Small optimizations & MultiBlockBase cleanup (#3197)

Co-authored-by: Martin Robertz <dream-master@gmx.net>

4 files changed, 77 insertions, 8 deletions

diff --git a/src/main/java/gregtech/api/util/ExoticEnergyInputHelper.java b/src/main/java/gregtech/api/util/ExoticEnergyInputHelper.java
index 6640f03835..55d2b87f3b 100644
--- a/src/main/java/gregtech/api/util/ExoticEnergyInputHelper.java
+++ b/src/main/java/gregtech/api/util/ExoticEnergyInputHelper.java
@@ -1,6 +1,6 @@
 package gregtech.api.util;
 
-import static gregtech.api.util.GTUtility.filterValidMTEs;
+import static gregtech.api.util.GTUtility.validMTEList;
 
 import java.util.ArrayList;
 import java.util.Collection;
@@ -52,7 +52,7 @@ public class ExoticEnergyInputHelper {
 
     public static long getTotalEuMulti(Collection<? extends MTEHatch> hatches) {
         long rEU = 0L;
-        for (MTEHatch tHatch : filterValidMTEs(hatches)) {
+        for (MTEHatch tHatch : validMTEList(hatches)) {
             rEU += tHatch.getBaseMetaTileEntity()
                 .getInputVoltage() * tHatch.maxWorkingAmperesIn();
         }
@@ -61,7 +61,7 @@ public class ExoticEnergyInputHelper {
 
     public static long getMaxInputVoltageMulti(Collection<? extends MTEHatch> hatches) {
         long rVoltage = 0;
-        for (MTEHatch tHatch : filterValidMTEs(hatches)) {
+        for (MTEHatch tHatch : validMTEList(hatches)) {
             rVoltage += tHatch.getBaseMetaTileEntity()
                 .getInputVoltage();
         }
@@ -70,7 +70,7 @@ public class ExoticEnergyInputHelper {
 
     public static long getAverageInputVoltageMulti(Collection<? extends MTEHatch> hatches) {
         long rVoltage = 0;
-        for (MTEHatch tHatch : filterValidMTEs(hatches)) {
+        for (MTEHatch tHatch : validMTEList(hatches)) {
             rVoltage += tHatch.getBaseMetaTileEntity()
                 .getInputVoltage();
         }
@@ -82,7 +82,7 @@ public class ExoticEnergyInputHelper {
 
     public static long getMaxInputAmpsMulti(Collection<? extends MTEHatch> hatches) {
         long rAmp = 0;
-        for (MTEHatch tHatch : filterValidMTEs(hatches)) {
+        for (MTEHatch tHatch : validMTEList(hatches)) {
             rAmp += tHatch.getBaseMetaTileEntity()
                 .getInputAmperage();
         }
@@ -91,7 +91,7 @@ public class ExoticEnergyInputHelper {
 
     public static long getMaxWorkingInputAmpsMulti(Collection<? extends MTEHatch> hatches) {
         long rAmp = 0;
-        for (MTEHatch tHatch : filterValidMTEs(hatches)) {
+        for (MTEHatch tHatch : validMTEList(hatches)) {
             rAmp += tHatch.maxWorkingAmperesIn();
         }
         return rAmp;
diff --git a/src/main/java/gregtech/api/util/GTUtil.java b/src/main/java/gregtech/api/util/GTUtil.java
index d1dd308449..8923bca954 100644
--- a/src/main/java/gregtech/api/util/GTUtil.java
+++ b/src/main/java/gregtech/api/util/GTUtil.java
@@ -1,6 +1,7 @@
 package gregtech.api.util;
 
 import static gregtech.api.util.GTUtility.filterValidMTEs;
+import static gregtech.api.util.GTUtility.validMTEList;
 
 import java.util.ArrayList;
 import java.util.List;
@@ -330,7 +331,7 @@ public class GTUtil {
 
     private static NBTTagList saveConfigurationToDataStick(EntityPlayer player, List<? extends MTEHatch> hatches) {
         NBTTagList list = new NBTTagList();
-        for (MTEHatch tHatch : filterValidMTEs(hatches)) {
+        for (MTEHatch tHatch : validMTEList(hatches)) {
             if (!(tHatch instanceof IDataCopyable copyable)) {
                 list.appendTag(new NBTTagCompound());
                 continue;
diff --git a/src/main/java/gregtech/api/util/GTUtility.java b/src/main/java/gregtech/api/util/GTUtility.java
index ede680ba62..442ba2a562 100644
--- a/src/main/java/gregtech/api/util/GTUtility.java
+++ b/src/main/java/gregtech/api/util/GTUtility.java
@@ -4028,13 +4028,21 @@ public class GTUtility {
     }
 
     /**
-     * @return Supplied collection that doesn't contain invalid MetaTileEntities
+     * @return Supplied collection that doesn't contain invalid MetaTileEntities.
      */
     public static <T extends Collection<E>, E extends MetaTileEntity> T filterValidMTEs(T metaTileEntities) {
         metaTileEntities.removeIf(mte -> mte == null || !mte.isValid());
         return metaTileEntities;
     }
 
+    /**
+     * @return Supplied collection that removes invalid MTEs from the collection while it is being iterated
+     */
+    public static <T extends Collection<E>, E extends MetaTileEntity> ValidMTEList<T, E> validMTEList(
+        T metaTileEntities) {
+        return new ValidMTEList<>(metaTileEntities);
+    }
+
     public static ForgeDirection getSideFromPlayerFacing(Entity player) {
         if (player == null) return ForgeDirection.UNKNOWN;
         if (player.rotationPitch >= 65) return ForgeDirection.UP;
diff --git a/src/main/java/gregtech/api/util/ValidMTEList.java b/src/main/java/gregtech/api/util/ValidMTEList.java
new file mode 100644
index 0000000000..95f4cd7ad0
--- /dev/null
+++ b/src/main/java/gregtech/api/util/ValidMTEList.java
@@ -0,0 +1,60 @@
+package gregtech.api.util;
+
+import java.util.Collection;
+import java.util.Iterator;
+import java.util.NoSuchElementException;
+
+import org.jetbrains.annotations.NotNull;
+
+import gregtech.api.metatileentity.MetaTileEntity;
+
+public class ValidMTEList<E extends Collection<T>, T extends MetaTileEntity> implements Iterable<T> {
+
+    private final E collection;
+
+    public ValidMTEList(E collection) {
+        this.collection = collection;
+    }
+
+    private class ValidMTEIterator implements Iterator<T> {
+
+        Iterator<T> iterator = collection.iterator();
+
+        T nextObject = null;
+        boolean nextObjectSet = false;
+
+        private boolean setNextObject() {
+            while (iterator.hasNext()) {
+                final T object = iterator.next();
+                if (object != null && object.isValid()) {
+                    nextObject = object;
+                    nextObjectSet = true;
+                    return true;
+                } else {
+                    iterator.remove();
+                }
+            }
+            return false;
+        }
+
+        @Override
+        public boolean hasNext() {
+            return nextObjectSet || setNextObject();
+        }
+
+        @Override
+        public T next() {
+            if (!nextObjectSet && !setNextObject()) {
+                throw new NoSuchElementException();
+            }
+            nextObjectSet = false;
+            return nextObject;
+
+        }
+    }
+
+    @Override
+    public @NotNull Iterator<T> iterator() {
+        return new ValidMTEIterator();
+    }
+}