Implement message caching (Only send LOGS packet to server when the LOGS_SIZE returned by server is different from cached one)

src/main/java/net/pixtaded/crab/client/CrabClient.java

@@ -18,6 +18,7 @@ public class CrabClient implements Crab {
     private BufferedReader in;
     private int lastBufferLength = 0;
     private String nickname;
+    private Logs cache = new Logs(0, "");
 
     public CrabClient() {
         this.nickname = "";
@@ -111,9 +112,12 @@ public class CrabClient implements Crab {
                 int response = in.read(buffer);
                 lastBufferLength = Integer.parseInt(new String(buffer).trim());
             } case LOGS -> {
-                byte[] bytes = socket.getInputStream().readNBytes(lastBufferLength);
-                System.out.print("\033[H\033[2J");
-                System.out.print(Sanitizer.sanitizeString(new String(bytes, StandardCharsets.UTF_8), false));
+                if (cache.sizeInBytes() != lastBufferLength) {
+                    byte[] bytes = socket.getInputStream().readNBytes(lastBufferLength);
+                    cache = new Logs(lastBufferLength, new String(bytes, StandardCharsets.UTF_8));
+                }
+                clearScreen();
+                System.out.print(Sanitizer.sanitizeString(cache.content(), false));
             } default -> {
             }
         }
@@ -135,4 +139,9 @@ public class CrabClient implements Crab {
         sendPacket(LOGS_SIZE, "");
         sendPacket(LOGS, "");
     }
+
+    private void clearScreen() {
+        System.out.print("\033[H\033[2J");
+    }
+
 }

src/main/java/net/pixtaded/crab/client/Logs.java

@@ -0,0 +1,4 @@
+package net.pixtaded.crab.client;
+
+public record Logs(int sizeInBytes, String content) {
+}

src/main/java/net/pixtaded/crab/server/CrabServer.java

@@ -12,7 +12,7 @@ public class CrabServer implements Crab {
     private Socket socket;
     private boolean isStopped = false;
     private int port;
-    private Database db;
+    private final Database db;
 
     public CrabServer() {
         this.db = new Database("data.db");