haul 2003/11/09 05:33:24
Added: src/blocks/scratchpad/java/org/apache/cocoon/util
SoftSourceCache.java SourceCache.java
SourceReloader.java
Log:
Initial version of source caches.
Revision Changes Path
1.1
cocoon-2.1/src/blocks/scratchpad/java/org/apache/cocoon/util/SoftSourceCache.java
Index: SoftSourceCache.java
===================================================================
/*
============================================================================
The Apache Software License, Version 1.1
============================================================================
Copyright (C) 1999-2003 The Apache Software Foundation. All rights reserved.
Redistribution and use in source and binary forms, with or without modifica-
tion, 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
[EMAIL PROTECTED]
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 (INCLU-
DING, 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 and was originally created by
Stefano Mazzocchi <[EMAIL PROTECTED]>. For more information on the Apache
Software Foundation, please see <http://www.apache.org/>.
*/
package org.apache.cocoon.util;
import java.io.IOException;
import java.net.MalformedURLException;
import java.util.Collections;
import java.util.Map;
import org.apache.commons.collections.ReferenceMap;
import org.apache.excalibur.source.Source;
import org.apache.excalibur.source.SourceResolver;
import org.apache.excalibur.source.SourceValidity;
/**
* Cache for objects created from a source. Objects and keys
* are held using [EMAIL PROTECTED] java.lang.ref.SoftReference} and are
* thus cleanable by the garbage collector if the VM is low on
* memory. If an object cannot be found in the cache or the
* source's validity has expired, the source is reread and the
* object is recreated using the registered
* [EMAIL PROTECTED] org.apache.cocoon.util.SourceReloader}.
*
* @since 2.1.4
* @author <a href="mailto:[EMAIL PROTECTED]">Christian Haul</a>
* @version CVS $Id: SoftSourceCache.java,v 1.1 2003/11/09 13:33:24 haul Exp $
*/
public class SoftSourceCache implements SourceCache {
/** Object cache. */
Map objectCache = null;
/** Callback for object reloading. */
SourceReloader reloader = null;
/**
* Initialize this instance. Create a new cache.
*/
private synchronized void init() {
if (this.objectCache == null)
this.objectCache =
Collections.synchronizedMap(
new ReferenceMap(ReferenceMap.SOFT,
ReferenceMap.SOFT));
}
/*
* (non-Javadoc)
* @see
org.apache.cocoon.util.SourceCache#register(org.apache.cocoon.util.SourceReloader)
*/
public void register(SourceReloader reloader) {
this.reloader = reloader;
}
/*
* (non-Javadoc)
* @see
org.apache.cocoon.util.SourceCache#getObject(org.apache.excalibur.source.SourceResolver,
java.lang.String, java.lang.Object)
*/
public Object getObject(SourceResolver resolver, Object key, String
uri, Object parameter)
throws MalformedURLException, IOException {
Object result = null;
if (this.objectCache == null)
init();
CacheEntry cacheEntry = (CacheEntry) this.objectCache.get(key);
if (cacheEntry != null) {
SourceValidity previous = cacheEntry.validity;
Source source = null;
switch (previous.isValid()) {
case SourceValidity.VALID:
result = cacheEntry.object;
break;
case SourceValidity.UNKNOWN:
source = resolver.resolveURI(uri);
SourceValidity fresh =
source.getValidity();
switch (previous.isValid(fresh)){
case SourceValidity.VALID:
result =
cacheEntry.object;
break;
case SourceValidity.UNKNOWN:
case SourceValidity.INVALID:
result =
this.reloader.reload(source, parameter);
this.objectCache.put(key, new CacheEntry(fresh, result));
break;
}
resolver.release(source);
break;
case SourceValidity.INVALID:
source = resolver.resolveURI(uri);
result = this.reloader.reload(source,
parameter);
this.objectCache.put(uri, new
CacheEntry(source.getValidity(), result));
resolver.release(source);
break;
}
}
return result;
}
/**
* Private helper to hold source validities and cached objects.
* @author <a href="mailto:[EMAIL PROTECTED]">Christian Haul</a>
*/
private class CacheEntry {
public SourceValidity validity = null;
public Object object = null;
public CacheEntry(SourceValidity val, Object obj) {
this.validity = val;
this.object = obj;
}
}
}
1.1
cocoon-2.1/src/blocks/scratchpad/java/org/apache/cocoon/util/SourceCache.java
Index: SourceCache.java
===================================================================
/*
============================================================================
The Apache Software License, Version 1.1
============================================================================
Copyright (C) 1999-2003 The Apache Software Foundation. All rights reserved.
Redistribution and use in source and binary forms, with or without modifica-
tion, 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
[EMAIL PROTECTED]
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 (INCLU-
DING, 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 and was originally created by
Stefano Mazzocchi <[EMAIL PROTECTED]>. For more information on the Apache
Software Foundation, please see <http://www.apache.org/>.
*/
package org.apache.cocoon.util;
import java.io.IOException;
import java.net.MalformedURLException;
import org.apache.excalibur.source.SourceResolver;
/**
* A source cache caches Objects that are created from a source. It handles
* transparently rereading sources and recreation of objects if the source
* validity has expired or the object has been cleaned from the cache. For
* this, a reloader callback needs to be registered that actually does the
* recreation of the cached object.
*
* <p>Example:</p>
* <pre>
*
* public void service(ServiceManager manager) {
* ...
* // obtain source cache on startup / service / initialize
* SourceCache cache = (SourceCache) manager.lookup(SourceCache.ROLE);
* // register reloader
* // with anonymous class handling the callback
* cache.register( new SourceReloader() {
* public Object reload(Source src, Object param) {
* return refresh(src, (String) param[0], (Integer)
param[1] );
* });
* }
*
* // have callback method. Private is OK because its used from a anonymous
* // nested class.
* private CreatedObject refresh(Source src, String param1, Integer param2)
{
* ...
* }
*
*
* public void foo() {
* ...
* // use cache
* CreatedObject foo = (CreatedObject) cache.getObject(resolver, key,
uri,
* ... Object[] {
param1, new Integer(param2) });
* }
*
* public void dispose() {
* // release source cache on dispose
* manager.release(cache);
* }
*
* </pre>
*
* @since 2.1.4
* @author <a href="mailto:[EMAIL PROTECTED]">Christian Haul</a>
* @version CVS $Id: SourceCache.java,v 1.1 2003/11/09 13:33:24 haul Exp $
*/
public interface SourceCache {
public static final String ROLE = SourceCache.class.getName();
/**
* Register a source reloader that will recreate cached objects.
* Often, this will be done using an anonymous nested class.
*
* @param reloader
*/
void register(SourceReloader reloader);
/**
* Retrieve an object from the cache. Transparently reloads and
* recreates objects using the registered source reloader if the
* objects identified by the key hasn't been cached or has been
* cleared from the cache, or source has changed.
*
* @param A source resolver to use.
* @param An object used as a key to the cached object.
* @param A string holding the URI.
* @param Parameters to pass to the source reloader.
* @return Cached object.
* @throws MalformedURLException
* @throws IOException
*/
Object getObject(SourceResolver resolver, Object key, String uri,
Object parameter)
throws MalformedURLException, IOException;
}
1.1
cocoon-2.1/src/blocks/scratchpad/java/org/apache/cocoon/util/SourceReloader.java
Index: SourceReloader.java
===================================================================
/*
============================================================================
The Apache Software License, Version 1.1
============================================================================
Copyright (C) 1999-2003 The Apache Software Foundation. All rights reserved.
Redistribution and use in source and binary forms, with or without modifica-
tion, 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
[EMAIL PROTECTED]
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 (INCLU-
DING, 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 and was originally created by
Stefano Mazzocchi <[EMAIL PROTECTED]>. For more information on the Apache
Software Foundation, please see <http://www.apache.org/>.
*/
package org.apache.cocoon.util;
import org.apache.excalibur.source.Source;
/**
* Load data from a source and return an object.
*
* @since 2.1.4
* @author <a href="mailto:[EMAIL PROTECTED]">Christian Haul</a>
* @version CVS $Id: SourceReloader.java,v 1.1 2003/11/09 13:33:24 haul Exp $
*/
public interface SourceReloader {
/**
* Load data from a source and return an object.
*
* @param A source.
* @param A parameter.
* @return An object.
*/
Object reload(Source src, Object parameter);
}
