Add connection attempt rate-limiting.

proxy/src/test/java/com/velocitypowered/proxy/util/RatelimiterTest.java

@@ -0,0 +1,30 @@
+package com.velocitypowered.proxy.util;
+
+import com.google.common.base.Ticker;
+import org.junit.jupiter.api.Test;
+
+import java.net.InetAddress;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicLong;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+class RatelimiterTest {
+
+    @Test
+    void attempt() {
+        long base = System.nanoTime();
+        AtomicLong extra = new AtomicLong();
+        Ticker testTicker = new Ticker() {
+            @Override
+            public long read() {
+                return base + extra.get();
+            }
+        };
+        Ratelimiter ratelimiter = new Ratelimiter(1000, testTicker);
+        assertTrue(ratelimiter.attempt(InetAddress.getLoopbackAddress()));
+        assertFalse(ratelimiter.attempt(InetAddress.getLoopbackAddress()));
+        extra.addAndGet(TimeUnit.SECONDS.toNanos(2));
+        assertTrue(ratelimiter.attempt(InetAddress.getLoopbackAddress()));
+    }
+}

proxy/src/test/java/com/velocitypowered/proxy/util/ServerMapTest.java

@@ -0,0 +1,35 @@
+package com.velocitypowered.proxy.util;
+
+import com.velocitypowered.api.server.ServerInfo;
+import org.junit.jupiter.api.Test;
+
+import java.net.InetAddress;
+import java.net.InetSocketAddress;
+import java.util.Optional;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+class ServerMapTest {
+    private static final InetSocketAddress TEST_ADDRESS = new InetSocketAddress(InetAddress.getLoopbackAddress(), 25565);
+
+    @Test
+    void respectsCaseInsensitivity() {
+        ServerMap map = new ServerMap();
+        ServerInfo info = new ServerInfo("TestServer", TEST_ADDRESS);
+        map.register(info);
+
+        assertEquals(Optional.of(info), map.getServer("TestServer"));
+        assertEquals(Optional.of(info), map.getServer("testserver"));
+        assertEquals(Optional.of(info), map.getServer("TESTSERVER"));
+    }
+
+    @Test
+    void rejectsRepeatedRegisterAttempts() {
+        ServerMap map = new ServerMap();
+        ServerInfo info = new ServerInfo("TestServer", TEST_ADDRESS);
+        map.register(info);
+
+        ServerInfo willReject = new ServerInfo("TESTSERVER", TEST_ADDRESS);
+        assertThrows(IllegalArgumentException.class, () -> map.register(willReject));
+    }
+}