Next nonce RPC (#2917)

rpc/src/v1/impls/ethcore.rs

@@ -334,4 +334,17 @@ impl<C, M, S: ?Sized, F> Ethcore for EthcoreClient<C, M, S, F> where
 		self.dapps_port
 			.ok_or_else(|| errors::dapps_disabled())
 	}
+
+	fn next_nonce(&self, address: H160) -> Result<U256, Error> {
+		try!(self.active());
+		let address: Address = address.into();
+		let miner = take_weak!(self.miner);
+		let client = take_weak!(self.client);
+
+		Ok(miner.last_nonce(&address)
+			.map(|n| n + 1.into())
+			.unwrap_or_else(|| client.latest_nonce(&address))
+			.into()
+		)
+	}
 }

rpc/src/v1/tests/mocked/ethcore.rs

@@ -16,7 +16,7 @@
 
 use std::sync::Arc;
 use util::log::RotatingLogger;
-use util::U256;
+use util::{U256, Address};
 use ethsync::ManageNetwork;
 use ethcore::client::{TestBlockChainClient};
 use ethstore::ethkey::{Generator, Random};
@@ -320,3 +320,25 @@ fn rpc_ethcore_dapps_port() {
 	assert_eq!(io1.handle_request_sync(request), Some(response1.to_owned()));
 	assert_eq!(io2.handle_request_sync(request), Some(response2.to_owned()));
 }
+
+#[test]
+fn rpc_ethcore_next_nonce() {
+	let deps = Dependencies::new();
+	let address = Address::default();
+	let io1 = deps.default_client();
+	let deps = Dependencies::new();
+	deps.miner.last_nonces.write().insert(address.clone(), 2.into());
+	let io2 = deps.default_client();
+
+	let request = r#"{
+		"jsonrpc": "2.0",
+		"method": "ethcore_nextNonce",
+		"params": [""#.to_owned() + &format!("0x{:?}", address) + r#""],
+		"id": 1
+	}"#;
+	let response1 = r#"{"jsonrpc":"2.0","result":"0x0","id":1}"#;
+	let response2 = r#"{"jsonrpc":"2.0","result":"0x3","id":1}"#;
+
+	assert_eq!(io1.handle_request_sync(&request), Some(response1.to_owned()));
+	assert_eq!(io2.handle_request_sync(&request), Some(response2.to_owned()));
+}

rpc/src/v1/traits/ethcore.rs

@@ -125,5 +125,9 @@ build_rpc_trait! {
 		/// Returns current Dapps Server port or an error if dapps server is disabled.
 		#[rpc(name = "ethcore_dappsPort")]
 		fn dapps_port(&self) -> Result<u16, Error>;
+
+		/// Returns next nonce for particular sender. Should include all transactions in the queue.
+		#[rpc(name = "ethcore_nextNonce")]
+		fn next_nonce(&self, H160) -> Result<U256, Error>;
 	}
 }