/*

 * reserved comment block

 * DO NOT REMOVE OR ALTER!

 */

/*

 * Copyright 2001-2004 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.

 */

/*

 * $Id: TemplatesImpl.java,v 1.8 2007/03/26 20:12:27 spericas Exp $

 */

package com.sun.org.apache.xalan.internal.xsltc.trax;

import java.io.IOException;

import java.io.ObjectInputStream;

import java.io.ObjectOutputStream;

import java.io.Serializable;

import java.util.Properties;

import java.security.AccessController;

import java.security.PrivilegedAction;

import javax.xml.XMLConstants;

import javax.xml.transform.Templates;

import javax.xml.transform.Transformer;

import javax.xml.transform.TransformerConfigurationException;

import javax.xml.transform.URIResolver;

import com.sun.org.apache.xalan.internal.xsltc.DOM;

import com.sun.org.apache.xalan.internal.xsltc.Translet;

import com.sun.org.apache.xalan.internal.xsltc.compiler.util.ErrorMsg;

import com.sun.org.apache.xalan.internal.xsltc.runtime.AbstractTranslet;

import com.sun.org.apache.xalan.internal.xsltc.runtime.Hashtable;

import com.sun.org.apache.xalan.internal.utils.ObjectFactory;

/**

 * @author Morten Jorgensen

 * @author G. Todd Millerj

 * @author Jochen Cordes <Jochen.Cordes@t-online.de>

 * @author Santiago Pericas-Geertsen

 */

public final class TemplatesImpl implements Templates, Serializable {

    static final long serialVersionUID = 673094361519270707L;

    /**

     * Name of the superclass of all translets. This is needed to

     * determine which, among all classes comprising a translet,

     * is the main one.

     */

    private static String ABSTRACT_TRANSLET

        = "com.sun.org.apache.xalan.internal.xsltc.runtime.AbstractTranslet";

    /**

     * Name of the main class or default name if unknown.

     */

    private String _name = null;

    /**

     * Contains the actual class definition for the translet class and

     * any auxiliary classes.

     */

    private byte[][] _bytecodes = null;

    /**

     * Contains the translet class definition(s). These are created when

     * this Templates is created or when it is read back from disk.

     */

    private Class[] _class = null;

    /**

     * The index of the main translet class in the arrays _class[] and

     * _bytecodes.

     */

    private int _transletIndex = -1;

    /**

     * Contains the list of auxiliary class definitions.

     */

    private Hashtable _auxClasses = null;

    /**

     * Output properties of this translet.

     */

    private Properties _outputProperties;

    /**

     * Number of spaces to add for output indentation.

     */

    private int _indentNumber;

    /**

     * This URIResolver is passed to all Transformers.

     * Declaring it transient to fix bug 22438

     */

    private transient URIResolver _uriResolver = null;

    /**

     * Cache the DTM for the stylesheet in a thread local variable,

     * which is used by the document('') function.

     * Use ThreadLocal because a DTM cannot be shared between

     * multiple threads.

     * Declaring it transient to fix bug 22438

     */

    private transient ThreadLocal _sdom = new ThreadLocal();

    /**

     * A reference to the transformer factory that this templates

     * object belongs to.

     */

    private transient TransformerFactoryImpl _tfactory = null;

    private boolean _useServicesMechanism;

    static final class TransletClassLoader extends ClassLoader {

        TransletClassLoader(ClassLoader parent) {

            super(parent);

        }

        /**

         * Access to final protected superclass member from outer class.

         */

        Class defineClass(final byte[] b) {

            return defineClass(null, b, 0, b.length);

        }

    }

    /**

     * Create an XSLTC template object from the bytecodes.

     * The bytecodes for the translet and auxiliary classes, plus the name of

     * the main translet class, must be supplied.

     */

    protected TemplatesImpl(byte[][] bytecodes, String transletName,

        Properties outputProperties, int indentNumber,

        TransformerFactoryImpl tfactory)

    {

        _bytecodes = bytecodes;

        init(transletName, outputProperties, indentNumber, tfactory);

    }

    /**

     * Create an XSLTC template object from the translet class definition(s).

     */

    protected TemplatesImpl(Class[] transletClasses, String transletName,

        Properties outputProperties, int indentNumber,

        TransformerFactoryImpl tfactory)

    {

        _class     = transletClasses;

        _transletIndex = 0;

        init(transletName, outputProperties, indentNumber, tfactory);

    }

    private void init(String transletName,

        Properties outputProperties, int indentNumber,

        TransformerFactoryImpl tfactory) {

        _name      = transletName;

        _outputProperties = outputProperties;

        _indentNumber = indentNumber;

        _tfactory = tfactory;

        _useServicesMechanism = tfactory.useServicesMechnism();

    }

    /**

     * Need for de-serialization, see readObject().

     */

    public TemplatesImpl() { }

    /**

     *  Overrides the default readObject implementation since we decided

     *  it would be cleaner not to serialize the entire tranformer

     *  factory.  [ ref bugzilla 12317 ]

     *  We need to check if the user defined class for URIResolver also

     *  implemented Serializable

     *  if yes then we need to deserialize the URIResolver

     *  Fix for bugzilla bug 22438

     */

    private void  readObject(ObjectInputStream is)

      throws IOException, ClassNotFoundException

    {

        is.defaultReadObject();

        if (is.readBoolean()) {

            _uriResolver = (URIResolver) is.readObject();

        }

        _tfactory = new TransformerFactoryImpl();

    }

    /**

     *  This is to fix bugzilla bug 22438

     *  If the user defined class implements URIResolver and Serializable

     *  then we want it to get serialized

     */

    private void writeObject(ObjectOutputStream os)

        throws IOException, ClassNotFoundException {

        os.defaultWriteObject();

        if (_uriResolver instanceof Serializable) {

            os.writeBoolean(true);

            os.writeObject((Serializable) _uriResolver);

        }

        else {

            os.writeBoolean(false);

        }

    }

    /**

     * Return the state of the services mechanism feature.

     */

    public boolean useServicesMechnism() {

        return _useServicesMechanism;

    }

     /**

     * Store URIResolver needed for Transformers.

     */

    public synchronized void setURIResolver(URIResolver resolver) {

        _uriResolver = resolver;

    }

    /**

     * The TransformerFactory must pass us the translet bytecodes using this

     * method before we can create any translet instances

     *

     * Note: This method is private for security reasons. See

     * CR 6537898. When merging with Apache, we must ensure

     * that the privateness of this method is maintained (that

     * is why it wasn't removed).

     */

    private synchronized void setTransletBytecodes(byte[][] bytecodes) {

        _bytecodes = bytecodes;

    }

    /**

     * Returns the translet bytecodes stored in this template

     *

     * Note: This method is private for security reasons. See

     * CR 6537898. When merging with Apache, we must ensure

     * that the privateness of this method is maintained (that

     * is why it wasn't removed).

     */

    private synchronized byte[][] getTransletBytecodes() {

        return _bytecodes;

    }

    /**

     * Returns the translet bytecodes stored in this template

     *

     * Note: This method is private for security reasons. See

     * CR 6537898. When merging with Apache, we must ensure

     * that the privateness of this method is maintained (that

     * is why it wasn't removed).

     */

    private synchronized Class[] getTransletClasses() {

        try {

            if (_class == null) defineTransletClasses();

        }

        catch (TransformerConfigurationException e) {

            // Falls through

        }

        return _class;

    }

    /**

     * Returns the index of the main class in array of bytecodes

     */

    public synchronized int getTransletIndex() {

        try {

            if (_class == null) defineTransletClasses();

        }

        catch (TransformerConfigurationException e) {

            // Falls through

        }

        return _transletIndex;

    }

    /**

     * The TransformerFactory should call this method to set the translet name

     */

    protected synchronized void setTransletName(String name) {

        _name = name;

    }

    /**

     * Returns the name of the main translet class stored in this template

     */

    protected synchronized String getTransletName() {

        return _name;

    }

    /**

     * Defines the translet class and auxiliary classes.

     * Returns a reference to the Class object that defines the main class

     */

    private void defineTransletClasses()

        throws TransformerConfigurationException {

        if (_bytecodes == null) {

            ErrorMsg err = new ErrorMsg(ErrorMsg.NO_TRANSLET_CLASS_ERR);

            throw new TransformerConfigurationException(err.toString());

        }

        TransletClassLoader loader = (TransletClassLoader)

            AccessController.doPrivileged(new PrivilegedAction() {

                public Object run() {

                    return new TransletClassLoader(ObjectFactory.findClassLoader());

                }

            });

        try {

            final int classCount = _bytecodes.length;

            _class = new Class[classCount];

            if (classCount > 1) {

                _auxClasses = new Hashtable();

            }

            for (int i = 0; i < classCount; i++) {

                _class[i] = loader.defineClass(_bytecodes[i]);

                final Class superClass = _class[i].getSuperclass();

                // Check if this is the main class

                if (superClass.getName().equals(ABSTRACT_TRANSLET)) {

                    _transletIndex = i;

                }

                else {

                    _auxClasses.put(_class[i].getName(), _class[i]);

                }

            }

            if (_transletIndex < 0) {

                ErrorMsg err= new ErrorMsg(ErrorMsg.NO_MAIN_TRANSLET_ERR, _name);

                throw new TransformerConfigurationException(err.toString());

            }

        }

        catch (ClassFormatError e) {

            ErrorMsg err = new ErrorMsg(ErrorMsg.TRANSLET_CLASS_ERR, _name);

            throw new TransformerConfigurationException(err.toString());

        }

        catch (LinkageError e) {

            ErrorMsg err = new ErrorMsg(ErrorMsg.TRANSLET_OBJECT_ERR, _name);

            throw new TransformerConfigurationException(err.toString());

        }

    }

    /**

     * This method generates an instance of the translet class that is

     * wrapped inside this Template. The translet instance will later

     * be wrapped inside a Transformer object.

     */

    private Translet getTransletInstance()

        throws TransformerConfigurationException {

        try {

            if (_name == null) return null;

            if (_class == null) defineTransletClasses();

            // The translet needs to keep a reference to all its auxiliary

            // class to prevent the GC from collecting them

            AbstractTranslet translet = (AbstractTranslet) _class[_transletIndex].newInstance();

            translet.postInitialization();

            translet.setTemplates(this);

            translet.setServicesMechnism(_useServicesMechanism);

            if (_auxClasses != null) {

                translet.setAuxiliaryClasses(_auxClasses);

            }

            return translet;

        }

        catch (InstantiationException e) {

            ErrorMsg err = new ErrorMsg(ErrorMsg.TRANSLET_OBJECT_ERR, _name);

            throw new TransformerConfigurationException(err.toString());

        }

        catch (IllegalAccessException e) {

            ErrorMsg err = new ErrorMsg(ErrorMsg.TRANSLET_OBJECT_ERR, _name);

            throw new TransformerConfigurationException(err.toString());

        }

    }

    /**

     * Implements JAXP's Templates.newTransformer()

     *

     * @throws TransformerConfigurationException

     */

    public synchronized Transformer newTransformer()

        throws TransformerConfigurationException

    {

        TransformerImpl transformer;

        transformer = new TransformerImpl(getTransletInstance(), _outputProperties,

            _indentNumber, _tfactory);

        if (_uriResolver != null) {

            transformer.setURIResolver(_uriResolver);

        }

        if (_tfactory.getFeature(XMLConstants.FEATURE_SECURE_PROCESSING)) {

            transformer.setSecureProcessing(true);

        }

        return transformer;

    }

    /**

     * Implements JAXP's Templates.getOutputProperties(). We need to

     * instanciate a translet to get the output settings, so

     * we might as well just instanciate a Transformer and use its

     * implementation of this method.

     */

    public synchronized Properties getOutputProperties() {

        try {

            return newTransformer().getOutputProperties();

        }

        catch (TransformerConfigurationException e) {

            return null;

        }

    }

    /**

     * Return the thread local copy of the stylesheet DOM.

     */

    public DOM getStylesheetDOM() {

        return (DOM)_sdom.get();

    }

    /**

     * Set the thread local copy of the stylesheet DOM.

     */

    public void setStylesheetDOM(DOM sdom) {

        _sdom.set(sdom);

    }

}