[api] add basic Rust client interface

src/client/client.rs

@@ -0,0 +1,62 @@
+use capnp::capability::Promise;
+use capnp_rpc::rpc_twoparty_capnp;
+use common::rpc::new_rpc_system;
+use futures::Future;
+use std::error::Error;
+use std::net::SocketAddr;
+use tokio_core::net::TcpStream;
+use tokio_core::reactor::Core;
+
+use CLIENT_PROTOCOL_VERSION;
+use super::session::Session;
+
+pub struct Client {
+    core: Core,
+    service: ::client_capnp::client_service::Client,
+}
+
+impl Client {
+    pub fn new(scheduler: &SocketAddr) -> Result<Self, Box<Error>> {
+        let mut core = Core::new()?;
+        let handle = core.handle();
+        let stream = core.run(TcpStream::connect(&scheduler, &handle))?;
+        stream.set_nodelay(true)?;
+
+        debug!("Connection to server {} established", scheduler);
+
+        let mut rpc = Box::new(new_rpc_system(stream, None));
+        let bootstrap: ::server_capnp::server_bootstrap::Client =
+            rpc.bootstrap(rpc_twoparty_capnp::Side::Server);
+        handle.spawn(rpc.map_err(|err| panic!("RPC error: {}", err)));
+
+        let mut request = bootstrap.register_as_client_request();
+        request.get().set_version(CLIENT_PROTOCOL_VERSION);
+
+        let service = core.run(
+            request
+                .send()
+                .promise
+                .and_then(|response| Promise::ok(pry!(response.get()).get_service())),
+        )??;
+
+        Ok(Client { core, service })
+    }
+
+    pub fn new_session(&mut self) -> Result<Session, Box<Error>> {
+        let id: i32 = self.core.run(
+            self.service
+                .new_session_request()
+                .send()
+                .promise
+                .and_then(|response| Promise::ok(pry!(response.get()).get_session_id())),
+        )?;
+
+        Ok(Session { id })
+    }
+
+    pub fn terminate_server(&mut self) -> Result<(), Box<Error>> {
+        self.core
+            .run(self.service.terminate_server_request().send().promise)?;
+        Ok(())
+    }
+}

src/client/mod.rs

@@ -0,0 +1,2 @@
+pub mod client;
+pub mod session;

src/client/session.rs

@@ -0,0 +1,3 @@
+pub struct Session {
+    pub id: i32,
+}

src/lib.rs

@@ -33,6 +33,7 @@ extern crate tokio_timer;
 extern crate tokio_uds;
 extern crate walkdir;
 
+pub mod client;
 pub mod common;
 pub mod worker;
 pub mod server;