Runtime API impls: gas_price, block_number, balance, code_at

rpc/core/src/eth.rs

@@ -57,7 +57,7 @@ pub trait EthApi {
 
 	/// Returns current gas_price.
 	#[rpc(name = "eth_gasPrice")]
-	fn gas_price(&self) -> BoxFuture<U256>;
+	fn gas_price(&self) -> Result<U256>;
 
 	/// Returns accounts list.
 	#[rpc(name = "eth_accounts")]
@@ -69,7 +69,7 @@ pub trait EthApi {
 
 	/// Returns balance of the given account.
 	#[rpc(name = "eth_getBalance")]
-	fn balance(&self, _: H160, _: Option<BlockNumber>) -> BoxFuture<U256>;
+	fn balance(&self, _: H160, _: Option<BlockNumber>) -> Result<U256>;
 
 	/// Returns the account- and storage-values of the specified account including the Merkle-proof
 	#[rpc(name = "eth_getProof")]
@@ -109,7 +109,7 @@ pub trait EthApi {
 
 	/// Returns the code at given address at given time (block number).
 	#[rpc(name = "eth_getCode")]
-	fn code_at(&self, _: H160, _: Option<BlockNumber>) -> BoxFuture<Bytes>;
+	fn code_at(&self, _: H160, _: Option<BlockNumber>) -> Result<Bytes>;
 
 	/// Sends signed transaction, returning its hash.
 	#[rpc(name = "eth_sendRawTransaction")]

rpc/primitives/src/lib.rs

@@ -16,7 +16,7 @@
 
 #![cfg_attr(not(feature = "std"), no_std)]
 
-use sp_core::{H160, H256};
+use sp_core::{H160, H256, U256};
 use ethereum::Log;
 use ethereum_types::Bloom;
 use codec::{Encode, Decode};
@@ -39,6 +39,9 @@ sp_api::decl_runtime_apis! {
 		fn chain_id() -> u64;
 		fn account_basic(address: H160) -> pallet_evm::Account;
 		fn transaction_status(hash: H256) -> Option<TransactionStatus>;
+		fn gas_price() -> U256;
+		fn evm_balance(address: H160) -> U256;
+		fn code_at(address: H160) -> Vec<u8>;
 	}
 }
 

rpc/src/lib.rs

@@ -18,7 +18,7 @@ use std::{marker::PhantomData, sync::Arc};
 use ethereum_types::{H160, H256, H64, U256, U64};
 use jsonrpc_core::{BoxFuture, Result, ErrorCode, Error, futures::future::{self, Future}};
 use futures::future::TryFutureExt;
-use sp_runtime::traits::{Block as BlockT, Header as _};
+use sp_runtime::traits::{Block as BlockT, Header as _, UniqueSaturatedInto};
 use sp_runtime::transaction_validity::TransactionSource;
 use sp_api::{ProvideRuntimeApi, BlockId};
 use sp_consensus::SelectChain;
@@ -98,20 +98,49 @@ impl<B, C, SC, P, CT> EthApiT for EthApi<B, C, SC, P, CT> where
 				.map_err(|_| internal_err("fetch runtime chain id failed"))?.into()))
 	}
 
-	fn gas_price(&self) -> BoxFuture<U256> {
-		unimplemented!("gas_price");
+	fn gas_price(&self) -> Result<U256> {
+		let header = self
+			.select_chain
+			.best_chain()
+			.map_err(|_| internal_err("fetch header failed"))?;
+		Ok(
+			self.client
+				.runtime_api()
+				.gas_price(&BlockId::Hash(header.hash()))
+				.map_err(|_| internal_err("fetch runtime chain id failed"))?
+				.into(),
+		)
 	}
 
 	fn accounts(&self) -> Result<Vec<H160>> {
 		unimplemented!("accounts");
 	}
 
 	fn block_number(&self) -> Result<U256> {
-		unimplemented!("block_number");
+		let header = self
+			.select_chain
+			.best_chain()
+			.map_err(|_| internal_err("fetch header failed"))?;
+		Ok(U256::from(header.number().clone().unique_saturated_into()))
 	}
 
-	fn balance(&self, _: H160, _: Option<BlockNumber>) -> BoxFuture<U256> {
-		unimplemented!("balance");
+	fn balance(&self, address: H160, number: Option<BlockNumber>) -> Result<U256> {
+		if let Some(number) = number {
+			if number != BlockNumber::Latest {
+				unimplemented!("fetch nonce for past blocks is not yet supported");
+			}
+		}
+		let header = self
+			.select_chain
+			.best_chain()
+			.map_err(|_| internal_err("fetch header failed"))?;
+		Ok(
+			self.client
+				.runtime_api()
+				.evm_balance(&BlockId::Hash(header.hash()), address)
+				.map_err(|_| internal_err("fetch runtime chain id failed"))?
+				.into(),
+		)
 	}
 
 	fn proof(&self, _: H160, _: Vec<H256>, _: Option<BlockNumber>) -> BoxFuture<EthAccount> {
@@ -159,8 +188,23 @@ impl<B, C, SC, P, CT> EthApiT for EthApi<B, C, SC, P, CT> where
 		unimplemented!("block_uncles_count_by_number");
 	}
 
-	fn code_at(&self, _: H160, _: Option<BlockNumber>) -> BoxFuture<Bytes> {
-		unimplemented!("code_at");
+	fn code_at(&self, address: H160, number: Option<BlockNumber>) -> Result<Bytes> {
+		if let Some(number) = number {
+			if number != BlockNumber::Latest {
+				unimplemented!("fetch nonce for past blocks is not yet supported");
+			}
+		}
+		let header = self
+			.select_chain
+			.best_chain()
+			.map_err(|_| internal_err("fetch header failed"))?;
+		Ok(
+			self.client
+				.runtime_api()
+				.code_at(&BlockId::Hash(header.hash()), address)
+				.map_err(|_| internal_err("fetch runtime chain id failed"))?
+				.into(),
+		)
 	}
 
 	fn send_raw_transaction(&self, bytes: Bytes) -> BoxFuture<H256> {

template/runtime/src/lib.rs

@@ -33,6 +33,7 @@ use sp_consensus_aura::sr25519::AuthorityId as AuraId;
 use sp_core::{crypto::KeyTypeId, OpaqueMetadata, U256, H160, H256};
 use sp_runtime::traits::{
 	BlakeTwo256, Block as BlockT, IdentifyAccount, IdentityLookup, NumberFor, Saturating, Verify,
+	UniqueSaturatedInto
 };
 use sp_runtime::{
 	create_runtime_str, generic, impl_opaque_keys,
@@ -448,6 +449,19 @@ impl_runtime_apis! {
 		fn transaction_status(hash: H256) -> Option<ethereum::TransactionStatus> {
 			ethereum::Module::<Runtime>::transaction_status(hash)
 		}
+
+		fn gas_price() -> U256 {
+			FixedGasPrice::min_gas_price()
+		}
+
+		fn evm_balance(address: H160) -> U256 {
+			let account: EVMAccount = evm::Module::<Runtime>::accounts(address);
+			account.balance
+		}
+
+		fn code_at(address: H160) -> Vec<u8> {
+			evm::Module::<Runtime>::account_codes(address)
+		}
 	}
 
 	impl pallet_transaction_payment_rpc_runtime_api::TransactionPaymentApi<