implementing message cache

server/CMakeLists.txt

@@ -13,6 +13,7 @@ file(GLOB source_files
 )
 add_executable(${PROJECT_NAME} ${source_files})
 
-target_include_directories(${PROJECT_NAME} PUBLIC ${source_dir}/include)
+target_include_directories(${PROJECT_NAME} PRIVATE ${source_dir}/include)
+
 target_link_libraries(${PROJECT_NAME} ${USOCKETS_LIBRARY})
 target_link_libraries(${PROJECT_NAME} ZLIB::ZLIB)

server/src/Main.cpp

@@ -1,28 +1,19 @@
+#include "include/DateTime.hpp"
+#include <MessageCache.hpp>
 #include <chrono>
 #include <ctime>
 #include <iomanip>
 #include <iostream>
+#include <memory>
 #include <uWebSockets/App.h>
 #include <uWebSockets/WebSocket.h>
 
-namespace DateTime
-{
-std::chrono::system_clock::time_point now()
-{
-    return std::chrono::system_clock::now();
-}
-
-void outputTime(const char *desc, std::chrono::system_clock::time_point &tp)
-{
-    std::time_t now = std::chrono::system_clock::to_time_t(tp);
-    std::cout << desc << std::put_time(std::localtime(&now), "%Y-%m-%d %H:%M") << "\n";
-}
-} // namespace DateTime
-
 int main()
 {
     std::cout << "Welcome to the homechat server!\n";
 
+    std::unique_ptr<MessageCache> message_cache = std::make_unique<MessageCache>();
+
     /* ws->getUserData returns one of these */
     struct PerSocketData
     {

server/src/MessageCache.cpp

@@ -0,0 +1,25 @@
+#include "include/MessageCache.hpp"
+
+bool MessageCache::add_message(std::string message)
+{
+    if (m_messages.size() == m_cache_size)
+    {
+        m_messages.erase(m_messages.begin());
+    }
+    m_messages.push_back(message);
+    return true;
+}
+
+MessageCache::MessageCache()
+{
+}
+
+bool MessageCache::empty()
+{
+    return m_messages.empty();
+}
+
+std::vector<std::string> MessageCache::last_ten_messages() const
+{
+    return m_messages.size() > 10 ? std::vector<std::string>(m_messages.end() - 10, m_messages.end()) : m_messages;
+}

server/src/include/DateTime.hpp

@@ -0,0 +1,18 @@
+#include <chrono>
+#include <ctime>
+#include <iomanip>
+#include <iostream>
+
+namespace DateTime
+{
+std::chrono::system_clock::time_point now()
+{
+    return std::chrono::system_clock::now();
+}
+
+void outputTime(const char *desc, std::chrono::system_clock::time_point &tp)
+{
+    std::time_t now = std::chrono::system_clock::to_time_t(tp);
+    std::cout << desc << std::put_time(std::localtime(&now), "%Y-%m-%d %H:%M") << "\n";
+}
+} // namespace DateTime

server/src/include/MessageCache.hpp

@@ -0,0 +1,18 @@
+#include <string>
+#include <vector>
+
+class MessageCache
+{
+  public:
+    MessageCache();
+
+    // adds and removes the oldest message if the cache is full
+    bool add_message(std::string message);
+
+    bool empty();
+    std::vector<std::string> last_ten_messages() const;
+
+  private:
+    std::vector<std::string> m_messages;
+    static constexpr int m_cache_size = 100;
+};