Merge pull request paritytech#374 from subspace/change/solution_adjus…

…tment

crates/pallet-subspace/Cargo.toml

@@ -37,7 +37,6 @@ subspace-solving = { version = "0.1.0", path = "../subspace-solving" }
 
 [features]
 default = ["std"]
-no-early-solution-range-updates = []
 std = [
 	"codec/std",
 	"frame-support/std",
@@ -52,5 +51,6 @@ std = [
 	"sp-runtime/std",
 	"sp-std/std",
 	"subspace-core-primitives/std",
+	"subspace-runtime-primitives/std"
 ]
 try-runtime = ["frame-support/try-runtime"]

crates/pallet-subspace/src/lib.rs

@@ -98,7 +98,7 @@ pub struct NormalEraChange;
 impl EraChangeTrigger for NormalEraChange {
     fn trigger<T: Config>(block_number: T::BlockNumber) {
         if <Pallet<T>>::should_era_change(block_number) {
-            <Pallet<T>>::enact_era_change(block_number);
+            <Pallet<T>>::enact_era_change();
         }
     }
 }
@@ -218,6 +218,8 @@ mod pallet {
         #[pallet::constant]
         type RecordedHistorySegmentSize: Get<u32>;
 
+        type ShouldAdjustSolutionRange: Get<bool>;
+
         /// Subspace requires periodic global randomness update.
         type GlobalRandomnessIntervalTrigger: GlobalRandomnessIntervalTrigger;
 
@@ -292,6 +294,11 @@ mod pallet {
         InitialSolutionRanges<T>,
     >;
 
+    /// Storage to check if the solution range is to be adjusted for next era
+    #[pallet::storage]
+    pub type ShouldAdjustSolutionRange<T: Config> =
+        StorageValue<_, bool, ValueQuery, T::ShouldAdjustSolutionRange>;
+
     /// Salts used for challenges.
     #[pallet::storage]
     #[pallet::getter(fn salts)]
@@ -357,6 +364,15 @@ mod pallet {
             ensure_none(origin)?;
             Self::do_store_root_blocks(root_blocks)
         }
+
+        /// Enables solution range adjustment after every era.
+        /// Note: No effect on the solution range for the current era
+        #[pallet::weight(T::DbWeight::get().writes(1))]
+        pub fn enable_solution_range_adjustment(origin: OriginFor<T>) -> DispatchResult {
+            ensure_root(origin)?;
+            ShouldAdjustSolutionRange::<T>::put(true);
+            Ok(())
+        }
     }
 
     #[pallet::inherent]
@@ -484,40 +500,37 @@ impl<T: Config> Pallet<T> {
     /// returned `true`, and the caller is the only caller of this function.
     ///
     /// This will update solution range used in consensus.
-    pub fn enact_era_change(block_number: T::BlockNumber) {
+    pub fn enact_era_change() {
         let slot_probability = T::SlotProbability::get();
 
         let current_slot = Self::current_slot();
 
         SolutionRanges::<T>::mutate(|solution_ranges| {
-            // If Era start slot is not found it means we have just finished the first era
-            let era_start_slot = EraStartSlot::<T>::get().unwrap_or_else(GenesisSlot::<T>::get);
-            let era_slot_count = u64::from(current_slot) - u64::from(era_start_slot);
-
-            // Now we need to re-calculate solution range. The idea here is to keep block production at
-            // the same pace while space pledged on the network changes. For this we adjust previous
-            // solution range according to actual and expected number of blocks per era.
-            let era_duration: u64 = T::EraDuration::get()
-                .try_into()
-                .unwrap_or_else(|_| panic!("Era duration is always within u64; qed"));
-            let actual_slots_per_block = era_slot_count as f64 / era_duration as f64;
-            let expected_slots_per_block = slot_probability.1 as f64 / slot_probability.0 as f64;
-            let adjustment_factor =
-                (actual_slots_per_block / expected_slots_per_block).clamp(0.25, 4.0);
-
             solution_ranges.next.replace(
-                // TODO: Temporary testnet hack, we don't update solution range for the first 15_000 blocks
-                //  in order to seed the blockchain with data quickly
-                if cfg!(all(feature = "no-early-solution-range-updates", not(test))) {
-                    if block_number < 15_000_u32.into() {
-                        solution_ranges.current
-                    } else {
-                        (solution_ranges.current as f64 * adjustment_factor).round() as u64
-                    }
-                } else {
+                // Check if the solution range should be adjusted for next era.
+                if ShouldAdjustSolutionRange::<T>::get() {
+                    // If Era start slot is not found it means we have just finished the first era
+                    let era_start_slot =
+                        EraStartSlot::<T>::get().unwrap_or_else(GenesisSlot::<T>::get);
+                    let era_slot_count = u64::from(current_slot) - u64::from(era_start_slot);
+
+                    // Now we need to re-calculate solution range. The idea here is to keep block production at
+                    // the same pace while space pledged on the network changes. For this we adjust previous
+                    // solution range according to actual and expected number of blocks per era.
+                    let era_duration: u64 = T::EraDuration::get()
+                        .try_into()
+                        .unwrap_or_else(|_| panic!("Era duration is always within u64; qed"));
+                    let actual_slots_per_block = era_slot_count as f64 / era_duration as f64;
+                    let expected_slots_per_block =
+                        slot_probability.1 as f64 / slot_probability.0 as f64;
+                    let adjustment_factor =
+                        (actual_slots_per_block / expected_slots_per_block).clamp(0.25, 4.0);
+
                     (solution_ranges.current as f64 * adjustment_factor).round() as u64
+                } else {
+                    solution_ranges.current
                 },
-            );
+            )
         });
 
         EraStartSlot::<T>::put(current_slot);

crates/pallet-subspace/src/mock.rs

@@ -142,6 +142,7 @@ parameter_types! {
     pub const ReplicationFactor: u16 = 1;
     pub const ReportLongevity: u64 = 34;
     pub const MaxPlotSize: u64 = 10 * 2u64.pow(18);
+    pub const ShouldAdjustSolutionRange: bool = false;
 }
 
 impl Config for Test {
@@ -164,6 +165,7 @@ impl Config for Test {
     type HandleEquivocation = EquivocationHandler<OffencesSubspace, ReportLongevity>;
 
     type WeightInfo = ();
+    type ShouldAdjustSolutionRange = ShouldAdjustSolutionRange;
 }
 
 pub fn go_to_block(keypair: &Keypair, block: u64, slot: u64) {

crates/pallet-subspace/src/tests.rs

@@ -99,6 +99,8 @@ fn can_update_solution_range_on_era_change() {
             next: None,
         };
         assert_eq!(Subspace::solution_ranges(), initial_solution_ranges);
+        // enable solution range adjustment
+        assert_ok!(Subspace::enable_solution_range_adjustment(Origin::root()));
 
         // Progress to almost era edge
         progress_to_block(&keypair, 3);
@@ -142,6 +144,67 @@ fn can_update_solution_range_on_era_change() {
     })
 }
 
+#[test]
+fn solution_range_should_not_update_when_disabled() {
+    new_test_ext().execute_with(|| {
+        let keypair = Keypair::generate();
+
+        assert_eq!(<Test as Config>::EraDuration::get(), 4);
+        assert_eq!(
+            <Test as Config>::InitialSolutionRange::get(),
+            INITIAL_SOLUTION_RANGE
+        );
+        let initial_solution_ranges = SolutionRanges {
+            current: INITIAL_SOLUTION_RANGE,
+            next: None,
+        };
+        assert_eq!(Subspace::solution_ranges(), initial_solution_ranges);
+
+        // Progress to almost era edge
+        progress_to_block(&keypair, 3);
+        // No solution range update
+        assert_eq!(Subspace::solution_ranges(), initial_solution_ranges);
+
+        // Era edge
+        progress_to_block(&keypair, 4);
+        // Next solution range should be updated, but current is still unchanged
+        let updated_solution_ranges = Subspace::solution_ranges();
+        assert_eq!(
+            updated_solution_ranges.current,
+            initial_solution_ranges.current
+        );
+        assert!(updated_solution_ranges.next.is_some());
+
+        progress_to_block(&keypair, 5);
+        // Next solution range should become current
+        assert_eq!(
+            Subspace::solution_ranges(),
+            SolutionRanges {
+                current: updated_solution_ranges.next.unwrap(),
+                next: None
+            }
+        );
+
+        // since solution range adjustment was disabled, solution range will remain the same
+        let last_solution_range = Subspace::solution_ranges().current;
+        assert_eq!(last_solution_range, INITIAL_SOLUTION_RANGE);
+
+        // Progress to era edge such that it takes more slots than expected
+        go_to_block(
+            &keypair,
+            8,
+            u64::from(Subspace::current_slot())
+                + (4 * SLOT_PROBABILITY.1 / SLOT_PROBABILITY.0 + 10),
+        );
+        // Solution rage will still be the same even after the apparent pledged space has decreased
+        // since adjustment is disabled
+        assert_eq!(
+            Subspace::solution_ranges().next.unwrap(),
+            INITIAL_SOLUTION_RANGE
+        );
+    })
+}
+
 #[test]
 fn can_update_salt_on_eon_change() {
     new_test_ext().execute_with(|| {

crates/subspace-runtime/Cargo.toml

@@ -30,7 +30,7 @@ pallet-grandpa-finality-verifier = { version = "1.0.0", default-features = false
 pallet-object-store = { version = "0.1.0", default-features = false, path = "../pallet-object-store" }
 pallet-offences-subspace = { version = "0.1.0", default-features = false, path = "../pallet-offences-subspace" }
 pallet-rewards = { version = "0.1.0", default-features = false, path = "../pallet-rewards" }
-pallet-subspace = { version = "0.1.0", default-features = false, features = ["no-early-solution-range-updates"], path = "../pallet-subspace" }
+pallet-subspace = { version = "0.1.0", default-features = false, path = "../pallet-subspace" }
 pallet-sudo = { version = "4.0.0-dev", default-features = false, git = "https://github.com/paritytech/substrate", rev = "c4f3d028621edb293d2c423516221aa396f76a2d" }
 pallet-timestamp = { version = "4.0.0-dev", default-features = false, git = "https://github.com/paritytech/substrate", rev = "c4f3d028621edb293d2c423516221aa396f76a2d" }
 pallet-transaction-fees = { version = "0.1.0", default-features = false, path = "../pallet-transaction-fees" }

crates/subspace-runtime/src/lib.rs

@@ -255,6 +255,9 @@ impl frame_system::Config for Runtime {
 parameter_types! {
     pub const SlotProbability: (u64, u64) = SLOT_PROBABILITY;
     pub const ExpectedBlockTime: Moment = MILLISECS_PER_BLOCK;
+    // Disable solution range adjustment at the start of chain.
+    // Root origin must enable later
+    pub const ShouldAdjustSolutionRange: bool = false;
 }
 
 impl pallet_subspace::Config for Runtime {
@@ -270,6 +273,7 @@ impl pallet_subspace::Config for Runtime {
     type RecordSize = ConstU32<RECORD_SIZE>;
     type MaxPlotSize = ConstU64<MAX_PLOT_SIZE>;
     type RecordedHistorySegmentSize = ConstU32<RECORDED_HISTORY_SEGMENT_SIZE>;
+    type ShouldAdjustSolutionRange = ShouldAdjustSolutionRange;
     type GlobalRandomnessIntervalTrigger = pallet_subspace::NormalGlobalRandomnessInterval;
     type EraChangeTrigger = pallet_subspace::NormalEraChange;
     type EonChangeTrigger = pallet_subspace::NormalEonChange;

substrate/substrate-test-runtime/src/lib.rs

@@ -651,6 +651,7 @@ impl pallet_babe::Config for Runtime {
 parameter_types! {
     pub const SlotProbability: (u64, u64) = (3, 10);
     pub const ExpectedBlockTime: u64 = 10_000;
+    pub const ShouldAdjustSolutionRange: bool = false;
 }
 
 impl pallet_subspace::Config for Runtime {
@@ -666,6 +667,7 @@ impl pallet_subspace::Config for Runtime {
     type RecordSize = ConstU32<3840>;
     type MaxPlotSize = ConstU64<{ 10 * 1024 * 1024 * 1024 / PIECE_SIZE as u64 }>;
     type RecordedHistorySegmentSize = ConstU32<{ 3840 * 256 / 2 }>;
+    type ShouldAdjustSolutionRange = ShouldAdjustSolutionRange;
     type GlobalRandomnessIntervalTrigger = pallet_subspace::NormalGlobalRandomnessInterval;
     type EraChangeTrigger = pallet_subspace::NormalEraChange;
     type EonChangeTrigger = pallet_subspace::NormalEonChange;

test/subspace-test-runtime/Cargo.toml

@@ -30,7 +30,7 @@ pallet-grandpa-finality-verifier = { version = "1.0.0", default-features = false
 pallet-object-store = { version = "0.1.0", default-features = false, path = "../../crates/pallet-object-store" }
 pallet-offences-subspace = { version = "0.1.0", default-features = false, path = "../../crates/pallet-offences-subspace" }
 pallet-rewards = { version = "0.1.0", default-features = false, path = "../../crates/pallet-rewards" }
-pallet-subspace = { version = "0.1.0", default-features = false, features = ["no-early-solution-range-updates"], path = "../../crates/pallet-subspace" }
+pallet-subspace = { version = "0.1.0", default-features = false, path = "../../crates/pallet-subspace" }
 pallet-sudo = { version = "4.0.0-dev", default-features = false, git = "https://github.com/paritytech/substrate", rev = "c4f3d028621edb293d2c423516221aa396f76a2d" }
 pallet-timestamp = { version = "4.0.0-dev", default-features = false, git = "https://github.com/paritytech/substrate", rev = "c4f3d028621edb293d2c423516221aa396f76a2d" }
 pallet-transaction-fees = { version = "0.1.0", default-features = false, path = "../../crates/pallet-transaction-fees" }

test/subspace-test-runtime/src/lib.rs

@@ -230,6 +230,7 @@ impl frame_system::Config for Runtime {
 parameter_types! {
     pub const SlotProbability: (u64, u64) = SLOT_PROBABILITY;
     pub const ExpectedBlockTime: Moment = MILLISECS_PER_BLOCK;
+    pub const ShouldAdjustSolutionRange: bool = false;
 }
 
 impl pallet_subspace::Config for Runtime {
@@ -245,6 +246,7 @@ impl pallet_subspace::Config for Runtime {
     type RecordSize = ConstU32<RECORD_SIZE>;
     type MaxPlotSize = ConstU64<MAX_PLOT_SIZE>;
     type RecordedHistorySegmentSize = ConstU32<RECORDED_HISTORY_SEGMENT_SIZE>;
+    type ShouldAdjustSolutionRange = ShouldAdjustSolutionRange;
     type GlobalRandomnessIntervalTrigger = pallet_subspace::NormalGlobalRandomnessInterval;
     type EraChangeTrigger = pallet_subspace::NormalEraChange;
     type EonChangeTrigger = pallet_subspace::NormalEonChange;