1 /*
   2  * Copyright (c) 2007, 2011, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 package jdk.internal.misc;
  27 
  28 import java.nio.Buffer;
  29 import java.nio.ByteBuffer;
  30 
  31 public interface JavaNioAccess {
  32     /**
  33      * Provides access to information on buffer usage.
  34      */
  35     interface BufferPool {
  36         String getName();
  37         long getCount();
  38         long getTotalCapacity();
  39         long getMemoryUsed();
  40     }
  41     BufferPool getDirectBufferPool();
  42 
  43     /**
  44      * Constructs a direct ByteBuffer referring to the block of memory starting
  45      * at the given memory address and extending {@code cap} bytes.
  46      * The {@code ob} parameter is an arbitrary object that is attached
  47      * to the resulting buffer.
  48      */
  49     ByteBuffer newDirectByteBuffer(long addr, int cap, Object ob);
  50 
  51     /**
  52      * Truncates a buffer by changing its capacity to 0.
  53      */
  54     void truncate(Buffer buf);
  55 
  56 }