src/java.base/share/classes/java/util/zip/ZipUtils.java

*** 1,7 ****
  /*
!  * Copyright (c) 2013, 2017, 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) 2013, 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
*** 23,32 ****
--- 23,34 ----
   * questions.
   */
  
  package java.util.zip;
  
+ import java.nio.Buffer;
+ import java.nio.ByteBuffer;
  import java.nio.file.attribute.FileTime;
  import java.security.AccessController;
  import java.security.PrivilegedAction;
  import java.time.DateTimeException;
  import java.time.Instant;
*** 35,52 ****
--- 37,60 ----
  import java.util.Date;
  import java.util.concurrent.TimeUnit;
  
  import static java.util.zip.ZipConstants.ENDHDR;
  
+ import jdk.internal.misc.Unsafe;
+ import sun.nio.ch.DirectBuffer;
+ 
  class ZipUtils {
  
      // used to adjust values between Windows and java epoch
      private static final long WINDOWS_EPOCH_IN_MICROSECONDS = -11644473600000000L;
  
      // used to indicate the corresponding windows time is not available
      public static final long WINDOWS_TIME_NOT_AVAILABLE = Long.MIN_VALUE;
  
+     // static final ByteBuffer defaultBuf = ByteBuffer.allocateDirect(0);
+     static final ByteBuffer defaultBuf = ByteBuffer.allocate(0);
+ 
      /**
       * Converts Windows time (in microseconds, UTC/GMT) time to FileTime.
       */
      public static final FileTime winTimeToFileTime(long wtime) {
          return FileTime.from(wtime / 10 + WINDOWS_EPOCH_IN_MICROSECONDS,
*** 279,284 ****
--- 287,305 ----
          } else {
              PrivilegedAction<Void> pa = () -> { System.loadLibrary("zip"); return null; };
              AccessController.doPrivileged(pa);
          }
      }
+ 
+     private static final Unsafe unsafe = Unsafe.getUnsafe();
+ 
+     private static final long byteBufferArrayOffset = unsafe.objectFieldOffset(ByteBuffer.class, "hb");
+     private static final long byteBufferOffsetOffset = unsafe.objectFieldOffset(ByteBuffer.class, "offset");
+ 
+     static byte[] getBufferArray(ByteBuffer byteBuffer) {
+         return (byte[]) unsafe.getObject(byteBuffer, byteBufferArrayOffset);
+     }
+ 
+     static int getBufferOffset(ByteBuffer byteBuffer) {
+         return unsafe.getInt(byteBuffer, byteBufferOffsetOffset);
+     }
  }