refactor(verification): move feature activation dependency

hathor/builder/builder.py

@@ -79,7 +79,7 @@ class BuildArtifacts(NamedTuple):
 
 
 _VertexVerifiersBuilder: TypeAlias = Callable[
-    [HathorSettingsType, DifficultyAdjustmentAlgorithm, FeatureService],
+    [HathorSettingsType, DifficultyAdjustmentAlgorithm],
     VertexVerifiers
 ]
 
@@ -493,7 +493,8 @@ 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()
-            self._verification_service = VerificationService(verifiers=verifiers)
+            feature_service = self._get_or_create_feature_service()
+            self._verification_service = VerificationService(verifiers=verifiers, feature_service=feature_service)
 
         return self._verification_service
 
@@ -509,17 +510,12 @@ def _get_or_create_feature_storage(self) -> FeatureActivationStorage | None:
     def _get_or_create_vertex_verifiers(self) -> VertexVerifiers:
         if self._vertex_verifiers is None:
             settings = self._get_or_create_settings()
-            feature_service = self._get_or_create_feature_service()
             daa = self._get_or_create_daa()
 
             if self._vertex_verifiers_builder:
-                self._vertex_verifiers = self._vertex_verifiers_builder(settings, daa, feature_service)
+                self._vertex_verifiers = self._vertex_verifiers_builder(settings, daa)
             else:
-                self._vertex_verifiers = VertexVerifiers.create_defaults(
-                    settings=settings,
-                    daa=daa,
-                    feature_service=feature_service,
-                )
+                self._vertex_verifiers = VertexVerifiers.create_defaults(settings=settings, daa=daa)
 
         return self._vertex_verifiers
 

hathor/builder/cli_builder.py

@@ -275,12 +275,8 @@ def create_manager(self, reactor: Reactor) -> HathorManager:
 
         daa = DifficultyAdjustmentAlgorithm(settings=settings, test_mode=test_mode)
 
-        vertex_verifiers = VertexVerifiers.create_defaults(
-            settings=settings,
-            daa=daa,
-            feature_service=self.feature_service
-        )
-        verification_service = VerificationService(verifiers=vertex_verifiers)
+        vertex_verifiers = VertexVerifiers.create_defaults(settings=settings, daa=daa)
+        verification_service = VerificationService(verifiers=vertex_verifiers, feature_service=self.feature_service)
 
         cpu_mining_service = CpuMiningService()
 

hathor/cli/mining.py

@@ -135,15 +135,13 @@ def execute(args: Namespace) -> None:
                                                                       block.nonce, block.weight))
 
         try:
-            from unittest.mock import Mock
-
             from hathor.conf.get_settings import get_global_settings
             from hathor.daa import DifficultyAdjustmentAlgorithm
             from hathor.verification.verification_service import VerificationService
             from hathor.verification.vertex_verifiers import VertexVerifiers
             settings = get_global_settings()
             daa = DifficultyAdjustmentAlgorithm(settings=settings)
-            verifiers = VertexVerifiers.create_defaults(settings=settings, daa=daa, feature_service=Mock())
+            verifiers = VertexVerifiers.create_defaults(settings=settings, daa=daa)
             verification_service = VerificationService(verifiers=verifiers)
             verification_service.verify_without_storage(block)
         except HathorError:

hathor/feature_activation/bit_signaling_service.py

@@ -163,7 +163,7 @@ def _log_signal_bits(self, feature: Feature, enable_bit: bool, support: bool, no
 
     def _get_signaling_features(self, block: Block) -> dict[Feature, Criteria]:
         """Given a specific block, return all features that are in a signaling state for that block."""
-        feature_descriptions = self._feature_service.get_bits_description(block=block)
+        feature_descriptions = self._feature_service.get_feature_info(block=block)
         signaling_features = {
             feature: description.criteria
             for feature, description in feature_descriptions.items()

hathor/feature_activation/feature_service.py

@@ -16,7 +16,7 @@
 from typing import TYPE_CHECKING, Optional, TypeAlias
 
 from hathor.feature_activation.feature import Feature
-from hathor.feature_activation.model.feature_description import FeatureDescription
+from hathor.feature_activation.model.feature_description import FeatureInfo
 from hathor.feature_activation.model.feature_state import FeatureState
 from hathor.feature_activation.settings import Settings as FeatureSettings
 
@@ -64,7 +64,7 @@ def is_signaling_mandatory_features(self, block: 'Block') -> BlockSignalingState
         height = block.get_height()
         offset_to_boundary = height % self._feature_settings.evaluation_interval
         remaining_blocks = self._feature_settings.evaluation_interval - offset_to_boundary - 1
-        descriptions = self.get_bits_description(block=block)
+        descriptions = self.get_feature_info(block=block)
 
         must_signal_features = (
             feature for feature, description in descriptions.items()
@@ -194,10 +194,10 @@ def _calculate_new_state(
 
         raise ValueError(f'Unknown previous state: {previous_state}')
 
-    def get_bits_description(self, *, block: 'Block') -> dict[Feature, FeatureDescription]:
+    def get_feature_info(self, *, block: 'Block') -> dict[Feature, FeatureInfo]:
         """Returns the criteria definition and feature state for all features at a certain block."""
         return {
-            feature: FeatureDescription(
+            feature: FeatureInfo(
                 criteria=criteria,
                 state=self.get_state(block=block, feature=feature)
             )

hathor/feature_activation/model/feature_description.py

@@ -18,7 +18,7 @@
 from hathor.feature_activation.model.feature_state import FeatureState
 
 
-class FeatureDescription(NamedTuple):
+class FeatureInfo(NamedTuple):
     """Represents all information related to one feature, that is, its criteria and state."""
     criteria: Criteria
     state: FeatureState

hathor/feature_activation/model/feature_state.py

@@ -42,3 +42,7 @@ def get_signaling_states() -> set['FeatureState']:
         support it or not through bit signals is valid during those states.
         """
         return {FeatureState.STARTED, FeatureState.MUST_SIGNAL, FeatureState.LOCKED_IN}
+
+    def is_active(self) -> bool:
+        """Return whether the state is active."""
+        return self is FeatureState.ACTIVE

hathor/feature_activation/resources/feature.py

@@ -68,7 +68,7 @@ def get_block_features(self, request: Request) -> bytes:
             return error.json_dumpb()
 
         signal_bits = []
-        feature_descriptions = self._feature_service.get_bits_description(block=block)
+        feature_descriptions = self._feature_service.get_feature_info(block=block)
 
         for feature, description in feature_descriptions.items():
             if description.state not in FeatureState.get_signaling_states():

hathor/manager.py

@@ -1077,7 +1077,7 @@ def _log_feature_states(self, vertex: BaseTransaction) -> None:
         if not isinstance(vertex, Block):
             return
 
-        feature_descriptions = self._feature_service.get_bits_description(block=vertex)
+        feature_descriptions = self._feature_service.get_feature_info(block=vertex)
         state_by_feature = {
             feature.value: description.state.value
             for feature, description in feature_descriptions.items()

hathor/simulator/simulator.py

@@ -24,7 +24,6 @@
 from hathor.conf.get_settings import get_global_settings
 from hathor.conf.settings import HathorSettings
 from hathor.daa import DifficultyAdjustmentAlgorithm
-from hathor.feature_activation.feature_service import FeatureService
 from hathor.manager import HathorManager
 from hathor.p2p.peer_id import PeerId
 from hathor.simulator.clock import HeapClock, MemoryReactorHeapClock
@@ -243,17 +242,12 @@ def run(self,
         return True
 
 
-def _build_vertex_verifiers(
-    settings: HathorSettings,
-    daa: DifficultyAdjustmentAlgorithm,
-    feature_service: FeatureService
-) -> VertexVerifiers:
+def _build_vertex_verifiers(settings: HathorSettings, daa: DifficultyAdjustmentAlgorithm) -> VertexVerifiers:
     """
     A custom VertexVerifiers builder to be used by the simulator.
     """
     return VertexVerifiers.create(
         settings=settings,
         vertex_verifier=SimulatorVertexVerifier(settings=settings, daa=daa),
         daa=daa,
-        feature_service=feature_service,
     )

hathor/verification/block_verifier.py

@@ -12,9 +12,11 @@
 #  See the License for the specific language governing permissions and
 #  limitations under the License.
 
+from typing_extensions import assert_never
+
 from hathor.conf.settings import HathorSettings
 from hathor.daa import DifficultyAdjustmentAlgorithm
-from hathor.feature_activation.feature_service import BlockIsMissingSignal, BlockIsSignaling, FeatureService
+from hathor.feature_activation.feature_service import BlockIsMissingSignal, BlockIsSignaling, BlockSignalingState
 from hathor.transaction import Block
 from hathor.transaction.exceptions import (
     BlockMustSignalError,
@@ -30,18 +32,16 @@
 
 
 class BlockVerifier:
-    __slots__ = ('_settings', '_daa', '_feature_service')
+    __slots__ = ('_settings', '_daa')
 
     def __init__(
         self,
         *,
         settings: HathorSettings,
         daa: DifficultyAdjustmentAlgorithm,
-        feature_service: FeatureService,
     ) -> None:
         self._settings = settings
         self._daa = daa
-        self._feature_service = feature_service
 
     def verify_height(self, block: Block) -> None:
         """Validate that the block height is enough to confirm all transactions being confirmed."""
@@ -86,10 +86,8 @@ 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, block: Block) -> None:
+    def verify_mandatory_signaling(self, signaling_state: BlockSignalingState) -> None:
         """Verify whether this block is missing mandatory signaling for any feature."""
-        signaling_state = self._feature_service.is_signaling_mandatory_features(block)
-
         match signaling_state:
             case BlockIsSignaling():
                 return
@@ -98,5 +96,4 @@ def verify_mandatory_signaling(self, block: Block) -> None:
                     f"Block must signal support for feature '{feature.value}' during MUST_SIGNAL phase."
                 )
             case _:
-                # TODO: This will be changed to assert_never() so mypy can check it.
-                raise NotImplementedError
+                assert_never(signaling_state)

hathor/verification/merge_mined_block_verifier.py

@@ -14,29 +14,25 @@
 
 from hathor.conf.settings import HathorSettings
 from hathor.feature_activation.feature import Feature
-from hathor.feature_activation.feature_service import FeatureService
+from hathor.feature_activation.model.feature_description import FeatureInfo
 from hathor.transaction import MergeMinedBlock
 
 
 class MergeMinedBlockVerifier:
-    __slots__ = ('_settings', '_feature_service',)
+    __slots__ = ('_settings',)
 
-    def __init__(self, *, settings: HathorSettings, feature_service: FeatureService):
+    def __init__(self, *, settings: HathorSettings) -> None:
         self._settings = settings
-        self._feature_service = feature_service
 
-    def verify_aux_pow(self, block: MergeMinedBlock) -> None:
+    def verify_aux_pow(self, block: MergeMinedBlock, feature_info: dict[Feature, FeatureInfo]) -> None:
         """ Verify auxiliary proof-of-work (for merged mining).
         """
         assert block.aux_pow is not None
 
-        is_feature_active = self._feature_service.is_feature_active(
-            block=block,
-            feature=Feature.INCREASE_MAX_MERKLE_PATH_LENGTH
-        )
-        max_merkle_path_length = (
-            self._settings.NEW_MAX_MERKLE_PATH_LENGTH if is_feature_active
-            else self._settings.OLD_MAX_MERKLE_PATH_LENGTH
-        )
+        max_merkle_path_length = self._settings.OLD_MAX_MERKLE_PATH_LENGTH
+        merkle_path_info = feature_info.get(Feature.INCREASE_MAX_MERKLE_PATH_LENGTH)
+
+        if merkle_path_info and merkle_path_info.state.is_active():
+            max_merkle_path_length = self._settings.NEW_MAX_MERKLE_PATH_LENGTH
 
         block.aux_pow.verify(block.get_base_hash(), max_merkle_path_length)

hathor/verification/verification_service.py

@@ -14,6 +14,9 @@
 
 from typing_extensions import assert_never
 
+from hathor.feature_activation.feature import Feature
+from hathor.feature_activation.feature_service import BlockSignalingState, FeatureService
+from hathor.feature_activation.model.feature_description import FeatureInfo
 from hathor.profiler import get_cpu_profiler
 from hathor.transaction import BaseTransaction, Block, MergeMinedBlock, Transaction, TxVersion
 from hathor.transaction.token_creation_tx import TokenCreationTransaction
@@ -26,10 +29,11 @@
 
 
 class VerificationService:
-    __slots__ = ('verifiers', )
+    __slots__ = ('verifiers', '_feature_service')
 
-    def __init__(self, *, verifiers: VertexVerifiers) -> None:
+    def __init__(self, *, verifiers: VertexVerifiers, feature_service: FeatureService | None = None) -> None:
         self.verifiers = verifiers
+        self._feature_service = feature_service
 
     def validate_basic(self, vertex: BaseTransaction, *, skip_block_weight_verification: bool = False) -> bool:
         """ Run basic validations (all that are possible without dependencies) and update the validation state.
@@ -124,14 +128,18 @@ def verify(self, vertex: BaseTransaction, *, reject_locked_reward: bool = True)
         """Run all verifications. Raises on error.
 
         Used by `self.validate_full`. Should not modify the validation state."""
+        assert self._feature_service is not None
         # We assert with type() instead of isinstance() because each subclass has a specific branch.
         match vertex.version:
             case TxVersion.REGULAR_BLOCK:
                 assert type(vertex) is Block
-                self._verify_block(vertex)
+                signaling_state = self._feature_service.is_signaling_mandatory_features(vertex)
+                self._verify_block(vertex, signaling_state)
             case TxVersion.MERGE_MINED_BLOCK:
                 assert type(vertex) is MergeMinedBlock
-                self._verify_merge_mined_block(vertex)
+                signaling_state = self._feature_service.is_signaling_mandatory_features(vertex)
+                feature_info = self._feature_service.get_feature_info(block=vertex)
+                self._verify_merge_mined_block(vertex, signaling_state, feature_info)
             case TxVersion.REGULAR_TRANSACTION:
                 assert type(vertex) is Transaction
                 self._verify_tx(vertex, reject_locked_reward=reject_locked_reward)
@@ -142,7 +150,7 @@ def verify(self, vertex: BaseTransaction, *, reject_locked_reward: bool = True)
                 assert_never(vertex.version)
 
     @cpu.profiler(key=lambda _, block: 'block-verify!{}'.format(block.hash.hex()))
-    def _verify_block(self, block: Block) -> None:
+    def _verify_block(self, block: Block, signaling_state: BlockSignalingState) -> None:
         """
             (1) confirms at least two pending transactions and references last block
             (2) solves the pow with the correct weight (done in HathorManager)
@@ -163,10 +171,16 @@ def _verify_block(self, block: Block) -> None:
 
         self.verifiers.block.verify_height(block)
 
-        self.verifiers.block.verify_mandatory_signaling(block)
+        self.verifiers.block.verify_mandatory_signaling(signaling_state)
 
-    def _verify_merge_mined_block(self, block: MergeMinedBlock) -> None:
-        self._verify_block(block)
+    def _verify_merge_mined_block(
+        self,
+        block: MergeMinedBlock,
+        signaling_state: BlockSignalingState,
+        feature_info: dict[Feature, FeatureInfo]
+    ) -> None:
+        self.verifiers.merge_mined_block.verify_aux_pow(block, feature_info)
+        self._verify_block(block, signaling_state)
 
     @cpu.profiler(key=lambda _, tx: 'tx-verify!{}'.format(tx.hash.hex()))
     def _verify_tx(
@@ -237,7 +251,6 @@ def _verify_without_storage_block(self, block: Block) -> None:
         self.verifiers.vertex.verify_sigops_output(block)
 
     def _verify_without_storage_merge_mined_block(self, block: MergeMinedBlock) -> None:
-        self.verifiers.merge_mined_block.verify_aux_pow(block)
         self._verify_without_storage_block(block)
 
     def _verify_without_storage_tx(self, tx: Transaction) -> None:

hathor/verification/vertex_verifiers.py

@@ -16,7 +16,6 @@
 
 from hathor.conf.settings import HathorSettings
 from hathor.daa import DifficultyAdjustmentAlgorithm
-from hathor.feature_activation.feature_service import FeatureService
 from hathor.verification.block_verifier import BlockVerifier
 from hathor.verification.merge_mined_block_verifier import MergeMinedBlockVerifier
 from hathor.verification.token_creation_transaction_verifier import TokenCreationTransactionVerifier
@@ -33,13 +32,7 @@ class VertexVerifiers(NamedTuple):
     token_creation_tx: TokenCreationTransactionVerifier
 
     @classmethod
-    def create_defaults(
-        cls,
-        *,
-        settings: HathorSettings,
-        daa: DifficultyAdjustmentAlgorithm,
-        feature_service: FeatureService,
-    ) -> 'VertexVerifiers':
+    def create_defaults(cls, *, settings: HathorSettings, daa: DifficultyAdjustmentAlgorithm) -> 'VertexVerifiers':
         """
         Create a VertexVerifiers instance using the default verifier for each vertex type,
         from all required dependencies.
@@ -50,7 +43,6 @@ def create_defaults(
             settings=settings,
             vertex_verifier=vertex_verifier,
             daa=daa,
-            feature_service=feature_service
         )
 
     @classmethod
@@ -60,13 +52,12 @@ def create(
         settings: HathorSettings,
         vertex_verifier: VertexVerifier,
         daa: DifficultyAdjustmentAlgorithm,
-        feature_service: FeatureService,
     ) -> 'VertexVerifiers':
         """
         Create a VertexVerifiers instance using a custom vertex_verifier.
         """
-        block_verifier = BlockVerifier(settings=settings, daa=daa, feature_service=feature_service)
-        merge_mined_block_verifier = MergeMinedBlockVerifier(settings=settings, feature_service=feature_service)
+        block_verifier = BlockVerifier(settings=settings, daa=daa)
+        merge_mined_block_verifier = MergeMinedBlockVerifier(settings=settings)
         tx_verifier = TransactionVerifier(settings=settings, daa=daa)
         token_creation_tx_verifier = TokenCreationTransactionVerifier(settings=settings)