/*
* Copyright 1999-2004 The Apache Software Foundation.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.cocoon.components.pipeline.impl;
import java.io.ByteArrayOutputStream;
import java.io.OutputStream;
import java.net.SocketException;
import java.util.Map;
import org.apache.avalon.framework.component.ComponentException;
import org.apache.avalon.framework.parameters.ParameterException;
import org.apache.avalon.framework.parameters.Parameters;
import org.apache.cocoon.ConnectionResetException;
import org.apache.cocoon.ProcessingException;
import org.apache.cocoon.caching.CachedResponse;
import org.apache.cocoon.caching.CachingOutputStream;
import org.apache.cocoon.caching.IdentifierCacheKey;
import org.apache.cocoon.components.sax.XMLDeserializer;
import org.apache.cocoon.components.sax.XMLSerializer;
import org.apache.cocoon.components.sax.XMLTeePipe;
import org.apache.cocoon.environment.Environment;
import org.apache.cocoon.environment.ObjectModelHelper;
import org.apache.cocoon.environment.Response;
import org.apache.cocoon.xml.XMLConsumer;
import org.apache.excalibur.source.SourceValidity;
import org.apache.excalibur.source.impl.validity.ExpiresValidity;
/**
* This pipeline implementation caches the complete content for a defined
* period of time (expires).
*
* <map:pipe name="expires" src="org.apache.cocoon.components.pipeline.impl.ExpiresCachingProcessingPipeline">
* <parameter name="cache-expires" value="180"/> <!-- Expires in secondes -->
* </map:pipe>
*
* @since 2.1
* @author <a href="mailto:cziegeler@apache.org">Carsten Ziegeler</a>
* @version CVS $Id: ExpiresCachingProcessingPipeline.java,v 1.5 2004/04/15 08:05:55 cziegeler Exp $
*/
public class ExpiresCachingProcessingPipeline
extends BaseCachingProcessingPipeline {
/** This key can be used to put a key in the object model */
public static final String CACHE_KEY_KEY = ExpiresCachingProcessingPipeline.class.getName() + "/CacheKey";
/** This key can be used to put an expires information in the object model */
public static final String CACHE_EXPIRES_KEY = ExpiresCachingProcessingPipeline.class.getName() + "/Expires";
/** The source validity */
protected SourceValidity cacheValidity;
/** The key used for caching */
protected IdentifierCacheKey cacheKey;
/** The expires information */
protected long cacheExpires;
/** Default value for expiration */
protected long defaultCacheExpires = 3600; // 1 hour
/** The cached response */
protected CachedResponse cachedResponse;
public void parameterize(Parameters params)
throws ParameterException {
super.parameterize(params);
this.defaultCacheExpires = params.getParameterAsLong("cache-expires", this.defaultCacheExpires);
}
/**
* Process the given <code>Environment</code>, producing the output.
*/
protected boolean processXMLPipeline(Environment environment)
throws ProcessingException {
try {
if ( this.cachedResponse != null ) {
byte[] content = cachedResponse.getResponse();
if ( this.serializer == this.lastConsumer ) {
final OutputStream outputStream = environment.getOutputStream(0);
if (content.length > 0) {
environment.setContentLength(content.length);
outputStream.write(content);
}
} else {
this.xmlDeserializer.setConsumer( this.lastConsumer );
this.xmlDeserializer.deserialize( content );
}
} else {
// generate new response
if ( this.cacheExpires == 0 ) {
return super.processXMLPipeline( environment );
}
byte[] cachedData;
if ( this.serializer == this.lastConsumer ) {
if (this.serializer.shouldSetContentLength()) {
OutputStream os = environment.getOutputStream(this.outputBufferSize);
// set the output stream
ByteArrayOutputStream baos = new ByteArrayOutputStream();
this.serializer.setOutputStream(baos);
this.generator.generate();
cachedData = baos.toByteArray();
environment.setContentLength(cachedData.length);
os.write(cachedData);
} else {
CachingOutputStream os = new CachingOutputStream( environment.getOutputStream(this.outputBufferSize) );
// set the output stream
this.serializer.setOutputStream( os );
this.generator.generate();
cachedData = os.getContent();
}
} else {
this.generator.generate();
cachedData = (byte[])this.xmlSerializer.getSAXFragment();
}
//
// Now that we have processed the pipeline,
// we do the actual caching
//
if ( this.cacheValidity != null ) {
cachedResponse = new CachedResponse(this.cacheValidity,
cachedData);
this.cache.store(this.cacheKey,
cachedResponse);
}
}
} catch ( SocketException se ) {
if (se.getMessage().indexOf("reset") > 0
|| se.getMessage().indexOf("aborted") > 0
|| se.getMessage().indexOf("connection abort") > 0) {
throw new ConnectionResetException("Connection reset by peer", se);
} else {
throw new ProcessingException("Failed to execute pipeline.", se);
}
} catch ( ProcessingException pe ) {
throw pe;
} catch ( Exception e ) {
throw new ProcessingException("Error executing pipeline.", e);
}
return true;
}
/**
* Connect the XML pipeline.
*/
protected void connectPipeline(Environment environment)
throws ProcessingException {
if ( this.lastConsumer != this.serializer ) {
// internal
if ( this.cachedResponse == null) {
// if we cache, we need an xml serializer
if ( this.cacheExpires > 0) {
try {
final XMLConsumer old = this.lastConsumer;
this.xmlSerializer = (XMLSerializer)this.manager.lookup( XMLSerializer.ROLE );
this.lastConsumer = new XMLTeePipe(this.lastConsumer, this.xmlSerializer);
super.connectPipeline( environment );
this.lastConsumer = old;
} catch ( ComponentException e ) {
throw new ProcessingException("Could not connect pipeline.", e);
}
} else {
super.connectPipeline( environment );
}
} else {
// we use the cache, so we need an xml deserializer
try {
this.xmlDeserializer = (XMLDeserializer)this.manager.lookup(XMLDeserializer.ROLE);
} catch ( ComponentException e ) {
throw new ProcessingException("Could not connect pipeline.", e);
}
}
} else {
// external: we only need to connect if we don't use a cached response
if ( this.cachedResponse == null) {
super.connectPipeline( environment );
}
}
}
/**
* Prepare the pipeline
*/
protected void preparePipeline(Environment environment)
throws ProcessingException {
// get the key and the expires info
// we must do this before we call super.preparePipeline,
// otherwise internal pipelines are instantiated and
// get a copy of the object model with our info!
final Map objectModel = environment.getObjectModel();
String key = (String)objectModel.get(CACHE_KEY_KEY);
if ( key == null ) {
key = this.parameters.getParameter("cache-key", null);
if ( key == null ) {
key = environment.getURIPrefix()+environment.getURI();
}
} else {
objectModel.remove(CACHE_KEY_KEY);
}
String expiresValue = (String)objectModel.get(CACHE_EXPIRES_KEY);
if ( expiresValue == null ) {
this.cacheExpires = this.parameters.getParameterAsLong("cache-expires", this.defaultCacheExpires);
} else {
this.cacheExpires = Long.valueOf(expiresValue).longValue();
objectModel.remove(CACHE_EXPIRES_KEY);
}
// prepare the pipeline
super.preparePipeline( environment );
// and now prepare the caching information
this.cacheKey = new IdentifierCacheKey(key,
this.serializer == this.lastConsumer);
if ( this.cacheExpires > 0) {
this.cacheValidity = new ExpiresValidity(this.cacheExpires*1000);
}
final boolean purge = this.parameters.getParameterAsBoolean("purge-cache", false);
this.cachedResponse = this.cache.get(this.cacheKey);
if ( this.cachedResponse != null ) {
final SourceValidity sv = cachedResponse.getValidityObjects()[0];
if ( purge
|| (this.cacheExpires != -1 && sv.isValid() != SourceValidity.VALID) ) {
this.cache.remove( this.cacheKey );
this.cachedResponse = null;
}
}
if ( this.cacheExpires > 0
&& (this.reader != null || this.lastConsumer == this.serializer )) {
Response res = ObjectModelHelper.getResponse(environment.getObjectModel());
res.setDateHeader("Expires", System.currentTimeMillis() + (this.cacheExpires*1000));
res.setHeader("Cache-Control", "max-age=" + this.cacheExpires + ", public");
}
}
/**
* Return valid validity objects for the event pipeline
* If the "event pipeline" (= the complete pipeline without the
* serializer) is cacheable and valid, return all validity objects.
* Otherwise return <code>null</code>
*/
public SourceValidity getValidityForEventPipeline() {
return this.cacheValidity;
}
/* (non-Javadoc)
* @see org.apache.cocoon.components.pipeline.ProcessingPipeline#getKeyForEventPipeline()
*/
public String getKeyForEventPipeline() {
if ( this.cacheKey != null && this.cacheValidity != null) {
return this.cacheKey.toString();
}
return null;
}
/**
* Recyclable Interface
*/
public void recycle() {
this.cacheKey = null;
this.cacheExpires = 0;
this.cachedResponse = null;
super.recycle();
}
/* (non-Javadoc)
* @see org.apache.cocoon.components.pipeline.AbstractProcessingPipeline#processReader(org.apache.cocoon.environment.Environment)
*/
protected boolean processReader(Environment environment)
throws ProcessingException {
try {
if ( this.cachedResponse != null ) {
final byte[] content = cachedResponse.getResponse();
environment.setContentLength(content.length);
final OutputStream os = environment.getOutputStream(0);
os.write(content);
} else {
// generate new response
if ( this.cacheExpires == 0 ) {
return super.processReader( environment );
}
byte[] cachedData;
if (this.reader.shouldSetContentLength()) {
final OutputStream os = environment.getOutputStream(this.outputBufferSize);
// set the output stream
final ByteArrayOutputStream baos = new ByteArrayOutputStream();
this.reader.setOutputStream(baos);
this.reader.generate();
cachedData = baos.toByteArray();
environment.setContentLength(cachedData.length);
os.write(cachedData);
} else {
final CachingOutputStream os = new CachingOutputStream( environment.getOutputStream(this.outputBufferSize) );
// set the output stream
this.reader.setOutputStream( os );
this.reader.generate();
cachedData = os.getContent();
}
//
// Now that we have processed the pipeline,
// we do the actual caching
//
if ( this.cacheValidity != null ) {
cachedResponse = new CachedResponse(this.cacheValidity,
cachedData);
this.cache.store(this.cacheKey,
cachedResponse);
}
}
} catch ( SocketException se ) {
if (se.getMessage().indexOf("reset") > 0
|| se.getMessage().indexOf("aborted") > 0
|| se.getMessage().indexOf("connection abort") > 0) {
throw new ConnectionResetException("Connection reset by peer", se);
} else {
throw new ProcessingException("Failed to execute pipeline.", se);
}
} catch ( ProcessingException pe ) {
throw pe;
} catch ( Exception e ) {
throw new ProcessingException("Error executing pipeline.", e);
}
return true;
}
}