Paper/patches/server/0451-incremental-chunk-and-player-saving.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Shane Freeder <theboyetronic@gmail.com>
Date: Sun, 9 Jun 2019 03:53:22 +0100
Subject: [PATCH] incremental chunk and player saving


diff --git a/src/main/java/net/minecraft/server/MinecraftServer.java b/src/main/java/net/minecraft/server/MinecraftServer.java
index 7d2fee97f4d08eae245475c4b60c1a7ba46c840d..48650bc1c09b18f1b57d9828dfe27f51c74c4a75 100644
--- a/src/main/java/net/minecraft/server/MinecraftServer.java
+++ b/src/main/java/net/minecraft/server/MinecraftServer.java
@@ -854,7 +854,7 @@ public abstract class MinecraftServer extends ReentrantBlockableEventLoop<TickTa
 
         try {
             this.isSaving = true;
-            this.getPlayerList().saveAll();
+            this.getPlayerList().saveAll(); // Diff on change
             flag3 = this.saveAllChunks(suppressLogs, flush, force);
         } finally {
             this.isSaving = false;
@@ -1400,13 +1400,28 @@ public abstract class MinecraftServer extends ReentrantBlockableEventLoop<TickTa
             }
         }
 
-        if (this.autosavePeriod > 0 && this.tickCount % this.autosavePeriod == 0) { // CraftBukkit
-            MinecraftServer.LOGGER.debug("Autosave started");
-            this.profiler.push("save");
-            this.saveEverything(true, false, false);
-            this.profiler.pop();
-            MinecraftServer.LOGGER.debug("Autosave finished");
+        // Paper start - incremental chunk and player saving
+        int playerSaveInterval = io.papermc.paper.configuration.GlobalConfiguration.get().playerAutoSave.rate;
+        if (playerSaveInterval < 0) {
+            playerSaveInterval = autosavePeriod;
         }
+        this.profiler.push("save");
+        final boolean fullSave = autosavePeriod > 0 && this.tickCount % autosavePeriod == 0;
+        try {
+            this.isSaving = true;
+            if (playerSaveInterval > 0) {
+                this.playerList.saveAll(playerSaveInterval);
+            }
+            for (ServerLevel level : this.getAllLevels()) {
+                if (level.paperConfig().chunks.autoSaveInterval.value() > 0) {
+                    level.saveIncrementally(fullSave);
+                }
+            }
+        } finally {
+            this.isSaving = false;
+        }
+        this.profiler.pop();
+        // Paper end
         io.papermc.paper.util.CachedLists.reset(); // Paper
         // Paper start - move executeAll() into full server tick timing
         try (co.aikar.timings.Timing ignored = MinecraftTimings.processTasksTimer.startTiming()) {
diff --git a/src/main/java/net/minecraft/server/level/ChunkHolder.java b/src/main/java/net/minecraft/server/level/ChunkHolder.java
index 0f75a109c06eb3113be74cf49ec560f5e2ea9cfc..ac42029596ae0c824bf33a4058ac1009740e29ea 100644
--- a/src/main/java/net/minecraft/server/level/ChunkHolder.java
+++ b/src/main/java/net/minecraft/server/level/ChunkHolder.java
@@ -99,6 +99,8 @@ public class ChunkHolder {
     com.destroystokyo.paper.util.misc.PooledLinkedHashSets.PooledObjectLinkedOpenHashSet<ServerPlayer> playersInMobSpawnRange;
     com.destroystokyo.paper.util.misc.PooledLinkedHashSets.PooledObjectLinkedOpenHashSet<ServerPlayer> playersInChunkTickRange;
     // Paper end - optimise anyPlayerCloseEnoughForSpawning
+    long lastAutoSaveTime; // Paper - incremental autosave
+    long inactiveTimeStart; // Paper - incremental autosave
 
     public ChunkHolder(ChunkPos pos, int level, LevelHeightAccessor world, LevelLightEngine lightingProvider, ChunkHolder.LevelChangeListener levelUpdateListener, ChunkHolder.PlayerProvider playersWatchingChunkProvider) {
         this.futures = new AtomicReferenceArray(ChunkHolder.CHUNK_STATUSES.size());
@@ -527,7 +529,19 @@ public class ChunkHolder {
         boolean flag2 = playerchunk_state.isOrAfter(ChunkHolder.FullChunkStatus.BORDER);
         boolean flag3 = playerchunk_state1.isOrAfter(ChunkHolder.FullChunkStatus.BORDER);
 
+        boolean prevHasBeenLoaded = this.wasAccessibleSinceLastSave; // Paper
         this.wasAccessibleSinceLastSave |= flag3;
+        // Paper start - incremental autosave
+        if (this.wasAccessibleSinceLastSave & !prevHasBeenLoaded) {
+            long timeSinceAutoSave = this.inactiveTimeStart - this.lastAutoSaveTime;
+            if (timeSinceAutoSave < 0) {
+                // safest bet is to assume autosave is needed here
+                timeSinceAutoSave = this.chunkMap.level.paperConfig().chunks.autoSaveInterval.value();
+            }
+            this.lastAutoSaveTime = this.chunkMap.level.getGameTime() - timeSinceAutoSave;
+            this.chunkMap.autoSaveQueue.add(this);
+        }
+        // Paper end
         if (!flag2 && flag3) {
             int expectCreateCount = ++this.fullChunkCreateCount; // Paper
             this.fullChunkFuture = chunkStorage.prepareAccessibleChunk(this);
@@ -689,8 +703,32 @@ public class ChunkHolder {
     }
 
     public void refreshAccessibility() {
+        boolean prev = this.wasAccessibleSinceLastSave; // Paper
         this.wasAccessibleSinceLastSave = ChunkHolder.getFullChunkStatus(this.ticketLevel).isOrAfter(ChunkHolder.FullChunkStatus.BORDER);
+        // Paper start - incremental autosave
+        if (prev != this.wasAccessibleSinceLastSave) {
+            if (this.wasAccessibleSinceLastSave) {
+                long timeSinceAutoSave = this.inactiveTimeStart - this.lastAutoSaveTime;
+                if (timeSinceAutoSave < 0) {
+                    // safest bet is to assume autosave is needed here
+                    timeSinceAutoSave = this.chunkMap.level.paperConfig().chunks.autoSaveInterval.value();
+                }
+                this.lastAutoSaveTime = this.chunkMap.level.getGameTime() - timeSinceAutoSave;
+                this.chunkMap.autoSaveQueue.add(this);
+            } else {
+                this.inactiveTimeStart = this.chunkMap.level.getGameTime();
+                this.chunkMap.autoSaveQueue.remove(this);
+            }
+        }
+        // Paper end
+    }
+
+    // Paper start - incremental autosave
+    public boolean setHasBeenLoaded() {
+        this.wasAccessibleSinceLastSave = getFullChunkStatus(this.ticketLevel).isOrAfter(ChunkHolder.FullChunkStatus.BORDER);
+        return this.wasAccessibleSinceLastSave;
     }
+    // Paper end
 
     public void replaceProtoChunk(ImposterProtoChunk chunk) {
         for (int i = 0; i < this.futures.length(); ++i) {
diff --git a/src/main/java/net/minecraft/server/level/ChunkMap.java b/src/main/java/net/minecraft/server/level/ChunkMap.java
index b0e0f85e04438affb8d8e0f75055ea83d0c03bcd..7493da0f1c3f8ab0ebc517347ef23fbe2747a306 100644
--- a/src/main/java/net/minecraft/server/level/ChunkMap.java
+++ b/src/main/java/net/minecraft/server/level/ChunkMap.java
@@ -103,6 +103,7 @@ import net.minecraft.world.level.levelgen.structure.templatesystem.StructureTemp
 import net.minecraft.world.level.storage.DimensionDataStorage;
 import net.minecraft.world.level.storage.LevelStorageSource;
 import net.minecraft.world.phys.Vec3;
+import it.unimi.dsi.fastutil.objects.ObjectRBTreeSet; // Paper
 import org.apache.commons.lang3.mutable.MutableBoolean;
 import org.apache.commons.lang3.mutable.MutableObject;
 import org.slf4j.Logger;
@@ -779,6 +780,64 @@ public class ChunkMap extends ChunkStorage implements ChunkHolder.PlayerProvider
 
     }
 
+    // Paper start - incremental autosave
+    final ObjectRBTreeSet<ChunkHolder> autoSaveQueue = new ObjectRBTreeSet<>((playerchunk1, playerchunk2) -> {
+        int timeCompare =  Long.compare(playerchunk1.lastAutoSaveTime, playerchunk2.lastAutoSaveTime);
+        if (timeCompare != 0) {
+            return timeCompare;
+        }
+
+        return Long.compare(MCUtil.getCoordinateKey(playerchunk1.pos), MCUtil.getCoordinateKey(playerchunk2.pos));
+    });
+
+    protected void saveIncrementally() {
+        int savedThisTick = 0;
+        // optimized since we search far less chunks to hit ones that need to be saved
+        List<ChunkHolder> reschedule = new java.util.ArrayList<>(this.level.paperConfig().chunks.maxAutoSaveChunksPerTick);
+        long currentTick = this.level.getGameTime();
+        long maxSaveTime = currentTick - this.level.paperConfig().chunks.autoSaveInterval.value();
+
+        for (Iterator<ChunkHolder> iterator = this.autoSaveQueue.iterator(); iterator.hasNext();) {
+            ChunkHolder playerchunk = iterator.next();
+            if (playerchunk.lastAutoSaveTime > maxSaveTime) {
+                break;
+            }
+
+            iterator.remove();
+
+            ChunkAccess ichunkaccess = playerchunk.getChunkToSave().getNow(null);
+            if (ichunkaccess instanceof LevelChunk) {
+                boolean shouldSave = ((LevelChunk)ichunkaccess).lastSaveTime <= maxSaveTime;
+
+                if (shouldSave && this.save(ichunkaccess) && this.level.entityManager.storeChunkSections(playerchunk.pos.toLong(), entity -> {})) {
+                    ++savedThisTick;
+
+                    if (!playerchunk.setHasBeenLoaded()) {
+                        // do not fall through to reschedule logic
+                        playerchunk.inactiveTimeStart = currentTick;
+                        if (savedThisTick >= this.level.paperConfig().chunks.maxAutoSaveChunksPerTick) {
+                            break;
+                        }
+                        continue;
+                    }
+                }
+            }
+
+            reschedule.add(playerchunk);
+
+            if (savedThisTick >= this.level.paperConfig().chunks.maxAutoSaveChunksPerTick) {
+                break;
+            }
+        }
+
+        for (int i = 0, len = reschedule.size(); i < len; ++i) {
+            ChunkHolder playerchunk = reschedule.get(i);
+            playerchunk.lastAutoSaveTime = this.level.getGameTime();
+            this.autoSaveQueue.add(playerchunk);
+        }
+    }
+    // Paper end
+
     protected void saveAllChunks(boolean flush) {
         // Paper start - do not overload I/O threads with too much work when saving
         int[] saved = new int[1];
@@ -874,13 +933,7 @@ public class ChunkMap extends ChunkStorage implements ChunkHolder.PlayerProvider
         }
 
         int l = 0;
-        Iterator objectiterator = net.minecraft.server.ChunkSystem.getVisibleChunkHolders(this.level).iterator(); // Paper
-
-        while (l < 20 && shouldKeepTicking.getAsBoolean() && objectiterator.hasNext()) {
-            if (this.saveChunkIfNeeded((ChunkHolder) objectiterator.next())) {
-                ++l;
-            }
-        }
+        // Paper - incremental chunk and player saving
 
     }
 
@@ -916,6 +969,7 @@ public class ChunkMap extends ChunkStorage implements ChunkHolder.PlayerProvider
 
                         this.level.unload(chunk);
                     }
+                    this.autoSaveQueue.remove(holder); // Paper
 
                     this.lightEngine.updateChunkStatus(ichunkaccess.getPos());
                     this.lightEngine.tryScheduleUpdate();
@@ -1367,6 +1421,7 @@ public class ChunkMap extends ChunkStorage implements ChunkHolder.PlayerProvider
             asyncSaveData, chunk);
 
         chunk.setUnsaved(false);
+        chunk.setLastSaved(this.level.getGameTime()); // Paper - track last saved time
     }
     // Paper end
 
@@ -1376,6 +1431,7 @@ public class ChunkMap extends ChunkStorage implements ChunkHolder.PlayerProvider
         if (!chunk.isUnsaved()) {
             return false;
         } else {
+            chunk.setLastSaved(this.level.getGameTime()); // Paper - track save time
             chunk.setUnsaved(false);
             ChunkPos chunkcoordintpair = chunk.getPos();
 
diff --git a/src/main/java/net/minecraft/server/level/ServerChunkCache.java b/src/main/java/net/minecraft/server/level/ServerChunkCache.java
index a59782d6f3640262c377a676e2b2ef5ec82563db..b5f46703e536f8138ff4e6769485c45b35941f9f 100644
--- a/src/main/java/net/minecraft/server/level/ServerChunkCache.java
+++ b/src/main/java/net/minecraft/server/level/ServerChunkCache.java
@@ -670,6 +670,15 @@ public class ServerChunkCache extends ChunkSource {
         } // Paper - Timings
     }
 
+    // Paper start - duplicate save, but call incremental
+    public void saveIncrementally() {
+        this.runDistanceManagerUpdates();
+        try (co.aikar.timings.Timing timed = level.timings.chunkSaveData.startTiming()) { // Paper - Timings
+            this.chunkMap.saveIncrementally();
+        } // Paper - Timings
+    }
+    // Paper end
+
     @Override
     public void close() throws IOException {
         // CraftBukkit start
diff --git a/src/main/java/net/minecraft/server/level/ServerLevel.java b/src/main/java/net/minecraft/server/level/ServerLevel.java
index c9ecc7593c299b351308634db44596a76fd0c09b..8b5eac2ad96c0ebb6eae04585998cade578ff74b 100644
--- a/src/main/java/net/minecraft/server/level/ServerLevel.java
+++ b/src/main/java/net/minecraft/server/level/ServerLevel.java
@@ -1087,6 +1087,37 @@ public class ServerLevel extends Level implements WorldGenLevel {
         return !this.server.isUnderSpawnProtection(this, pos, player) && this.getWorldBorder().isWithinBounds(pos);
     }
 
+    // Paper start - derived from below
+    public void saveIncrementally(boolean doFull) {
+        ServerChunkCache chunkproviderserver = this.getChunkSource();
+
+        if (doFull) {
+            org.bukkit.Bukkit.getPluginManager().callEvent(new org.bukkit.event.world.WorldSaveEvent(getWorld()));
+        }
+
+        try (co.aikar.timings.Timing ignored = this.timings.worldSave.startTiming()) {
+            if (doFull) {
+                this.saveLevelData();
+            }
+
+            this.timings.worldSaveChunks.startTiming(); // Paper
+            if (!this.noSave()) chunkproviderserver.saveIncrementally();
+            this.timings.worldSaveChunks.stopTiming(); // Paper
+
+            // Copied from save()
+            // CraftBukkit start - moved from MinecraftServer.saveChunks
+            if (doFull) { // Paper
+                ServerLevel worldserver1 = this;
+
+                this.serverLevelData.setWorldBorder(worldserver1.getWorldBorder().createSettings());
+                this.serverLevelData.setCustomBossEvents(this.server.getCustomBossEvents().save());
+                this.convertable.saveDataTag(this.server.registryHolder, this.serverLevelData, this.server.getPlayerList().getSingleplayerData());
+            }
+            // CraftBukkit end
+        }
+    }
+    // Paper end
+
     public void save(@Nullable ProgressListener progressListener, boolean flush, boolean savingDisabled) {
         ServerChunkCache chunkproviderserver = this.getChunkSource();
 
diff --git a/src/main/java/net/minecraft/server/level/ServerPlayer.java b/src/main/java/net/minecraft/server/level/ServerPlayer.java
index be7d2275548936beade4aba02dc5b14fec95117a..6f2b52165c1935511790a429792d3754251537c8 100644
--- a/src/main/java/net/minecraft/server/level/ServerPlayer.java
+++ b/src/main/java/net/minecraft/server/level/ServerPlayer.java
@@ -179,6 +179,7 @@ import org.bukkit.inventory.MainHand;
 public class ServerPlayer extends Player {
 
     private static final Logger LOGGER = LogUtils.getLogger();
+    public long lastSave = MinecraftServer.currentTick; // Paper
     private static final int NEUTRAL_MOB_DEATH_NOTIFICATION_RADII_XZ = 32;
     private static final int NEUTRAL_MOB_DEATH_NOTIFICATION_RADII_Y = 10;
     public ServerGamePacketListenerImpl connection;
diff --git a/src/main/java/net/minecraft/server/players/PlayerList.java b/src/main/java/net/minecraft/server/players/PlayerList.java
index 32ab0cd6cb42b0ab8a14f790dfcf4b155c945d6d..1850ce4566e6c5d19140cbf2636b3573f16c4239 100644
--- a/src/main/java/net/minecraft/server/players/PlayerList.java
+++ b/src/main/java/net/minecraft/server/players/PlayerList.java
@@ -569,6 +569,7 @@ public abstract class PlayerList {
     protected void save(ServerPlayer player) {
         if (!player.getBukkitEntity().isPersistent()) return; // CraftBukkit
         if (!player.didPlayerJoinEvent) return; // Paper - If we never fired PJE, we disconnected during login. Data has not changed, and additionally, our saved vehicle is not loaded! If we save now, we will lose our vehicle (CraftBukkit bug)
+        player.lastSave = MinecraftServer.currentTick; // Paper
         this.playerIo.save(player);
         ServerStatsCounter serverstatisticmanager = (ServerStatsCounter) player.getStats(); // CraftBukkit
 
@@ -1171,10 +1172,22 @@ public abstract class PlayerList {
     }
 
     public void saveAll() {
+        // Paper start - incremental player saving
+        this.saveAll(-1);
+    }
+
+    public void saveAll(int interval) {
         net.minecraft.server.MCUtil.ensureMain("Save Players" , () -> { // Paper - Ensure main
         MinecraftTimings.savePlayers.startTiming(); // Paper
+        int numSaved = 0;
+        long now = MinecraftServer.currentTick;
         for (int i = 0; i < this.players.size(); ++i) {
-            this.save(this.players.get(i));
+            ServerPlayer entityplayer = this.players.get(i);
+            if (interval == -1 || now - entityplayer.lastSave >= interval) {
+                this.save(entityplayer);
+                if (interval != -1 && ++numSaved <= io.papermc.paper.configuration.GlobalConfiguration.get().playerAutoSave.maxPerTick()) { break; }
+            }
+            // Paper end
         }
         MinecraftTimings.savePlayers.stopTiming(); // Paper
         return null; }); // Paper - ensure main
diff --git a/src/main/java/net/minecraft/world/level/chunk/ChunkAccess.java b/src/main/java/net/minecraft/world/level/chunk/ChunkAccess.java
index dc164608bfb2fb18a1adf83fa10bac4028dcac0a..a97909e77b9b28aede8c8716831c3f9a90618f09 100644
--- a/src/main/java/net/minecraft/world/level/chunk/ChunkAccess.java
+++ b/src/main/java/net/minecraft/world/level/chunk/ChunkAccess.java
@@ -457,6 +457,7 @@ public abstract class ChunkAccess implements BlockGetter, BiomeManager.NoiseBiom
     public LevelHeightAccessor getHeightAccessorForGeneration() {
         return this;
     }
+    public void setLastSaved(long ticks) {} // Paper
 
     public static record TicksToSave(SerializableTickContainer<Block> blocks, SerializableTickContainer<Fluid> fluids) {
 
diff --git a/src/main/java/net/minecraft/world/level/chunk/LevelChunk.java b/src/main/java/net/minecraft/world/level/chunk/LevelChunk.java
index c8444f4bfd127b7d8194aaa984505eff249ae094..2981ba61e347b8660082ff946521fc7f219d2c0d 100644
--- a/src/main/java/net/minecraft/world/level/chunk/LevelChunk.java
+++ b/src/main/java/net/minecraft/world/level/chunk/LevelChunk.java
@@ -87,6 +87,12 @@ public class LevelChunk extends ChunkAccess {
     private final Int2ObjectMap<GameEventDispatcher> gameEventDispatcherSections;
     private final LevelChunkTicks<Block> blockTicks;
     private final LevelChunkTicks<Fluid> fluidTicks;
+    // Paper start - track last save time
+    public long lastSaveTime;
+    public void setLastSaved(long ticks) {
+        this.lastSaveTime = ticks;
+    }
+    // Paper end
 
     public LevelChunk(Level world, ChunkPos pos) {
         this(world, pos, UpgradeData.EMPTY, new LevelChunkTicks<>(), new LevelChunkTicks<>(), 0L, (LevelChunkSection[]) null, (LevelChunk.PostLoadProcessor) null, (BlendingData) null);