/*

 * Copyright (c) 2007, 2016, Oracle and/or its affiliates. All rights reserved.

 */

/*

 * Licensed to the Apache Software Foundation (ASF) under one or more

 * contributor license agreements.  See the NOTICE file distributed with

 * this work for additional information regarding copyright ownership.

 * The ASF licenses this file to You 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 com.sun.org.apache.xalan.internal.XalanConstants;

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

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

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.Constants;

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

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

import java.io.IOException;

import java.io.NotSerializableException;

import java.io.ObjectInputStream;

import java.io.ObjectOutputStream;

import java.io.ObjectStreamField;

import java.io.Serializable;

import java.lang.module.Configuration;

import java.lang.module.ModuleDescriptor;

import java.lang.module.ModuleFinder;

import java.lang.module.ModuleReference;

import java.lang.reflect.Layer;

import java.lang.reflect.Module;

import java.security.AccessController;

import java.security.PrivilegedAction;

import java.util.Arrays;

import java.util.HashMap;

import java.util.Map;

import java.util.Optional;

import java.util.Properties;

import java.util.Set;

import javax.xml.XMLConstants;

import javax.xml.transform.Templates;

import javax.xml.transform.Transformer;

import javax.xml.transform.TransformerConfigurationException;

import javax.xml.transform.URIResolver;

/**

 * @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;

    public final static String DESERIALIZE_TRANSLET = "jdk.xml.enableTemplatesImplDeserialization";

    /**

     * 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 transient Map<String, Class<?>> _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;

    /**

     * A flag to determine whether the Service Mechanism is used

     */

    private transient boolean _useServicesMechanism;

    /**

     * protocols allowed for external references set by the stylesheet processing instruction, Import and Include element.

     */

    private transient String _accessExternalStylesheet = XalanConstants.EXTERNAL_ACCESS_DEFAULT;

    /**

     * @serialField _name String The Name of the main class

     * @serialField _bytecodes byte[][] Class definition

     * @serialField _class Class[] The translet class definition(s).

     * @serialField _transletIndex int The index of the main translet class

     * @serialField _outputProperties Properties Output properties of this translet.

     * @serialField _indentNumber int Number of spaces to add for output indentation.

     */

    private static final ObjectStreamField[] serialPersistentFields =

        new ObjectStreamField[] {

            new ObjectStreamField("_name", String.class),

            new ObjectStreamField("_bytecodes", byte[][].class),

            new ObjectStreamField("_class", Class[].class),

            new ObjectStreamField("_transletIndex", int.class),

            new ObjectStreamField("_outputProperties", Properties.class),

            new ObjectStreamField("_indentNumber", int.class),

        };

    static final class TransletClassLoader extends ClassLoader {

        private final Map<String, Class<?>> _loadedExternalExtensionFunctions;

         TransletClassLoader(ClassLoader parent) {

             super(parent);

            _loadedExternalExtensionFunctions = null;

        }

        TransletClassLoader(ClassLoader parent, Map<String, Class<?>> mapEF) {

            super(parent);

            _loadedExternalExtensionFunctions = mapEF;

        }

        public Class<?> loadClass(String name) throws ClassNotFoundException {

            Class<?> ret = null;

            // The _loadedExternalExtensionFunctions will be empty when the

            // SecurityManager is not set and the FSP is turned off

            if (_loadedExternalExtensionFunctions != null) {

                ret = _loadedExternalExtensionFunctions.get(name);

            }

            if (ret == null) {

                ret = super.loadClass(name);

            }

            return ret;

         }

        /**

         * 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();

        _accessExternalStylesheet = (String) tfactory.getAttribute(XMLConstants.ACCESS_EXTERNAL_STYLESHEET);

    }

    /**

     * 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

     */

    @SuppressWarnings("unchecked")

    private void  readObject(ObjectInputStream is)

      throws IOException, ClassNotFoundException

    {

        SecurityManager security = System.getSecurityManager();

        if (security != null){

            String temp = SecuritySupport.getSystemProperty(DESERIALIZE_TRANSLET);

            if (temp == null || !(temp.length()==0 || temp.equalsIgnoreCase("true"))) {

                ErrorMsg err = new ErrorMsg(ErrorMsg.DESERIALIZE_TRANSLET_ERR);

                throw new UnsupportedOperationException(err.toString());

            }

        }

        // We have to read serialized fields first.

        ObjectInputStream.GetField gf = is.readFields();

        _name = (String)gf.get("_name", null);

        _bytecodes = (byte[][])gf.get("_bytecodes", null);

        _class = (Class[])gf.get("_class", null);

        _transletIndex = gf.get("_transletIndex", -1);

        _outputProperties = (Properties)gf.get("_outputProperties", null);

        _indentNumber = gf.get("_indentNumber", 0);

        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 {

        if (_auxClasses != null) {

            //throw with the same message as when Hashtable was used for compatibility.

            throw new NotSerializableException(

                    "com.sun.org.apache.xalan.internal.xsltc.runtime.Hashtable");

        }

        // Write serialized fields

        ObjectOutputStream.PutField pf = os.putFields();

        pf.put("_name", _name);

        pf.put("_bytecodes", _bytecodes);

        pf.put("_class", _class);

        pf.put("_transletIndex", _transletIndex);

        pf.put("_outputProperties", _outputProperties);

        pf.put("_indentNumber", _indentNumber);

        os.writeFields();

        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;

    }

    /**

     * Creates a module layer with one module that is defined to the given class

     * loader.

     */

    private Module createModule(ModuleDescriptor descriptor, ClassLoader loader) {

        String mn = descriptor.name();

        ModuleFinder finder = new ModuleFinder() {

            @Override

            public Optional<ModuleReference> find(String name) {

                if (name.equals(mn)) {

                    return Optional.of(mref);

                } else {

                    return Optional.empty();

                }

            }

            @Override

            public Set<ModuleReference> findAll() {

                return Set.of(mref);

            }

        };

        Layer bootLayer = Layer.boot();

        Configuration cf = bootLayer.configuration()

                .resolveRequires(finder, ModuleFinder.of(), Set.of(mn));

        PrivilegedAction<Layer> pa = () -> bootLayer.defineModules(cf, name -> loader);

        Layer layer = AccessController.doPrivileged(pa);

        Module m = layer.findModule(mn).get();

        assert m.getLayer() == layer;

        return m;

    }

    /**

     * 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(),_tfactory.getExternalExtensionsMap());

                }

            });

        try {

            final int classCount = _bytecodes.length;

            _class = new Class[classCount];

            if (classCount > 1) {

                _auxClasses = new HashMap<>();

            }

            // create a module for the translet

            String mn = "jdk.translet";

            String pn = _tfactory.getPackageName();

            assert pn != null && pn.length() > 0;

            ModuleDescriptor descriptor = ModuleDescriptor.module(mn)

                    .requires("java.xml")

                    .exports(pn)

                    .build();

            Module m = createModule(descriptor, loader);

            // the module needs access to runtime classes

            Module thisModule = TemplatesImpl.class.getModule();

            Arrays.asList(Constants.PKGS_USED_BY_TRANSLET_CLASSES).forEach(p -> {

                thisModule.addExports(p, m);

            });

            // java.xml needs to instanitate the translet class

            thisModule.addReads(m);

            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());