Fixed /.. exportdata

MMOCore-API/src/main/java/net/Indyuce/mmocore/command/rpg/admin/ExportDataTreeNode.java

@@ -5,10 +5,11 @@ import io.lumine.mythic.lib.command.api.CommandTreeNode;
 import net.Indyuce.mmocore.MMOCore;
 import net.Indyuce.mmocore.api.player.PlayerData;
 import net.Indyuce.mmocore.manager.data.mysql.MySQLDataProvider;
-import org.bukkit.Bukkit;
 import org.bukkit.command.CommandSender;
+import org.bukkit.scheduler.BukkitRunnable;
 
 import java.io.File;
+import java.text.DecimalFormat;
 import java.util.Arrays;
 import java.util.List;
 import java.util.UUID;
@@ -25,9 +26,27 @@ public class ExportDataTreeNode extends CommandTreeNode {
         super(parent, "exportdata");
     }
 
+    /**
+     * Amount of requests generated every batch
+     */
+    private static final int BATCH_AMOUNT = 50;
+
+    /**
+     * Period in ticks
+     */
+    private static final int BATCH_PERIOD = 20;
+
+    private static final DecimalFormat decFormat = new DecimalFormat("0.#");
+
     @Override
     public CommandResult execute(CommandSender sender, String[] strings) {
 
+        if (!MMOCore.plugin.dataProvider.getDataManager().getLoaded().isEmpty()) {
+            sender.sendMessage("Please make sure no players are logged in when using this command. " +
+                    "If you are still seeing this message, restart your server and execute this command before any player logs in.");
+            return CommandResult.FAILURE;
+        }
+
         final List<UUID> playerIds = Arrays.stream(new File(MMOCore.plugin.getDataFolder() + "/userdata").listFiles())
                 .map(file -> UUID.fromString(file.getName().replace(".yml", ""))).collect(Collectors.toList());
 
@@ -40,31 +59,48 @@ public class ExportDataTreeNode extends CommandTreeNode {
             return CommandResult.FAILURE;
         }
 
+        final double timeEstimation = (double) playerIds.size() / BATCH_AMOUNT * BATCH_PERIOD / 20;
         sender.sendMessage("Exporting " + playerIds.size() + " player data(s).. See console for details");
+        sender.sendMessage("Minimum expected time: " + decFormat.format(timeEstimation) + "s");
 
         // Save player data
-        Bukkit.getScheduler().runTaskAsynchronously(MMOCore.plugin, () -> {
+        new BukkitRunnable() {
-
-            // Loop first for garbage collection
             int errorCount = 0;
-            for (UUID playerId : playerIds)
+            int batchCounter = 0;
-                try {
-                    final PlayerData offlinePlayerData = new PlayerData(new MMOPlayerData(playerId));
-                    MMOCore.plugin.dataProvider.getDataManager().loadData(offlinePlayerData);
 
-                    // Player data is loaded, now it gets saved through SQL
+            @Override
-                    sqlProvider.getDataManager().saveData(offlinePlayerData);
+            public void run() {
-                } catch (RuntimeException exception) {
+                for (int i = 0; i < BATCH_AMOUNT; i++) {
-                    errorCount++;
+                    final int index = BATCH_AMOUNT * batchCounter + i;
-                    exception.printStackTrace();
+
+                    /*
+                     * Saving is done. Close connection to avoid memory
+                     * leaks and ouput the results to the command executor
+                     */
+                    if (index >= playerIds.size()) {
+                        cancel();
+
+                        sqlProvider.close();
+                        MMOCore.plugin.getLogger().log(Level.WARNING, "Exported " + playerIds.size() + " player datas to SQL database. Total errors: " + errorCount);
+                        return;
+                    }
+
+                    final UUID playerId = playerIds.get(index);
+                    try {
+                        final PlayerData offlinePlayerData = new PlayerData(new MMOPlayerData(playerId));
+                        MMOCore.plugin.dataProvider.getDataManager().loadData(offlinePlayerData);
+
+                        // Player data is loaded, now it gets saved through SQL
+                        sqlProvider.getDataManager().saveData(offlinePlayerData);
+                    } catch (RuntimeException exception) {
+                        errorCount++;
+                        exception.printStackTrace();
+                    }
                 }
 
-            MMOCore.plugin.getLogger().log(Level.WARNING, "Exported player data to SQL database. Total errors: " + errorCount);
+                batchCounter++;
-
+            }
-            // Close connection to avoid memory leaks
+        }.runTaskTimerAsynchronously(MMOCore.plugin, 0, BATCH_PERIOD);
-            sqlProvider.close();
-
-        });
 
         return CommandResult.SUCCESS;
     }