Introduce async messaging

raft.nimble

@@ -20,6 +20,7 @@ requires "nim >= 1.6.14"
 requires "stew >= 0.1.0"
 requires "unittest2 >= 0.0.4"
 requires "uuids >= 0.1.11"
+requires "chronicles >= 0.10.3"
 
 proc buildBinary(name: string, srcDir = "./", params = "", lang = "c") =
   if not dirExists "build":
@@ -47,7 +48,7 @@ proc test(path: string, name: string, params = "", lang = "c") =
   exec runPrefix & "build/" & name
 
 task test, "Run tests":
-  test "tests", "all_tests", "-d:chronicles_log_level=ERROR -d:unittest2DisableParamFiltering"
+  test "tests", "all_tests", "-d:chronicles_sinks=textlines -d:chronicles_log_level=ERROR -d:unittest2DisableParamFiltering"
 
 
 # Helper functions

raft/consensus_module.nim

@@ -10,11 +10,14 @@
 import protocol
 import types
 
-proc RaftConsensusProcessRequestVote*(consensus: RaftConsensusModule, msg: RaftMessageRequestVote): RaftMessageRequestVoteResponse =
+proc RaftNodeConsensusStartElection*(consensus: RaftConsensusModule) =
   discard
 
-proc RaftConsensusProcessAppendEntries*(consensus: RaftConsensusModule, msg: RaftMessageAppendEntries): RaftMessageAppendEntriesResponse =
+proc RaftNodeConsensusProcessRequestVote*(consensus: RaftConsensusModule, msg: RaftMessageRequestVote): RaftMessageRequestVoteResponse =
   discard
 
-proc RaftConsensusQuorumMin(consensus: RaftConsensusModule): bool =
+proc RaftNodeConsensusProcessAppendEntries*(consensus: RaftConsensusModule, msg: RaftMessageAppendEntries): RaftMessageAppendEntriesResponse =
+  discard
+
+proc RaftNodeConsensusQuorumMin(consensus: RaftConsensusModule): bool =
   discard

raft/protocol.nim

@@ -26,6 +26,7 @@ type
   RaftMessageRequestVote* = ref object of RaftMessageBase
     lastLogTerm*: RaftNodeTerm
     lastLogIndex*: RaftLogIndex
+    senderTerm*: RaftNodeTerm               # Sender Raft Node Term
 
   RaftMessageRequestVoteResponse* = ref object of RaftMessageResponseBase
     granted*: bool
@@ -35,6 +36,7 @@ type
     prevLogTerm*: RaftNodeTerm
     commitIndex*: RaftLogIndex
     logEntries*: Option[seq[RaftNodeLogEntry[SmCommandType]]]         # Optional log entry(ies). Will be empty for a Heart-Beat
+    senderTerm*: RaftNodeTerm                                         # Sender Raft Node Term
 
   RaftMessageAppendEntriesResponse*[SmStateType] = ref object of RaftMessageResponseBase
     success*: bool

raft/raft_api.nim

@@ -10,6 +10,8 @@
 import types
 import protocol
 import consensus_module
+import chronicles
+import asyncdispatch
 
 export types, protocol, consensus_module
 
@@ -62,11 +64,11 @@ func RaftNodeIsLeader*[SmCommandType, SmStateType](node: RaftNode[SmCommandType,
   node.state == rnsLeader
 
 # Deliver Raft Message to the Raft Node and dispatch it
-proc RaftNodeMessageDeliver*[SmCommandType, SmStateType](node: RaftNode[SmCommandType, SmStateType], raftMessage: RaftMessageBase): RaftMessageResponseBase =
+proc RaftNodeMessageDeliver*[SmCommandType, SmStateType](node: RaftNode[SmCommandType, SmStateType], raftMessage: RaftMessageBase): Future[RaftMessageResponseBase] {.async, gcsafe.} =
   discard
 
 # Process RaftNodeClientRequests
-proc RaftNodeClientRequest*[SmCommandType, SmStateType](node: RaftNode[SmCommandType, SmStateType], req: RaftNodeClientRequest[SmCommandType]): RaftNodeClientResponse[SmStateType] =
+proc RaftNodeClientRequest*[SmCommandType, SmStateType](node: RaftNode[SmCommandType, SmStateType], req: RaftNodeClientRequest[SmCommandType]): Future[RaftNodeClientResponse[SmStateType]] {.async, gcsafe.} =
   discard
 
 # Abstract State Machine Ops

raft/types.nim

@@ -13,6 +13,7 @@ import std/locks
 import options
 import stew/results
 import uuids
+import asyncdispatch
 
 export results, options, locks, uuids
 
@@ -73,17 +74,12 @@ type
   RaftMessageBase* = ref object of RootObj # Base Type for Raft Protocol Messages
     msgId*: RaftMessageId                  # Message UUID
     senderId*: RaftNodeId                  # Sender Raft Node ID
-    receiverId*: RaftNodeId                 # Receiver Raft Node ID
-    senderTerm*: RaftNodeTerm              # Sender Raft Node Term
+    receiverId*: RaftNodeId                # Receiver Raft Node ID
 
-  RaftMessageResponseBase* = ref object of RootObj
-    msgId*: RaftMessageId                  # Original Message ID
-    senderId*: RaftNodeId                  # Sender Raft Node ID
-    respondentId: RaftNodeId               # Responding RaftNodeId
-    senderTerm*: RaftNodeTerm              # Sender Raft Node Term
+  RaftMessageResponseBase* = ref object of RaftMessageBase
 
-  RaftMessageSendCallback* = proc (raftMessage: RaftMessageBase): RaftMessageResponseBase {.gcsafe.}  # Callback for Sending Raft Node Messages
-                                                                                                      # out of this Raft Node.
+  RaftMessageSendCallback* = proc (raftMessage: RaftMessageBase): Future[RaftMessageResponseBase] {.async, gcsafe.}  # Callback for Sending Raft Node Messages
+                                                                                                                     # out of this Raft Node.
 
   # For later use when adding/removing new nodes (dynamic configuration chganges)
   RaftNodeConfiguration* = object
@@ -115,7 +111,7 @@ type
     timeout*: int
     oneshot*: bool
 
-  RaftTimerCallback* = proc (timer: RaftTimer) {.nimcall, gcsafe.}   # Pass any function wrapped in a closure
+  RaftTimerCallback* = proc (timer: RaftTimer) {.gcsafe.}   # Pass any function wrapped in a closure
 
   # Raft Node Object type
   RaftNode*[SmCommandType, SmStateType] = ref object

tests/basic_cluster.nim

@@ -19,7 +19,7 @@ type
     nodes*: seq[BasicRaftNode]
 
 proc BasicRaftClusterRaftMessageSendCallbackCreate(cluster: BasicRaftCluster): RaftMessageSendCallback =
-  proc (msg: RaftMessageBase): RaftMessageResponseBase {.closure.} =
+  proc (msg: RaftMessageBase): Future[RaftMessageResponseBase] {.async, gcsafe.} =
     var
       nodeIdx: int = -1
 
@@ -28,7 +28,7 @@ proc BasicRaftClusterRaftMessageSendCallbackCreate(cluster: BasicRaftCluster): R
         nodeIdx = i
         break
 
-    cluster.nodes[nodeIdx].RaftNodeMessageDeliver(msg)
+    result = await cluster.nodes[nodeIdx].RaftNodeMessageDeliver(msg)
 
 proc BasicRaftClusterStart*(cluster: BasicRaftCluster) =
   for node in cluster.nodes: