contracts: Add storage deposits

bin/node/executor/Cargo.toml

@@ -20,6 +20,7 @@ sc-executor = { version = "0.10.0-dev", path = "../../../client/executor" }
 sp-core = { version = "4.0.0-dev", path = "../../../primitives/core" }
 sp-keystore = { version = "0.10.0-dev", path = "../../../primitives/keystore" }
 sp-state-machine = { version = "0.10.0-dev", path = "../../../primitives/state-machine" }
+sp-tracing = { version = "4.0.0-dev", path = "../../../primitives/tracing" }
 sp-trie = { version = "4.0.0-dev", path = "../../../primitives/trie" }
 frame-benchmarking = { version = "4.0.0-dev", path = "../../../frame/benchmarking" }
 

bin/node/executor/tests/basic.rs

@@ -684,7 +684,7 @@ fn deploying_wasm_contract_should_work() {
 
 	let addr = pallet_contracts::Pallet::<Runtime>::contract_address(&charlie(), &transfer_ch, &[]);
 
-	let subsistence = pallet_contracts::Pallet::<Runtime>::subsistence_threshold();
+	let min_balance = <Runtime as pallet_contracts::Config>::Currency::minimum_balance();
 
 	let time = 42 * 1000;
 	let b = construct_block(
@@ -700,8 +700,9 @@ fn deploying_wasm_contract_should_work() {
 				signed: Some((charlie(), signed_extra(0, 0))),
 				function: Call::Contracts(
 					pallet_contracts::Call::instantiate_with_code::<Runtime> {
-						endowment: 1000 * DOLLARS + subsistence,
+						endowment: 1000 * DOLLARS + min_balance,
 						gas_limit: 500_000_000,
+						storage_limit: None,
 						code: transfer_code,
 						data: Vec::new(),
 						salt: Vec::new(),
@@ -714,6 +715,7 @@ fn deploying_wasm_contract_should_work() {
 					dest: sp_runtime::MultiAddress::Id(addr.clone()),
 					value: 10,
 					gas_limit: 500_000_000,
+					storage_limit: None,
 					data: vec![0x00, 0x01, 0x02, 0x03],
 				}),
 			},

bin/node/executor/tests/common.rs

@@ -119,7 +119,7 @@ pub fn executor_call<
 		hash: sp_core::blake2_256(&code).to_vec(),
 		heap_pages: heap_pages.and_then(|hp| Decode::decode(&mut &hp[..]).ok()),
 	};
-
+	sp_tracing::try_init_simple();
 	executor().call::<R, NC>(&mut t, &runtime_code, method, data, use_native, native_call)
 }
 

bin/node/runtime/src/lib.rs

@@ -895,10 +895,8 @@ impl pallet_tips::Config for Runtime {
 }
 
 parameter_types! {
-	pub ContractDeposit: Balance = deposit(
-		1,
-		<pallet_contracts::Pallet<Runtime>>::contract_info_size(),
-	);
+	pub const DepositPerItem: Balance = deposit(1, 0);
+	pub const DepositPerByte: Balance = deposit(0, 1);
 	pub const MaxValueSize: u32 = 16 * 1024;
 	// The lazy deletion runs inside on_initialize.
 	pub DeletionWeightLimit: Weight = AVERAGE_ON_INITIALIZE_RATIO *
@@ -925,7 +923,8 @@ impl pallet_contracts::Config for Runtime {
 	/// change because that would break already deployed contracts. The `Call` structure itself
 	/// is not allowed to change the indices of existing pallets, too.
 	type CallFilter = Nothing;
-	type ContractDeposit = ContractDeposit;
+	type DepositPerItem = DepositPerItem;
+	type DepositPerByte = DepositPerByte;
 	type CallStack = [pallet_contracts::Frame<Self>; 31];
 	type WeightPrice = pallet_transaction_payment::Pallet<Self>;
 	type WeightInfo = pallet_contracts::weights::SubstrateWeight<Self>;
@@ -1518,21 +1517,32 @@ impl_runtime_apis! {
 			dest: AccountId,
 			value: Balance,
 			gas_limit: u64,
+			storage_limit: Option<Balance>,
 			input_data: Vec<u8>,
-		) -> pallet_contracts_primitives::ContractExecResult {
-			Contracts::bare_call(origin, dest, value, gas_limit, input_data, true)
+		) -> pallet_contracts_primitives::ContractExecResult<Balance> {
+			Contracts::bare_call(origin, dest, value, gas_limit, storage_limit, input_data, true)
 		}
 
 		fn instantiate(
 			origin: AccountId,
 			endowment: Balance,
 			gas_limit: u64,
+			storage_limit: Option<Balance>,
 			code: pallet_contracts_primitives::Code<Hash>,
 			data: Vec<u8>,
 			salt: Vec<u8>,
-		) -> pallet_contracts_primitives::ContractInstantiateResult<AccountId>
+		) -> pallet_contracts_primitives::ContractInstantiateResult<AccountId, Balance>
+		{
+			Contracts::bare_instantiate(origin, endowment, gas_limit, storage_limit, code, data, salt, true)
+		}
+
+		fn upload_code(
+			origin: AccountId,
+			code: Vec<u8>,
+			storage_limit: Option<Balance>,
+		) -> pallet_contracts_primitives::CodeUploadResult<Hash, Balance>
 		{
-			Contracts::bare_instantiate(origin, endowment, gas_limit, code, data, salt, true)
+			Contracts::bare_upload_code(origin, code, storage_limit)
 		}
 
 		fn get_storage(

frame/contracts/common/src/lib.rs

@@ -22,7 +22,10 @@
 use bitflags::bitflags;
 use codec::{Decode, Encode};
 use sp_core::Bytes;
-use sp_runtime::{DispatchError, RuntimeDebug};
+use sp_runtime::{
+	traits::{Saturating, Zero},
+	DispatchError, RuntimeDebug,
+};
 use sp_std::prelude::*;
 
 #[cfg(feature = "std")]
@@ -34,7 +37,7 @@ use serde::{Deserialize, Serialize};
 #[derive(Eq, PartialEq, Encode, Decode, RuntimeDebug)]
 #[cfg_attr(feature = "std", derive(Serialize, Deserialize))]
 #[cfg_attr(feature = "std", serde(rename_all = "camelCase"))]
-pub struct ContractResult<T> {
+pub struct ContractResult<R, Balance> {
 	/// How much gas was consumed during execution.
 	pub gas_consumed: u64,
 	/// How much gas is required as gas limit in order to execute this call.
@@ -45,7 +48,14 @@ pub struct ContractResult<T> {
 	///
 	/// This can only different from [`Self::gas_consumed`] when weight pre charging
 	/// is used. Currently, only `seal_call_runtime` makes use of pre charging.
+	/// Additionally, any `seal_call` or `seal_instantiate` makes use of pre-charging
+	/// when a non-zero `gas_limit` argument is supplied.
 	pub gas_required: u64,
+	/// How much balance was deposited and reserved during execution in order to pay for storage.
+	///
+	/// The storage deposit is never actually charged from the caller in case of [`Self::result`]
+	/// is `Err`. This is because on error all storage changes are rolled back.
+	pub storage_deposit: StorageDeposit<Balance>,
 	/// An optional debug message. This message is only filled when explicitly requested
 	/// by the code that calls into the contract. Otherwise it is empty.
 	///
@@ -63,15 +73,20 @@ pub struct ContractResult<T> {
 	#[cfg_attr(feature = "std", serde(with = "as_string"))]
 	pub debug_message: Vec<u8>,
 	/// The execution result of the wasm code.
-	pub result: T,
+	pub result: R,
 }
 
 /// Result type of a `bare_call` call.
-pub type ContractExecResult = ContractResult<Result<ExecReturnValue, DispatchError>>;
+pub type ContractExecResult<Balance> =
+	ContractResult<Result<ExecReturnValue, DispatchError>, Balance>;
 
 /// Result type of a `bare_instantiate` call.
-pub type ContractInstantiateResult<AccountId> =
-	ContractResult<Result<InstantiateReturnValue<AccountId>, DispatchError>>;
+pub type ContractInstantiateResult<AccountId, Balance> =
+	ContractResult<Result<InstantiateReturnValue<AccountId>, DispatchError>, Balance>;
+
+/// Result type of a `bare_code_upload` call.
+pub type CodeUploadResult<CodeHash, Balance> =
+	Result<CodeUploadReturnValue<CodeHash, Balance>, DispatchError>;
 
 /// Result type of a `get_storage` call.
 pub type GetStorageResult = Result<Option<Vec<u8>>, ContractAccessError>;
@@ -123,6 +138,17 @@ pub struct InstantiateReturnValue<AccountId> {
 	pub account_id: AccountId,
 }
 
+/// The result of succesfully uploading a contract.
+#[derive(PartialEq, Eq, Encode, Decode, RuntimeDebug)]
+#[cfg_attr(feature = "std", derive(Serialize, Deserialize))]
+#[cfg_attr(feature = "std", serde(rename_all = "camelCase"))]
+pub struct CodeUploadReturnValue<CodeHash, Balance> {
+	/// The key under which the new code is stored.
+	pub code_hash: CodeHash,
+	/// The deposit that was reserved at the caller. Is zero when the code already existed.
+	pub deposit: Balance,
+}
+
 /// Reference to an existing code hash or a new wasm module.
 #[derive(Eq, PartialEq, Encode, Decode, RuntimeDebug)]
 #[cfg_attr(feature = "std", derive(Serialize, Deserialize))]
@@ -134,6 +160,100 @@ pub enum Code<Hash> {
 	Existing(Hash),
 }
 
+/// The amount of balance that was either charged or refunded in order to pay for storage.
+#[derive(Eq, PartialEq, Ord, PartialOrd, Encode, Decode, RuntimeDebug, Clone)]
+#[cfg_attr(feature = "std", derive(Serialize, Deserialize))]
+#[cfg_attr(feature = "std", serde(rename_all = "camelCase"))]
+pub enum StorageDeposit<Balance> {
+	/// The transaction reduced storage consumption.
+	///
+	/// This means that the specified amount of balance was transferred from the involved
+	/// contracts to the call origin.
+	Refund(Balance),
+	/// The transaction increased overall storage usage.
+	///
+	/// This means that the specified amount of balance was transferred from the call origin
+	/// to the contracts involved.
+	Charge(Balance),
+}
+
+impl<Balance: Zero> Default for StorageDeposit<Balance> {
+	fn default() -> Self {
+		Self::Charge(Zero::zero())
+	}
+}
+
+impl<Balance: Zero> StorageDeposit<Balance> {
+	/// Returns how much balance is charged or `0` in case of a refund.
+	pub fn charge_or_zero(self) -> Balance {
+		match self {
+			Self::Charge(amount) => amount,
+			Self::Refund(_) => Zero::zero(),
+		}
+	}
+}
+
+impl<Balance> StorageDeposit<Balance>
+where
+	Balance: Saturating + Ord + Copy,
+{
+	/// This is essentially a saturating signed add.
+	pub fn saturating_add(&self, rhs: &Self) -> Self {
+		use StorageDeposit::*;
+		match (self, rhs) {
+			(Charge(lhs), Charge(rhs)) => Charge(lhs.saturating_add(*rhs)),
+			(Refund(lhs), Refund(rhs)) => Refund(lhs.saturating_add(*rhs)),
+			(Charge(lhs), Refund(rhs)) =>
+				if lhs >= rhs {
+					Charge(lhs.saturating_sub(*rhs))
+				} else {
+					Refund(rhs.saturating_sub(*lhs))
+				},
+			(Refund(lhs), Charge(rhs)) =>
+				if lhs > rhs {
+					Refund(lhs.saturating_sub(*rhs))
+				} else {
+					Charge(rhs.saturating_sub(*lhs))
+				},
+		}
+	}
+
+	/// This is essentially a saturating signed sub.
+	pub fn saturating_sub(&self, rhs: &Self) -> Self {
+		use StorageDeposit::*;
+		match (self, rhs) {
+			(Charge(lhs), Refund(rhs)) => Charge(lhs.saturating_add(*rhs)),
+			(Refund(lhs), Charge(rhs)) => Refund(lhs.saturating_add(*rhs)),
+			(Charge(lhs), Charge(rhs)) =>
+				if lhs >= rhs {
+					Charge(lhs.saturating_sub(*rhs))
+				} else {
+					Refund(rhs.saturating_sub(*lhs))
+				},
+			(Refund(lhs), Refund(rhs)) =>
+				if lhs > rhs {
+					Refund(lhs.saturating_sub(*rhs))
+				} else {
+					Charge(rhs.saturating_sub(*lhs))
+				},
+		}
+	}
+
+	/// If the amount of deposit (this type) is constrained by a `limit` this calcuates how
+	/// much balance (if any) is still available from this limit.
+	///
+	/// # Note
+	///
+	/// In case of a refund the return value can be larger than `limit`.
+	pub fn available(&self, limit: &Balance) -> Balance {
+		use StorageDeposit::*;
+		match self {
+			Charge(amount) => limit.saturating_sub(*amount),
+			Refund(amount) => limit.saturating_add(*amount),
+		}
+	}
+}
+
 #[cfg(feature = "std")]
 mod as_string {
 	use super::*;

frame/contracts/fixtures/drain.wat

@@ -33,7 +33,9 @@
 			)
 		)
 
-		;; Self-destruct by sending full balance to the 0 address.
+		;; Try to self-destruct by sending full balance to the 0 address.
+		;; All the free balance will be send away but the contract's which is a valid
+		;; thing to do because the storage deposits will keep the account alive.
 		(call $assert
 			(i32.eq
 				(call $seal_transfer
@@ -42,7 +44,7 @@
 					(i32.const 0)	;; Pointer to the buffer with value to transfer
 					(i32.const 8)	;; Length of the buffer with value to transfer
 				)
-				(i32.const 4) ;; ReturnCode::BelowSubsistenceThreshold
+				(i32.const 0) ;; ReturnCode::Success
 			)
 		)
 	)

frame/contracts/rpc/runtime-api/src/lib.rs

@@ -25,7 +25,7 @@
 
 use codec::Codec;
 use pallet_contracts_primitives::{
-	Code, ContractExecResult, ContractInstantiateResult, GetStorageResult,
+	Code, CodeUploadResult, ContractExecResult, ContractInstantiateResult, GetStorageResult,
 };
 use sp_std::vec::Vec;
 
@@ -45,8 +45,9 @@ sp_api::decl_runtime_apis! {
 			dest: AccountId,
 			value: Balance,
 			gas_limit: u64,
+			storage_limit: Option<Balance>,
 			input_data: Vec<u8>,
-		) -> ContractExecResult;
+		) -> ContractExecResult<Balance>;
 
 		/// Instantiate a new contract.
 		///
@@ -55,10 +56,21 @@ sp_api::decl_runtime_apis! {
 			origin: AccountId,
 			endowment: Balance,
 			gas_limit: u64,
+			storage_limit: Option<Balance>,
 			code: Code<Hash>,
 			data: Vec<u8>,
 			salt: Vec<u8>,
-		) -> ContractInstantiateResult<AccountId>;
+		) -> ContractInstantiateResult<AccountId, Balance>;
+
+
+		/// Upload new code without instantiating a contract from it.
+		///
+		/// See `pallet_contracts::Pallet::upload_code`.
+		fn upload_code(
+			origin: AccountId,
+			code: Vec<u8>,
+			storage_limit: Option<Balance>,
+		) -> CodeUploadResult<Hash, Balance>;
 
 		/// Query a given storage key in a given contract.
 		///