refactor!: remove the Routing state machine

The Bootstrapping and Joining states were removed. The bootstrapping/joining process was extracted into a single async function which returns a node that is fully bootstrapped.

BREAKING CHANGE: some methods of `Routing` that previosuly returned `Option<T>` or `Result<T>` now return just T.

src/messages/mod.rs

@@ -308,15 +308,6 @@ pub enum VerifyStatus {
     Unknown,
 }
 
-impl VerifyStatus {
-    pub fn require_full(self) -> Result<(), Error> {
-        match self {
-            Self::Full => Ok(()),
-            Self::Unknown => Err(Error::UntrustedMessage),
-        }
-    }
-}
-
 /// Status of an incomming message.
 pub enum MessageStatus {
     /// Message is useful and should be handled.

src/node.rs

@@ -8,7 +8,11 @@
 
 use crate::{crypto, event::Event, peer::Peer, NetworkParams};
 use ed25519_dalek::Keypair;
-use std::{net::SocketAddr, sync::Arc};
+use std::{
+    fmt::{self, Display, Formatter},
+    net::SocketAddr,
+    sync::Arc,
+};
 use tokio::sync::mpsc;
 use xor_name::XorName;
 
@@ -58,3 +62,9 @@ impl Node {
         }
     }
 }
+
+impl Display for Node {
+    fn fmt(&self, f: &mut Formatter) -> fmt::Result {
+        write!(f, "{:<8}", hex_fmt::HexFmt(self.keypair.public.as_bytes()))
+    }
+}

src/relocation.rs

@@ -16,8 +16,10 @@ use crate::{
     network::Network,
     section::{MemberInfo, Section},
 };
-
+use bytes::Bytes;
 use serde::{de::Error as SerdeDeError, Deserialize, Deserializer, Serialize, Serializer};
+use std::net::SocketAddr;
+use tokio::sync::mpsc;
 use xor_name::XorName;
 
 /// Find all nodes to relocate after a churn event and create the relocate actions for them.
@@ -169,11 +171,21 @@ impl RelocatePayload {
 }
 
 #[derive(Copy, Clone, Eq, PartialEq, Hash, Debug, Serialize, Deserialize)]
-pub struct RelocatePromise {
+pub(crate) struct RelocatePromise {
     pub name: XorName,
     pub destination: XorName,
 }
 
+pub(crate) enum RelocateState {
+    // Node is undergoing delayed relocation. This happens when the node is selected for relocation
+    // while being an elder. It must keep fulfilling its duties as elder until its demoted, then it
+    // can send the bytes (which are serialized `RelocatePromise` message) back to the elders who
+    // will exchange it for an actual `Relocate` message.
+    Delayed(Bytes),
+    // Relocation in progress. The sender is used to pass messages to the bootstrap task.
+    InProgress(mpsc::Sender<(Message, SocketAddr)>),
+}
+
 /// Action to relocate a node.
 pub(crate) enum RelocateAction {
     /// Relocate the node instantly.