Feature: add rkyv support

Cargo.toml

@@ -29,6 +29,7 @@ maplit = "1.0.2"
 pin-utils = "0.1.0"
 pretty_assertions = "1.0.0"
 rand = "0.8"
+rkyv = { version = "0.7.42", features=["validation"] }
 serde = { version="1.0.114", features=["derive", "rc"]}
 serde_json = "1.0.57"
 tempfile = { version = "3.4.0" }

openraft/Cargo.toml

@@ -25,6 +25,7 @@ pin-utils       = { workspace = true }
 rand            = { workspace = true }
 serde           = { workspace = true, optional = true }
 serde_json      = { workspace = true, optional = true }
+rkyv            = { workspace = true, optional = true }
 clap            = { workspace = true }
 tempfile        = { workspace = true, optional = true }
 thiserror       = { workspace = true }
@@ -58,6 +59,10 @@ bt  = ["anyerror/backtrace", "anyhow/backtrace"]
 # If you'd like to use `serde` to serialize messages.
 serde = ["dep:serde"]
 
+# Add rkyv::Archive, rkyv:Deserialize and rkyv::Serialize derives and archive(check_bytes) to data types.
+# If you'd like to use `rkyv` to serialize messages.
+rkyv = ["dep:rkyv"]
+
 # Turn on this feature it allows at most ONE quorum-granted leader for each term.
 # This is the way standard raft does, by making the LeaderId a partial order value.
 #

openraft/src/change_members.rs

@@ -9,6 +9,11 @@ use crate::NodeId;
 #[derive(Debug, Clone)]
 #[derive(PartialEq, Eq)]
 #[cfg_attr(feature = "serde", derive(serde::Deserialize, serde::Serialize), serde(bound = ""))]
+#[cfg_attr(
+    feature = "rkyv",
+    derive(rkyv::Archive, rkyv::Deserialize, rkyv::Serialize),
+    archive(check_bytes)
+)]
 pub enum ChangeMembers<NID: NodeId, N: Node> {
     /// Upgrade learners to voters.
     ///

openraft/src/core/server_state.rs

@@ -2,6 +2,11 @@
 #[derive(Debug, Clone, Copy, Default)]
 #[derive(PartialEq, Eq)]
 #[cfg_attr(feature = "serde", derive(serde::Deserialize, serde::Serialize))]
+#[cfg_attr(
+    feature = "rkyv",
+    derive(rkyv::Archive, rkyv::Deserialize, rkyv::Serialize),
+    archive(check_bytes)
+)]
 pub enum ServerState {
     /// The node is completely passive; replicating entries, but neither voting nor timing out.
     #[default]

openraft/src/docs/feature_flags/feature-flags.md

@@ -7,6 +7,9 @@ By default openraft enables no features.
 - `serde`: derives `serde::Serialize, serde::Deserialize` for type that are used
   in storage and network, such as `Vote` or `AppendEntriesRequest`.
 
+- `rkyv`: derives `rkyv::Archive, rkyv::Deserialize, rkyv::Serialize, rkyv::CheckBytes`
+  for types that are used in storage and network, such as `Vote` or `AppendEntriesRequest`.
+
 - `single-term-leader`: allows only one leader to be elected in each `term`.
   This is the standard raft policy, which increases election confliction rate
   but reduce `LogId`(`(term, node_id, index)` to `(term, index)`) size.

openraft/src/entry/mod.rs

@@ -17,6 +17,11 @@ pub use traits::RaftPayload;
 
 /// A Raft log entry.
 #[cfg_attr(feature = "serde", derive(serde::Deserialize, serde::Serialize), serde(bound = ""))]
+#[cfg_attr(
+    feature = "rkyv",
+    derive(rkyv::Archive, rkyv::Deserialize, rkyv::Serialize),
+    archive(check_bytes)
+)]
 pub struct Entry<C>
 where C: RaftTypeConfig
 {

openraft/src/entry/payload.rs

@@ -9,6 +9,11 @@ use crate::RaftTypeConfig;
 /// Log entry payload variants.
 #[derive(PartialEq)]
 #[cfg_attr(feature = "serde", derive(serde::Deserialize, serde::Serialize))]
+#[cfg_attr(
+    feature = "rkyv",
+    derive(rkyv::Archive, rkyv::Deserialize, rkyv::Serialize),
+    archive(check_bytes)
+)]
 pub enum EntryPayload<C: RaftTypeConfig> {
     /// An empty payload committed by a new cluster leader.
     Blank,

openraft/src/error.rs

@@ -28,6 +28,12 @@ use crate::Vote;
     derive(serde::Deserialize, serde::Serialize),
     serde(bound = "E:serde::Serialize + for <'d> serde::Deserialize<'d>")
 )]
+#[cfg_attr(
+    feature = "rkyv",
+    derive(rkyv::Archive, rkyv::Deserialize, rkyv::Serialize),
+    archive(check_bytes)
+)]
+
 pub enum RaftError<NID, E = Infallible>
 where NID: NodeId
 {
@@ -470,6 +476,35 @@ pub struct EmptyMembership {}
 #[error("infallible")]
 pub enum Infallible {}
 
+#[cfg(feature = "rkyv")]
+mod rkyv_serialization {
+    //! Manual implementations for the required `rkyv` traits since it is not
+    //! possible to derive them on an enum with no variant. All implementations
+    //! use `unreachable` since `Infallible` cannot be constructed.
+
+    impl rkyv::Archive for super::Infallible {
+        type Archived = ();
+        type Resolver = ();
+
+        #[inline]
+        unsafe fn resolve(&self, _: usize, _: Self::Resolver, _: *mut Self::Archived) {
+            unreachable!()
+        }
+    }
+
+    impl<S: rkyv::Fallible + ?Sized> rkyv::Serialize<S> for super::Infallible {
+        fn serialize(&self, _: &mut S) -> Result<Self::Resolver, S::Error> {
+            unreachable!()
+        }
+    }
+
+    impl<D: rkyv::Fallible + ?Sized> rkyv::Deserialize<super::Infallible, D> for u16 {
+        fn deserialize(&self, _: &mut D) -> Result<super::Infallible, D::Error> {
+            unreachable!()
+        }
+    }
+}
+
 /// A place holder to mark RaftError won't have a ForwardToLeader variant.
 #[derive(Debug, Clone, PartialEq, Eq, thiserror::Error)]
 #[cfg_attr(feature = "serde", derive(serde::Deserialize, serde::Serialize))]

openraft/src/log_id/mod.rs

@@ -22,6 +22,11 @@ use crate::NodeId;
 /// parts: a leader id, which refers to the leader that proposed this log, and an integer index.
 #[derive(Debug, Default, Copy, Clone, PartialOrd, Ord, PartialEq, Eq)]
 #[cfg_attr(feature = "serde", derive(serde::Deserialize, serde::Serialize), serde(bound = ""))]
+#[cfg_attr(
+    feature = "rkyv",
+    derive(rkyv::Archive, rkyv::Deserialize, rkyv::Serialize),
+    archive(check_bytes)
+)]
 pub struct LogId<NID: NodeId> {
     /// The id of the leader that proposed this log
     pub leader_id: CommittedLeaderId<NID>,

openraft/src/membership/membership.rs

@@ -21,6 +21,11 @@ use crate::NodeId;
 /// of a majority of every config.
 #[derive(Clone, Debug, Default, PartialEq, Eq)]
 #[cfg_attr(feature = "serde", derive(serde::Deserialize, serde::Serialize), serde(bound = ""))]
+#[cfg_attr(
+    feature = "rkyv",
+    derive(rkyv::Archive, rkyv::Deserialize, rkyv::Serialize),
+    archive(check_bytes)
+)]
 pub struct Membership<NID, N>
 where
     N: Node,

openraft/src/membership/stored_membership.rs

@@ -19,6 +19,11 @@ use crate::NodeId;
 #[derive(Clone, Debug, Default)]
 #[derive(PartialEq, Eq)]
 #[cfg_attr(feature = "serde", derive(serde::Deserialize, serde::Serialize), serde(bound = ""))]
+#[cfg_attr(
+    feature = "rkyv",
+    derive(rkyv::Archive, rkyv::Deserialize, rkyv::Serialize),
+    archive(check_bytes)
+)]
 pub struct StoredMembership<NID, N>
 where
     N: Node,

openraft/src/metrics/raft_metrics.rs

@@ -15,6 +15,11 @@ use crate::Vote;
 /// A set of metrics describing the current state of a Raft node.
 #[derive(Clone, Debug, PartialEq, Eq)]
 #[cfg_attr(feature = "serde", derive(serde::Deserialize, serde::Serialize), serde(bound = ""))]
+#[cfg_attr(
+    feature = "rkyv",
+    derive(rkyv::Archive, rkyv::Deserialize, rkyv::Serialize),
+    archive(check_bytes)
+)]
 pub struct RaftMetrics<NID, N>
 where
     NID: NodeId,

openraft/src/raft.rs

@@ -1060,6 +1060,11 @@ impl fmt::Display for ExternalCommand {
 /// An RPC sent by a cluster leader to replicate log entries (§5.3), and as a heartbeat (§5.2).
 #[derive(Clone)]
 #[cfg_attr(feature = "serde", derive(serde::Deserialize, serde::Serialize), serde(bound = ""))]
+#[cfg_attr(
+    feature = "rkyv",
+    derive(rkyv::Archive, rkyv::Deserialize, rkyv::Serialize),
+    archive(check_bytes)
+)]
 pub struct AppendEntriesRequest<C: RaftTypeConfig> {
     pub vote: Vote<C::NodeId>,
 
@@ -1110,6 +1115,11 @@ impl<C: RaftTypeConfig> MessageSummary<AppendEntriesRequest<C>> for AppendEntrie
 #[derive(Debug)]
 #[derive(PartialEq, Eq)]
 #[cfg_attr(feature = "serde", derive(serde::Deserialize, serde::Serialize), serde(bound = ""))]
+#[cfg_attr(
+    feature = "rkyv",
+    derive(rkyv::Archive, rkyv::Deserialize, rkyv::Serialize),
+    archive(check_bytes)
+)]
 pub enum AppendEntriesResponse<NID: NodeId> {
     /// Successfully replicated all log entries to the target node.
     Success,
@@ -1168,6 +1178,11 @@ impl<NID: NodeId> fmt::Display for AppendEntriesResponse<NID> {
 /// An RPC sent by candidates to gather votes (§5.2).
 #[derive(Debug, Clone, PartialEq, Eq)]
 #[cfg_attr(feature = "serde", derive(serde::Deserialize, serde::Serialize), serde(bound = ""))]
+#[cfg_attr(
+    feature = "rkyv",
+    derive(rkyv::Archive, rkyv::Deserialize, rkyv::Serialize),
+    archive(check_bytes)
+)]
 pub struct VoteRequest<NID: NodeId> {
     pub vote: Vote<NID>,
     pub last_log_id: Option<LogId<NID>>,
@@ -1194,6 +1209,11 @@ impl<NID: NodeId> VoteRequest<NID> {
 /// The response to a `VoteRequest`.
 #[derive(Debug, Clone, PartialEq, Eq)]
 #[cfg_attr(feature = "serde", derive(serde::Deserialize, serde::Serialize), serde(bound = ""))]
+#[cfg_attr(
+    feature = "rkyv",
+    derive(rkyv::Archive, rkyv::Deserialize, rkyv::Serialize),
+    archive(check_bytes)
+)]
 pub struct VoteResponse<NID: NodeId> {
     /// vote after a node handling vote-request.
     /// Thus `resp.vote >= req.vote` always holds.
@@ -1221,6 +1241,11 @@ impl<NID: NodeId> MessageSummary<VoteResponse<NID>> for VoteResponse<NID> {
 #[derive(Clone, Debug)]
 #[derive(PartialEq, Eq)]
 #[cfg_attr(feature = "serde", derive(serde::Deserialize, serde::Serialize), serde(bound = ""))]
+#[cfg_attr(
+    feature = "rkyv",
+    derive(rkyv::Archive, rkyv::Deserialize, rkyv::Serialize),
+    archive(check_bytes)
+)]
 pub struct InstallSnapshotRequest<C: RaftTypeConfig> {
     pub vote: Vote<C::NodeId>,
 
@@ -1255,6 +1280,11 @@ impl<C: RaftTypeConfig> MessageSummary<InstallSnapshotRequest<C>> for InstallSna
 #[derive(derive_more::Display)]
 #[display(fmt = "{{vote:{}}}", vote)]
 #[cfg_attr(feature = "serde", derive(serde::Deserialize, serde::Serialize), serde(bound = ""))]
+#[cfg_attr(
+    feature = "rkyv",
+    derive(rkyv::Archive, rkyv::Deserialize, rkyv::Serialize),
+    archive(check_bytes)
+)]
 pub struct InstallSnapshotResponse<NID: NodeId> {
     pub vote: Vote<NID>,
 }
@@ -1265,6 +1295,11 @@ pub struct InstallSnapshotResponse<NID: NodeId> {
     derive(serde::Deserialize, serde::Serialize),
     serde(bound = "C::R: AppDataResponse")
 )]
+#[cfg_attr(
+    feature = "rkyv",
+    derive(rkyv::Archive, rkyv::Deserialize, rkyv::Serialize),
+    archive(check_bytes)
+)]
 pub struct ClientWriteResponse<C: RaftTypeConfig> {
     /// The id of the log that is applied.
     pub log_id: LogId<C::NodeId>,

openraft/src/storage/mod.rs

@@ -34,6 +34,11 @@ use crate::Vote;
 
 #[derive(Debug, Clone, Default, PartialEq, Eq)]
 #[cfg_attr(feature = "serde", derive(serde::Deserialize, serde::Serialize), serde(bound = ""))]
+#[cfg_attr(
+    feature = "rkyv",
+    derive(rkyv::Archive, rkyv::Deserialize, rkyv::Serialize),
+    archive(check_bytes)
+)]
 pub struct SnapshotMeta<NID, N>
 where
     NID: NodeId,

openraft/src/vote/leader_id/leader_id_adv.rs

@@ -14,6 +14,11 @@ use crate::NodeId;
 #[derive(Debug, Default, Clone, Copy, PartialEq, Eq)]
 #[derive(PartialOrd, Ord)]
 #[cfg_attr(feature = "serde", derive(serde::Deserialize, serde::Serialize), serde(bound = ""))]
+#[cfg_attr(
+    feature = "rkyv",
+    derive(rkyv::Archive, rkyv::Deserialize, rkyv::Serialize),
+    archive(check_bytes)
+)]
 pub struct LeaderId<NID>
 where NID: NodeId
 {

openraft/src/vote/leader_id/leader_id_std.rs

@@ -6,6 +6,11 @@
 
 #[derive(Debug, Default, Clone, Copy, PartialEq, Eq)]
 #[cfg_attr(feature = "serde", derive(serde::Deserialize, serde::Serialize), serde(bound = ""))]
+#[cfg_attr(
+    feature = "rkyv",
+    derive(rkyv::Archive, rkyv::Deserialize, rkyv::Serialize),
+    archive(check_bytes)
+)]
 pub struct LeaderId<NID>
 where NID: NodeId
 {
@@ -76,6 +81,11 @@
 #[derive(Debug, Default, Clone, Copy, PartialEq, Eq)]
 #[derive(PartialOrd, Ord)]
 #[cfg_attr(feature = "serde", derive(serde::Deserialize, serde::Serialize), serde(bound = ""))]
+#[cfg_attr(
+    feature = "rkyv",
+    derive(rkyv::Archive, rkyv::Deserialize, rkyv::Serialize),
+    archive(check_bytes)
+)]
 #[cfg_attr(feature = "serde", serde(transparent))]
 pub struct CommittedLeaderId<NID> {
     pub term: u64,
@@ -97,7 +107,7 @@
 
 #[cfg(test)]
 mod tests {
     use crate::CommittedLeaderId;
     use crate::LeaderId;
 
     #[cfg(feature = "serde")]

openraft/src/vote/vote.rs

@@ -9,6 +9,11 @@ use crate::NodeId;
 /// `Vote` represent the privilege of a node.
 #[derive(Debug, Clone, Copy, Default, PartialEq, Eq)]
 #[cfg_attr(feature = "serde", derive(serde::Deserialize, serde::Serialize), serde(bound = ""))]
+#[cfg_attr(
+    feature = "rkyv",
+    derive(rkyv::Archive, rkyv::Deserialize, rkyv::Serialize),
+    archive(check_bytes)
+)]
 pub struct Vote<NID: NodeId> {
     /// The id of the node that tries to become the leader.
     pub leader_id: LeaderId<NID>,