Backport 1.20's 'pause-when-empty-seconds' server property

dependencies.gradle

@@ -61,7 +61,7 @@ dependencies {
     transformedModCompileOnly(deobf("https://forum.industrial-craft.net/core/attachment/4316-advancedsolarpanel-1-7-10-3-5-1-jar/"))
     transformedModCompileOnly(rfg.deobf("curse.maven:candycraft-251118:2330488"))
 
-    devOnlyNonPublishable(deobf("https://github.com/makamys/CoreTweaks/releases/download/0.3.3.2/CoreTweaks-1.7.10-0.3.3.2+nomixin.jar"))
+    transformedModCompileOnly(deobf("https://github.com/makamys/CoreTweaks/releases/download/0.3.3.2/CoreTweaks-1.7.10-0.3.3.2+nomixin.jar"))
 }
 
 // Replace when RFG support deobfuscation from notch mappings

src/main/java/com/mitchej123/hodgepodge/config/TweaksConfig.java

@@ -128,6 +128,10 @@ public class TweaksConfig {
     @Config.DefaultInt(900)
     public static int autoSaveInterval;
 
+    @Config.Comment({ "Backports 1.20's 'pause-when-empty-seconds' server property", "Default value: 0 (off)" })
+    @Config.DefaultBoolean(true)
+    public static boolean pauseWhenEmpty;
+
     @Config.Comment("Reduces water opacity from 3 to 1, to match modern")
     @Config.DefaultBoolean(false)
     public static boolean useLighterWater;
@@ -306,5 +310,4 @@ public class TweaksConfig {
     @Config.Comment("Avoids droping items on container close, and instead places them in the player inventory. (Inspired from EFR)")
     @Config.DefaultBoolean(true)
     public static boolean avoidDroppingItemsWhenClosing;
-
 }

src/main/java/com/mitchej123/hodgepodge/mixins/Mixins.java

@@ -421,6 +421,13 @@ public enum Mixins {
             .addMixinClasses("minecraft.server.MixinMinecraftServer_AutoSaveInterval")
             .setApplyIf(() -> TweaksConfig.autoSaveInterval != 900)),
 
+    PAUSE_WHEN_EMPTY(new Builder("Pauses the server when empty after X seconds; Servers Only").setPhase(Phase.EARLY)
+            .setSide(Side.SERVER).addTargetedMod(TargetedMod.VANILLA)
+            .addMixinClasses(
+                    "minecraft.server.MixinMinecraftServer_PauseWhenEmpty",
+                    "minecraft.server.MixinDedicatedServer_PauseWhenEmpty")
+            .setApplyIf(() -> TweaksConfig.pauseWhenEmpty)),
+
     LIGHTER_WATER(new Builder("Decreases water opacity from 3 to 1, like in modern").setPhase(Phase.EARLY)
             .setSide(Side.BOTH).addTargetedMod(TargetedMod.VANILLA).addMixinClasses("minecraft.MixinBlock_LighterWater")
             .setApplyIf(() -> TweaksConfig.useLighterWater)),

src/main/java/com/mitchej123/hodgepodge/mixins/early/minecraft/server/MixinDedicatedServer_PauseWhenEmpty.java

@@ -0,0 +1,39 @@
+package com.mitchej123.hodgepodge.mixins.early.minecraft.server;
+
+import net.minecraft.server.dedicated.DedicatedServer;
+import net.minecraft.server.dedicated.PropertyManager;
+
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Shadow;
+import org.spongepowered.asm.mixin.Unique;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfoReturnable;
+
+import com.mitchej123.hodgepodge.mixins.interfaces.IPauseWhenEmpty;
+
+@Mixin(DedicatedServer.class)
+public class MixinDedicatedServer_PauseWhenEmpty implements IPauseWhenEmpty {
+
+    @Shadow
+    private PropertyManager settings;
+
+    @Unique
+    private int hodgepodge$pauseWhenEmptySeconds = 0;
+
+    @Override
+    public int getPauseWhenEmptySeconds() {
+        return hodgepodge$pauseWhenEmptySeconds;
+    }
+
+    @Inject(
+            method = "startServer",
+            at = @At(
+                    value = "INVOKE",
+                    target = "Lcpw/mods/fml/common/FMLCommonHandler;onServerStarted()V",
+                    remap = false,
+                    shift = At.Shift.AFTER))
+    public void hodgepodge$setupServer(CallbackInfoReturnable<Boolean> cir) {
+        hodgepodge$pauseWhenEmptySeconds = settings.getIntProperty("pause-when-empty-seconds", 0);
+    }
+}

src/main/java/com/mitchej123/hodgepodge/mixins/early/minecraft/server/MixinMinecraftServer_PauseWhenEmpty.java

@@ -0,0 +1,64 @@
+package com.mitchej123.hodgepodge.mixins.early.minecraft.server;
+
+import net.minecraft.network.NetworkSystem;
+import net.minecraft.server.MinecraftServer;
+import net.minecraft.server.dedicated.DedicatedServer;
+import net.minecraft.server.management.ServerConfigurationManager;
+
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Shadow;
+import org.spongepowered.asm.mixin.Unique;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
+
+import com.mitchej123.hodgepodge.Common;
+import com.mitchej123.hodgepodge.mixins.interfaces.IPauseWhenEmpty;
+
+@Mixin(MinecraftServer.class)
+public abstract class MixinMinecraftServer_PauseWhenEmpty {
+
+    @Shadow
+    public abstract int getCurrentPlayerCount();
+
+    @Shadow
+    private ServerConfigurationManager serverConfigManager;
+
+    @Shadow
+    protected abstract void saveAllWorlds(boolean dontLog);
+
+    @Shadow
+    public abstract NetworkSystem func_147137_ag();
+
+    @Unique
+    private int hodgepodge$emptyTicks = 0;
+
+    @Inject(method = "tick", at = @At("HEAD"), cancellable = true, order = 9000)
+    public void hodgepodge$tick(CallbackInfo ci) {
+        if ((Object) this instanceof DedicatedServer ds && ds instanceof IPauseWhenEmpty p) {
+            int pauseTicks = p.getPauseWhenEmptySeconds() * 20;
+            if (pauseTicks > 0) {
+                if (this.getCurrentPlayerCount() == 0) {
+                    this.hodgepodge$emptyTicks++;
+                } else {
+                    this.hodgepodge$emptyTicks = 0;
+                }
+
+                if (hodgepodge$emptyTicks >= pauseTicks) {
+                    if (hodgepodge$emptyTicks == pauseTicks) {
+                        Common.log
+                                .info("Server empty for {} seconds, saving and pausing", p.getPauseWhenEmptySeconds());
+                        this.serverConfigManager.saveAllPlayerData();
+                        this.saveAllWorlds(true);
+                    }
+
+                    net.minecraftforge.common.chunkio.ChunkIOExecutor.tick();
+                    // to process new connections
+                    this.func_147137_ag().networkTick();
+                    ds.executePendingCommands();
+                    ci.cancel();
+                }
+            }
+        }
+    }
+}

src/main/java/com/mitchej123/hodgepodge/mixins/interfaces/IPauseWhenEmpty.java

@@ -0,0 +1,6 @@
+package com.mitchej123.hodgepodge.mixins.interfaces;
+
+public interface IPauseWhenEmpty {
+
+    int getPauseWhenEmptySeconds();
+}