Trim arrays to size after mutations for memory savings (#277)

src/main/java/appeng/crafting/v2/CraftingContext.java

@@ -76,7 +76,7 @@ public final class CraftingContext {
         /**
          * Ordered by priority
          */
-        public final Deque<CraftingTask> resolvers = new ArrayDeque<>(4);
+        public final ArrayList<CraftingTask> resolvers = new ArrayList<>(4);
 
         public RequestInProcessing(CraftingRequest<StackType> request) {
             this.request = request;
@@ -127,6 +127,7 @@ public final class CraftingContext {
         }
         final RequestInProcessing<?> processing = new RequestInProcessing<>(request);
         processing.resolvers.addAll(CraftingCalculations.tryResolveCraftingRequest(request, this));
+        Collections.reverse(processing.resolvers); // We remove from the end for efficient ArrayList usage
         liveRequests.add(processing);
         if (processing.resolvers.isEmpty()) {
             throw new IllegalStateException("No resolvers available for request " + request.toString());
@@ -305,10 +306,13 @@ public final class CraftingContext {
         if (request.request.remainingToProcess <= 0 || request.resolvers.isEmpty()) {
             return false;
         }
-        CraftingTask nextResolver = request.resolvers.removeFirst();
+        CraftingTask nextResolver = request.resolvers.remove(request.resolvers.size() - 1);
         if (addResolverTask && !request.resolvers.isEmpty()) {
             tasksToProcess.addFirst(new CheckOtherResolversTask(request));
         }
+        if (request.resolvers.isEmpty()) {
+            request.resolvers.trimToSize();
+        }
         tasksToProcess.addFirst(nextResolver);
         return true;
     }

src/main/java/appeng/crafting/v2/resolvers/CraftableItemResolver.java

@@ -53,8 +53,8 @@ public class CraftableItemResolver implements CraftingRequestResolver<IAEItemSta
         // With the recursive part subtracted
         protected final IAEItemStack[] patternOutputs;
         protected final IAEItemStack matchingOutput;
-        protected final List<RequestAndPerCraftAmount> childRequests = new ArrayList<>();
-        protected final List<CraftingRequest> complexRequestPerSlot = new ArrayList<>();
+        protected final ArrayList<RequestAndPerCraftAmount> childRequests = new ArrayList<>();
+        protected final ArrayList<CraftingRequest> complexRequestPerSlot = new ArrayList<>();
         protected final Map<IAEItemStack, CraftingRequest<IAEItemStack>> childRecursionRequests = new HashMap<>();
         // byproduct injected -> amount per craft
         protected final IdentityHashMap<IAEItemStack, Long> byproducts = new IdentityHashMap<>();
@@ -302,6 +302,8 @@ public class CraftableItemResolver implements CraftingRequestResolver<IAEItemSta
                         childRequests.add(new RequestAndPerCraftAmount(req, input.getStackSize()));
                     }
                 }
+                childRequests.trimToSize();
+                complexRequestPerSlot.trimToSize();
                 requestedInputs = true;
                 state = State.NEEDS_MORE_WORK;
                 return new StepOutput(Collections.unmodifiableList(newChildren));

src/main/java/appeng/crafting/v2/resolvers/ExtractItemResolver.java

@@ -18,8 +18,8 @@ public class ExtractItemResolver implements CraftingRequestResolver<IAEItemStack
 
     public static class ExtractItemTask extends CraftingTask<IAEItemStack> {
 
-        public final List<IAEItemStack> removedFromSystem = new ArrayList<>();
-        public final List<IAEItemStack> removedFromByproducts = new ArrayList<>();
+        public final ArrayList<IAEItemStack> removedFromSystem = new ArrayList<>();
+        public final ArrayList<IAEItemStack> removedFromByproducts = new ArrayList<>();
 
         public ExtractItemTask(CraftingRequest<IAEItemStack> request) {
             super(request, CraftingTask.PRIORITY_EXTRACT); // always try to extract items first
@@ -42,6 +42,8 @@ public class ExtractItemResolver implements CraftingRequestResolver<IAEItemStack
                     extractFuzzy(context, context.itemModel, removedFromSystem);
                 }
             }
+            removedFromSystem.trimToSize();
+            removedFromByproducts.trimToSize();
             return new StepOutput(Collections.emptyList());
         }