From 3303434d52ca01be5f80a5611d165654d5146838 Mon Sep 17 00:00:00 2001
From: Jesse Boyd <jessepaleg@gmail.com>
Date: Mon, 29 Jul 2019 05:03:17 +1000
Subject: [PATCH] listchunks doesn't need to be a list

Nor does it need to be a string. As long as we can iterate, it should be fine.

This somewhat mitigates OOM from listchunks.
---
 .../worldedit/command/ChunkCommands.java      |  3 +-
 .../formatting/component/PaginationBox.java   | 30 +++++++++++++++++--
 2 files changed, 29 insertions(+), 4 deletions(-)

diff --git a/worldedit-core/src/main/java/com/sk89q/worldedit/command/ChunkCommands.java b/worldedit-core/src/main/java/com/sk89q/worldedit/command/ChunkCommands.java
index 36d288eb4..4a170883c 100644
--- a/worldedit-core/src/main/java/com/sk89q/worldedit/command/ChunkCommands.java
+++ b/worldedit-core/src/main/java/com/sk89q/worldedit/command/ChunkCommands.java
@@ -94,8 +94,7 @@ public class ChunkCommands {
                             @ArgFlag(name = 'p', desc = "Page number.", def = "1") int page) throws WorldEditException {
         Set<BlockVector2> chunks = session.getSelection(player.getWorld()).getChunks();
 
-        PaginationBox paginationBox = PaginationBox.fromStrings("Selected Chunks", "/listchunks -p %page%",
-                chunks.stream().map(BlockVector2::toString).collect(Collectors.toList()));
+        PaginationBox paginationBox = PaginationBox.fromStrings("Selected Chunks", "/listchunks -p %page%", chunks);
         player.print(paginationBox.create(page));
     }
 
diff --git a/worldedit-core/src/main/java/com/sk89q/worldedit/util/formatting/component/PaginationBox.java b/worldedit-core/src/main/java/com/sk89q/worldedit/util/formatting/component/PaginationBox.java
index 3f9b95267..6125643ed 100644
--- a/worldedit-core/src/main/java/com/sk89q/worldedit/util/formatting/component/PaginationBox.java
+++ b/worldedit-core/src/main/java/com/sk89q/worldedit/util/formatting/component/PaginationBox.java
@@ -26,6 +26,9 @@ import com.sk89q.worldedit.util.formatting.text.event.HoverEvent;
 import com.sk89q.worldedit.util.formatting.text.format.TextColor;
 
 import javax.annotation.Nullable;
+import java.util.Collection;
+import java.util.Iterator;
+import java.util.LinkedHashSet;
 import java.util.List;
 
 public abstract class PaginationBox extends MessageBox {
@@ -128,21 +131,44 @@ public abstract class PaginationBox extends MessageBox {
         throw new IllegalStateException("Pagination components must be created with a page");
     }
 
+    public static PaginationBox fromStrings(String header, @Nullable String pageCommand, Collection lines) {
+        return new ListPaginationBox(header, pageCommand, lines);
+    }
+
     public static PaginationBox fromStrings(String header, @Nullable String pageCommand, List<String> lines) {
         return new ListPaginationBox(header, pageCommand, lines);
     }
 
     private static class ListPaginationBox extends PaginationBox {
-        private final List<String> lines;
+        private final Collection lines;
+        private int iterIndex;
+        private Iterator iterator;
 
         ListPaginationBox(String header, String pageCommand, List<String> lines) {
+            this(header, pageCommand, (Collection) lines);
+        }
+
+        ListPaginationBox(String header, String pageCommand, Collection lines) {
             super(header, pageCommand);
             this.lines = lines;
         }
 
         @Override
         public Component getComponent(int number) {
-            return TextComponent.of(lines.get(number));
+            Object obj;
+            if (lines instanceof List) {
+                obj = ((List) lines).get(number);
+            } else {
+                if (iterator == null || iterIndex > number) {
+                    iterator = lines.iterator();
+                    iterIndex = 0;
+                }
+                do {
+                    obj = iterator.next();
+                    iterIndex++;
+                } while (iterIndex < number);
+            }
+            return TextComponent.of(obj.toString());
         }
 
         @Override