persistence: Ensure that CompoundSavedData always saves to file

SilkMC · May 13, 2024 · a8ca3f6 · a8ca3f6
1 parent 1f96e5f
commit a8ca3f6
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Showing 6 changed files with 58 additions and 9 deletions.
diff --git a/build.gradle.kts b/build.gradle.kts
@@ -9,7 +9,7 @@ repositories {
 
 allprojects {
     group = "net.silkmc"
-    version = "1.10.5"
+    version = "1.10.6"
     if (this.name.startsWith("silk")) {
         description = "Silk is a Minecraft API for Kotlin"
     }

diff --git a/buildSrc/src/main/kotlin/BuildConstants.kt b/buildSrc/src/main/kotlin/BuildConstants.kt
@@ -15,8 +15,8 @@ object BuildConstants {
     const val majorMinecraftVersion = "1.20"
 
     // check these values here: https://jakobk.net/mcdev
-    const val minecraftVersion = "1.20.5"
-    const val fabricLoaderVersion = "0.15.10"
+    const val minecraftVersion = "1.20.6"
+    const val fabricLoaderVersion = "0.15.11"
     const val fabricLanguageKotlinVersion = "1.10.19+kotlin.1.9.23"
 
     const val kotestVersion = "5.8.1"

diff --git a/silk-persistence/src/main/java/net/silkmc/silk/persistence/mixin/other/MixinSavedData.java b/silk-persistence/src/main/java/net/silkmc/silk/persistence/mixin/other/MixinSavedData.java
@@ -0,0 +1,34 @@
+package net.silkmc.silk.persistence.mixin.other;
+
+import net.minecraft.core.HolderLookup;
+import net.minecraft.world.level.saveddata.SavedData;
+import net.silkmc.silk.persistence.internal.CompoundSavedData;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
+
+import java.io.File;
+
+@Mixin(SavedData.class)
+public class MixinSavedData {
+
+    @SuppressWarnings("UnreachableCode")
+    @Inject(
+        method = "save(Ljava/io/File;Lnet/minecraft/core/HolderLookup$Provider;)V",
+        at = @At(
+            value = "INVOKE",
+            target = "Lnet/minecraft/nbt/NbtUtils;addCurrentDataVersion(Lnet/minecraft/nbt/CompoundTag;)Lnet/minecraft/nbt/CompoundTag;",
+            shift = At.Shift.BEFORE
+        ),
+        cancellable = true
+    )
+    private void onSave(File file, HolderLookup.Provider provider,
+                        CallbackInfo ci) {
+        if (((SavedData) (Object) this) instanceof CompoundSavedData compoundSavedData) {
+            if (compoundSavedData.getCompound().isEmpty() && !file.exists()) {
+                ci.cancel();
+            }
+        }
+    }
+}
diff --git a/silk-persistence/src/main/kotlin/net/silkmc/silk/persistence/PersistentCompound.kt b/silk-persistence/src/main/kotlin/net/silkmc/silk/persistence/PersistentCompound.kt
@@ -13,6 +13,12 @@ abstract class PersistentCompound {
     @PublishedApi
     internal val values = HashMap<CompoundKey<*>, Any>()
 
+    /**
+     * Returns whether this compound contains no data.
+     */
+    val isEmpty: Boolean
+        get() = values.isEmpty() && (data?.isEmpty != false)
+
     /**
      * Puts the given value into the persistent storage.
      *
@@ -165,6 +171,8 @@ internal class PersistentCompoundImpl : PersistentCompound() {
     }
 
     override fun putInCompound(nbtCompound: CompoundTag, writeRaw: Boolean) {
+        if (isEmpty) return
+
         val currentData = data!!
 
         for ((untypedKey, value) in values) {
@@ -174,11 +182,10 @@ internal class PersistentCompoundImpl : PersistentCompound() {
             currentData.put(typedKey.name, typedKey.convertValueToNbtElement(value))
         }
 
-        if (!currentData.isEmpty) {
-            if (writeRaw)
-                nbtCompound.merge(currentData)
-            else
-                nbtCompound.put(CUSTOM_DATA_KEY, currentData)
+        if (writeRaw) {
+            nbtCompound.merge(currentData)
+        } else {
+            nbtCompound.put(CUSTOM_DATA_KEY, currentData)
         }
     }
 }
diff --git a/silk-persistence/src/main/kotlin/net/silkmc/silk/persistence/internal/CompoundSavedData.kt b/silk-persistence/src/main/kotlin/net/silkmc/silk/persistence/internal/CompoundSavedData.kt
@@ -8,7 +8,14 @@ import net.silkmc.silk.core.annotations.InternalSilkApi
 import net.silkmc.silk.persistence.PersistentCompound
 
 @InternalSilkApi
-class CompoundSavedData(internal val compound: PersistentCompound) : SavedData() {
+class CompoundSavedData(val compound: PersistentCompound) : SavedData() {
+
+    // a compound does not track whether it is dirty, however custom
+    // logic is implemented via a mixin to prevent file creation for
+    // empty compounds
+    override fun isDirty(): Boolean {
+        return true
+    }
 
     override fun save(nbt: CompoundTag, provider: HolderLookup.Provider) =
         nbt.also { compound.putInCompound(it, writeRaw = true) }

diff --git a/silk-persistence/src/main/resources/silk-persistence.mixins.json b/silk-persistence/src/main/resources/silk-persistence.mixins.json
@@ -10,6 +10,7 @@
     "chunk.ProtoChunkMixin",
     "entity.EntityMixin",
     "other.MixinDataFixTypes",
+    "other.MixinSavedData",
     "world.ServerWorldMixin"
   ]
 }