/*
============================================================================
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
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 (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 <stefano@apache.org>. For more information on the Apache
Software Foundation, please see <http://www.apache.org/>.
*/
package org.apache.cocoon.components.pipeline;
import org.apache.avalon.excalibur.pool.Recyclable;
import org.apache.avalon.framework.component.Component;
import org.apache.avalon.framework.component.ComponentException;
import org.apache.avalon.framework.component.ComponentManager;
import org.apache.avalon.framework.component.ComponentSelector;
import org.apache.avalon.framework.logger.AbstractLogEnabled;
import org.apache.avalon.framework.parameters.ParameterException;
import org.apache.avalon.framework.parameters.Parameterizable;
import org.apache.avalon.framework.parameters.Parameters;
import org.apache.cocoon.ConnectionResetException;
import org.apache.cocoon.Constants;
import org.apache.cocoon.ProcessingException;
import org.apache.cocoon.components.CocoonComponentManager;
import org.apache.cocoon.environment.Environment;
import org.apache.cocoon.environment.ObjectModelHelper;
import org.apache.cocoon.environment.Response;
import org.apache.cocoon.generation.Generator;
import org.apache.cocoon.reading.Reader;
import org.apache.cocoon.serialization.Serializer;
import org.apache.cocoon.sitemap.SitemapModelComponent;
import org.apache.cocoon.transformation.Transformer;
import org.apache.cocoon.xml.XMLConsumer;
import org.apache.cocoon.xml.XMLProducer;
import org.apache.excalibur.source.SourceValidity;
import org.xml.sax.SAXException;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.net.SocketException;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.NoSuchElementException;
import java.util.StringTokenizer;
/**
* This is the base for all implementations of a <code>ProcessingPipeline</code>.
*
* @since 2.1
* @author <a href="mailto:cziegeler@apache.org">Carsten Ziegeler</a>
* @version CVS $Id: AbstractProcessingPipeline.java,v 1.18 2004/02/11 14:53:15 cziegeler Exp $
*/
public abstract class AbstractProcessingPipeline
extends AbstractLogEnabled
implements ProcessingPipeline, Parameterizable, Recyclable {
// Generator stuff
protected Generator generator;
protected Parameters generatorParam;
protected String generatorSource;
protected ComponentSelector generatorSelector;
// Transformer stuff
protected ArrayList transformers = new ArrayList();
protected ArrayList transformerParams = new ArrayList();
protected ArrayList transformerSources = new ArrayList();
protected ArrayList transformerSelectors = new ArrayList();
// Serializer stuff
protected Serializer serializer;
protected Parameters serializerParam;
protected String serializerSource;
protected String serializerMimeType;
protected String sitemapSerializerMimeType;
protected OutputComponentSelector serializerSelector;
// Reader stuff
protected Reader reader;
protected Parameters readerParam;
protected String readerSource;
protected String readerMimeType;
protected String sitemapReaderMimeType;
protected OutputComponentSelector readerSelector;
/** This is the last component in the pipeline, either the serializer
* or a custom xmlconsumer for the cocoon: protocol etc.
*/
protected XMLConsumer lastConsumer;
/** the component manager set with compose() */
protected ComponentManager manager;
/** the component manager set with compose() and recompose() */
protected ComponentManager newManager;
/** The configuration */
protected Parameters configuration;
/** The parameters */
protected Parameters parameters;
/** Expires value */
protected long expires;
/** Configured Expires value */
protected long configuredExpires;
/** Configured Output Buffer Size */
protected int configuredOutputBufferSize;
/** Output Buffer Size */
protected int outputBufferSize;
/**
* Composable Interface
*/
public void compose (ComponentManager manager)
throws ComponentException {
this.manager = manager;
this.newManager = manager;
}
/**
* Recomposable Interface
*/
public void recompose (ComponentManager manager)
throws ComponentException {
this.newManager = manager;
}
/**
* Parameterizable Interface - Configuration
*/
public void parameterize(Parameters params)
throws ParameterException {
this.configuration = params;
final String expiresValue = params.getParameter("expires", null);
if (expiresValue != null) {
this.configuredExpires = parseExpires(expiresValue);
}
this.configuredOutputBufferSize = params.getParameterAsInteger("outputBufferSize", -1);
}
/**
* Setup this component
*/
public void setup(Parameters params) {
this.parameters = params;
final String expiresValue = params.getParameter("expires", null);
if (expiresValue != null) {
this.expires = parseExpires(expiresValue);
} else {
this.expires = this.configuredExpires;
}
this.outputBufferSize = params.getParameterAsInteger("outputBufferSize",
this.configuredOutputBufferSize);
}
/**
* Release this component
* If you get an instance not by a component manager but for example
* by a processor, you have to release this component by calling
* this method and NOT by using a component manager!
*/
public void release() {
try {
CocoonComponentManager.removeFromAutomaticRelease(this);
} catch (ProcessingException pe) {
// ignore this
getLogger().error("Unabled to release processing component.", pe);
}
}
/**
* Get the generator - used for content aggregation
*/
public Generator getGenerator() {
return this.generator;
}
/**
* Informs pipeline we have come across a branch point
* Default Behaviour is do nothing
*/
public void informBranchPoint() {}
/**
* Set the generator that will be used as the initial step in the pipeline.
* The generator role is given : the actual <code>Generator</code> is fetched
* from the latest <code>ComponentManager</code> given by <code>compose()</code>
* or <code>recompose()</code>.
*
* @param role the generator role in the component manager.
* @param source the source where to produce XML from, or <code>null</code> if no
* source is given.
* @param param the parameters for the generator.
* @throws ProcessingException if the generator couldn't be obtained.
*/
public void setGenerator (String role, String source, Parameters param, Parameters hintParam)
throws ProcessingException {
if (this.generator != null) {
throw new ProcessingException ("Generator already set. Cannot set generator '" + role +
"' at " + getLocation(param));
}
if (this.reader != null) {
throw new ProcessingException ("Reader already set. Cannot set generator '" + role +
"' at " + getLocation(param));
}
try {
this.generatorSelector = (ComponentSelector) this.newManager.lookup(Generator.ROLE + "Selector");
} catch (ComponentException ce) {
throw new ProcessingException("Lookup of generator selector failed at " +getLocation(param), ce);
}
try {
this.generator = (Generator) this.generatorSelector.select(role);
} catch (ComponentException ce) {
throw new ProcessingException("Lookup of generator '" + role + "' failed at " + getLocation(param), ce);
}
this.generatorSource = source;
this.generatorParam = param;
}
/**
* Add a transformer at the end of the pipeline.
* The transformer role is given : the actual <code>Transformer</code> is fetched
* from the latest <code>ComponentManager</code> given by <code>compose()</code>
* or <code>recompose()</code>.
*
* @param role the transformer role in the component manager.
* @param source the source used to setup the transformer (e.g. XSL file), or
* <code>null</code> if no source is given.
* @param param the parameters for the transfomer.
* @throws ProcessingException if the generator couldn't be obtained.
*/
public void addTransformer (String role, String source, Parameters param, Parameters hintParam)
throws ProcessingException {
if (this.reader != null) {
// Should normally never happen as setting a reader starts pipeline processing
throw new ProcessingException ("Reader already set. Cannot add transformer '" + role +
"' at " + getLocation(param));
}
if (this.generator == null) {
throw new ProcessingException ("Must set a generator before adding transformer '" + role +
"' at " + getLocation(param));
}
ComponentSelector selector = null;
try {
selector = (ComponentSelector) this.newManager.lookup(Transformer.ROLE + "Selector");
} catch (ComponentException ce) {
throw new ProcessingException("Lookup of transformer selector failed at " + getLocation(param), ce);
}
try {
this.transformers.add(selector.select(role));
this.transformerSelectors.add(selector);
} catch (ComponentException ce) {
throw new ProcessingException("Lookup of transformer '"+role+"' failed at " + getLocation(param), ce);
}
this.transformerSources.add(source);
this.transformerParams.add(param);
}
/**
* Set the serializer for this pipeline
* @param mimeType Can be null
*/
public void setSerializer (String role, String source, Parameters param, Parameters hintParam, String mimeType)
throws ProcessingException {
if (this.serializer != null) {
// Should normally not happen as adding a serializer starts pipeline processing
throw new ProcessingException ("Serializer already set. Cannot set serializer '" + role +
"' at " + getLocation(param));
}
if (this.reader != null) {
// Should normally never happen as setting a reader starts pipeline processing
throw new ProcessingException ("Reader already set. Cannot set serializer '" + role +
"' at " + getLocation(param));
}
if (this.generator == null) {
throw new ProcessingException ("Must set a generator before setting serializer '" + role +
"' at " + getLocation(param));
}
try {
this.serializerSelector = (OutputComponentSelector) this.newManager.lookup(Serializer.ROLE + "Selector");
} catch (ComponentException ce) {
throw new ProcessingException("Lookup of serializer selector failed at " + getLocation(param), ce);
}
try {
this.serializer = (Serializer)serializerSelector.select(role);
} catch (ComponentException ce) {
throw new ProcessingException("Lookup of serializer '" + role + "' failed at " + getLocation(param), ce);
}
this.serializerSource = source;
this.serializerParam = param;
this.serializerMimeType = mimeType;
this.sitemapSerializerMimeType = serializerSelector.getMimeTypeForHint(role);
this.lastConsumer = this.serializer;
}
/**
* Set the reader for this pipeline
* @param mimeType Can be null
*/
public void setReader (String role, String source, Parameters param, String mimeType)
throws ProcessingException {
if (this.reader != null) {
// Should normally never happen as setting a reader starts pipeline processing
throw new ProcessingException ("Reader already set. Cannot set reader '" + role +
"' at " + getLocation(param));
}
if (this.generator != null) {
// Should normally never happen as setting a reader starts pipeline processing
throw new ProcessingException ("Generator already set. Cannot use reader '" + role +
"' at " + getLocation(param));
}
try {
this.readerSelector = (OutputComponentSelector) this.newManager.lookup(Reader.ROLE + "Selector");
} catch (ComponentException ce) {
throw new ProcessingException("Lookup of reader selector failed at " + getLocation(param), ce);
}
try {
this.reader = (Reader)readerSelector.select(role);
} catch (ComponentException ce) {
throw new ProcessingException("Lookup of reader '"+role+"' failed at " + getLocation(param), ce);
}
this.readerSource = source;
this.readerParam = param;
this.readerMimeType = mimeType;
this.sitemapReaderMimeType = readerSelector.getMimeTypeForHint(role);
}
/**
* Sanity check
* @return true if the pipeline is 'sane', false otherwise.
*/
protected boolean checkPipeline() {
if ( this.generator == null && this.reader == null) {
return false;
}
if ( this.generator != null && this.serializer == null ) {
return false;
}
return true;
}
/**
* Setup pipeline components.
*/
protected void setupPipeline(Environment environment)
throws ProcessingException {
try {
// setup the generator
this.generator.setup(
environment,
environment.getObjectModel(),
generatorSource,
generatorParam
);
Iterator transformerItt = this.transformers.iterator();
Iterator transformerSourceItt = this.transformerSources.iterator();
Iterator transformerParamItt = this.transformerParams.iterator();
while (transformerItt.hasNext()) {
Transformer trans = (Transformer)transformerItt.next();
trans.setup(environment,
environment.getObjectModel(),
(String)transformerSourceItt.next(),
(Parameters)transformerParamItt.next()
);
}
if (this.serializer instanceof SitemapModelComponent) {
((SitemapModelComponent)this.serializer).setup(
environment,
environment.getObjectModel(),
this.serializerSource,
this.serializerParam
);
}
if (this.lastConsumer == null) {
// internal processing: text/xml
environment.setContentType("text/xml");
} else {
String mimeType = this.serializer.getMimeType();
if (mimeType != null) {
// we have a mimeType from the component itself
environment.setContentType (mimeType);
} else if (serializerMimeType != null) {
// there was a mimeType specified in the sitemap pipeline
environment.setContentType (serializerMimeType);
} else if (this.sitemapSerializerMimeType != null) {
// use the mimeType specified in the sitemap component declaration
environment.setContentType (this.sitemapSerializerMimeType);
} else {
// No mimeType available
String message = "Unable to determine MIME type for " +
environment.getURIPrefix() + "/" + environment.getURI();
throw new ProcessingException(message);
}
}
} catch (SAXException e) {
throw new ProcessingException(
"Could not setup pipeline.",
e
);
} catch (IOException e) {
throw new ProcessingException(
"Could not setup pipeline.",
e
);
}
}
/**
* Connect the next component
*/
protected void connect(Environment environment,
XMLProducer producer,
XMLConsumer consumer)
throws ProcessingException {
XMLProducer next = producer;
// Connect next component.
next.setConsumer(consumer);
}
/**
* Connect the XML pipeline.
*/
protected void connectPipeline(Environment environment)
throws ProcessingException {
XMLProducer prev = this.generator;
Iterator itt = this.transformers.iterator();
while (itt.hasNext()) {
Transformer next = (Transformer) itt.next();
connect(environment, prev, next);
prev = next;
}
// insert the serializer
connect(environment, prev, this.lastConsumer);
}
/**
* Process the given <code>Environment</code>, producing the output.
*/
public boolean process(Environment environment)
throws ProcessingException {
// If this is an internal request, lastConsumer was reset!
if (null == this.lastConsumer) {
this.lastConsumer = this.serializer;
} else {
this.preparePipeline(environment);
}
if ( this.reader != null ) {
this.preparePipeline(environment);
}
// See if we need to set an "Expires:" header
if (this.expires != 0) {
Response res = ObjectModelHelper.getResponse(environment.getObjectModel());
res.setDateHeader("Expires", System.currentTimeMillis() + expires);
res.setHeader("Cache-Control", "max-age=" + expires/1000 + ", public");
if (getLogger().isDebugEnabled()) {
getLogger().debug("Setting a new Expires object for this resource");
}
environment.getObjectModel().put(ObjectModelHelper.EXPIRES_OBJECT,
new Long(expires + System.currentTimeMillis()));
}
if (this.reader != null) {
if (checkIfModified(environment, this.reader.getLastModified())) {
return true;
}
return this.processReader(environment);
} else {
this.connectPipeline(environment);
return this.processXMLPipeline(environment);
}
}
/**
* Prepare the pipeline
*/
protected void preparePipeline(Environment environment)
throws ProcessingException {
if ( !checkPipeline() ) {
throw new ProcessingException("Attempted to process incomplete pipeline.");
}
if ( this.reader != null ) {
this.setupReader( environment );
} else {
this.setupPipeline(environment);
}
}
/**
* Prepare an internal processing
* @param environment The current environment.
* @throws ProcessingException
*/
public void prepareInternal(Environment environment)
throws ProcessingException {
this.lastConsumer = null;
this.preparePipeline(environment);
}
/**
* Process the SAX event pipeline
*/
protected boolean processXMLPipeline(Environment environment)
throws ProcessingException {
try {
if (this.serializer != this.lastConsumer) {
// internal processing
this.generator.generate();
} else {
if (this.serializer.shouldSetContentLength()) {
// set the output stream
ByteArrayOutputStream os = new ByteArrayOutputStream();
this.serializer.setOutputStream(os);
// execute the pipeline:
this.generator.generate();
byte[] data = os.toByteArray();
environment.setContentLength(data.length);
environment.getOutputStream(0).write(data);
} else {
// set the output stream
this.serializer.setOutputStream(environment.getOutputStream(this.outputBufferSize));
// execute the pipeline:
this.generator.generate();
}
}
} catch ( ProcessingException e ) {
throw e;
} catch ( Exception e ) {
// TODO: Unwrap SAXException ?
throw new ProcessingException("Failed to execute pipeline.", e);
}
return true;
}
/**
* Setup the reader
*/
protected void setupReader(Environment environment)
throws ProcessingException {
try {
String mimeType;
this.reader.setup(environment,environment.getObjectModel(),readerSource,readerParam);
mimeType = this.reader.getMimeType();
if ( mimeType != null ) {
environment.setContentType(mimeType);
} else if ( readerMimeType != null ) {
environment.setContentType(this.readerMimeType);
} else {
environment.setContentType(this.sitemapReaderMimeType);
}
} catch (SAXException e){
throw new ProcessingException("Failed to execute reader pipeline.", e);
} catch (IOException e){
throw new ProcessingException("Failed to execute reader pipeline.", e);
}
}
protected boolean checkIfModified(Environment environment,
long lastModified)
throws ProcessingException {
// has the read resource been modified?
if(!environment.isResponseModified(lastModified)) {
// environment supports this, so we are finished
environment.setResponseIsNotModified();
return true;
}
return false;
}
/**
* Process the pipeline using a reader.
* @throws ProcessingException if
*/
protected boolean processReader(Environment environment)
throws ProcessingException {
try {
if (this.reader.shouldSetContentLength()) {
ByteArrayOutputStream os = new ByteArrayOutputStream();
this.reader.setOutputStream(os);
this.reader.generate();
byte[] data = os.toByteArray();
environment.setContentLength(data.length);
environment.getOutputStream(0).write(data);
} else {
this.reader.setOutputStream(environment.getOutputStream(this.outputBufferSize));
this.reader.generate();
}
} 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 reader pipeline.", se);
}
} catch ( ProcessingException e ) {
throw e;
} catch ( Exception e ) {
throw new ProcessingException("Error executing reader pipeline.",e);
}
return true;
}
public void recycle() {
// release reader.
if ( this.readerSelector != null) {
this.readerSelector.release(this.reader);
this.newManager.release( this.readerSelector );
this.readerSelector = null;
this.reader = null;
this.readerParam = null;
}
// Release generator.
if ( this.generatorSelector != null) {
this.generatorSelector.release( this.generator );
this.newManager.release( this.generatorSelector );
this.generatorSelector = null;
this.generator = null;
this.generatorParam = null;
}
// Release transformers
int size = this.transformerSelectors.size();
for (int i = 0; i < size; i++) {
final ComponentSelector selector =
(ComponentSelector)this.transformerSelectors.get(i);
selector.release( (Component)this.transformers.get(i) );
this.newManager.release( selector );
}
this.transformerSelectors.clear();
this.transformers.clear();
this.transformerParams.clear();
this.transformerSources.clear();
// release serializer
if ( this.serializerSelector != null ) {
this.serializerSelector.release(this.serializer);
this.newManager.release( this.serializerSelector );
this.serializerSelector = null;
this.serializerParam = null;
}
this.serializer = null;
this.parameters = null;
this.lastConsumer = null;
}
/**
* Process the given <code>Environment</code>, but do not use the
* serializer. Instead the sax events are streamed to the XMLConsumer.
*/
public boolean process(Environment environment, XMLConsumer consumer)
throws ProcessingException {
this.lastConsumer = consumer;
if ( this.reader != null ) {
throw new ProcessingException("Streaming of an internal pipeline is not possible with a reader.");
} else {
this.connectPipeline(environment);
return this.processXMLPipeline(environment);
}
}
/**
* 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 null;
}
/**
* Parse the expires parameter
*/
private long parseExpires(String expire) {
StringTokenizer tokens = new StringTokenizer(expire);
// get <base>
String current = tokens.nextToken();
if (current.equals("modification")) {
getLogger().warn("the \"modification\" keyword is not yet" +
" implemented. Assuming \"now\" as the base attribute");
current = "now";
}
if (!current.equals("now") && !current.equals("access")) {
getLogger().error("bad <base> attribute, Expires header will not be set");
return -1;
}
long number = 0;
long modifier = 0;
long expires = 0;
while (tokens.hasMoreTokens()) {
current = tokens.nextToken();
// get rid of the optional <plus> keyword
if (current.equals("plus")) {
current = tokens.nextToken();
}
// We're expecting a sequence of <number> and <modification> here
// get <number> first
try {
number = Long.parseLong(current);
} catch (NumberFormatException nfe) {
getLogger().error("state violation: a number was expected here");
return -1;
}
// now get <modifier>
try {
current = tokens.nextToken();
} catch (NoSuchElementException nsee) {
getLogger().error("State violation: expecting a modifier" +
" but no one found: Expires header will not be set");
}
if (current.equals("years")) {
modifier = 365L * 24L * 60L * 60L * 1000L;
} else if (current.equals("months")) {
modifier = 30L * 24L * 60L * 60L * 1000L;
} else if (current.equals("weeks")) {
modifier = 7L * 24L * 60L * 60L * 1000L;
} else if (current.equals("days")) {
modifier = 24L * 60L * 60L * 1000L;
} else if (current.equals("hours")) {
modifier = 60L * 60L * 1000L;
} else if (current.equals("minutes")) {
modifier = 60L * 1000L;
} else if (current.equals("seconds")) {
modifier = 1000L;
} else {
getLogger().error("Bad modifier (" + current +
"): ignoring expires configuration");
return -1;
}
expires += number * modifier;
}
return expires;
}
/* (non-Javadoc)
* @see org.apache.cocoon.components.pipeline.ProcessingPipeline#getKeyForEventPipeline()
*/
public String getKeyForEventPipeline() {
return null;
}
protected String getLocation(Parameters param) {
return param.getParameter(Constants.SITEMAP_PARAMETERS_LOCATION, "[unknown location]");
}
}