RPC & Client (#21)

* Initial version of http server.

* Refactor the structure.

* add unassigned ports info.

* Rename servers to match conventions.

* Add client crate and some proper RPC implementations.

* Style & docs.

substrate/rpc_servers/src/lib.rs

@@ -0,0 +1,46 @@
+// Copyright 2017 Parity Technologies (UK) Ltd.
+// This file is part of Polkadot.
+
+// Polkadot is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// Polkadot is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with Polkadot.  If not, see <http://www.gnu.org/licenses/>.
+
+//! Polkadot RPC servers.
+
+#[warn(missing_docs)]
+
+extern crate polkadot_rpc as apis;
+
+extern crate jsonrpc_core as rpc;
+extern crate jsonrpc_http_server as http;
+
+use std::io;
+
+/// Construct rpc `IoHandler`
+pub fn rpc_handler<S>(state: S) -> rpc::IoHandler where
+	S: apis::state::StateApi,
+{
+	let mut io = rpc::IoHandler::new();
+	io.extend_with(state.to_delegate());
+	io
+}
+
+/// Start HTTP server listening on given address.
+pub fn start_http(
+	addr: &std::net::SocketAddr,
+	io: rpc::IoHandler,
+) -> io::Result<http::Server> {
+	http::ServerBuilder::new(io)
+		.threads(4)
+		.rest_api(http::RestApi::Unsecure)
+		.start_http(addr)
+}