1 /*
   2  * Copyright (c) 2015, 2017, 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 package jdk.incubator.http.internal.common;
  26 
  27 import java.nio.ByteBuffer;
  28 import java.util.Objects;
  29 import java.util.function.Supplier;
  30 
  31 public class ByteBufferReference  implements Supplier<ByteBuffer> {
  32 
  33     private ByteBuffer buffer;
  34     private final ByteBufferPool pool;
  35 
  36     public static ByteBufferReference of(ByteBuffer buffer) {
  37         return of(buffer, null);
  38     }
  39 
  40     public static ByteBufferReference of(ByteBuffer buffer, ByteBufferPool pool) {
  41         Objects.requireNonNull(buffer);
  42         return new ByteBufferReference(buffer, pool);
  43     }
  44 
  45     public static ByteBuffer[] toBuffers(ByteBufferReference... refs) {
  46         ByteBuffer[] bufs = new ByteBuffer[refs.length];
  47         for (int i = 0; i < refs.length; i++) {
  48             bufs[i] = refs[i].get();
  49         }
  50         return bufs;
  51     }
  52 
  53     public static ByteBufferReference[] toReferences(ByteBuffer... buffers) {
  54         ByteBufferReference[] refs = new ByteBufferReference[buffers.length];
  55         for (int i = 0; i < buffers.length; i++) {
  56             refs[i] = of(buffers[i]);
  57         }
  58         return refs;
  59     }
  60 
  61 
  62     public static void clear(ByteBufferReference[] refs) {
  63         for(ByteBufferReference ref : refs) {
  64             ref.clear();
  65         }
  66     }
  67 
  68     private ByteBufferReference(ByteBuffer buffer, ByteBufferPool pool) {
  69         this.buffer = buffer;
  70         this.pool = pool;
  71     }
  72 
  73     @Override
  74     public ByteBuffer get() {
  75         ByteBuffer buf = this.buffer;
  76         assert buf!=null : "getting ByteBuffer after clearance";
  77         return buf;
  78     }
  79 
  80     public void clear() {
  81         ByteBuffer buf = this.buffer;
  82         assert buf!=null : "double ByteBuffer clearance";
  83         this.buffer = null;
  84         if (pool != null) {
  85             pool.release(buf);
  86         }
  87     }
  88 }