Protocol v6 (#49)

* Update protocol version

* Protocol V6 and random seed support

Author: slinkydeveloper

service-protocol/dev/restate/service/protocol.proto

@@ -33,6 +33,9 @@ enum ServiceProtocolVersion {
   // * New command to attach to existing invocation
   // * New command to get output of existing invocation
   V5 = 5;
+  // Added:
+  // * StartMessage.random_seed
+  V6 = 6;
 }
 
 // --- Core frames ---
@@ -74,6 +77,10 @@ message StartMessage {
   // Please note this duration might not be accurate,
   // and might change depending on which Restate replica executes the request.
   uint64 duration_since_last_stored_entry = 8;
+
+  // Random seed to use to seed the deterministic RNG exposed in the context API.
+  // This will be stable across restarts.
+  uint64 random_seed = 9;
 }
 
 // Type: 0x0000 + 1

src/service_protocol/encoding.rs

@@ -220,6 +220,7 @@ mod tests {
             key: "key".to_string(),
             retry_count_since_last_stored_entry: 0,
             duration_since_last_stored_entry: 0,
+            random_seed: 0,
         };
 
         let expected_msg_1 = messages::InputCommandMessage {

src/service_protocol/generated/dev.restate.service.protocol.rs

@@ -33,6 +33,10 @@ pub struct StartMessage {
     /// and might change depending on which Restate replica executes the request.
     #[prost(uint64, tag = "8")]
     pub duration_since_last_stored_entry: u64,
+    /// Random seed to use to seed the deterministic RNG exposed in the context API.
+    /// This will be stable across restarts.
+    #[prost(uint64, tag = "9")]
+    pub random_seed: u64,
 }
 /// Nested message and enum types in `StartMessage`.
 pub mod start_message {
@@ -925,6 +929,9 @@ pub enum ServiceProtocolVersion {
     /// * New command to attach to existing invocation
     /// * New command to get output of existing invocation
     V5 = 5,
+    /// Added:
+    /// * StartMessage.random_seed
+    V6 = 6,
 }
 impl ServiceProtocolVersion {
     /// String value of the enum field names used in the ProtoBuf definition.
@@ -939,6 +946,7 @@ impl ServiceProtocolVersion {
             Self::V3 => "V3",
             Self::V4 => "V4",
             Self::V5 => "V5",
+            Self::V6 => "V6",
         }
     }
     /// Creates an enum from field names used in the ProtoBuf definition.
@@ -950,6 +958,7 @@ impl ServiceProtocolVersion {
             "V3" => Some(Self::V3),
             "V4" => Some(Self::V4),
             "V5" => Some(Self::V5),
+            "V6" => Some(Self::V6),
             _ => None,
         }
     }

src/service_protocol/version.rs

@@ -8,13 +8,15 @@ pub enum Version {
     V3 = 3,
     V4 = 4,
     V5 = 5,
+    V6 = 6,
 }
 
 const CONTENT_TYPE_V1: &str = "application/vnd.restate.invocation.v1";
 const CONTENT_TYPE_V2: &str = "application/vnd.restate.invocation.v2";
 const CONTENT_TYPE_V3: &str = "application/vnd.restate.invocation.v3";
 const CONTENT_TYPE_V4: &str = "application/vnd.restate.invocation.v4";
 const CONTENT_TYPE_V5: &str = "application/vnd.restate.invocation.v5";
+const CONTENT_TYPE_V6: &str = "application/vnd.restate.invocation.v6";
 
 impl Version {
     pub const fn content_type(&self) -> &'static str {
@@ -24,6 +26,7 @@ impl Version {
             Version::V3 => CONTENT_TYPE_V3,
             Version::V4 => CONTENT_TYPE_V4,
             Version::V5 => CONTENT_TYPE_V5,
+            Version::V6 => CONTENT_TYPE_V6,
         }
     }
 
@@ -32,7 +35,7 @@ impl Version {
     }
 
     pub const fn maximum_supported_version() -> Self {
-        Version::V5
+        Version::V6
     }
 }
 
@@ -61,6 +64,7 @@ impl FromStr for Version {
             CONTENT_TYPE_V3 => Ok(Version::V3),
             CONTENT_TYPE_V4 => Ok(Version::V4),
             CONTENT_TYPE_V5 => Ok(Version::V5),
+            CONTENT_TYPE_V6 => Ok(Version::V6),
             s if s.starts_with("application/vnd.restate.invocation.") => {
                 Err(ContentTypeError::RestateContentType(s.to_owned()))
             }

src/tests/mod.rs

@@ -201,6 +201,7 @@ pub fn start_message(known_entries: u32) -> StartMessage {
         key: "".to_string(),
         retry_count_since_last_stored_entry: 0,
         duration_since_last_stored_entry: 0,
+        random_seed: 0,
     }
 }
 

src/vm/context.rs

@@ -18,6 +18,7 @@ pub(crate) struct StartInfo {
     pub(crate) entries_to_replay: u32,
     pub(crate) retry_count_since_last_stored_entry: u32,
     pub(crate) duration_since_last_stored_entry: u64,
+    pub(crate) random_seed: Option<u64>,
 }
 
 pub(crate) struct Journal {
@@ -434,6 +435,7 @@ pub(crate) struct Context {
     // It's not very Rusty I know, but it makes much more reasonable handling failure cases.
     pub(crate) start_info: Option<StartInfo>,
     pub(crate) journal: Journal,
+    pub(crate) negotiated_protocol_version: Version,
 
     pub(crate) input_is_closed: bool,
     pub(crate) output: Output,