Expire UserMap cache more aggressively and add cache debugging

Essentials/src/main/java/com/earth2me/essentials/ISettings.java

@@ -282,6 +282,8 @@ public interface ISettings extends IConf {
 
     int getMaxUserCacheCount();
 
+    long getMaxUserCacheValueExpiry();
+
     boolean allowSilentJoinQuit();
 
     boolean isCustomJoinMessage();

Essentials/src/main/java/com/earth2me/essentials/Settings.java

@@ -1469,10 +1469,16 @@ public boolean isDropItemsIfFull() {
     // #easteregg
     @Override
     public int getMaxUserCacheCount() {
-        final long count = Runtime.getRuntime().maxMemory() / 1024 / 96;
+        final long count = Runtime.getRuntime().maxMemory() / 1024 / 1024;
         return config.getInt("max-user-cache-count", (int) count);
     }
 
+    // #easteregg
+    @Override
+    public long getMaxUserCacheValueExpiry() {
+        return config.getLong("max-user-cache-value-expiry", 600);
+    }
+
     @Override
     public boolean isLastMessageReplyRecipient() {
         return config.getBoolean("last-message-reply-recipient", false);

Essentials/src/main/java/com/earth2me/essentials/userstorage/ModernUserMap.java

@@ -16,6 +16,7 @@
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.ConcurrentMap;
 import java.util.concurrent.ExecutionException;
+import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicLong;
 import java.util.logging.Level;
 
@@ -26,23 +27,28 @@ public class ModernUserMap extends CacheLoader<UUID, User> implements IUserMap {
 
     private final boolean debugPrintStackWithWarn;
     private final long debugMaxWarnsPerType;
+    private final boolean debugLogCache;
     private final ConcurrentMap<String, AtomicLong> debugNonPlayerWarnCounts;
 
     public ModernUserMap(final IEssentials ess) {
         this.ess = ess;
         this.uuidCache = new ModernUUIDCache(ess);
         this.userCache = CacheBuilder.newBuilder()
                 .maximumSize(ess.getSettings().getMaxUserCacheCount())
+                .expireAfterAccess(ess.getSettings().getMaxUserCacheValueExpiry(), TimeUnit.SECONDS)
                 .softValues()
                 .build(this);
 
         // -Dnet.essentialsx.usermap.print-stack=true
         final String printStackProperty = System.getProperty("net.essentialsx.usermap.print-stack", "false");
         // -Dnet.essentialsx.usermap.max-warns=20
         final String maxWarnProperty = System.getProperty("net.essentialsx.usermap.max-warns", "100");
+        // -Dnet.essentialsx.usermap.log-cache=true
+        final String logCacheProperty = System.getProperty("net.essentialsx.usermap.log-cache", "false");
 
         this.debugMaxWarnsPerType = NumberUtil.isLong(maxWarnProperty) ? Long.parseLong(maxWarnProperty) : -1;
         this.debugPrintStackWithWarn = Boolean.parseBoolean(printStackProperty);
+        this.debugLogCache = Boolean.parseBoolean(logCacheProperty);
         this.debugNonPlayerWarnCounts = new ConcurrentHashMap<>();
     }
 
@@ -81,6 +87,7 @@ public User getUser(final UUID uuid) {
     public User getUser(final Player base) {
         final User user = loadUncachedUser(base);
         userCache.put(user.getUUID(), user);
+        debugLogCache(user);
         return user;
     }
 
@@ -114,6 +121,7 @@ public void addCachedNpcName(final UUID uuid, final String name) {
     public User load(final UUID uuid) throws Exception {
         final User user = loadUncachedUser(uuid);
         if (user != null) {
+            debugLogCache(user);
             return user;
         }
 
@@ -168,6 +176,7 @@ public User loadUncachedUser(final UUID uuid) {
 
     public void addCachedUser(final User user) {
         userCache.put(user.getUUID(), user);
+        debugLogCache(user);
     }
 
     @Override
@@ -196,6 +205,14 @@ public void shutdown() {
         uuidCache.shutdown();
     }
 
+    private void debugLogCache(final User user) {
+        if (!debugLogCache) {
+            return;
+        }
+        final Throwable throwable = new Throwable();
+        ess.getLogger().log(Level.INFO, String.format("Caching user %s (%s)", user.getName(), user.getUUID()), throwable);
+    }
+
     private void debugLogUncachedNonPlayer(final Player base) {
         final String typeName = base.getClass().getName();
         final long count = debugNonPlayerWarnCounts.computeIfAbsent(typeName, name -> new AtomicLong(0)).getAndIncrement();