persistentspace.java

java pos,你可以直接编译运行,

/*
 * Copyright (c) 2000 jPOS.org.  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 jPOS project 
 *    (http://www.jpos.org/)". Alternately, this acknowledgment may 
 *    appear in the software itself, if and wherever such third-party 
 *    acknowledgments normally appear.
 *
 * 4. The names "jPOS" and "jPOS.org" must not be used to endorse 
 *    or promote products derived from this software without prior 
 *    written permission. For written permission, please contact 
 *    [e-mail].
 *
 * 5. Products derived from this software may not be called "jPOS",
 *    nor may "jPOS" appear in their name, without prior written
 *    permission of the jPOS project.
 *
 * 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 JPOS PROJECT 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 jPOS Project.  For more
 * information please see <http://www.jpos.org/>.
 */

package org.jpos.space;

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.FilenameFilter;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.util.Arrays;
import java.util.HashMap;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.Set;

/**
 * Persistent Space implementation
 * @author Alejandro Revilla, modified by Kris Leite for Persistent
 * @version $Revision: 1.14 $ $Date: 2004/12/17 20:38:17 $
 * @since 2.0
 */
public class PersistentSpace implements LocalSpace // PersistentSpaceMBean {
{
    protected Map map;
    static LocalSpace defaultSpace = new PersistentSpace ();
    static int cacheSize = 16;

    public PersistentSpace() {
        super();
        map = new HashMap ();
    }
    public synchronized void setCacheSize (int cacheSize) {
        PersistentSpace.cacheSize = cacheSize;
    }
    public void out (Object key, Object value) {
        List listeners;
        synchronized (this) {
            Data data = (Data) map.get (key);
            if (data == null) 
                map.put (key, (data = new Data (key)));
            data.add (value);
            listeners = data.getListeners();
            this.notifyAll ();
        }
        if (listeners != null) {
            Iterator iter = listeners.iterator();
            while (iter.hasNext()) {
                ((SpaceListener)iter.next()).notify (key, value);
            }
        }
    }
    public void out (Object id, Object value, long timeout) {
        LeasedReference ref = new LeasedReference (value, timeout);
        out (id, ref);
    }
    public synchronized int size (Object key) {
        Data data  = (Data) map.get (key);
        if (data == null)
            map.put (key, (data = new Data (key)));
        return data.size ();
    }
    public synchronized Object rdp (Object key) {
        Data data  = (Data) map.get (key);
        if (data == null)
            map.put (key, (data = new Data (key)));
        return data.get (key);
    }
    public synchronized Object inp (Object key) {
        Data data  = (Data) map.get (key);
        if (data == null)
            map.put (key, (data = new Data (key)));
        return data.remove ();
    }
    public synchronized Object in (Object key) {
        Object obj;
        while ((obj = inp (key)) == null) {
            try {
                this.wait ();
            } catch (InterruptedException e) { }
        }
        return obj;
    }
    public synchronized Object in  (Object key, long timeout) {
        Object obj;
        long now = System.currentTimeMillis();
        long end = now + timeout;
        while ((obj = inp (key)) == null && 
                ((now = System.currentTimeMillis()) < end))
        {
            try {
                this.wait (end - now);
            } catch (InterruptedException e) { }
        }
        return obj;
    }
    public synchronized Object rd  (Object key) {
        Object obj;
        while ((obj = rdp (key)) == null) {
            try {
                this.wait ();
            } catch (InterruptedException e) { }
        }
        return obj;
    }
    public synchronized Object rd  (Object key, long timeout) {
        Object obj;
        long now = System.currentTimeMillis();
        long end = now + timeout;
        while ((obj = rdp (key)) == null && 
                ((now = System.currentTimeMillis()) < end))
        {
            try {
                this.wait (end - now);
            } catch (InterruptedException e) { }
        }
        return obj;
    }
    public synchronized void addListener    (Object key, SpaceListener listener) {
        Data data = (Data) map.get (key);
        if (data == null)
             map.put (key, (data = new Data (key)));
        data.addListener (listener);
    }
    public synchronized void addListener 
        (Object key, SpaceListener listener, long timeout) {
        // #FIXME# not implemented 
        addListener (key, listener);
    }
    public synchronized void removeListener (Object key, SpaceListener listener) {
        Data data = (Data) map.get (key);
        if (data != null)
            data.removeListener (listener);
    }

    protected static final class Data {
        LinkedList data;
        LinkedList stored;
        LinkedList listeners;
        File dir;

        protected Data (Object name) {
            super();
            data = new LinkedList ();
            stored = new LinkedList ();
            listeners = null;
            String n = "space" + File.separatorChar;
                if (name instanceof String)
                    n += name;
                else
                    n += "H" + Integer.toString(name.hashCode());
            dir = new File (n);
            dir.mkdirs ();
            FilenameFilter filter = new FilenameFilter() {
                public boolean accept(File f, String name) {
                    return name.toUpperCase().startsWith("S");
                }
            };
            File file[] = dir.listFiles (filter);
            Arrays.sort (file);
            for (int i=0; file.length > i; i++) {
                if (cacheSize > data.size()) {
                    Object value = readValue (file[i].getAbsolutePath ());
                    if (value == null) {
                        (new File (file[i].getAbsolutePath ())).delete ();
                    } else {
                        stored.add(file[i].getAbsolutePath ());
                        data.add (value);
                    }
                } else
                    stored.add(file[i].getAbsolutePath ());
            }
        }
        private Object readValue (String f) {
            Object value = null;
            ObjectInputStream fin = null;
            try {
                fin = new ObjectInputStream (
                      new BufferedInputStream (
                      new FileInputStream (f)));
                value = fin.readObject ();
            } catch (Exception e) { 
                throw new SpaceError (e);
            } finally {
                if (fin != null)
                    try {
                        fin.close();
                    } catch (Exception e) { 
                        throw new SpaceError (e);
                    }
            }
            return value;
        }
        
        protected File createTempFile (String prefex, File dir) {
            long t = System.currentTimeMillis();
            File f = null;
            do {
                String fn = prefex + Long.toHexString(t);
                t = t + 1;
                f = new File (dir, fn);
            } while (f.exists());
            return f;
        }
        
        protected void add (Object value) {
            File f = null;
            FileOutputStream fos = null;
            try {
                f = createTempFile ("S", dir);
                fos = new FileOutputStream (f);
                ObjectOutputStream fout = new ObjectOutputStream (
                                          new BufferedOutputStream (fos));
                fout.writeObject (value);
                fout.flush();
                fos.getFD().sync();
            } catch (Exception e) {
                throw new SpaceError (e);
            } finally {
                if (fos != null)
                    try {
                        fos.close();
                    } catch (Exception e) { 
                        throw new SpaceError (e);
                    };
            }
            stored.add(f.getAbsolutePath());
            /* fill cache */
            if (cacheSize > data.size ())
                if ((data.size() + 1) == stored.size ())
                    data.add (value);
        }
        protected Object get (Object value) {
            Object obj = null;
            while (size() > 0) {
                obj = getFirst();
                if (obj instanceof LeasedReference)
                    obj = ((LeasedReference)obj).get ();
                if (obj == null) {
                    data.removeFirst ();
                    File f = new File ((String) stored.removeFirst ());
                    f.delete ();
                    continue;
                }
                break;
            }
            return obj;
        }
        protected Object getFirst () {
            Object object = null;
            if (data.size() > 0) {
                object = data.getFirst ();
            } else if (stored.size() > 0) {
                object = readValue ((String) stored.getFirst ());
            }
            return object;
        }
        protected int size () {
            return stored.size ();
        }
        protected Object remove () {
            Object obj = null;
            File f = null;
            while (size() > 0) {
                obj = getFirst ();
                if (data.size () > 0) 
                    data.removeFirst();
                f = new File ((String) stored.removeFirst ());
                f.delete ();
                if (obj instanceof LeasedReference) {
                    LeasedReference ref = (LeasedReference) obj;
                    obj = ref.get ();
                    if (obj == null) {
                        continue;
                    }
                    ref.discard ();
                }
                break;
            }
            return obj;
        }
        protected boolean isEmpty () {
            return stored.isEmpty () && listeners == null;
        }
        protected void addListener (SpaceListener l) {
            if (listeners == null)
                listeners = new LinkedList ();
            listeners.add (l);
        }
        protected void removeListener (SpaceListener l) {
            if (listeners != null) {
                listeners.remove (l);
                if (listeners.isEmpty ())
                    listeners = null;
            }
        }
        protected List getListeners () {
            return listeners;
        }
    }
    public static final LocalSpace getSpace () {
        return defaultSpace;
    }
    public static final LocalSpace getSpace (String spaceName) {
        String key = "jpos:pSpace/"+spaceName;
        Space sp   = TransientSpace.getSpace();
        Object obj = sp.rdp (key);
        if (obj == null) {
            synchronized (PersistentSpace.class) {
                obj = sp.rdp (key);
                if (obj == null) {
                    obj = new PersistentSpace ();
                    sp.out (key, obj);
                }
            }
        } 
        return (LocalSpace) obj;
    }
    public Set getKeySet () {
        Set keySet;
        synchronized (this) {
            keySet = map.keySet();
        }
        return keySet;
    }
    public String getKeys () {
        StringBuffer sb = new StringBuffer ();
        Iterator iter = map.keySet().iterator ();
        boolean first = true;
        while (iter.hasNext()) {
            if (!first)
                sb.append (' ');
            else
                first = false;
            sb.append (iter.next().toString ());
        }
        return sb.toString ();
    }

    public void write (String key, String value) {
        out (key, value);
    }

    public String read (String key) {
        Object o = inp (key);
        return (o != null) ? o.toString() : "null";
    }
}