Implement follower

resetius · Nov 23, 2023 · 2f6e9fd · 2f6e9fd
1 parent 9d6a330
commit 2f6e9fd
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Showing 2 changed files with 28 additions and 8 deletions.
diff --git a/src/raft.cpp b/src/raft.cpp
@@ -15,7 +15,27 @@ TRaft::TRaft(int node, const TNodeDict& nodes, const std::shared_ptr<ITimeSource
     , LastTime(TimeSource->Now())
 { }
 
+std::unique_ptr<TResult> TRaft::OnRequestVote(TMessageHolder<TRequestVoteRequest> message) {
+    return nullptr;
+}
+
+std::unique_ptr<TResult> TRaft::OnAppendEntries(TMessageHolder<TAppendEntriesRequest> message) {
+    return nullptr;
+}
+
 std::unique_ptr<TResult> TRaft::Follower(ITimeSource::Time now, TMessageHolder<TMessage> message) {
+    if (auto maybeTimeout = message.Maybe<TTimeout>()) {
+        if (now - LastTime > TTimeout::Election) {
+            return std::make_unique<TResult>(TResult {
+                .NextStateName = EState::CANDIDATE,
+                .UpdateLastTime = true
+            });
+        }
+    } else if (auto maybeRequestVote = message.Maybe<TRequestVoteRequest>()) {
+        return OnRequestVote(std::move(maybeRequestVote.Cast()));
+    } else if (auto maybeAppendEntries = message.Maybe<TAppendEntriesRequest>()) {
+        return OnAppendEntries(maybeAppendEntries.Cast());
+    }
     return nullptr;
 }
 
@@ -95,7 +115,7 @@ void TRaft::ApplyResult(ITimeSource::Time now, std::unique_ptr<TResult> result,
             Nodes[m->Dst]->Send(m);
         }
     }
-    if (result->NextStateName) {
-        StateName = static_cast<EState>(result->NextStateName);
+    if (result->NextStateName != EState::NONE) {
+        StateName = result->NextStateName;
     }
 }
diff --git a/src/raft.h b/src/raft.h
@@ -64,21 +64,18 @@ struct TVolatileState {
     TVolatileState& MergeMatchIndex(const std::vector<int>& matchIndex);
 };
 
-struct TResult;
-
 enum class EState: int {
+    NONE = 0,
     CANDIDATE = 1,
     FOLLOWER = 2,
     LEADER = 3,
 };
 
-using TStateFunc = std::function<std::unique_ptr<TResult>(uint64_t now, const TMessageHolder<TMessage>& message)>;
-
 struct TResult {
     std::unique_ptr<TState> NextState;
     std::unique_ptr<TVolatileState> NextVolatileState;
-    int NextStateName;
-    bool UpdateLastTime;
+    EState NextStateName = EState::NONE;
+    bool UpdateLastTime = false;
     TMessageHolder<TMessage> Message;
     std::vector<TMessageHolder<TAppendEntriesRequest>> Messages;
 };
@@ -101,6 +98,9 @@ class TRaft {
     std::unique_ptr<TResult> Candidate(ITimeSource::Time now, TMessageHolder<TMessage> message);
     std::unique_ptr<TResult> Leader(ITimeSource::Time now, TMessageHolder<TMessage> message);
 
+    std::unique_ptr<TResult> OnRequestVote(TMessageHolder<TRequestVoteRequest> message);
+    std::unique_ptr<TResult> OnAppendEntries(TMessageHolder<TAppendEntriesRequest> message);
+
     int Id;
     TNodeDict Nodes;
     std::shared_ptr<ITimeSource> TimeSource;