adjust recipe input expected cache size dynamically (GregTechCEu#2331)

src/main/java/gregtech/GregTechMod.java

@@ -3,6 +3,7 @@
 import gregtech.api.GTValues;
 import gregtech.api.GregTechAPI;
 import gregtech.api.modules.ModuleContainerRegistryEvent;
+import gregtech.api.persistence.PersistentData;
 import gregtech.client.utils.BloomEffectUtil;
 import gregtech.modules.GregTechModules;
 import gregtech.modules.ModuleManager;
@@ -50,6 +51,7 @@ public GregTechMod() {
 
     @EventHandler
     public void onConstruction(FMLConstructionEvent event) {
+        PersistentData.instance().init();
         moduleManager = ModuleManager.getInstance();
         GregTechAPI.moduleManager = moduleManager;
         moduleManager.registerContainer(new GregTechModules());

src/main/java/gregtech/api/persistence/PersistentData.java

@@ -0,0 +1,108 @@
+package gregtech.api.persistence;
+
+import gregtech.api.GTValues;
+import gregtech.api.util.GTLog;
+
+import net.minecraft.nbt.CompressedStreamTools;
+import net.minecraft.nbt.NBTTagCompound;
+import net.minecraftforge.fml.common.Loader;
+
+import org.jetbrains.annotations.ApiStatus;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+import java.nio.file.Files;
+import java.nio.file.Path;
+
+public final class PersistentData {
+
+    private static final PersistentData INSTANCE = new PersistentData();
+
+    private @Nullable Path path;
+    private @Nullable NBTTagCompound tag;
+
+    public static @NotNull PersistentData instance() {
+        return INSTANCE;
+    }
+
+    private PersistentData() {}
+
+    @ApiStatus.Internal
+    public void init() {
+        this.path = Loader.instance().getConfigDir().toPath()
+                .resolve(GTValues.MODID)
+                .resolve("persistent_data.dat");
+    }
+
+    /**
+     * @return the stored persistent data
+     */
+    public synchronized @NotNull NBTTagCompound getTag() {
+        if (this.tag == null) {
+            this.tag = read();
+        }
+        return this.tag;
+    }
+
+    /**
+     * @return the read NBTTagCompound from disk
+     */
+    private @NotNull NBTTagCompound read() {
+        GTLog.logger.debug("Reading persistent data from path {}", path);
+        if (this.path == null) {
+            throw new IllegalStateException("Persistent data path cannot be null");
+        }
+
+        if (!Files.exists(path)) {
+            return new NBTTagCompound();
+        }
+
+        try (InputStream inputStream = Files.newInputStream(this.path)) {
+            return CompressedStreamTools.readCompressed(inputStream);
+        } catch (IOException e) {
+            GTLog.logger.error("Failed to read persistent data", e);
+            return new NBTTagCompound();
+        }
+    }
+
+    /**
+     * Save the GT Persistent data to disk
+     */
+    public synchronized void save() {
+        if (this.tag != null) {
+            write(this.tag);
+        }
+    }
+
+    /**
+     * @param tagCompound the tag compound to save to disk
+     */
+    private void write(@NotNull NBTTagCompound tagCompound) {
+        GTLog.logger.debug("Writing persistent data to path {}", path);
+        if (tagCompound.isEmpty()) {
+            return;
+        }
+
+        if (this.path == null) {
+            throw new IllegalStateException("Persistent data path cannot be null");
+        }
+
+        if (!Files.exists(path)) {
+            try {
+                Files.createDirectories(path.getParent());
+            } catch (IOException e) {
+                GTLog.logger.error("Could not create persistent data dir", e);
+                return;
+            }
+        }
+
+        try (OutputStream outputStream = Files.newOutputStream(path)) {
+            CompressedStreamTools.writeCompressed(tagCompound, outputStream);
+        } catch (IOException e) {
+            GTLog.logger.error("Failed to write persistent data", e);
+        }
+    }
+}

src/main/java/gregtech/api/recipes/GTRecipeInputCache.java

@@ -1,11 +1,18 @@
 package gregtech.api.recipes;
 
 import gregtech.api.GTValues;
+import gregtech.api.persistence.PersistentData;
 import gregtech.api.recipes.ingredients.GTRecipeInput;
 import gregtech.api.util.GTLog;
 import gregtech.common.ConfigHolder;
 
+import net.minecraft.nbt.NBTTagCompound;
+import net.minecraft.util.math.MathHelper;
+
+import it.unimi.dsi.fastutil.Hash;
 import it.unimi.dsi.fastutil.objects.ObjectOpenHashSet;
+import org.jetbrains.annotations.ApiStatus;
+import org.jetbrains.annotations.NotNull;
 
 import java.util.ArrayList;
 import java.util.Collections;
@@ -14,64 +21,87 @@
 /**
  * Cache of GTRecipeInput instances for deduplication.
  * <p>
- * Each GTRecipeInput is cached by an internal hashtable, and any duplicative
- * instances will be replaced by identical object previously created.
+ * Each GTRecipeInput is cached by an internal hashtable, and any duplicative instances will be replaced by identical
+ * object previously created.
  * <p>
- * Caching and duplication is only available during recipe registration; once
- * recipe registration is over, the cache will be discarded and no further entries
- * will be put into cache.
+ * Caching and duplication is only available during recipe registration; once recipe registration is over, the cache
+ * will be discarded and no further entries will be put into cache.
  */
-public class GTRecipeInputCache {
+public final class GTRecipeInputCache {
+
+    private static final int MINIMUM_CACHE_SIZE = 1 << 13;
+    private static final int MAXIMUM_CACHE_SIZE = 1 << 30;
+
+    private static ObjectOpenHashSet<GTRecipeInput> instances;
 
-    private static final int EXPECTED_CACHE_SIZE = 16384;
-    private static ObjectOpenHashSet<GTRecipeInput> INSTANCES;
+    private static final String DATA_NAME = "expectedIngredientInstances";
+
+    private GTRecipeInputCache() {}
 
     public static boolean isCacheEnabled() {
-        return INSTANCES != null;
+        return instances != null;
     }
 
+    @ApiStatus.Internal
     public static void enableCache() {
         if (!isCacheEnabled()) {
-            INSTANCES = new ObjectOpenHashSet<>(EXPECTED_CACHE_SIZE, 1);
-            if (ConfigHolder.misc.debug || GTValues.isDeobfEnvironment())
-                GTLog.logger.info("GTRecipeInput cache enabled");
+            int size = calculateOptimalExpectedSize();
+            instances = new ObjectOpenHashSet<>(size);
+
+            if (ConfigHolder.misc.debug || GTValues.isDeobfEnvironment()) {
+                GTLog.logger.info("GTRecipeInput cache enabled with expected size {}", size);
+            }
         }
     }
 
+    @ApiStatus.Internal
     public static void disableCache() {
         if (isCacheEnabled()) {
-            if (ConfigHolder.misc.debug || GTValues.isDeobfEnvironment())
-                GTLog.logger.info("GTRecipeInput cache disabled; releasing {} unique instances", INSTANCES.size());
-            INSTANCES = null;
+            int size = instances.size();
+            if (ConfigHolder.misc.debug || GTValues.isDeobfEnvironment()) {
+                GTLog.logger.info("GTRecipeInput cache disabled; releasing {} unique instances", size);
+            }
+            instances = null;
+
+            if (size >= MINIMUM_CACHE_SIZE && size < MAXIMUM_CACHE_SIZE) {
+                NBTTagCompound tagCompound = PersistentData.instance().getTag();
+                if (getExpectedInstanceAmount(tagCompound) != size) {
+                    tagCompound.setInteger(DATA_NAME, size);
+                    PersistentData.instance().save();
+                }
+            }
         }
     }
 
+    private static int getExpectedInstanceAmount(@NotNull NBTTagCompound tagCompound) {
+        return MathHelper.clamp(tagCompound.getInteger(DATA_NAME), MINIMUM_CACHE_SIZE, MAXIMUM_CACHE_SIZE);
+    }
+
     /**
-     * Tries to deduplicate the instance with previously cached instances.
-     * If there is no identical GTRecipeInput present in cache, the
-     * {@code recipeInput} will be put into cache, marked as cached, and returned subsequently.
+     * Tries to deduplicate the instance with previously cached instances. If there is no identical GTRecipeInput
+     * present in cache, the {@code recipeInput} will be put into cache, marked as cached, and returned subsequently.
      * <p>
      * This operation returns {@code recipeInput} without doing anything if cache is disabled.
      *
      * @param recipeInput ingredient instance to be deduplicated
-     * @return Either previously cached instance, or {@code recipeInput} marked cached;
-     *         or unmodified {@code recipeInput} instance if the cache is disabled
+     * @return Either previously cached instance, or {@code recipeInput} marked cached; or unmodified
+     *         {@code recipeInput} instance if the cache is disabled
      */
     public static GTRecipeInput deduplicate(GTRecipeInput recipeInput) {
         if (!isCacheEnabled() || recipeInput.isCached()) {
             return recipeInput;
         }
-        GTRecipeInput cached = INSTANCES.addOrGet(recipeInput);
+        GTRecipeInput cached = instances.addOrGet(recipeInput);
         if (cached == recipeInput) { // If recipeInput is cached just now...
             cached.setCached();
         }
         return cached;
     }
 
     /**
-     * Tries to deduplicate each instance in the list with previously cached instances.
-     * If there is no identical GTRecipeInput present in cache, the
-     * {@code recipeInput} will be put into cache, marked as cached, and returned subsequently.
+     * Tries to deduplicate each instance in the list with previously cached instances. If there is no identical
+     * GTRecipeInput present in cache, the {@code recipeInput} will be put into cache, marked as cached, and returned
+     * subsequently.
      * <p>
      * This operation returns {@code inputs} without doing anything if cache is disabled.
      *
@@ -91,4 +121,50 @@ public static List<GTRecipeInput> deduplicateInputs(List<GTRecipeInput> inputs)
         }
         return list;
     }
+
+    /**
+     * Calculates the optimal expected size for the input cache:
+     * <ol>
+     * <li>Pick a Load Factor to test: i.e. {@code 0.75f} (default).</li>
+     * <li>Pick a Size to test: i.e. {@code 8192}.</li>
+     * <li>Internal array's size: next highest power of 2 for {@code size / loadFactor},
+     * {@code nextHighestPowerOf2(8192 / 0.75) = 16384}.</li>
+     * <li>The maximum amount of stored values before a rehash is required {@code arraySize * loadFactor},
+     * {@code 16384 * 0.75 = 12288}.</li>
+     * <li>Compare with the known amount of values stored: {@code 12288 >= 11774}.</li>
+     * <li>If larger or equal, the initial capacity and load factor will not induce a rehash/resize.</li>
+     * </ol>
+     *
+     * @return the optimal expected input cache size
+     */
+    private static int calculateOptimalExpectedSize() {
+        int min = Math.max(getExpectedInstanceAmount(PersistentData.instance().getTag()), MINIMUM_CACHE_SIZE);
+        for (int i = 13; i < 31; i++) {
+            int sizeToTest = 1 << i;
+            int arraySize = nextHighestPowerOf2((int) (sizeToTest / Hash.DEFAULT_LOAD_FACTOR));
+            int maxStoredBeforeRehash = (int) (arraySize * Hash.DEFAULT_LOAD_FACTOR);
+
+            if (maxStoredBeforeRehash >= min) {
+                return sizeToTest;
+            }
+        }
+        return MINIMUM_CACHE_SIZE;
+    }
+
+    /**
+     * <a href="https://graphics.stanford.edu/~seander/bithacks.html#RoundUpPowerOf2">Algorithm source.</a>
+     *
+     * @param x the number to use
+     * @return the next highest power of 2 relative to the number
+     */
+    private static int nextHighestPowerOf2(int x) {
+        x--;
+        x |= x >> 1;
+        x |= x >> 2;
+        x |= x >> 4;
+        x |= x >> 8;
+        x |= x >> 16;
+        x++;
+        return x;
+    }
 }