src/java.base/share/classes/java/util/stream/ReduceOps.java

rev 53968 : enable Collector pre-sizing
rev 53969 : added map loadfactor and collector nullchecks

@@ -29,20 +29,11 @@
 import java.util.OptionalDouble;
 import java.util.OptionalInt;
 import java.util.OptionalLong;
 import java.util.Spliterator;
 import java.util.concurrent.CountedCompleter;
-import java.util.function.BiConsumer;
-import java.util.function.BiFunction;
-import java.util.function.BinaryOperator;
-import java.util.function.DoubleBinaryOperator;
-import java.util.function.IntBinaryOperator;
-import java.util.function.LongBinaryOperator;
-import java.util.function.ObjDoubleConsumer;
-import java.util.function.ObjIntConsumer;
-import java.util.function.ObjLongConsumer;
-import java.util.function.Supplier;
+import java.util.function.*;
 
 /**
  * Factory for creating instances of {@code TerminalOp} that implement
  * reductions.
  *

@@ -153,17 +144,21 @@
      * @return a {@code ReduceOp} implementing the reduction
      */
     public static <T, I> TerminalOp<T, I>
     makeRef(Collector<? super T, I, ?> collector) {
         Supplier<I> supplier = Objects.requireNonNull(collector).supplier();
+        IntFunction<I> sizedSupplier = collector.sizedSupplier();
         BiConsumer<I, ? super T> accumulator = collector.accumulator();
         BinaryOperator<I> combiner = collector.combiner();
         class ReducingSink extends Box<I>
                 implements AccumulatingSink<T, I, ReducingSink> {
             @Override
             public void begin(long size) {
+                if (size < 0 || size > Integer.MAX_VALUE)
                 state = supplier.get();
+                else
+                    state = sizedSupplier.apply((int) size);
             }
 
             @Override
             public void accept(T t) {
                 accumulator.accept(state, t);