hotshot: add tests for drb results

hotshot-example-types/src/node_types.rs

@@ -15,6 +15,7 @@ use hotshot::traits::{
         randomized_committee_members::RandomizedCommitteeMembers,
         static_committee::StaticCommittee,
         static_committee_leader_two_views::StaticCommitteeLeaderForTwoViews,
+        static_committee_with_drb::StaticCommitteeWithDrb,
         two_static_committees::TwoStaticCommittees,
     },
     implementations::{CombinedNetworks, Libp2pNetwork, MemoryNetwork, PushCdnNetwork},
@@ -69,6 +70,38 @@ impl NodeType for TestTypes {
     type BuilderSignatureKey = BuilderKey;
 }
 
+#[derive(
+    Copy,
+    Clone,
+    Debug,
+    Default,
+    Hash,
+    PartialEq,
+    Eq,
+    PartialOrd,
+    Ord,
+    serde::Serialize,
+    serde::Deserialize,
+)]
+/// filler struct to implement node type and allow us
+/// to select our traits
+pub struct TestTypesWithDrb;
+impl NodeType for TestTypesWithDrb {
+    const UPGRADE_CONSTANTS: UpgradeConstants = TEST_UPGRADE_CONSTANTS;
+
+    type AuctionResult = TestAuctionResult;
+    type View = ViewNumber;
+    type Epoch = EpochNumber;
+    type BlockHeader = TestBlockHeader;
+    type BlockPayload = TestBlockPayload;
+    type SignatureKey = BLSPubKey;
+    type Transaction = TestTransaction;
+    type ValidatedState = TestValidatedState;
+    type InstanceState = TestInstanceState;
+    type Membership = StaticCommitteeWithDrb<TestTypesWithDrb>;
+    type BuilderSignatureKey = BuilderKey;
+}
+
 #[derive(
     Copy,
     Clone,

hotshot-testing/tests/tests_6/test_epochs.rs

@@ -10,7 +10,7 @@ use hotshot_example_types::{
     node_types::{
         CombinedImpl, EpochUpgradeTestVersions, EpochsTestVersions, Libp2pImpl, MemoryImpl,
         PushCdnImpl, RandomOverlapQuorumFilterConfig, StableQuorumFilterConfig,
-        TestConsecutiveLeaderTypes, TestTwoStakeTablesTypes, TestTypes,
+        TestConsecutiveLeaderTypes, TestTwoStakeTablesTypes, TestTypes,TestTypesWithDrb,
         TestTypesRandomizedCommitteeMembers, TestTypesRandomizedLeader,
     },
     testable_delay::{DelayConfig, DelayOptions, DelaySettings, SupportedTraitTypesForAsyncDelay},
@@ -60,6 +60,7 @@ cross_tests!(
         TestTypesRandomizedCommitteeMembers<StableQuorumFilterConfig<123, 5>>,                 // Overlap = 2F+1
         TestTypesRandomizedCommitteeMembers<StableQuorumFilterConfig<123, 6>>,                 // Overlap = 3F
         TestTypesRandomizedCommitteeMembers<RandomOverlapQuorumFilterConfig<123, 4, 7, 0, 2>>, // Overlap = Dynamic
+        TestTypesWithDrb,
     ],
     Versions: [EpochsTestVersions],
     Ignore: false,
@@ -79,7 +80,7 @@ cross_tests!(
 cross_tests!(
     TestName: test_success_with_async_delay_with_epochs,
     Impls: [Libp2pImpl, PushCdnImpl, CombinedImpl],
-    Types: [TestTypes, TestTwoStakeTablesTypes],
+    Types: [TestTypes, TestTwoStakeTablesTypes, TestTypesWithDrb],
     Versions: [EpochsTestVersions],
     Ignore: false,
     Metadata: {
@@ -111,7 +112,7 @@ cross_tests!(
 cross_tests!(
     TestName: test_success_with_async_delay_2_with_epochs,
     Impls: [Libp2pImpl, PushCdnImpl, CombinedImpl],
-    Types: [TestTypes, TestTwoStakeTablesTypes],
+    Types: [TestTypes, TestTwoStakeTablesTypes, TestTypesWithDrb],
     Versions: [EpochsTestVersions],
     Ignore: false,
     Metadata: {
@@ -168,7 +169,7 @@ cross_tests!(
 cross_tests!(
     TestName: test_epoch_end,
     Impls: [CombinedImpl, Libp2pImpl, PushCdnImpl],
-    Types: [TestTypes, TestTwoStakeTablesTypes],
+    Types: [TestTypes, TestTwoStakeTablesTypes, TestTypesWithDrb],
     Versions: [EpochsTestVersions],
     Ignore: false,
     Metadata: {
@@ -192,7 +193,7 @@ cross_tests!(
 cross_tests!(
     TestName: test_shorter_decide,
     Impls: [Libp2pImpl, PushCdnImpl, CombinedImpl],
-    Types: [TestTypes, TestTwoStakeTablesTypes],
+    Types: [TestTypes, TestTwoStakeTablesTypes, TestTypesWithDrb],
     Versions: [EpochsTestVersions],
     Ignore: false,
     Metadata: {
@@ -495,7 +496,7 @@ cross_tests!(
 cross_tests!(
     TestName: test_all_restart_epochs,
     Impls: [CombinedImpl, PushCdnImpl],
-    Types: [TestTypes, TestTypesRandomizedLeader, TestTwoStakeTablesTypes],
+    Types: [TestTypes, TestTypesRandomizedLeader, TestTwoStakeTablesTypes, TestTypesWithDrb],
     Versions: [EpochsTestVersions],
     Ignore: false,
     Metadata: {
@@ -544,7 +545,7 @@ cross_tests!(
 cross_tests!(
     TestName: test_all_restart_one_da_with_epochs,
     Impls: [CombinedImpl],
-    Types: [TestTypes, TestTwoStakeTablesTypes],
+    Types: [TestTypes, TestTwoStakeTablesTypes, TestTypesWithDrb],
     Versions: [EpochsTestVersions],
     Ignore: false,
     Metadata: {

hotshot-types/src/drb.rs

@@ -4,12 +4,18 @@
 // You should have received a copy of the MIT License
 // along with the HotShot repository. If not, see <https://mit-license.org/>.
 
-use std::collections::BTreeMap;
+use std::{
+    collections::BTreeMap,
+    hash::{DefaultHasher, Hash, Hasher},
+};
 
 use sha2::{Digest, Sha256};
 use tokio::task::JoinHandle;
 
-use crate::traits::node_implementation::{ConsensusTime, NodeType};
+use crate::traits::{
+    node_implementation::{ConsensusTime, NodeType},
+    signature_key::SignatureKey,
+};
 
 // TODO: Add the following consts once we bench the hash time.
 // <https://github.com/EspressoSystems/HotShot/issues/3880>
@@ -70,6 +76,31 @@ pub fn compute_drb_result<TYPES: NodeType>(drb_seed_input: DrbSeedInput) -> DrbR
     drb_result
 }
 
+/// Use the DRB result to get the leader.
+///
+/// The DRB result is the output of a spawned `compute_drb_result` call.
+#[must_use]
+pub fn leader<TYPES: NodeType>(
+    view_number: TYPES::View,
+    stake_table: &[<TYPES::SignatureKey as SignatureKey>::StakeTableEntry],
+    drb_result: DrbResult,
+) -> TYPES::SignatureKey {
+    let mut hasher = DefaultHasher::new();
+
+    drb_result.hash(&mut hasher);
+    view_number.hash(&mut hasher);
+
+    #[allow(clippy::cast_possible_truncation)]
+    let hash = hasher.finish() as usize;
+
+    // TODO: Use the total stake rather than `len()` and update the indexing after switching to
+    // a weighted stake table.
+    // <https://github.com/EspressoSystems/HotShot/issues/3898>
+    let index = hash % stake_table.len();
+    let entry = stake_table[index].clone();
+    TYPES::SignatureKey::public_key(&entry)
+}
+
 /// Alias for in-progress DRB computation task, if there's any.
 pub type DrbComputation<TYPES> = Option<(<TYPES as NodeType>::Epoch, JoinHandle<DrbResult>)>;
 

hotshot/src/traits/election/mod.rs

@@ -15,6 +15,9 @@ pub mod randomized_committee_members;
 /// static (round robin) committee election
 pub mod static_committee;
 
+/// static (round robin) committee election with DRB
+pub mod static_committee_with_drb;
+
 /// static (round robin leader for 2 consecutive views) committee election
 pub mod static_committee_leader_two_views;
 /// two static (round robin) committees for even and odd epochs