add transport layer (#9)

Author: version513

Diff for: src/dkg/mod.rs

@@ -0,0 +1 @@
+pub mod state_machine;

Diff for: src/dkg/state_machine/mod.rs

@@ -0,0 +1 @@
+pub mod state;

Diff for: src/dkg/state_machine/state.rs

@@ -0,0 +1,80 @@
+#[derive(Debug, Copy, Clone, PartialEq)]
+#[repr(u8)]
+/// Status is pre-auth layer for any interaction with [`DBState`]
+//  DEV: partial type-state pattern might be considered
+pub enum Status {
+    // Fresh is the state all nodes start in - both pre-genesis, and if the network is running but they aren't
+    // yet participating
+    Fresh,
+    // Proposed implies somebody else has sent me a proposal
+    Proposed,
+    // Proposing implies I have sent the others in the network a proposal
+    Proposing,
+    // Accepted means I have accepted a proposal received from somebody else
+    // note Joiners do not accept/reject proposals
+    Accepted,
+    // Rejected means I have rejected a proposal received from somebody else
+    // it doesn't automatically abort the DKG, but the leader is advised to abort and suggest some new terms
+    Rejected,
+    // Aborted means the leader has told the network to abort the proposal; a node may have rejected,
+    // they may have found an error in the proposal, or any other reason could have occurred
+    Aborted,
+    // Executing means the leader has reviewed accepts/rejects and decided to go ahead with the DKG
+    // this implies that the Kyber DKG process has been started
+    Executing,
+    // Complete means the DKG has finished and a new group file has been created successfully
+    Complete,
+    // TimedOut means the proposal timeout has been reached without entering the `Executing` state
+    // any node can trigger this for themselves should they identify timeout has been reached
+    // it does _not_ guarantee that other nodes have also timed out - a network error or something else
+    // could have occurred. If the rest of the network continues, our node will likely transition to `Evicted`
+    TimedOut,
+    // Joined is the state a new proposed group member enters when they have been proposed a DKG and they run the
+    // `join` DKG command to signal their acceptance to join the network
+    Joined,
+    // Left is used when a node has left the network by their own choice after a DKG. It's not entirely necessary,
+    // an operator could just turn their node off. It's used to determine if an existing state is the current state
+    // of the network, or whether epochs have happened in between times
+    Left,
+    // Failed signals that a key sharing execution was attempted, but this node did not see it complete successfully.
+    // This could be either due to it being evicted or the DKG not completing for the whole network. Operators should
+    // check the node and network status, and manually transition the node to `Left` or create a new proposal depending
+    // on the outcome of the DKG
+    Failed,
+}
+
+#[derive(thiserror::Error, Debug)]
+pub enum StateError {
+    #[error("invalid transition attempt from {from} to {to}")]
+    InvalidStateChange { from: Status, to: Status },
+    #[error("impossible DKG state received: {0}")]
+    ImpossibleDkgState(u32),
+}
+
+impl TryFrom<u32> for Status {
+    type Error = StateError;
+
+    fn try_from(value: u32) -> Result<Self, Self::Error> {
+        match value {
+            0 => Ok(Status::Fresh),
+            1 => Ok(Status::Proposed),
+            2 => Ok(Status::Proposing),
+            3 => Ok(Status::Accepted),
+            4 => Ok(Status::Rejected),
+            5 => Ok(Status::Aborted),
+            6 => Ok(Status::Executing),
+            7 => Ok(Status::Complete),
+            8 => Ok(Status::TimedOut),
+            9 => Ok(Status::Joined),
+            10 => Ok(Status::Left),
+            11 => Ok(Status::Failed),
+            _ => Err(StateError::ImpossibleDkgState(value)),
+        }
+    }
+}
+
+impl std::fmt::Display for Status {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(f, "{self:?}")
+    }
+}

Diff for: src/lib.rs

@@ -1,7 +1,9 @@
 pub mod cli;
+pub mod dkg;
 pub mod key;
 pub mod log;
 pub mod net;
 #[allow(clippy::empty_docs)]
 pub mod protobuf;
 pub mod store;
+pub mod transport;