Add better feedback to users about biome changing process.

src/main/java/world/bentobox/biomes/panels/user/AdvancedPanel.java

@@ -427,7 +427,7 @@ private void changeBiome()
     /**
      * This variable stores update range
      */
-    private int range;
+    private int range = 1;
 
     /**
      * This variable stores update mode

src/main/java/world/bentobox/biomes/tasks/BiomeUpdateHelper.java

@@ -9,6 +9,10 @@
 import java.util.Optional;
 import java.util.Set;
 import java.util.concurrent.CompletableFuture;
+import java.util.function.BiConsumer;
+import java.util.function.BiFunction;
+import java.util.function.Consumer;
+import java.util.function.Function;
 import java.util.stream.Collectors;
 
 import org.bukkit.Bukkit;
@@ -421,12 +425,9 @@ public void updateIslandBiome()
     {
         // Calculate minimal and maximal coordinate based on update mode.
 
-        CompletableFuture<UpdateQueue.Result> completableFuture = new CompletableFuture<>();
-
         BiomeUpdateTask task = new BiomeUpdateTask(this.addon,
             this.callerUser,
-            this.biome,
-            completableFuture);
+            this.biome);
 
         // Select world depending on environment.
 
@@ -465,7 +466,7 @@ else if (World.Environment.THE_END.equals(this.biome.getEnvironment()))
         {
             task.updateChunkQueue();
 
-            this.addon.getUpdateQueue().addUpdateTask(task).thenAccept(result ->
+            this.addon.getUpdateQueue().addUpdateTask(task).thenAccept((result) ->
             {
                 switch (result)
                 {

src/main/java/world/bentobox/biomes/tasks/BiomeUpdateTask.java

@@ -3,6 +3,7 @@
 
 import java.util.Queue;
 import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.CompletionStage;
 import java.util.concurrent.ConcurrentLinkedQueue;
 import java.util.concurrent.atomic.AtomicInteger;
 
@@ -31,12 +32,10 @@ public class BiomeUpdateTask
      * @param addon BiomeAddon object.
      * @param user Player who calls biome update.
      * @param biome BiomeObject that will changed.
-     * @param result Result exposer.
      */
     public BiomeUpdateTask(BiomesAddon addon,
         User user,
-        BiomesObject biome,
-        CompletableFuture<UpdateQueue.Result> result)
+        BiomesObject biome)
     {
         this.addon = addon;
         this.user = user;
@@ -45,7 +44,7 @@ public BiomeUpdateTask(BiomesAddon addon,
         this.biomesObject = biome;
 
         this.chunksToUpdate = new ConcurrentLinkedQueue<>();
-        this.result = result;
+        this.result = new CompletableFuture<>();
 
         this.processCounter = new AtomicInteger(0);
     }
@@ -88,8 +87,10 @@ public void processBiomeChange(UpdateQueue updateQueue)
                 this.addon.logError("scanChunk not on Primary Thread!");
             }
 
+            long runTime = System.currentTimeMillis() - updateQueue.getProcessStartMap().get(this);
+
             // Timeout check
-            if (System.currentTimeMillis() - updateQueue.getProcessStartMap().get(this) > this.addon.getSettings().getChangeTimeout() * 60000)
+            if (runTime > this.addon.getSettings().getChangeTimeout() * 60000)
             {
                 // Done
                 updateQueue.getProcessStartMap().remove(this);
@@ -106,6 +107,9 @@ public void processBiomeChange(UpdateQueue updateQueue)
                 if (this.chunksToUpdate.isEmpty())
                 {
                     // Done there are no more things to process
+                    updateQueue.updateTimer(runTime, this.getNumberOfChunks());
+                    updateQueue.getProcessStartMap().remove(this);
+
                     this.result.complete(UpdateQueue.Result.FINISHED);
                 }
                 else
@@ -337,14 +341,27 @@ public int getNumberOfChunks()
 
 
     /**
-     * Notify biome change process starting to the user.
+     * Notify that biome is added in processing queue.
      */
     public void notifyStarting()
     {
         Utils.sendMessage(this.user, this.user.getTranslation(
             Constants.MESSAGES + "update-start",
             "[biome]", this.biomesObject.getFriendlyName(),
-            "[number]", String.valueOf(this.numberOfChunks)));
+            "[number]", String.valueOf(this.getNumberOfChunks()),
+            "[time]", String.valueOf((int)
+                Math.max(1, this.getNumberOfChunks() * this.addon.getUpdateQueue().getChunkTime()))));
+    }
+
+
+    /**
+     * Notify that biome is added in waiting queue.
+     */
+    public void notifyWaiting()
+    {
+        Utils.sendMessage(this.user,
+            this.user.getTranslation(Constants.MESSAGES + "waiting",
+                "[time]", String.valueOf(this.addon.getUpdateQueue().getQueueTime())));
     }
 
 

src/main/java/world/bentobox/biomes/tasks/UpdateQueue.java

@@ -9,11 +9,10 @@
 
 import org.bukkit.Bukkit;
 import org.bukkit.scheduler.BukkitTask;
-import java.util.HashMap;
-import java.util.Map;
-import java.util.Queue;
+import java.util.*;
 import java.util.concurrent.CompletionStage;
 import java.util.concurrent.ConcurrentLinkedQueue;
+import java.util.concurrent.atomic.AtomicLong;
 
 import world.bentobox.bentobox.BentoBox;
 import world.bentobox.biomes.BiomesAddon;
@@ -34,6 +33,9 @@ public UpdateQueue(BiomesAddon addon)
         this.processQueue = new ConcurrentLinkedQueue<>();
         this.processStartMap = new HashMap<>();
 
+        this.timer = new AtomicLong(0);
+        this.counter = new AtomicLong(0);
+
         this.task = Bukkit.getScheduler().runTaskTimer(BentoBox.getInstance(), () -> {
             if (!BentoBox.getInstance().isEnabled() || !this.addon.isEnabled())
             {
@@ -50,6 +52,7 @@ public UpdateQueue(BiomesAddon addon)
             for (int i = 0; i < this.addon.getSettings().getConcurrentBiomeUpdates() && !this.processQueue.isEmpty(); i++)
             {
                 BiomeUpdateTask updateTask = this.processQueue.poll();
+                // Notify starting
                 updateTask.notifyStarting();
                 this.processStartMap.put(updateTask, System.currentTimeMillis());
                 // Start the scanning of an area chunks
@@ -114,11 +117,61 @@ public BukkitTask getTask()
      */
     public CompletionStage<Result> addUpdateTask(BiomeUpdateTask task)
     {
+        if (this.processStartMap.size() >= this.addon.getSettings().getConcurrentBiomeUpdates())
+        {
+            task.notifyWaiting();
+        }
+
         this.processQueue.add(task);
         return task.getResult();
     }
 
 
+    /**
+     * Updates timer for changing biome.
+     *
+     * @param timer the timer
+     * @param chunks the number of chunks
+     */
+    public void updateTimer(long timer, long chunks)
+    {
+        this.counter.addAndGet(chunks);
+        this.timer.addAndGet(timer);
+    }
+
+
+    /**
+     * Get the average time it takes to run a level check
+     * @return the average time in seconds
+     */
+    public int getQueueTime()
+    {
+        double average = this.getChunkTime();
+
+        int time = 0;
+
+        List<BiomeUpdateTask> updateTaskList = new ArrayList<>(this.processQueue);
+        updateTaskList.addAll(this.processStartMap.keySet());
+
+        for (BiomeUpdateTask biomeUpdateTask : updateTaskList)
+        {
+            time += biomeUpdateTask.getNumberOfChunks() * average;
+        }
+
+        return time == 0 ? 1 : time;
+    }
+
+
+    /**
+     * Gets average time per processing a chunk.
+     * @return the chunk time
+     */
+    public double getChunkTime()
+    {
+        return this.counter.get() == 0 ? 0.05 : 1.0 * this.timer.get() / this.counter.get() / 1000;
+    }
+
+
 // ---------------------------------------------------------------------
 // Section: Emums
 // ---------------------------------------------------------------------
@@ -168,4 +221,14 @@ public enum Result
      * Main bukkit task that process queue.
      */
     private final BukkitTask task;
+
+    /**
+     * Stores how long on average biome change took per each chunk.
+     */
+    private final AtomicLong timer;
+
+    /**
+     * Stores how many chunks were updated.
+     */
+    private final AtomicLong counter;
 }

src/main/resources/locales/en-US.yml

@@ -781,11 +781,12 @@ biomes:
     import-count: "&e Imported [biomes] biomes and [bundles] bundles."
     # Message that appears after clicking on download button in web library.
     start-downloading: "&e Start downloading library."
-    # This message is sent to use when biome changing is started.
-    update-start: "&a Starting biome changing to [biome] in [number] chunks."
-    # This message is sent to use when biome changing is finished.
+    # This message is sent to user when biome changing is started.
+    update-start: "&a Starting biome changing to [biome] in [number] chunks. &e Estimated time: [time] sec."
+    # This message is sent to user when biome changing is finished.
     update-done: "&a Finished changing biome to [biome]."
-
+    # This message is sent to user when his change is placed in queue.
+    waiting: "&a Added biome change in queue. &e Estimated waiting time: [time] sec."
     skipping: "&a Skipping loading &r [biome] &r&a."
     overwriting: "&a Overwriting &r [biome] &r&a in cache."
     imported: "&a Imported &r [biome] &r&a in cache."