Specify how much gas to allot for a create

Author: pepyakin

substrate/runtime/contract/src/tests.rs

@@ -343,18 +343,20 @@ fn code_create(constructor: &[u8]) -> String {
 	;; ext_create(
 	;;     code_ptr: u32,
 	;;     code_len: u32,
+	;;     gas: u64,
 	;;     value_ptr: u32,
 	;;     value_len: u32,
 	;;     input_data_ptr: u32,
 	;;     input_data_len: u32,
 	;; ) -> u32
-	(import "env" "ext_create" (func $ext_create (param i32 i32 i32 i32 i32 i32) (result i32)))
+	(import "env" "ext_create" (func $ext_create (param i32 i32 i64 i32 i32 i32 i32) (result i32)))
 	(import "env" "memory" (memory 1 1))
 	(func (export "call")
 		(drop
 			(call $ext_create
 				(i32.const 12)   ;; Pointer to `code`
 				(i32.const {code_len}) ;; Length of `code`
+				(i64.const 0)   ;; How much gas to devote for the execution. 0 = all.
 				(i32.const 4)   ;; Pointer to the buffer with value to transfer
 				(i32.const 8)   ;; Length of the buffer with value to transfer
 				(i32.const 0)   ;; Pointer to input data buffer address
@@ -398,12 +400,12 @@ fn contract_create() {
 		);
 
 		// 11 - value sent with the transaction
-		// 2 * 138 - gas spent by the deployer contract (138) multiplied by gas price (2)
+		// 2 * 139 - gas spent by the deployer contract (139) multiplied by gas price (2)
 		// 2 * 135 - base gas fee for call (top level)
 		// 2 * 175 - base gas fee for create (by contract)
 		// ((21 / 2) * 2) - price per account creation
 		let expected_gas_after_create =
-			100_000_000 - 11 - (2 * 138) - (2 * 135) - (2 * 175) - ((21 / 2) * 2);
+			100_000_000 - 11 - (2 * 139) - (2 * 135) - (2 * 175) - ((21 / 2) * 2);
 		assert_eq!(Staking::free_balance(&0), expected_gas_after_create);
 		assert_eq!(Staking::free_balance(&1), 8);
 		assert_eq!(Staking::free_balance(&derived_address), 3);

substrate/runtime/contract/src/vm/env_def/mod.rs

@@ -222,10 +222,11 @@ define_env!(init_env, <E: Ext>,
 		}
 	},
 
-	// ext_create(code_ptr: u32, code_len: u32, value_ptr: u32, value_len: u32, input_data_ptr: u32, input_data_len: u32) -> u32
+	// ext_create(code_ptr: u32, code_len: u32, gas: u64, value_ptr: u32, value_len: u32, input_data_ptr: u32, input_data_len: u32) -> u32
 	ext_create(
 		ctx, code_ptr: u32,
 		code_len: u32,
+		gas: u64,
 		value_ptr: u32,
 		value_len: u32,
 		input_data_ptr: u32,
@@ -245,8 +246,11 @@ define_env!(init_env, <E: Ext>,
 		input_data.resize(input_data_len as usize, 0u8);
 		ctx.memory().get(input_data_ptr, &mut input_data)?;
 
-		// TODO: Let user to choose how much gas to allocate for the execution.
-		let nested_gas_limit = ctx.gas_meter.gas_left();
+		let nested_gas_limit = if gas == 0 {
+			ctx.gas_meter.gas_left()
+		} else {
+			<<<E as Ext>::T as Trait>::Gas as As<u64>>::sa(gas)
+		};
 		let ext = &mut ctx.ext;
 		let create_outcome = ctx.gas_meter.with_nested(nested_gas_limit, |nested_meter| {
 			match nested_meter {

substrate/runtime/contract/src/vm/mod.rs

@@ -276,6 +276,7 @@ mod tests {
 		code: Vec<u8>,
 		endowment: u64,
 		data: Vec<u8>,
+		gas_left: u64,
 	}
 	#[derive(Debug, PartialEq, Eq)]
 	struct TransferEntry {
@@ -304,13 +305,14 @@ mod tests {
 			&mut self,
 			code: &[u8],
 			endowment: u64,
-			_gas_meter: &mut GasMeter<Test>,
+			gas_meter: &mut GasMeter<Test>,
 			data: &[u8],
 		) -> Result<CreateReceipt<Test>, ()> {
 			self.creates.push(CreateEntry {
 				code: code.to_vec(),
 				endowment,
 				data: data.to_vec(),
+				gas_left: gas_meter.gas_left(),
 			});
 			let address = self.next_account_id;
 			self.next_account_id += 1;
@@ -405,18 +407,20 @@ mod tests {
 	;; ext_create(
 	;;     code_ptr: u32,
 	;;     code_len: u32,
+	;;     gas: u64,
 	;;     value_ptr: u32,
 	;;     value_len: u32,
 	;;     input_data_ptr: u32,
 	;;     input_data_len: u32,
 	;; ) -> u32
-	(import "env" "ext_create" (func $ext_create (param i32 i32 i32 i32 i32 i32) (result i32)))
+	(import "env" "ext_create" (func $ext_create (param i32 i32 i64 i32 i32 i32 i32) (result i32)))
 	(import "env" "memory" (memory 1 1))
 	(func (export "call")
 		(drop
 			(call $ext_create
 				(i32.const 12)   ;; Pointer to `code`
 				(i32.const 8)    ;; Length of `code`
+				(i64.const 0)    ;; How much gas to devote for the execution. 0 = all.
 				(i32.const 4)    ;; Pointer to the buffer with value to transfer
 				(i32.const 8)    ;; Length of the buffer with value to transfer
 				(i32.const 20)   ;; Pointer to input data buffer address
@@ -454,6 +458,7 @@ mod tests {
 				data: vec![
 					1, 2, 3, 4,
 				],
+				gas_left: 49990,
 			}]
 		);
 	}