Reorganize code

1 files changed, 360 insertions, 0 deletions

diff --git a/src/rpc/rpc_client.rs b/src/rpc/rpc_client.rs
new file mode 100644
index 00000000..027a3cde
--- /dev/null
+++ b/src/rpc/rpc_client.rs
@@ -0,0 +1,360 @@
+use std::borrow::Borrow;
+use std::marker::PhantomData;
+use std::net::SocketAddr;
+use std::pin::Pin;
+use std::sync::atomic::Ordering;
+use std::sync::Arc;
+use std::time::Duration;
+
+use arc_swap::ArcSwapOption;
+use bytes::IntoBuf;
+use err_derive::Error;
+use futures::future::Future;
+use futures::stream::futures_unordered::FuturesUnordered;
+use futures::stream::StreamExt;
+use futures_util::future::FutureExt;
+use hyper::client::{Client, HttpConnector};
+use hyper::{Body, Method, Request};
+use tokio::sync::{watch, Semaphore};
+
+use crate::background::BackgroundRunner;
+use crate::data::*;
+use crate::error::Error;
+
+use crate::rpc::membership::Status;
+use crate::rpc::rpc_server::RpcMessage;
+use crate::rpc::tls_util;
+
+use crate::config::TlsConfig;
+
+const DEFAULT_TIMEOUT: Duration = Duration::from_secs(10);
+
+#[derive(Debug, Error)]
+pub enum RPCError {
+	#[error(display = "Node is down: {:?}.", _0)]
+	NodeDown(UUID),
+	#[error(display = "Timeout: {}", _0)]
+	Timeout(#[error(source)] tokio::time::Elapsed),
+	#[error(display = "HTTP error: {}", _0)]
+	HTTP(#[error(source)] http::Error),
+	#[error(display = "Hyper error: {}", _0)]
+	Hyper(#[error(source)] hyper::Error),
+	#[error(display = "Messagepack encode error: {}", _0)]
+	RMPEncode(#[error(source)] rmp_serde::encode::Error),
+	#[error(display = "Messagepack decode error: {}", _0)]
+	RMPDecode(#[error(source)] rmp_serde::decode::Error),
+	#[error(display = "Too many errors: {:?}", _0)]
+	TooManyErrors(Vec<String>),
+}
+
+#[derive(Copy, Clone)]
+pub struct RequestStrategy {
+	pub rs_timeout: Duration,
+	pub rs_quorum: usize,
+	pub rs_interrupt_after_quorum: bool,
+}
+
+impl RequestStrategy {
+	pub fn with_quorum(quorum: usize) -> Self {
+		RequestStrategy {
+			rs_timeout: DEFAULT_TIMEOUT,
+			rs_quorum: quorum,
+			rs_interrupt_after_quorum: false,
+		}
+	}
+	pub fn with_timeout(mut self, timeout: Duration) -> Self {
+		self.rs_timeout = timeout;
+		self
+	}
+	pub fn interrupt_after_quorum(mut self, interrupt: bool) -> Self {
+		self.rs_interrupt_after_quorum = interrupt;
+		self
+	}
+}
+
+pub type LocalHandlerFn<M> =
+	Box<dyn Fn(Arc<M>) -> Pin<Box<dyn Future<Output = Result<M, Error>> + Send>> + Send + Sync>;
+
+pub struct RpcClient<M: RpcMessage> {
+	status: watch::Receiver<Arc<Status>>,
+	background: Arc<BackgroundRunner>,
+
+	local_handler: ArcSwapOption<(UUID, LocalHandlerFn<M>)>,
+
+	pub rpc_addr_client: RpcAddrClient<M>,
+}
+
+impl<M: RpcMessage + 'static> RpcClient<M> {
+	pub fn new(
+		rac: RpcAddrClient<M>,
+		background: Arc<BackgroundRunner>,
+		status: watch::Receiver<Arc<Status>>,
+	) -> Arc<Self> {
+		Arc::new(Self {
+			rpc_addr_client: rac,
+			background,
+			status,
+			local_handler: ArcSwapOption::new(None),
+		})
+	}
+
+	pub fn set_local_handler<F, Fut>(&self, my_id: UUID, handler: F)
+	where
+		F: Fn(Arc<M>) -> Fut + Send + Sync + 'static,
+		Fut: Future<Output = Result<M, Error>> + Send + 'static,
+	{
+		let handler_arc = Arc::new(handler);
+		let handler: LocalHandlerFn<M> = Box::new(move |msg| {
+			let handler_arc2 = handler_arc.clone();
+			Box::pin(async move { handler_arc2(msg).await })
+		});
+		self.local_handler.swap(Some(Arc::new((my_id, handler))));
+	}
+
+	pub fn by_addr(&self) -> &RpcAddrClient<M> {
+		&self.rpc_addr_client
+	}
+
+	pub async fn call(&self, to: UUID, msg: M, timeout: Duration) -> Result<M, Error> {
+		self.call_arc(to, Arc::new(msg), timeout).await
+	}
+
+	pub async fn call_arc(&self, to: UUID, msg: Arc<M>, timeout: Duration) -> Result<M, Error> {
+		if let Some(lh) = self.local_handler.load_full() {
+			let (my_id, local_handler) = lh.as_ref();
+			if to.borrow() == my_id {
+				return local_handler(msg).await;
+			}
+		}
+		let status = self.status.borrow().clone();
+		let node_status = match status.nodes.get(&to) {
+			Some(node_status) => {
+				if node_status.is_up() {
+					node_status
+				} else {
+					return Err(Error::from(RPCError::NodeDown(to)));
+				}
+			}
+			None => {
+				return Err(Error::Message(format!(
+					"Peer ID not found: {:?}",
+					to.borrow()
+				)))
+			}
+		};
+		match self
+			.rpc_addr_client
+			.call(&node_status.addr, msg, timeout)
+			.await
+		{
+			Err(rpc_error) => {
+				node_status.num_failures.fetch_add(1, Ordering::SeqCst);
+				// TODO: Save failure info somewhere
+				Err(Error::from(rpc_error))
+			}
+			Ok(x) => x,
+		}
+	}
+
+	pub async fn call_many(&self, to: &[UUID], msg: M, timeout: Duration) -> Vec<Result<M, Error>> {
+		let msg = Arc::new(msg);
+		let mut resp_stream = to
+			.iter()
+			.map(|to| self.call_arc(*to, msg.clone(), timeout))
+			.collect::<FuturesUnordered<_>>();
+
+		let mut results = vec![];
+		while let Some(resp) = resp_stream.next().await {
+			results.push(resp);
+		}
+		results
+	}
+
+	pub async fn try_call_many(
+		self: &Arc<Self>,
+		to: &[UUID],
+		msg: M,
+		strategy: RequestStrategy,
+	) -> Result<Vec<M>, Error> {
+		let timeout = strategy.rs_timeout;
+
+		let msg = Arc::new(msg);
+		let mut resp_stream = to
+			.to_vec()
+			.into_iter()
+			.map(|to| {
+				let self2 = self.clone();
+				let msg = msg.clone();
+				async move { self2.call_arc(to, msg, timeout).await }
+			})
+			.collect::<FuturesUnordered<_>>();
+
+		let mut results = vec![];
+		let mut errors = vec![];
+
+		while let Some(resp) = resp_stream.next().await {
+			match resp {
+				Ok(msg) => {
+					results.push(msg);
+					if results.len() >= strategy.rs_quorum {
+						break;
+					}
+				}
+				Err(e) => {
+					errors.push(e);
+				}
+			}
+		}
+
+		if results.len() >= strategy.rs_quorum {
+			// Continue requests in background.
+			// Continue the remaining requests immediately using tokio::spawn
+			// but enqueue a task in the background runner
+			// to ensure that the process won't exit until the requests are done
+			// (if we had just enqueued the resp_stream.collect directly in the background runner,
+			// the requests might have been put on hold in the background runner's queue,
+			// in which case they might timeout or otherwise fail)
+			if !strategy.rs_interrupt_after_quorum {
+				let wait_finished_fut = tokio::spawn(async move {
+					resp_stream.collect::<Vec<_>>().await;
+					Ok(())
+				});
+				self.background.spawn(wait_finished_fut.map(|x| {
+					x.unwrap_or_else(|e| Err(Error::Message(format!("Await failed: {}", e))))
+				}));
+			}
+
+			Ok(results)
+		} else {
+			let errors = errors.iter().map(|e| format!("{}", e)).collect::<Vec<_>>();
+			Err(Error::from(RPCError::TooManyErrors(errors)))
+		}
+	}
+}
+
+pub struct RpcAddrClient<M: RpcMessage> {
+	phantom: PhantomData<M>,
+
+	pub http_client: Arc<RpcHttpClient>,
+	pub path: String,
+}
+
+impl<M: RpcMessage> RpcAddrClient<M> {
+	pub fn new(http_client: Arc<RpcHttpClient>, path: String) -> Self {
+		Self {
+			phantom: PhantomData::default(),
+			http_client: http_client,
+			path,
+		}
+	}
+
+	pub async fn call<MB>(
+		&self,
+		to_addr: &SocketAddr,
+		msg: MB,
+		timeout: Duration,
+	) -> Result<Result<M, Error>, RPCError>
+	where
+		MB: Borrow<M>,
+	{
+		self.http_client
+			.call(&self.path, to_addr, msg, timeout)
+			.await
+	}
+}
+
+pub struct RpcHttpClient {
+	request_limiter: Semaphore,
+	method: ClientMethod,
+}
+
+enum ClientMethod {
+	HTTP(Client<HttpConnector, hyper::Body>),
+	HTTPS(Client<tls_util::HttpsConnectorFixedDnsname<HttpConnector>, hyper::Body>),
+}
+
+impl RpcHttpClient {
+	pub fn new(
+		max_concurrent_requests: usize,
+		tls_config: &Option<TlsConfig>,
+	) -> Result<Self, Error> {
+		let method = if let Some(cf) = tls_config {
+			let ca_certs = tls_util::load_certs(&cf.ca_cert)?;
+			let node_certs = tls_util::load_certs(&cf.node_cert)?;
+			let node_key = tls_util::load_private_key(&cf.node_key)?;
+
+			let mut config = rustls::ClientConfig::new();
+
+			for crt in ca_certs.iter() {
+				config.root_store.add(crt)?;
+			}
+
+			config.set_single_client_cert([&node_certs[..], &ca_certs[..]].concat(), node_key)?;
+
+			let connector =
+				tls_util::HttpsConnectorFixedDnsname::<HttpConnector>::new(config, "garage");
+
+			ClientMethod::HTTPS(Client::builder().build(connector))
+		} else {
+			ClientMethod::HTTP(Client::new())
+		};
+		Ok(RpcHttpClient {
+			method,
+			request_limiter: Semaphore::new(max_concurrent_requests),
+		})
+	}
+
+	async fn call<M, MB>(
+		&self,
+		path: &str,
+		to_addr: &SocketAddr,
+		msg: MB,
+		timeout: Duration,
+	) -> Result<Result<M, Error>, RPCError>
+	where
+		MB: Borrow<M>,
+		M: RpcMessage,
+	{
+		let uri = match self.method {
+			ClientMethod::HTTP(_) => format!("http://{}/{}", to_addr, path),
+			ClientMethod::HTTPS(_) => format!("https://{}/{}", to_addr, path),
+		};
+
+		let req = Request::builder()
+			.method(Method::POST)
+			.uri(uri)
+			.body(Body::from(rmp_to_vec_all_named(msg.borrow())?))?;
+
+		let resp_fut = match &self.method {
+			ClientMethod::HTTP(client) => client.request(req).fuse(),
+			ClientMethod::HTTPS(client) => client.request(req).fuse(),
+		};
+
+		let slot = self.request_limiter.acquire().await;
+		let resp = tokio::time::timeout(timeout, resp_fut)
+			.await
+			.map_err(|e| {
+				debug!(
+					"RPC timeout to {}: {}",
+					to_addr,
+					debug_serialize(msg.borrow())
+				);
+				e
+			})?
+			.map_err(|e| {
+				warn!(
+					"RPC HTTP client error when connecting to {}: {}",
+					to_addr, e
+				);
+				e
+			})?;
+		drop(slot);
+
+		let status = resp.status();
+		let body = hyper::body::to_bytes(resp.into_body()).await?;
+		match rmp_serde::decode::from_read::<_, Result<M, String>>(body.into_buf())? {
+			Err(e) => Ok(Err(Error::RemoteError(e, status))),
+			Ok(x) => Ok(Ok(x)),
+		}
+	}
+}