big multiprecision values and serialize an Ethereum transaction for RPC

libraries/plugins/peerplays_sidechain/include/graphene/peerplays_sidechain/sidechain_net_handler_eth.hpp

@@ -19,6 +19,16 @@
 
 #include <fc/thread/thread.hpp>
 
+#include <boost/multiprecision/cpp_int.hpp>
+
+using namespace boost::multiprecision::literals;
+using u256 =  boost::multiprecision::number<boost::multiprecision::cpp_int_backend<256, 256, boost::multiprecision::unsigned_magnitude, boost::multiprecision::unchecked, void>>;
+using s256 =  boost::multiprecision::number<boost::multiprecision::cpp_int_backend<256, 256, boost::multiprecision::signed_magnitude, boost::multiprecision::unchecked, void>>;
+u256 constexpr Invalid256 = 0xffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff_cppui256;
+using byte = uint8_t;
+using bytes = std::vector<byte>;
+
+
 namespace graphene { namespace peerplays_sidechain {
 
 	typedef websocketpp::client<websocketpp::config::asio_client> client;
@@ -124,6 +134,29 @@ namespace graphene { namespace peerplays_sidechain {
 			std::vector<std::string> owners;
 			std::string safe_account_addr;
 		private:
+			/// Encodes an Ethereum transaction for exporting in JSON
+			class Transaction
+			{
+				public:
+					/// JSON serialization
+					std::string serialize(const std::string& from, const std::string& to, const std::string& tx_id, u256 const& _value, u256 const& _gasPrice, u256 const& _gas, bytes const& _data, u256 const& _nonce = Invalid256);
+				protected:
+					/// Type of transaction.
+					enum Type
+					{
+						NullTransaction,                    ///< Null transaction.
+						ContractCreation,                   ///< Transaction to create contracts - receiveAddress() is ignored.
+						MessageCall                         ///< Transaction to invoke a message call - receiveAddress() is used.
+					};
+
+					Type m_type = NullTransaction;              ///< Is this a contract-creation transaction or a message-call transaction?
+					u256 m_nonce;                               ///< The transaction-count of the sender.
+					u256 m_value;                               ///< The amount of ETH to be transferred by this transaction. Called 'endowment' for contract-creation transactions.
+					u256 m_gasPrice;                            ///< The base fee and thus the implied exchange rate of ETH to GAS.
+					u256 m_gas;                                 ///< The total gas to convert, paid for from sender's account. Any unused gas gets refunded once the contract is ended.
+					bytes m_data;                               ///< The data associated with the transaction, or the initialiser if it's a creation transaction.
+			};
+
 			class ethereum_function_call_encoder {
 				public:
 					enum operation_t {

libraries/plugins/peerplays_sidechain/sidechain_net_handler_eth.cpp

@@ -28,6 +28,12 @@ extern "C" {
 }
 
 namespace graphene { namespace peerplays_sidechain {
+	std::string eth_rpc_client::Transaction::serialize(const std::string& from, const std::string& to, const std::string& tx_id,u256 const& _value, u256 const& _gasPrice, u256 const& _gas, bytes const& _data, u256 const& _nonce) {
+		std::string m_data_str(m_data.begin(), m_data.end());
+		std::string req = str(boost::format("{\"jsonrpc\":\"2.0\",\"method\":\"account_signTransaction\",\"params\":[{\"from\": \"%1%\", \"gas\": \"%2%\", \"gasPrice\": \"%3%\", \"input\": \"%4%\", \"nonce\": \"%5%\", \"to\": \"%6%\", \"value\": \"%7%\" }],\"id\":%8%}") % from.c_str() % m_gas.str() % m_gasPrice.str() % m_data_str % m_nonce.str() % to.c_str() % m_value.str() %  tx_id.c_str());
+		return req;
+	}
+
 	// =============================================================================
 	std::string eth_rpc_client::ethereum_function_call_encoder::encode_function_signature(const std::string& function_signature) {
 		sha3_context c;