simple uuid query cache

src/main/java/me/fallenbreath/velocitywhitelist/MojangAPI.java

@@ -1,6 +1,7 @@
 package me.fallenbreath.velocitywhitelist;
 
 import com.google.common.base.Strings;
+import com.google.common.collect.Lists;
 import com.google.gson.Gson;
 import org.slf4j.Logger;
 
@@ -10,6 +11,7 @@
 import java.net.http.HttpRequest;
 import java.net.http.HttpResponse;
 import java.time.Duration;
+import java.util.List;
 import java.util.Optional;
 import java.util.UUID;
 
@@ -22,12 +24,26 @@ private static class ResponseObject
 		public String id;
 	}
 
+	private record QueryCacheEntry(QueryResult result, long timestampMs)
+	{
+	}
+
 	public record QueryResult(UUID uuid, String playerName)
 	{
 	}
 
+	private static final int QUERY_CACHE_TTL_MS = 5 * 60 * 1000;  // 5min
+	private static final int QUERY_CACHE_CAPACITY = 100;
+	private static final List<QueryCacheEntry> queryCache = Lists.newLinkedList();
+
 	public static Optional<QueryResult> queryPlayerByName(Logger logger, String name)
 	{
+		synchronized (queryCache)
+		{
+			long now = System.currentTimeMillis();
+			queryCache.removeIf(e -> now - e.timestampMs > QUERY_CACHE_TTL_MS);
+		}
+
 		// TODO: use http proxy from my fork
 		// TODO: simple expiring lru cache?
 		String url = "https://api.mojang.com/users/profiles/minecraft/" + name;
@@ -47,7 +63,19 @@ public static Optional<QueryResult> queryPlayerByName(Logger logger, String name
 			{
 				return Optional.empty();
 			}
-			return Utils.tryParseUuid(obj.id).map(uuid -> new QueryResult(uuid, obj.name));
+			var ret = Utils.tryParseUuid(obj.id).map(uuid -> new QueryResult(uuid, obj.name));
+
+			ret.ifPresent(result -> {
+				synchronized (queryCache)
+				{
+					queryCache.add(new QueryCacheEntry(result, System.currentTimeMillis()));
+					while (queryCache.size() > QUERY_CACHE_CAPACITY)
+					{
+						queryCache.remove(0);
+					}
+				}
+			});
+			return ret;
 		}
 		catch (IOException | InterruptedException | IllegalArgumentException e)
 		{