1 /*
   2  * Copyright (c) 2009, 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 java.util.zip;
  27 
  28 import java.util.function.LongConsumer;
  29 import java.util.function.LongSupplier;
  30 import java.lang.ref.Cleaner.Cleanable;
  31 import jdk.internal.ref.CleanerFactory;
  32 
  33 /**
  34  * A reference to the native zlib's z_stream structure. It also
  35  * serves as the "cleaner" to clean up the native resource when
  36  * the deflater or infalter is ended, closed or cleaned.
  37  */
  38 class ZStreamRef implements Runnable {
  39 
  40     private LongConsumer end;
  41     private long address;
  42     private final Cleanable cleanable;
  43 
  44     private ZStreamRef (Object owner, LongSupplier addr, LongConsumer end) {
  45         this.cleanable = CleanerFactory.cleaner().register(owner, this);
  46         this.end = end;
  47         this.address = addr.getAsLong();
  48     }
  49 
  50     long address() {
  51         return address;
  52     }
  53 
  54     void clean() {
  55         cleanable.clean();
  56     }
  57 
  58     public synchronized void run() {
  59         long addr = address;
  60         address = 0;
  61         if (addr != 0) {
  62             end.accept(addr);
  63         }
  64     }
  65 
  66     private ZStreamRef (LongSupplier addr, LongConsumer end) {
  67         this.cleanable = null;
  68         this.end = end;
  69         this.address = addr.getAsLong();
  70     }
  71 
  72     /*
  73      * If {@code Inflater/Deflater} has been subclassed and the {@code end} method
  74      * is overridden, uses {@code finalizer} mechanism for resource cleanup. So
  75      * {@code end} method can be called when the {@code Inflater/Deflater} is
  76      * unreachable. This mechanism will be removed when the {@code finalize} method
  77      * is removed from {@code Inflater/Deflater}.
  78      */
  79     static ZStreamRef get(Object owner, LongSupplier addr, LongConsumer end) {
  80         Class<?> clz = owner.getClass();
  81         while (clz != Deflater.class && clz != Inflater.class) {
  82             try {
  83                 clz.getDeclaredMethod("end");
  84                 return new FinalizableZStreamRef(owner, addr, end);
  85             } catch (NoSuchMethodException nsme) {}
  86             clz = clz.getSuperclass();
  87         }
  88         return new ZStreamRef(owner, addr, end);
  89     }
  90 
  91     private static class FinalizableZStreamRef extends ZStreamRef {
  92         final Object owner;
  93 
  94         FinalizableZStreamRef (Object owner, LongSupplier addr, LongConsumer end) {
  95             super(addr, end);
  96             this.owner = owner;
  97         }
  98 
  99         @Override
 100         void clean() {
 101             run();
 102         }
 103 
 104         @Override
 105         @SuppressWarnings("deprecation")
 106         protected void finalize() {
 107             if (owner instanceof Inflater)
 108                 ((Inflater)owner).end();
 109             else
 110                 ((Deflater)owner).end();
 111         }
 112     }
 113 }