src/java.base/share/classes/java/util/AbstractCollection.java

rev 54801 : [mq]: 8223593-Refactor-code-for-reallocating-storage

*** 1,7 ****
  /*
!  * Copyright (c) 1997, 2018, Oracle and/or its affiliates. All rights reserved.
   * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   *
   * This code is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License version 2 only, as
   * published by the Free Software Foundation.  Oracle designates this
--- 1,7 ----
  /*
!  * Copyright (c) 1997, 2019, Oracle and/or its affiliates. All rights reserved.
   * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   *
   * This code is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License version 2 only, as
   * published by the Free Software Foundation.  Oracle designates this
*** 23,32 ****
--- 23,34 ----
   * questions.
   */
  
  package java.util;
  
+ import jdk.internal.util.ArraysSupport;
+ 
  /**
   * This class provides a skeletal implementation of the {@code Collection}
   * interface, to minimize the effort required to implement this interface. <p>
   *
   * To implement an unmodifiable collection, the programmer needs only to
*** 202,219 ****
          // more elements than expected
          return it.hasNext() ? finishToArray(r, it) : r;
      }
  
      /**
-      * The maximum size of array to allocate.
-      * Some VMs reserve some header words in an array.
-      * Attempts to allocate larger arrays may result in
-      * OutOfMemoryError: Requested array size exceeds VM limit
-      */
-     private static final int MAX_ARRAY_SIZE = Integer.MAX_VALUE - 8;
- 
-     /**
       * Reallocates the array being used within toArray when the iterator
       * returned more elements than expected, and finishes filling it from
       * the iterator.
       *
       * @param r the array, replete with previously stored elements
--- 204,213 ----
*** 221,253 ****
       * @return array containing the elements in the given array, plus any
       *         further elements returned by the iterator, trimmed to size
       */
      @SuppressWarnings("unchecked")
      private static <T> T[] finishToArray(T[] r, Iterator<?> it) {
-         int i = r.length;
-         while (it.hasNext()) {
              int cap = r.length;
              if (i == cap) {
!                 int newCap = cap + (cap >> 1) + 1;
!                 // overflow-conscious code
!                 if (newCap - MAX_ARRAY_SIZE > 0)
!                     newCap = hugeCapacity(cap + 1);
!                 r = Arrays.copyOf(r, newCap);
              }
              r[i++] = (T)it.next();
          }
          // trim if overallocated
!         return (i == r.length) ? r : Arrays.copyOf(r, i);
!     }
! 
!     private static int hugeCapacity(int minCapacity) {
!         if (minCapacity < 0) // overflow
!             throw new OutOfMemoryError
!                 ("Required array size too large");
!         return (minCapacity > MAX_ARRAY_SIZE) ?
!             Integer.MAX_VALUE :
!             MAX_ARRAY_SIZE;
      }
  
      // Modification Operations
  
      /**
--- 215,235 ----
       * @return array containing the elements in the given array, plus any
       *         further elements returned by the iterator, trimmed to size
       */
      @SuppressWarnings("unchecked")
      private static <T> T[] finishToArray(T[] r, Iterator<?> it) {
          int cap = r.length;
+         int i = cap;
+         while (it.hasNext()) {
              if (i == cap) {
!                 cap = ArraysSupport.newCapacity(cap, 1, (cap >> 1) + 1);
!                 r = Arrays.copyOf(r, cap);
              }
              r[i++] = (T)it.next();
          }
          // trim if overallocated
!         return (i == cap) ? r : Arrays.copyOf(r, i);
      }
  
      // Modification Operations
  
      /**