limit iterations on evict_anchors (centrifuge#969)

* limit iterations on evict_anchors

* adapt tests to allow different MAX_LOOP_IN_TX values

* add migration for evict_anchors

* update versions

* add nix

* add migration to altair upgrade

* add pre/post migrations from altair

* fix migration on altair

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "centrifuge-chain"
-version = "0.10.19"
+version = "0.10.20"
 authors = ["Centrifuge <admin@centrifuge.io>"]
 description = "Centrifuge chain implementation in Rust."
 build = "build.rs"
@@ -198,6 +198,7 @@ cli = [
 ]
 try-runtime = [
 	"centrifuge-runtime/try-runtime",
+	"altair-runtime/try-runtime",
 	"try-runtime-cli"
 ]
 

flake.nix

@@ -96,7 +96,7 @@
             };
 
             # This is a hash of all the Cargo dependencies, for reproducibility.
-            cargoSha256 = "kFHDl4I5rcr70DlXOA45JijbGE/s3rhQhq2mSOUeH1c=";
+            cargoSha256 = "sha256-cR0wDbc3hJr0wXUbOKjsBppVmQQLLPeZs4O/j3f1MBc=";
 
             nativeBuildInputs = with pkgs; [ clang git-mock pkg-config ];
             buildInputs = with pkgs; [ openssl ] ++ (

pallets/anchors/Cargo.toml

@@ -39,6 +39,7 @@ runtime-benchmarks = [
     "frame-benchmarking/runtime-benchmarks",
     "pallet-timestamp/runtime-benchmarks",
 ]
+try-runtime = ["frame-support/try-runtime"]
 std = [
     'codec/std',
     'sp-core/std',

pallets/anchors/src/benchmarking.rs

@@ -114,7 +114,7 @@ benchmarks! {
 			)?;
 		}
 
-		pallet_timestamp::Pallet::<T>::set_timestamp(day(2));
+		pallet_timestamp::Pallet::<T>::set_timestamp(day(MAX_LOOP_IN_TX));
 
 	}: _(RawOrigin::Signed(caller))
 	verify {

pallets/anchors/src/lib.rs

@@ -46,6 +46,8 @@ mod tests;
 #[cfg(feature = "runtime-benchmarks")]
 mod benchmarking;
 
+pub mod migration;
+
 mod common;
 
 type BalanceOf<T> =
@@ -58,7 +60,7 @@ type BalanceOf<T> =
 const PRE_COMMIT_EXPIRATION_DURATION_BLOCKS: u32 = 800;
 
 /// Determines how many loop iterations are allowed to run at a time inside the runtime.
-const MAX_LOOP_IN_TX: u64 = 500;
+const MAX_LOOP_IN_TX: u64 = 100;
 
 /// date 3000-01-01 -> 376200 days from unix epoch
 const STORAGE_MAX_DAYS: u32 = 376200;
@@ -385,10 +387,15 @@ pub mod pallet {
 				.ok_or(ArithmeticError::Overflow)?;
 
 			// store yesterday as the last day of eviction
-			let yesterday = today_in_days_from_epoch
+			let mut yesterday = today_in_days_from_epoch
 				.checked_sub(1)
 				.ok_or(ArithmeticError::Underflow)?;
 
+			// Avoid to iterate more than 500 days
+			if yesterday > evict_date + MAX_LOOP_IN_TX as u32 {
+				yesterday = evict_date + MAX_LOOP_IN_TX as u32 - 1;
+			}
+
 			// remove child tries starting from day next to last evicted day
 			let _evicted_trie_count =
 				Self::evict_anchor_child_tries(evict_date, today_in_days_from_epoch);

pallets/anchors/src/migration.rs

@@ -0,0 +1,78 @@
+use super::*;
+
+pub mod fix_evict_date {
+	use super::*;
+
+	use frame_support::{log, traits::Get, weights::Weight};
+
+	pub const HARDCODED_EVICTED_DATE: u32 = 19200;
+
+	#[cfg(feature = "try-runtime")]
+	use frame_support::ensure; // Not in prelude for try-runtime
+
+	#[cfg(feature = "try-runtime")]
+	pub fn pre_migrate<T: Config>() -> Result<(), &'static str> {
+		ensure!(
+			LatestEvictedDate::<T>::get() == None,
+			"State already initialized"
+		);
+		Ok(())
+	}
+
+	pub fn migrate<T: Config>() -> Weight {
+		if LatestEvictedDate::<T>::get().is_none() {
+			LatestEvictedDate::<T>::put(HARDCODED_EVICTED_DATE);
+			log::info!("pallet_anchors: fix evict date");
+			return T::DbWeight::get().writes(1);
+		}
+
+		0
+	}
+
+	#[cfg(feature = "try-runtime")]
+	pub fn post_migrate<T: Config>() -> Result<(), &'static str> {
+		ensure!(
+			LatestEvictedDate::<T>::get() == Some(HARDCODED_EVICTED_DATE),
+			"State not initialized"
+		);
+		Ok(())
+	}
+}
+
+#[cfg(test)]
+#[cfg(feature = "try-runtime")]
+mod test {
+	use super::*;
+	use crate::mock::{new_test_ext, Origin, Test};
+	use crate::{self as pallet_anchors};
+	use frame_support::assert_ok;
+
+	#[test]
+	fn evict_anchors_working_after_migration() {
+		new_test_ext().execute_with(|| {
+			// Check migration:
+			assert_ok!(fix_evict_date::pre_migrate::<Test>());
+			assert!(fix_evict_date::post_migrate::<Test>().is_err());
+
+			fix_evict_date::migrate::<Test>();
+
+			assert_ok!(fix_evict_date::post_migrate::<Test>());
+			assert!(fix_evict_date::pre_migrate::<Test>().is_err());
+
+			// Check correct evict behaviour after migration:
+			let current_day = common::MILLISECS_PER_DAY
+				* (fix_evict_date::HARDCODED_EVICTED_DATE as u64 + MAX_LOOP_IN_TX * 3);
+
+			pallet_timestamp::Pallet::<Test>::set_timestamp(current_day);
+
+			assert_ok!(pallet_anchors::Pallet::<Test>::evict_anchors(
+				Origin::signed(1)
+			));
+
+			assert_eq!(
+				LatestEvictedDate::<Test>::get(),
+				Some(fix_evict_date::HARDCODED_EVICTED_DATE + MAX_LOOP_IN_TX as u32)
+			);
+		});
+	}
+}