CatServer/patches/net/minecraft/server/management/PlayerChunkMap.java.patch

--- ../src-base/minecraft/net/minecraft/server/management/PlayerChunkMap.java
+++ ../src-work/minecraft/net/minecraft/server/management/PlayerChunkMap.java
@@ -10,9 +10,12 @@
 import java.util.Collections;
 import java.util.Comparator;
 import java.util.Iterator;
+import java.util.LinkedList;
 import java.util.List;
 import java.util.Set;
 import javax.annotation.Nullable;
+
+import net.minecraft.entity.player.EntityPlayer;
 import net.minecraft.entity.player.EntityPlayerMP;
 import net.minecraft.util.math.BlockPos;
 import net.minecraft.util.math.ChunkPos;
@@ -52,7 +55,7 @@
     public PlayerChunkMap(WorldServer serverWorld)
     {
         this.world = serverWorld;
-        this.setPlayerViewRadius(serverWorld.getMinecraftServer().getPlayerList().getViewDistance());
+        this.setPlayerViewRadius(serverWorld.spigotConfig.viewDistance); // Spigot
     }
 
     public WorldServer getWorldServer()
@@ -157,6 +160,12 @@
         {
             long l = System.nanoTime() + 50000000L;
             int k = 49;
+
+            // Spigot start
+            org.spigotmc.SlackActivityAccountant activityAccountant = net.minecraft.server.MinecraftServer.getServerInst().slackActivityAccountant;
+            activityAccountant.startActivity(Math.min(catserver.server.CatServer.getConfig().worldGenMaxTickTime, 18.75) / (18.75 * 2)); // CatServer - 50 * 0.375 = 18.75
+            // Spigot end
+
             Iterator<PlayerChunkMapEntry> iterator = this.entriesWithoutChunks.iterator();
 
             while (iterator.hasNext())
@@ -178,13 +187,18 @@
 
                         --k;
 
-                        if (k < 0 || System.nanoTime() > l)
+                        if (k < 0 || activityAccountant.activityTimeIsExhausted()) // CatServer
                         {
                             break;
                         }
                     }
+                } else {
+                    // CraftBukkit - SPIGOT-2891: remove once chunk has been provided
+                    iterator.remove();
                 }
             }
+
+            activityAccountant.endActivity(); // Spigot
         }
 
         if (!this.pendingSendToPlayers.isEmpty())
@@ -257,8 +271,17 @@
         return playerchunkmapentry;
     }
 
+    public final boolean isChunkInUse(int x, int z) {
+        PlayerChunkMapEntry pi = getEntry(x, z);
+        if (pi != null) {
+            return (pi.players.size() > 0);
+        }
+        return false;
+    }
+
     public void markBlockForUpdate(BlockPos pos)
     {
+        if (catserver.server.AsyncCatcher.checkAndPostPrimaryThread("update block", () -> markBlockForUpdate(pos))) return; // CatServer
         int i = pos.getX() >> 4;
         int j = pos.getZ() >> 4;
         PlayerChunkMapEntry playerchunkmapentry = this.getEntry(i, j);
@@ -276,14 +299,22 @@
         player.managedPosX = player.posX;
         player.managedPosZ = player.posZ;
 
+        List<ChunkPos> chunkList = new LinkedList<>();
+
         for (int k = i - this.playerViewRadius; k <= i + this.playerViewRadius; ++k)
         {
             for (int l = j - this.playerViewRadius; l <= j + this.playerViewRadius; ++l)
             {
-                this.getOrCreateEntry(k, l).addPlayer(player);
+                // this.getOrCreateEntry(k, l).addPlayer(player);
+                chunkList.add(new ChunkPos(k, l));
             }
         }
 
+        Collections.sort(chunkList, new ChunkCoordComparator(player));
+        for (ChunkPos pair : chunkList) {
+            this.getOrCreateEntry(pair.x, pair.z).addPlayer(player);
+        }
+
         this.players.add(player);
         this.markSortPending();
     }
@@ -341,6 +372,8 @@
             int j1 = i - k;
             int k1 = j - l;
 
+            List<ChunkPos> chunksToLoad = new LinkedList<>();
+
             if (j1 != 0 || k1 != 0)
             {
                 for (int l1 = i - i1; l1 <= i + i1; ++l1)
@@ -349,7 +382,8 @@
                     {
                         if (!this.overlaps(l1, i2, k, l, i1))
                         {
-                            this.getOrCreateEntry(l1, i2).addPlayer(player);
+                            // this.getOrCreateEntry(l1, i2).addPlayer(player);
+                            chunksToLoad.add(new ChunkPos(l1, i2));
                         }
 
                         if (!this.overlaps(l1 - j1, i2 - k1, i, j, i1))
@@ -367,6 +401,12 @@
                 player.managedPosX = player.posX;
                 player.managedPosZ = player.posZ;
                 this.markSortPending();
+                // CraftBukkit start - send nearest chunks first
+                Collections.sort(chunksToLoad, new ChunkCoordComparator(player));
+                for (ChunkPos pair : chunksToLoad) {
+                    this.getOrCreateEntry(pair.x, pair.z).addPlayer(player);
+                }
+                // CraftBukkit end
             }
         }
     }
@@ -443,11 +483,13 @@
 
     public void entryChanged(PlayerChunkMapEntry entry)
     {
+        org.spigotmc.AsyncCatcher.catchOp("Async Player Chunk Add"); // Paper
         this.dirtyEntries.add(entry);
     }
 
     public void removeEntry(PlayerChunkMapEntry entry)
     {
+        org.spigotmc.AsyncCatcher.catchOp("Async Player Chunk Remove"); // Paper
         ChunkPos chunkpos = entry.getPos();
         long i = getIndex(chunkpos.x, chunkpos.z);
         entry.updateChunkInhabitedTime();
@@ -458,9 +500,78 @@
         this.entriesWithoutChunks.remove(entry);
         Chunk chunk = entry.getChunk();
 
-        if (chunk != null)
+        if (false && chunk != null) // CatServer - use craftbukkit timing unload chunk
         {
             this.getWorldServer().getChunkProvider().queueUnload(chunk);
         }
     }
+
+    // CraftBukkit start - Sorter to load nearby chunks first
+    private static class ChunkCoordComparator implements java.util.Comparator<ChunkPos> {
+        private int x;
+        private int z;
+
+        public ChunkCoordComparator (EntityPlayer entityplayer) {
+            x = (int) entityplayer.posX >> 4;
+            z = (int) entityplayer.posZ >> 4;
+        }
+
+        // CatServer start
+        public ChunkCoordComparator(int x, int z) {
+            this.x = x;
+            this.z = z;
+        }
+        // CatServer end
+
+        public int compare(ChunkPos a, ChunkPos b) {
+            if (a.equals(b)) {
+                return 0;
+            }
+
+            // Subtract current position to set center point
+            int ax = a.x - this.x;
+            int az = a.z - this.z;
+            int bx = b.x - this.x;
+            int bz = b.z - this.z;
+
+            int result = ((ax - bx) * (ax + bx)) + ((az - bz) * (az + bz));
+            if (result != 0) {
+                return result;
+            }
+
+            if (ax < 0) {
+                if (bx < 0) {
+                    return bz - az;
+                } else {
+                    return -1;
+                }
+            } else {
+                if (bx < 0) {
+                    return 1;
+                } else {
+                    return az - bz;
+                }
+            }
+        }
+    }
+    // CraftBukkit end
+
+    // CatServer start
+    public void prepareForAsync(int chunkX, int chunkZ) {
+        List<ChunkPos> chunkList = new LinkedList<>();
+
+        for (int k = chunkX - this.playerViewRadius; k <= chunkX + this.playerViewRadius; ++k) {
+            for (int l = chunkZ - this.playerViewRadius; l <= chunkZ + this.playerViewRadius; ++l) {
+                chunkList.add(new ChunkPos(k, l));
+            }
+        }
+
+        Collections.sort(chunkList, new ChunkCoordComparator(chunkX, chunkZ));
+        for (ChunkPos pair : chunkList) {
+            this.getOrCreateEntry(pair.x, pair.z);
+        }
+
+        this.markSortPending();
+    }
+    // CatServer end
 }