Avoid Object2LongMap.Entry allocations (#8362)

Small tweaks to reduce the number of entries that get allocated on each
server tick when updating the cached stacks.

A number of remaining allocations here appear to be from
https://github.com/AppliedEnergistics/Applied-Energistics-2/blob/126ff28d93ffc717c9dda8a40503660165e7a4de/src/main/java/appeng/api/stacks/VariantCounter.java#L95.
Ideally that should use `Object2LongMaps.fastIterator`, but I am not
sure if doing so is safe, since I'm not familiar with the rest of the
code.

---------

Co-authored-by: shartte <shartte@users.noreply.github.com>

Author: embeddedt

src/main/java/appeng/api/stacks/VariantCounter.java

@@ -5,6 +5,7 @@
 import java.util.NoSuchElementException;
 
 import it.unimi.dsi.fastutil.objects.Object2LongMap;
+import it.unimi.dsi.fastutil.objects.Object2LongMaps;
 import it.unimi.dsi.fastutil.objects.Object2LongSortedMap;
 
 import appeng.api.config.FuzzyMode;
@@ -92,7 +93,7 @@ public boolean isEmpty() {
     @Override
     public Iterator<Object2LongMap.Entry<AEKey>> iterator() {
         if (!dropZeros) {
-            return getRecords().object2LongEntrySet().iterator();
+            return Object2LongMaps.fastIterator(getRecords());
         }
 
         return new NonDefaultIterator();
@@ -141,7 +142,7 @@ private class NonDefaultIterator implements Iterator<Object2LongMap.Entry<AEKey>
         private Object2LongMap.Entry<AEKey> next;
 
         public NonDefaultIterator() {
-            this.parent = getRecords().object2LongEntrySet().iterator();
+            this.parent = Object2LongMaps.fastIterator(getRecords());
             this.next = seekNext();
         }
 

src/main/java/appeng/me/cells/BasicCellInventory.java

@@ -28,6 +28,7 @@
 import net.minecraft.world.item.ItemStack;
 
 import it.unimi.dsi.fastutil.objects.Object2LongMap;
+import it.unimi.dsi.fastutil.objects.Object2LongMaps;
 import it.unimi.dsi.fastutil.objects.Object2LongOpenHashMap;
 
 import appeng.api.config.Actionable;
@@ -239,7 +240,7 @@ private void loadCellItems() {
 
     @Override
     public void getAvailableStacks(KeyCounter out) {
-        for (var entry : this.getCellItems().object2LongEntrySet()) {
+        for (var entry : Object2LongMaps.fastIterable(this.getCellItems())) {
             out.add(entry.getKey(), entry.getLongValue());
         }
     }

src/main/java/appeng/me/service/StorageService.java

@@ -127,8 +127,7 @@ private void updateCachedStacks() {
                 }
             }
             // Post watcher update for removed stacks
-            for (var entry : cachedAvailableAmounts.object2LongEntrySet()) {
-                var what = entry.getKey();
+            for (var what : cachedAvailableAmounts.keySet()) {
                 var newAmount = cachedAvailableStacks.get(what);
                 if (newAmount == 0) {
                     postWatcherUpdate(what, newAmount);