Add option to limit baltop entries

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

@@ -53,7 +53,10 @@ private void calculateBalanceTopMap() {
         }
         final LinkedHashMap<UUID, Entry> sortedMap = new LinkedHashMap<>();
         entries.sort((entry1, entry2) -> entry2.getBalance().compareTo(entry1.getBalance()));
-        for (Entry entry : entries) {
+        final int entryLimit = ess.getSettings().getBaltopEntryLimit();
+        final int limit = entryLimit == -1 ? entries.size() : Math.min(entryLimit, entries.size());
+        for (int i = 0; i < limit; i++) {
+            final Entry entry = entries.get(i);
             sortedMap.put(entry.getUuid(), entry);
         }
         topCache = sortedMap;

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

@@ -446,6 +446,8 @@ public interface ISettings extends IConf {
 
     long getBaltopMinPlaytime();
 
+    int getBaltopEntryLimit();
+
     enum KeepInvPolicy {
         KEEP,
         DELETE,

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

@@ -2231,6 +2231,11 @@ public BigDecimal getBaltopMinBalance() {
         return config.getBigDecimal("baltop-requirements.minimum-balance", BigDecimal.ZERO);
     }
 
+    @Override
+    public int getBaltopEntryLimit() {
+        return config.getInt("baltop-entry-limit", -1);
+    }
+
     @Override
     public long getBaltopMinPlaytime() {
         return config.getLong("baltop-requirements.minimum-playtime", 0);

Essentials/src/main/resources/config.yml

@@ -893,6 +893,11 @@ baltop-requirements:
   minimum-balance: 0
   minimum-playtime: 0
 
+# Allows to limit cached balance top (/baltop) entries. This is especially recommended if
+# you have a large number of players, then only a certain number of entries will be stored
+# in the server's memory. Set to -1 to disable the limit
+baltop-entry-limit: -1
+
 # The format of currency, excluding symbols. For symbol configuration, see 'currency-symbol-format-locale' below.
 #
 # "#,##0.00" is how the majority of countries display currency.