.tx_id)
             except TransactionDoesNotExist:
                 raise InexistentInput('Input tx does not exist: {}'.format(tx_input.tx_id.hex()))
             assert spent_tx.hash is not None
@@ -93,7 +92,7 @@ def verify_sigops_input(self, tx: Transaction) -> None:
             raise TooManySigOps(
                 'TX[{}]: Max number of sigops for inputs exceeded ({})'.format(tx.hash_hex, n_txops))
 
-    def verify_inputs(self, tx: Transaction, *, skip_script: bool = False) -> None:
+    def verify_inputs(self, tx: Transaction, tx_deps: TransactionDependencies, *, skip_script: bool = False) -> None:
         """Verify inputs signatures and ownership and all inputs actually exist"""
         from hathor.transaction.storage.exceptions import TransactionDoesNotExist
 
@@ -105,7 +104,7 @@ def verify_inputs(self, tx: Transaction, *, skip_script: bool = False) -> None:
                 ))
 
             try:
-                spent_tx = tx.get_spent_tx(input_tx)
+                spent_tx = tx_deps.storage.get_vertex(input_tx.tx_id)
                 assert spent_tx.hash is not None
                 if input_tx.index >= len(spent_tx.outputs):
                     raise InexistentInput('Output spent by this input does not exist: {} index {}'.format(

hathor/verification/verification_dependencies.py

@@ -0,0 +1,68 @@
+#  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 dataclasses import dataclass
+
+from typing_extensions import Self
+
+from hathor.daa import DifficultyAdjustmentAlgorithm
+from hathor.feature_activation.feature_service import BlockSignalingState, FeatureService
+from hathor.transaction import Block
+from hathor.transaction.storage.simple_memory_storage import SimpleMemoryStorage
+from hathor.transaction.transaction import Transaction
+
+
+@dataclass(frozen=True, slots=True)
+class VertexDependencies:
+    """A dataclass of dependencies necessary for vertex verification."""
+    storage: SimpleMemoryStorage
+
+
+@dataclass(frozen=True, slots=True)
+class BlockDependencies(VertexDependencies):
+    """A dataclass of dependencies necessary for block verification."""
+    signaling_state: BlockSignalingState
+
+    @classmethod
+    def create(cls, block: Block, daa: DifficultyAdjustmentAlgorithm, feature_service: FeatureService) -> Self:
+        """Create a block dependencies instance."""
+        assert block.storage is not None
+        signaling_state = feature_service.is_signaling_mandatory_features(block)
+        simple_storage = SimpleMemoryStorage()
+        daa_deps = daa.get_block_dependencies(block)
+        deps = block.parents + daa_deps
+
+        simple_storage.add_vertices_from_storage(block.storage, deps)
+        simple_storage.add_vertex(block)  # we add the block itself so its metadata can be used as a dependency.
+
+        return cls(
+            storage=simple_storage,
+            signaling_state=signaling_state
+        )
+
+
+class TransactionDependencies(VertexDependencies):
+    """A dataclass of dependencies necessary for transaction verification."""
+
+    @classmethod
+    def create(cls, tx: Transaction) -> Self:
+        """Create a transaction dependencies instance."""
+        assert tx.storage is not None
+        simple_storage = SimpleMemoryStorage()
+        spent_txs = [tx_input.tx_id for tx_input in tx.inputs]
+        deps = tx.parents + spent_txs
+
+        simple_storage.add_vertices_from_storage(tx.storage, deps)
+
+        return cls(storage=simple_storage)