add migration

pallets/loans/src/entities/loans.rs

@@ -574,3 +574,62 @@ impl<T: Config> TryFrom<(T::PoolId, ActiveLoan<T>)> for ActiveLoanInfo<T> {
 		})
 	}
 }
+
+/// Migration module that contains old loans types.
+/// Can be removed once chains contains pallet-loans version v3
+pub(crate) mod v2 {
+	use cfg_traits::Seconds;
+	use parity_scale_codec::Decode;
+
+	use crate::{
+		entities::pricing::{external::v2::ExternalActivePricing, internal::InternalActivePricing},
+		types::{LoanRestrictions, RepaidAmount, RepaymentSchedule},
+		AssetOf, Config,
+	};
+
+	#[derive(Decode)]
+	pub enum ActivePricing<T: Config> {
+		Internal(InternalActivePricing<T>),
+		External(ExternalActivePricing<T>),
+	}
+
+	#[derive(Decode)]
+	pub struct ActiveLoan<T: Config> {
+		pub schedule: RepaymentSchedule,
+		pub collateral: AssetOf<T>,
+		pub restrictions: LoanRestrictions,
+		pub borrower: T::AccountId,
+		pub write_off_percentage: T::Rate,
+		pub origination_date: Seconds,
+		pub pricing: ActivePricing<T>,
+		pub total_borrowed: T::Balance,
+		pub total_repaid: RepaidAmount<T::Balance>,
+		pub repayments_on_schedule_until: Seconds,
+	}
+
+	impl<T: Config> ActiveLoan<T> {
+		pub fn migrate(self) -> crate::entities::loans::ActiveLoan<T> {
+			crate::entities::loans::ActiveLoan {
+				schedule: self.schedule,
+				collateral: self.collateral,
+				restrictions: self.restrictions,
+				borrower: self.borrower,
+				write_off_percentage: self.write_off_percentage,
+				origination_date: self.origination_date,
+				pricing: match self.pricing {
+					ActivePricing::Internal(inner) => {
+						crate::entities::pricing::ActivePricing::Internal(inner)
+					}
+					ActivePricing::External(inner) => {
+						crate::entities::pricing::ActivePricing::External(
+							inner.migrate(self.origination_date),
+						)
+					}
+				},
+				total_borrowed: self.total_borrowed,
+				total_repaid: self.total_repaid,
+				repayments_on_schedule_until: self.repayments_on_schedule_until,
+			}
+		}
+	}
+}

pallets/loans/src/entities/pricing/external.rs

@@ -289,3 +289,38 @@ impl<T: Config> ExternalActivePricing<T> {
 		Ok(())
 	}
 }
+
+/// Migration module that contains old loans types.
+/// Can be removed once chains contains pallet-loans version v3
+pub(crate) mod v2 {
+	use cfg_traits::Seconds;
+	use parity_scale_codec::Decode;
+
+	use crate::{
+		entities::{interest::ActiveInterestRate, pricing::external::ExternalPricing},
+		Config,
+	};
+
+	#[derive(Decode)]
+	pub struct ExternalActivePricing<T: Config> {
+		pub info: ExternalPricing<T>,
+		pub outstanding_quantity: T::Quantity,
+		pub interest: ActiveInterestRate<T>,
+		pub latest_settlement_price: T::Balance,
+	}
+
+	impl<T: Config> ExternalActivePricing<T> {
+		pub fn migrate(
+			self,
+			settlement_price_updated: Seconds,
+		) -> crate::entities::pricing::external::ExternalActivePricing<T> {
+			crate::entities::pricing::external::ExternalActivePricing {
+				info: self.info,
+				outstanding_quantity: self.outstanding_quantity,
+				interest: self.interest,
+				latest_settlement_price: self.latest_settlement_price,
+				settlement_price_updated,
+			}
+		}
+	}
+}

pallets/loans/src/lib.rs

@@ -65,6 +65,8 @@ mod tests;
 #[cfg(feature = "runtime-benchmarks")]
 mod benchmarking;
 
+mod migrations;
+
 pub use pallet::*;
 pub use weights::WeightInfo;
 
@@ -115,7 +117,7 @@ pub mod pallet {
 	pub type AssetOf<T> = (<T as Config>::CollectionId, <T as Config>::ItemId);
 	pub type PriceOf<T> = (<T as Config>::Balance, <T as Config>::Moment);
 
-	const STORAGE_VERSION: StorageVersion = StorageVersion::new(2);
+	const STORAGE_VERSION: StorageVersion = StorageVersion::new(3);
 
 	#[pallet::pallet]
 	#[pallet::storage_version(STORAGE_VERSION)]
@@ -433,6 +435,13 @@ pub mod pallet {
 		}
 	}
 
+	#[pallet::hooks]
+	impl<T: Config> Hooks<BlockNumberFor<T>> for Pallet<T> {
+		fn on_runtime_upgrade() -> frame_support::weights::Weight {
+			migrations::migrate_from_v2_to_v3::<T>()
+		}
+	}
+
 	#[pallet::call]
 	impl<T: Config> Pallet<T> {
 		/// Creates a new loan against the collateral provided

pallets/loans/src/migrations.rs

@@ -0,0 +1,65 @@
+// Copyright 2024 Centrifuge Foundation (centrifuge.io).
+//
+// This file is part of the Centrifuge chain project.
+// Centrifuge is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version (see http://www.gnu.org/licenses).
+// Centrifuge is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+use frame_support::{
+	dispatch::GetStorageVersion, inherent::Vec, log, pallet_prelude::StorageVersion, traits::Get,
+	weights::Weight,
+};
+
+use crate::{ActiveLoans, Config, Pallet};
+
+mod v2 {
+	use frame_support::{pallet_prelude::*, storage_alias};
+
+	use crate::{entities::loans::v2, Config, Pallet};
+
+	pub type ActiveLoansVec<T> = BoundedVec<
+		(<T as Config>::LoanId, v2::ActiveLoan<T>),
+		<T as Config>::MaxActiveLoansPerPool,
+	>;
+
+	#[storage_alias]
+	pub type ActiveLoans<T: Config> = StorageMap<
+		Pallet<T>,
+		Blake2_128Concat,
+		<T as Config>::PoolId,
+		ActiveLoansVec<T>,
+		ValueQuery,
+	>;
+}
+
+pub fn migrate_from_v2_to_v3<T: Config>() -> Weight {
+	if Pallet::<T>::on_chain_storage_version() == StorageVersion::new(2) {
+		log::info!("Loans: Starting migration v2 -> v3");
+
+		ActiveLoans::<T>::translate::<v2::ActiveLoansVec<T>, _>(|_, active_loans| {
+			Some(
+				active_loans
+					.into_iter()
+					.map(|(loan_id, active_loan)| (loan_id, active_loan.migrate()))
+					.collect::<Vec<_>>()
+					.try_into()
+					.expect("size doest not change, qed"),
+			)
+		});
+
+		Pallet::<T>::current_storage_version().put::<Pallet<T>>();
+
+		let count = ActiveLoans::<T>::iter().count() as u64;
+		log::info!("Loans: Migrated {} pools", count);
+		T::DbWeight::get().reads_writes(count + 1, count + 1)
+	} else {
+		// wrong storage version
+		log::info!("Loans: Migration did not execute. This probably should be removed");
+		T::DbWeight::get().reads_writes(1, 0)
+	}
+}