Implement transaction_by_hash Runtime API (#35)

* Wip implement transaction_by_hash for EthApi

* pallet-ethereum: add Transactions StorageMap

* Implement transaction_by_hash Runtime API

* pallet-ethereum: change Transactions to store references only

* polkadot-evm/frontier/pull/35#discussion_r438019271

* Move Transaction build logic to Rpc module

frame/ethereum/src/lib.rs

@@ -67,6 +67,7 @@ decl_storage! {
 		BlockNumbers: map hasher(blake2_128_concat) T::BlockNumber => H256;
 		PendingTransactionsAndReceipts: Vec<(ethereum::Transaction, ethereum::Receipt)>;
 		TransactionStatuses: map hasher(blake2_128_concat) H256 => Option<TransactionStatus>;
+		Transactions: map hasher(blake2_128_concat) H256 => Option<(H256, u32)>;
 	}
 }
 
@@ -193,10 +194,22 @@ decl_module! {
 
 			let block = ethereum::Block {
 				header,
-				transactions,
+				transactions: transactions.clone(),
 				ommers,
 			};
 
+			for t in &transactions {
+				let transaction_hash = H256::from_slice(
+					Keccak256::digest(&rlp::encode(t)).as_slice()
+				);
+				if let Some(status) = TransactionStatuses::get(transaction_hash) {
+					Transactions::insert(
+						transaction_hash, 
+						(hash, status.transaction_index)
+					);
+				}
+			}
+
 			BlocksAndReceipts::insert(hash, (block, receipts));
 			BlockNumbers::<T>::insert(n, hash);
 		}
@@ -231,6 +244,18 @@ impl<T: Trait> Module<T> {
 	pub fn transaction_status(hash: H256) -> Option<TransactionStatus> {
 		TransactionStatuses::get(hash)
 	}
+
+	pub fn transaction_by_hash(hash: H256) -> Option<(
+		ethereum::Transaction, 
+		ethereum::Block, 
+		TransactionStatus
+	)> {
+		let (block_hash, transaction_index) = Transactions::get(hash)?;
+		let transaction_status = TransactionStatuses::get(hash)?;
+		let (block,_receipt) = BlocksAndReceipts::get(block_hash)?;
+		let transaction = &block.transactions[transaction_index as usize];
+		Some((transaction.clone(), block, transaction_status))
+	}
 
 	pub fn block_by_number(number: T::BlockNumber) -> Option<ethereum::Block> {
 		if <BlockNumbers<T>>::contains_key(number) {

rpc/core/src/eth.rs

@@ -129,7 +129,7 @@ pub trait EthApi {
 
 	/// Get transaction by its hash.
 	#[rpc(name = "eth_getTransactionByHash")]
-	fn transaction_by_hash(&self, _: H256) -> BoxFuture<Option<Transaction>>;
+	fn transaction_by_hash(&self, _: H256) -> Result<Option<Transaction>>;
 
 	/// Returns transaction at given block hash and index.
 	#[rpc(name = "eth_getTransactionByBlockHashAndIndex")]

rpc/primitives/src/lib.rs

@@ -17,7 +17,7 @@
 #![cfg_attr(not(feature = "std"), no_std)]
 
 use sp_core::{H160, H256, U256};
-use ethereum::{Log, Block as EthereumBlock};
+use ethereum::{Log, Block as EthereumBlock, Transaction as EthereumTransaction};
 use ethereum_types::Bloom;
 use codec::{Encode, Decode};
 use sp_std::vec::Vec;
@@ -46,6 +46,11 @@ sp_api::decl_runtime_apis! {
 		fn block_transaction_count_by_number(number: u32) -> Option<U256>;
 		fn block_by_hash(hash: H256) -> Option<EthereumBlock>;
 		fn block_transaction_count_by_hash(hash: H256) -> Option<U256>;
+		fn transaction_by_hash(hash: H256) -> Option<(
+			EthereumTransaction,
+			EthereumBlock,
+			TransactionStatus
+		)>;
 	}
 }
 

rpc/src/lib.rs

@@ -348,8 +348,47 @@ impl<B, C, SC, P, CT, BE> EthApiT for EthApi<B, C, SC, P, CT, BE> where
 		unimplemented!("estimate_gas");
 	}
 
-	fn transaction_by_hash(&self, _: H256) -> BoxFuture<Option<Transaction>> {
-		unimplemented!("transaction_by_hash");
+	fn transaction_by_hash(&self, hash: H256) -> Result<Option<Transaction>> {
+		let header = self
+			.select_chain
+			.best_chain()
+			.map_err(|_| internal_err("fetch header failed"))?;
+
+		if let Ok(Some((transaction, block, status))) = self.client.runtime_api()
+			.transaction_by_hash(&BlockId::Hash(header.hash()), hash) {
+
+			return Ok(Some(
+				Transaction {
+					hash: hash,
+					nonce: transaction.nonce,
+					block_hash: Some(H256::from_slice(
+						Keccak256::digest(&rlp::encode(&block.header)).as_slice()
+					)),
+					block_number: Some(block.header.number),
+					transaction_index: Some(U256::from(
+						UniqueSaturatedInto::<u32>::unique_saturated_into(
+							status.transaction_index
+						)
+					)),
+					from: status.from,
+					to: status.to,
+					value: transaction.value,
+					gas_price: transaction.gas_price,
+					gas: transaction.gas_limit,
+					input: Bytes(transaction.input),
+					creates: status.contract_address,
+					raw: Bytes(vec![]), // TODO
+					public_key: None, // TODO
+					chain_id: None, // TODO
+					standard_v: U256::zero(), // TODO
+					v: U256::zero(), // TODO
+					r: U256::zero(), // TODO
+					s: U256::zero(), // TODO
+					condition: None // TODO
+				}
+			));
+		}
+		Ok(None)
 	}
 
 	fn transaction_by_block_hash_and_index(

template/runtime/src/lib.rs

@@ -58,7 +58,8 @@ pub use frame_support::{
 	},
 	StorageValue,
 };
-use ethereum::Block as EthereumBlock;
+use ethereum::{Block as EthereumBlock, Transaction as EthereumTransaction};
+use frontier_rpc_primitives::{TransactionStatus};
 
 
 #[cfg(any(feature = "std", test))]
@@ -495,6 +496,13 @@ impl_runtime_apis! {
 		fn block_by_hash(hash: H256) -> Option<EthereumBlock> {
 			<ethereum::Module<Runtime>>::block_by_hash(hash)
 		}
+
+		fn transaction_by_hash(hash: H256) -> Option<(
+			EthereumTransaction, 
+			EthereumBlock, 
+			TransactionStatus)> {
+			<ethereum::Module<Runtime>>::transaction_by_hash(hash)
+		}
 	}
 
 	impl pallet_transaction_payment_rpc_runtime_api::TransactionPaymentApi<