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From froehl...@apache.org
Subject cvs commit: jakarta-commons-sandbox/simplestore/src/java/org/apache/commons/simplestore/cache/impl SynchronizedCache.java SoftRefMemoryCache.java
Date Mon, 11 Feb 2002 20:23:15 GMT
froehlich    02/02/11 12:23:15

  Added:       simplestore/src/java/org/apache/commons/simplestore/cache/impl
                        SynchronizedCache.java SoftRefMemoryCache.java
  Log:
  re-structured repository
  
  Revision  Changes    Path
  1.1                  jakarta-commons-sandbox/simplestore/src/java/org/apache/commons/simplestore/cache/impl/SynchronizedCache.java
  
  Index: SynchronizedCache.java
  ===================================================================
  /*
   * The Apache Software License, Version 1.1
   *
   *
   * Copyright (c) 2001 The Apache Software Foundation.  All rights
   * reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   *
   * 1. Redistributions of source code must retain the above copyright
   *    notice, this list of conditions and the following disclaimer.
   *
   * 2. Redistributions in binary form must reproduce the above copyright
   *    notice, this list of conditions and the following disclaimer in
   *    the documentation and/or other materials provided with the
   *    distribution.
   *
   * 3. The end-user documentation included with the redistribution,
   *    if any, must include the following acknowledgment:
   *       "This product includes software developed by the
   *        Apache Software Foundation (http://www.apache.org/)."
   *    Alternately, this acknowledgment may appear in the software itself,
   *    if and wherever such third-party acknowledgments normally appear.
   *
   * 4. The names "Apache Cocoon" and "Apache Software Foundation" must
   *    not be used to endorse or promote products derived from this
   *    software without prior written permission. For written
   *    permission, please contact apache@apache.org.
   *
   * 5. Products derived from this software may not be called "Apache",
   *    nor may "Apache" appear in their name, without prior written
   *    permission of the Apache Software Foundation.
   *
   * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
   * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
   * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
   * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
   * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
   * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
   * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
   * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
   * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
   * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
   * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   * SUCH DAMAGE.
   * ====================================================================
   *
   * This software consists of voluntary contributions made by many
   * individuals on behalf of the Apache Software Foundation.  For more
   * information on the Apache Software Foundation, please see
   * <http://www.apache.org/>.
   */
  package org.apache.commons.simplestore.cache.impl;
  
  import org.apache.commons.simplestore.cache.Cache;
  
  /**
   *@author     Juozas Baliuka <a href="mailto:baliuka@mwm.lt">
   *      baliuka@mwm.lt</a>
   *@author     Gerhard Froehlich <a href="mailto:g-froehlich@gmx.de">
   *      g-froehlich@gmx.de</a>
   *@version    $Id: SynchronizedCache.java,v 1.1 2002/02/11 20:23:15 froehlich Exp $
   */
  final class SynchronizedCache implements Cache {
  
      private Cache mCache;
  
      /**
       * Creates new SynchronizedCache
       *
       *@param  cache
       */
      public SynchronizedCache(Cache cache) {
          if (cache == null) {
              throw new NullPointerException();
          }
          this.mCache = cache;
      }
  
      /**
       * Get the object associated to the given unique key.
       *
       *@param  key  the Key Object
       *@return requested object or null
       */
      public Object get(Object key) {
          synchronized (mCache) {
              return mCache.get(key);
          }
      }
  
      /**
       * Cache the object associated to the given unique key.
       *
       *@param  key  the key object
       *@param  value  the value Object
       */
      public void put(Object key, Object value) {
          synchronized (mCache) {
              mCache.put(key, value);
          }
      }
  }
  
  
  
  
  1.1                  jakarta-commons-sandbox/simplestore/src/java/org/apache/commons/simplestore/cache/impl/SoftRefMemoryCache.java
  
  Index: SoftRefMemoryCache.java
  ===================================================================
  /*
   * The Apache Software License, Version 1.1
   *
   *
   * Copyright (c) 2001 The Apache Software Foundation.  All rights
   * reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   *
   * 1. Redistributions of source code must retain the above copyright
   *    notice, this list of conditions and the following disclaimer.
   *
   * 2. Redistributions in binary form must reproduce the above copyright
   *    notice, this list of conditions and the following disclaimer in
   *    the documentation and/or other materials provided with the
   *    distribution.
   *
   * 3. The end-user documentation included with the redistribution,
   *    if any, must include the following acknowledgment:
   *       "This product includes software developed by the
   *        Apache Software Foundation (http://www.apache.org/)."
   *    Alternately, this acknowledgment may appear in the software itself,
   *    if and wherever such third-party acknowledgments normally appear.
   *
   * 4. The names "Apache Cocoon" and "Apache Software Foundation" must
   *    not be used to endorse or promote products derived from this
   *    software without prior written permission. For written
   *    permission, please contact apache@apache.org.
   *
   * 5. Products derived from this software may not be called "Apache",
   *    nor may "Apache" appear in their name, without prior written
   *    permission of the Apache Software Foundation.
   *
   * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
   * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
   * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
   * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
   * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
   * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
   * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
   * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
   * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
   * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
   * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   * SUCH DAMAGE.
   * ====================================================================
   *
   * This software consists of voluntary contributions made by many
   * individuals on behalf of the Apache Software Foundation.  For more
   * information on the Apache Software Foundation, please see
   * <http://www.apache.org/>.
   */
  package org.apache.commons.simplestore.cache.impl;
  
  import org.apache.commons.simplestore.cache.Cache;
  
  import java.lang.ref.ReferenceQueue;
  import java.lang.ref.SoftReference;
  import java.util.Map;
  
  /**
   *@author     Juozas Baliuka <a href="mailto:baliuka@mwm.lt">
   *      baliuka@mwm.lt</a>
   *@author     Gerhard Froehlich <a href="mailto:g-froehlich@gmx.de">
   *      g-froehlich@gmx.de</a>
   *@version    $Id: SoftRefMemoryCache.java,v 1.1 2002/02/11 20:23:15 froehlich Exp $
   */
  public class SoftRefMemoryCache implements Cache {
  
      private static boolean DEBUG = true;
      
      private int m_current = 0;
      private int m_maxStrongRefCount;
      private Map m_map;
      private Object[] m_strongRefs;
      private ReferenceQueue m_queue = new ReferenceQueue();
  
      /**
       * Creates new SoftRefMemoryCache
       *
       *@param  map 
       *@param  maxStrongRefCount
       */
      protected SoftRefMemoryCache(Map map, int maxStrongRefCount) {
          this.m_map = map;
  
          if (maxStrongRefCount < 0) {
              throw new java.lang.IllegalArgumentException();
          }
          this.m_maxStrongRefCount = maxStrongRefCount;
  
          if (maxStrongRefCount > 0) {
              m_strongRefs = new Object[maxStrongRefCount];
          }
      }
  
      public static Cache getInstance(Map map, int maxStrongRef) {
          return new SynchronizedCache(new SoftRefMemoryCache(map, maxStrongRef));
      }
  
      /**
       * Get the object associated to the given unique key.
       *
       *@param  key  the Key Object
       *@return requested object or null
       */
      public Object get(Object key) {
          removeSoftRef();
          Object object = null;
          SoftRef ref = (SoftRef) m_map.get(key);
  
          if (ref != null) {
              object = ref.get();
          }
  
          addStrongRef(object);
          return object;
      }
  
      /**
       * Cache the object associated to the given unique key.
       *
       *@param  key  the key object
       *@param  value  the value Object
       */
      public void put(Object key, Object object) {
          removeSoftRef();
          internalStoreObject(key, object);
      }
  
      private SoftRef makeValue(Object key, Object value, ReferenceQueue queue) {
          return new SoftRef(key, value, queue);
      }
  
      // remove unused keys
      private void removeSoftRef() {
          SoftRef ref = (SoftRef) m_queue.poll();
  
          while (ref != null) {
              m_map.remove(ref.key);
  
              if (DEBUG) {
                  System.out.println("Key " + ref.key + " removed from Reference queue, map
size is " + m_map.size());
              }
              ref = (SoftRef) m_queue.poll();
          }
      }
  
      private void addStrongRef(Object object) {
          if (m_strongRefs != null) {
              m_strongRefs[(m_current++) % m_maxStrongRefCount] = object;
          }
      }
  
      private void internalStoreObject(Object key, Object object) {
          SoftRef ref = makeValue(key, object, m_queue);
          addStrongRef(ref.get());
          m_map.put(key, ref);
      }
  
      static class SoftRef extends SoftReference {
          Object key;
  
          private SoftRef(Object key, Object object, ReferenceQueue queue) {
              super(object, queue);
              this.key = key;
          }
      }
  }
  
  
  
  

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