Introduce `add_memo` for Crowdloans (#2728)

* Add memo, but don't use it yet

* add_memo

* add weights

* Update lib.rs

* Update crowdloan.rs

* add event

polkadot/runtime/common/src/crowdloan.rs

@@ -101,6 +101,7 @@ pub trait WeightInfo {
 	fn withdraw() -> Weight;
 	fn dissolve(k: u32, ) -> Weight;
 	fn edit() -> Weight;
+	fn add_memo() -> Weight;
 	fn on_initialize(n: u32, ) -> Weight;
 }
 
@@ -111,6 +112,7 @@ impl WeightInfo for TestWeightInfo {
 	fn withdraw() -> Weight { 0 }
 	fn dissolve(_k: u32, ) -> Weight { 0 }
 	fn edit() -> Weight { 0 }
+	fn add_memo() -> Weight { 0 }
 	fn on_initialize(_n: u32, ) -> Weight { 0 }
 }
 
@@ -148,6 +150,9 @@ pub trait Config: frame_system::Config {
 		LeasePeriod=Self::BlockNumber,
 	>;
 
+	/// The maximum length for the memo attached to a crowdloan contribution.
+	type MaxMemoLength: Get<u8>;
+
 	/// Weight Information for the Extrinsics in the Pallet
 	type WeightInfo: WeightInfo;
 }
@@ -242,6 +247,8 @@ decl_event! {
 		HandleBidResult(ParaId, DispatchResult),
 		/// The configuration to a crowdloan has been edited. [fund_index]
 		Edited(ParaId),
+		/// A memo has been updated. [who, fund_index, memo]
+		MemoUpdated(AccountId, ParaId, Vec<u8>),
 	}
 }
 
@@ -287,6 +294,8 @@ decl_error! {
 		NotReadyToDissolve,
 		/// Invalid signature.
 		InvalidSignature,
+		/// The provided memo is too large.
+		MemoTooLarge,
 	}
 }
 
@@ -357,7 +366,7 @@ decl_module! {
 		pub fn contribute(origin,
 			#[compact] index: ParaId,
 			#[compact] value: BalanceOf<T>,
-			signature: Option<MultiSignature>
+			signature: Option<MultiSignature>,
 		) {
 			let who = ensure_signed(origin)?;
 
@@ -370,7 +379,7 @@ decl_module! {
 			let now = <frame_system::Pallet<T>>::block_number();
 			ensure!(now < fund.end, Error::<T>::ContributionPeriodOver);
 
-			let old_balance = Self::contribution_get(fund.trie_index, &who);
+			let (old_balance, memo) = Self::contribution_get(fund.trie_index, &who);
 
 			if let Some(ref verifier) = fund.verifier {
 				let signature = signature.ok_or(Error::<T>::InvalidSignature)?;
@@ -382,7 +391,7 @@ decl_module! {
 			CurrencyOf::<T>::transfer(&who, &Self::fund_account_id(index), value, AllowDeath)?;
 
 			let balance = old_balance.saturating_add(value);
-			Self::contribution_put(fund.trie_index, &who, &balance);
+			Self::contribution_put(fund.trie_index, &who, &balance, &memo);
 
 			if T::Auctioneer::is_ending(now).is_some() {
 				match fund.last_contribution {
@@ -443,7 +452,7 @@ decl_module! {
 			let fund_account = Self::fund_account_id(index);
 			Self::ensure_crowdloan_ended(now, &fund_account, &fund)?;
 
-			let balance = Self::contribution_get(fund.trie_index, &who);
+			let (balance, _) = Self::contribution_get(fund.trie_index, &who);
 			ensure!(balance > Zero::zero(), Error::<T>::NoContributions);
 
 			CurrencyOf::<T>::transfer(&fund_account, &who, balance, AllowDeath)?;
@@ -531,6 +540,23 @@ decl_module! {
 			Self::deposit_event(RawEvent::Edited(index));
 		}
 
+		/// Add an optional memo to an existing crowdloan contribution.
+		///
+		/// Origin must be Signed, and the user must have contributed to the crowdloan.
+		#[weight = T::WeightInfo::add_memo()]
+		pub fn add_memo(origin, index: ParaId, memo: Vec<u8>) {
+			let who = ensure_signed(origin)?;
+
+			ensure!(memo.len() <= T::MaxMemoLength::get().into(), Error::<T>::MemoTooLarge);
+			let fund = Self::funds(index).ok_or(Error::<T>::InvalidParaId)?;
+
+			let (balance, _) = Self::contribution_get(fund.trie_index, &who);
+			ensure!(balance > Zero::zero(), Error::<T>::NoContributions);
+
+			Self::contribution_put(fund.trie_index, &who, &balance, &memo);
+			Self::deposit_event(RawEvent::MemoUpdated(who, index, memo));
+		}
+
 		fn on_initialize(n: T::BlockNumber) -> frame_support::weights::Weight {
 			if let Some(n) = T::Auctioneer::is_ending(n) {
 				if n.is_zero() {
@@ -576,12 +602,12 @@ impl<T: Config> Module<T> {
 		child::ChildInfo::new_default(T::Hashing::hash(&buf[..]).as_ref())
 	}
 
-	pub fn contribution_put(index: TrieIndex, who: &T::AccountId, balance: &BalanceOf<T>) {
-		who.using_encoded(|b| child::put(&Self::id_from_index(index), b, balance));
+	pub fn contribution_put(index: TrieIndex, who: &T::AccountId, balance: &BalanceOf<T>, memo: &[u8]) {
+		who.using_encoded(|b| child::put(&Self::id_from_index(index), b, &(balance, memo)));
 	}
 
-	pub fn contribution_get(index: TrieIndex, who: &T::AccountId) -> BalanceOf<T> {
-		who.using_encoded(|b| child::get_or_default::<BalanceOf<T>>(
+	pub fn contribution_get(index: TrieIndex, who: &T::AccountId) -> (BalanceOf<T>, Vec<u8>) {
+		who.using_encoded(|b| child::get_or_default::<(BalanceOf<T>, Vec<u8>)>(
 			&Self::id_from_index(index),
 			b,
 		))
@@ -806,6 +832,7 @@ mod tests {
 		pub const RetirementPeriod: u64 = 5;
 		pub const CrowdloanModuleId: ModuleId = ModuleId(*b"py/cfund");
 		pub const RemoveKeysLimit: u32 = 10;
+		pub const MaxMemoLength: u8 = 32;
 	}
 
 	impl Config for Test {
@@ -818,6 +845,7 @@ mod tests {
 		type RemoveKeysLimit = RemoveKeysLimit;
 		type Registrar = TestRegistrar<Test>;
 		type Auctioneer = TestAuctioneer;
+		type MaxMemoLength = MaxMemoLength;
 		type WeightInfo = crate::crowdloan::TestWeightInfo;
 	}
 
@@ -865,7 +893,7 @@ mod tests {
 			assert_eq!(Crowdloan::funds(ParaId::from(0)), None);
 			let empty: Vec<ParaId> = Vec::new();
 			assert_eq!(Crowdloan::new_raise(), empty);
-			assert_eq!(Crowdloan::contribution_get(0u32, &1), 0);
+			assert_eq!(Crowdloan::contribution_get(0u32, &1).0, 0);
 			assert_eq!(Crowdloan::endings_count(), 0);
 
 			assert_ok!(TestAuctioneer::new_auction(5, 0));
@@ -976,14 +1004,14 @@ mod tests {
 			assert_ok!(Crowdloan::create(Origin::signed(1), para, 1000, 1, 4, 9, None));
 
 			// No contributions yet
-			assert_eq!(Crowdloan::contribution_get(u32::from(para), &1), 0);
+			assert_eq!(Crowdloan::contribution_get(u32::from(para), &1).0, 0);
 
 			// User 1 contributes to their own crowdloan
 			assert_ok!(Crowdloan::contribute(Origin::signed(1), para, 49, None));
 			// User 1 has spent some funds to do this, transfer fees **are** taken
 			assert_eq!(Balances::free_balance(1), 950);
 			// Contributions are stored in the trie
-			assert_eq!(Crowdloan::contribution_get(u32::from(para), &1), 49);
+			assert_eq!(Crowdloan::contribution_get(u32::from(para), &1).0, 49);
 			// Contributions appear in free balance of crowdloan
 			assert_eq!(Balances::free_balance(Crowdloan::fund_account_id(para)), 49);
 			// Crowdloan is added to NewRaise
@@ -1006,7 +1034,7 @@ mod tests {
 			assert_ok!(Crowdloan::create(Origin::signed(1), para, 1000, 1, 4, 9, Some(pubkey.clone())));
 
 			// No contributions yet
-			assert_eq!(Crowdloan::contribution_get(u32::from(para), &1), 0);
+			assert_eq!(Crowdloan::contribution_get(u32::from(para), &1).0, 0);
 
 			// Missing signature
 			assert_noop!(Crowdloan::contribute(Origin::signed(1), para, 49, None), Error::<Test>::InvalidSignature);
@@ -1351,6 +1379,34 @@ mod tests {
 			assert!(old_crowdloan.last_slot != new_crowdloan.last_slot);
 		});
 	}
+
+	#[test]
+	fn add_memo_works() {
+		new_test_ext().execute_with(|| {
+			let para_1 = new_para();
+
+			assert_ok!(Crowdloan::create(Origin::signed(1), para_1, 1000, 1, 1, 9, None));
+			// Cant add a memo before you have contributed.
+			assert_noop!(
+				Crowdloan::add_memo(Origin::signed(1), para_1, b"hello, world".to_vec()),
+				Error::<Test>::NoContributions,
+			);
+			// Make a contribution. Initially no memo.
+			assert_ok!(Crowdloan::contribute(Origin::signed(1), para_1, 100, None));
+			assert_eq!(Crowdloan::contribution_get(0u32, &1), (100, vec![]));
+			// Can't place a memo that is too large.
+			assert_noop!(
+				Crowdloan::add_memo(Origin::signed(1), para_1, vec![123; 123]),
+				Error::<Test>::MemoTooLarge,
+			);
+			// Adding a memo to an existing contribution works
+			assert_ok!(Crowdloan::add_memo(Origin::signed(1), para_1, b"hello, world".to_vec()));
+			assert_eq!(Crowdloan::contribution_get(0u32, &1), (100, b"hello, world".to_vec()));
+			// Can contribute again and data persists
+			assert_ok!(Crowdloan::contribute(Origin::signed(1), para_1, 100, None));
+			assert_eq!(Crowdloan::contribution_get(0u32, &1), (200, b"hello, world".to_vec()));
+		});
+	}
 }
 
 #[cfg(feature = "runtime-benchmarks")]
@@ -1520,6 +1576,20 @@ mod benchmarking {
 			assert_last_event::<T>(RawEvent::Edited(para_id).into())
 		}
 
+		add_memo {
+			let fund_index = create_fund::<T>(1, 100u32.into());
+			let caller: T::AccountId = whitelisted_caller();
+			contribute_fund::<T>(&caller, fund_index);
+			let worst_memo = vec![42; T::MaxMemoLength::get().into()];
+		}: _(RawOrigin::Signed(caller.clone()), fund_index, worst_memo.clone())
+		verify {
+			let fund = Funds::<T>::get(fund_index).expect("fund was created...");
+			assert_eq!(
+				Crowdloan::<T>::contribution_get(fund.trie_index, &caller),
+				(T::MinContribution::get(), worst_memo),
+			);
+		}
+
 		// Worst case scenario: N funds are all in the `NewRaise` list, we are
 		// in the beginning of the ending period, and each fund outbids the next
 		// over the same slot.

polkadot/runtime/common/src/integration_tests.rs

@@ -216,7 +216,7 @@ parameter_types! {
 	pub const MinContribution: Balance = 1;
 	pub const RetirementPeriod: BlockNumber = 10;
 	pub const RemoveKeysLimit: u32 = 100;
-
+	pub const MaxMemoLength: u8 = 32;
 }
 
 impl crowdloan::Config for Test {
@@ -229,6 +229,7 @@ impl crowdloan::Config for Test {
 	type RemoveKeysLimit = RemoveKeysLimit;
 	type Registrar = Registrar;
 	type Auctioneer = Auctions;
+	type MaxMemoLength = MaxMemoLength;
 	type WeightInfo = crate::crowdloan::TestWeightInfo;
 }
 

polkadot/runtime/rococo/src/lib.rs

@@ -660,6 +660,8 @@ parameter_types! {
 	pub const MinContribution: Balance = 1 * DOLLARS;
 	pub const RetirementPeriod: BlockNumber = 6 * HOURS;
 	pub const RemoveKeysLimit: u32 = 500;
+	// Allow 32 bytes for an additional memo to a crowdloan.
+	pub const MaxMemoLength: u8 = 32;
 }
 
 impl crowdloan::Config for Runtime {
@@ -672,6 +674,7 @@ impl crowdloan::Config for Runtime {
 	type RemoveKeysLimit = RemoveKeysLimit;
 	type Registrar = Registrar;
 	type Auctioneer = Auctions;
+	type MaxMemoLength = MaxMemoLength;
 	type WeightInfo = crowdloan::TestWeightInfo;
 }