modules/cldc-compact/src/main/java/cc/squirreljme/runtime/cldc/util/SynchronizedEntrySetNotNull.java

   1 // -*- Mode: Java; indent-tabs-mode: t; tab-width: 4 -*-
   2 // ---------------------------------------------------------------------------
   3 // SquirrelJME
   4 //     Copyright (C) Stephanie Gawroriski <xer@multiphasicapps.net>
   5 // ---------------------------------------------------------------------------
   6 // SquirrelJME is under the GNU General Public License v3+, or later.
   7 // See license.mkd for licensing and copyright information.
   8 // ---------------------------------------------------------------------------
   9
  10 package cc.squirreljme.runtime.cldc.util;
  11
  12 import java.util.AbstractSet;
  13 import java.util.Iterator;
  14 import java.util.Map;
  15 import java.util.Set;
  16
  17 /**
  18  * This is an entry set which is synchronized against a lock, null values
  19  * are not allowed.
  20  *
  21  * @param <K> The entry keys.
  22  * @param <V> The entry values.
  23  * @since 2019/05/05
  24  */
  25 public final class SynchronizedEntrySetNotNull<K, V>
  26         extends AbstractSet<Map.Entry<K, V>>
  27 {
  28         /** The locking object. */
  29         protected final Object lock;
  30
  31         /** The backing set. */
  32         protected final Set<Map.Entry<K, V>> set;
  33
  34         /**
  35          * Initializes the synchronized entry set.
  36          *
  37          * @param __lock The locking object.
  38          * @param __set The entry set object.
  39          * @throws NullPointerException On null arguments.
  40          * @since 2019/05/05
  41          */
  42         public SynchronizedEntrySetNotNull(Object __lock,
  43                 Set<Map.Entry<K, V>> __set)
  44                 throws NullPointerException
  45         {
  46                 if (__lock == null || __set == null)
  47                         throw new NullPointerException("NARG");
  48
  49                 this.lock = __lock;
  50                 this.set = __set;
  51         }
  52
  53         /**
  54          * {@inheritDoc}
  55          * @since 2019/05/05
  56          */
  57         @Override
  58         public final Iterator<Map.Entry<K, V>> iterator()
  59         {
  60                 Object lock = this.lock;
  61                 synchronized (lock)
  62                 {
  63                         return new SynchronizedEntrySetIteratorNotNull<K, V>(
  64                                 lock, this.set.iterator());
  65                 }
  66         }
  67
  68         /**
  69          * {@inheritDoc}
  70          * @since 2019/05/05
  71          */
  72         @Override
  73         public final int size()
  74         {
  75                 synchronized (this.lock)
  76                 {
  77                         return this.set.size();
  78                 }
  79         }
  80 }