Start work on kv example (#6)

CMakeLists.txt

@@ -26,11 +26,13 @@ add_executable(test_raft test/test_raft.cpp)
 add_executable(test_read_write test/test_read_write.cpp)
 add_executable(server server/server.cpp)
 add_executable(client client/client.cpp)
+add_executable(kv examples/kv.cpp)
 
 include_directories(${CMAKE_CURRENT_SOURCE_DIR}/src ${CMAKE_CURRENT_SOURCE_DIR}/coroio)
 
 target_link_libraries(server miniraft coroio)
 target_link_libraries(client miniraft coroio)
+target_link_libraries(kv miniraft coroio)
 
 target_include_directories(test_raft PRIVATE ${CMOCKA_INCLUDE_DIRS})
 target_link_directories(test_raft PRIVATE ${CMOCKA_LIBRARY_DIRS})

examples/kv.cpp

@@ -0,0 +1,46 @@
+#include <string_view>
+
+#include "kv.h"
+
+struct TWriteKv: public TLogEntry {
+    uint16_t KeySize;
+    uint16_t ValSize;
+    char Data[0];
+};
+
+struct TReadKv: public TCommandRequest {
+    uint16_t KeySize;
+    char Data[0];
+};
+
+TMessageHolder<TMessage> TKv::Read(TMessageHolder<TCommandRequest> message) {
+    auto readKv = message.Cast<TReadKv>();
+    std::string_view k(readKv->Data, readKv->KeySize);
+    auto it = H.find(std::string(k));
+    if (it == H.end()) {
+        // TODO
+    } else {
+        // TODO
+    }
+    return {};
+}
+
+void TKv::Write(TMessageHolder<TLogEntry> message) {
+    auto writeKv = message.Cast<TWriteKv>();
+    std::string_view k(writeKv->Data, writeKv->KeySize);
+    std::string_view v(writeKv->Data + writeKv->KeySize, writeKv->ValSize);
+    H[std::string(k)] = std::string(v);
+    return;
+}
+
+TMessageHolder<TLogEntry> TKv::Prepare(TMessageHolder<TCommandRequest> command, uint64_t term) {
+    auto dataSize = command->Len - sizeof(TCommandRequest);
+    auto entry = NewHoldedMessage<TLogEntry>(sizeof(TLogEntry)+dataSize);
+    memcpy(entry->Data, command->Data, dataSize);
+    entry->Term = term;
+    return entry;
+}
+
+int main(int argc, char** argv) {
+    return 0;
+}

examples/kv.h

@@ -0,0 +1,16 @@
+#pragma once
+
+#include <unordered_map>
+#include <string>
+
+#include <raft.h>
+
+class TKv: public IRsm {
+public:
+    TMessageHolder<TMessage> Read(TMessageHolder<TCommandRequest> message) override;
+    void Write(TMessageHolder<TLogEntry> message) override;
+    TMessageHolder<TLogEntry> Prepare(TMessageHolder<TCommandRequest> message, uint64_t term) override;
+
+private:
+    std::unordered_map<std::string, std::string> H;
+};

src/raft.h

@@ -16,6 +16,15 @@ struct INode {
     virtual void Drain() = 0;
 };
 
+// CommandRequest -> Write? -> LogEntry -> Append -> Committed As Index -> Applied As Index (Same) -> Index -> CommandResponse
+// CommandRequest -> Read? -> CurrentIndex (fixate) >= CommittedIndex -> CommandResponse
+struct IRsm {
+    virtual ~IRsm() = default;
+    virtual TMessageHolder<TMessage> Read(TMessageHolder<TCommandRequest> message) = 0;
+    virtual void Write(TMessageHolder<TLogEntry> message) = 0;
+    virtual TMessageHolder<TLogEntry> Prepare(TMessageHolder<TCommandRequest> message, uint64_t term) = 0;
+};
+
 using TNodeDict = std::unordered_map<uint32_t, std::shared_ptr<INode>>;
 
 struct TState {