/**
 * (The MIT License)
 *
 * Copyright (c) 2008 - 2011:
 *
 * * {Aaron Patterson}[http://tenderlovemaking.com]
 * * {Mike Dalessio}[http://mike.daless.io]
 * * {Charles Nutter}[http://blog.headius.com]
 * * {Sergio Arbeo}[http://www.serabe.com]
 * * {Patrick Mahoney}[http://polycrystal.org]
 * * {Yoko Harada}[http://yokolet.blogspot.com]
 *
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files (the
 * 'Software'), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sublicense, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 * 
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 * 
 * THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
 * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
 * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */

package nokogiri;

import java.util.Collections;
import java.util.HashMap;
import java.util.Map;

import org.jruby.Ruby;
import org.jruby.RubyArray;
import org.jruby.RubyClass;
import org.jruby.RubyFixnum;
import org.jruby.RubyModule;
import org.jruby.runtime.ObjectAllocator;
import org.jruby.runtime.builtin.IRubyObject;
import org.jruby.runtime.load.BasicLibraryService;

/**
 * Class to provide Nokogiri. This class is used to make "require 'nokogiri'" work
 * in JRuby. Also, this class holds a Ruby type cache and allocators of Ruby types.
 * 
 * @author headius
 * @author Yoko Harada <yokolet@gmail.com>
 */
public class NokogiriService implements BasicLibraryService {
    public static final String nokogiriClassCacheGvarName = "$NOKOGIRI_CLASS_CACHE";
    public static Map<String, RubyClass> nokogiriClassCache;

    public boolean basicLoad(Ruby ruby) {
        init(ruby);
        createNokogiriClassCahce(ruby);
        return true;
    }
    
    private static void createNokogiriClassCahce(Ruby ruby) {
        nokogiriClassCache = Collections.synchronizedMap(new HashMap<String, RubyClass>());
        nokogiriClassCache.put("Nokogiri::EncodingHandler", (RubyClass)ruby.getClassFromPath("Nokogiri::EncodingHandler"));
        nokogiriClassCache.put("Nokogiri::HTML::Document", (RubyClass)ruby.getClassFromPath("Nokogiri::HTML::Document"));
        nokogiriClassCache.put("Nokogiri::HTML::ElementDescription", (RubyClass)ruby.getClassFromPath("Nokogiri::HTML::ElementDescription"));
        nokogiriClassCache.put("Nokogiri::XML::Attr", (RubyClass)ruby.getClassFromPath("Nokogiri::XML::Attr"));
        nokogiriClassCache.put("Nokogiri::XML::Document", (RubyClass)ruby.getClassFromPath("Nokogiri::XML::Document"));
        nokogiriClassCache.put("Nokogiri::XML::DocumentFragment", (RubyClass)ruby.getClassFromPath("Nokogiri::XML::DocumentFragment"));
        nokogiriClassCache.put("Nokogiri::XML::DTD", (RubyClass)ruby.getClassFromPath("Nokogiri::XML::DTD"));
        nokogiriClassCache.put("Nokogiri::XML::Text", (RubyClass)ruby.getClassFromPath("Nokogiri::XML::Text"));
        nokogiriClassCache.put("Nokogiri::XML::Comment", (RubyClass)ruby.getClassFromPath("Nokogiri::XML::Comment"));
        nokogiriClassCache.put("Nokogiri::XML::Element", (RubyClass)ruby.getClassFromPath("Nokogiri::XML::Element"));
        nokogiriClassCache.put("Nokogiri::XML::ElementContent", (RubyClass)ruby.getClassFromPath("Nokogiri::XML::ElementContent"));
        nokogiriClassCache.put("Nokogiri::XML::ElementDecl", (RubyClass)ruby.getClassFromPath("Nokogiri::XML::ElementDecl"));
        nokogiriClassCache.put("Nokogiri::XML::EntityDecl", (RubyClass)ruby.getClassFromPath("Nokogiri::XML::EntityDecl"));
        nokogiriClassCache.put("Nokogiri::XML::EntityReference", (RubyClass)ruby.getClassFromPath("Nokogiri::XML::EntityReference"));
        nokogiriClassCache.put("Nokogiri::XML::ProcessingInstruction", (RubyClass)ruby.getClassFromPath("Nokogiri::XML::ProcessingInstruction"));
        nokogiriClassCache.put("Nokogiri::XML::CDATA", (RubyClass)ruby.getClassFromPath("Nokogiri::XML::CDATA"));
        nokogiriClassCache.put("Nokogiri::XML::Node", (RubyClass)ruby.getClassFromPath("Nokogiri::XML::Node"));
        nokogiriClassCache.put("Nokogiri::XML::NodeSet", (RubyClass)ruby.getClassFromPath("Nokogiri::XML::NodeSet"));
        nokogiriClassCache.put("Nokogiri::XML::Namespace", (RubyClass)ruby.getClassFromPath("Nokogiri::XML::Namespace"));
        nokogiriClassCache.put("Nokogiri::XML::SyntaxError", (RubyClass)ruby.getClassFromPath("Nokogiri::XML::SyntaxError"));
        nokogiriClassCache.put("Nokogiri::XML::Reader", (RubyClass)ruby.getClassFromPath("Nokogiri::XML::Reader"));
        nokogiriClassCache.put("Nokogiri::XML::RelaxNG", (RubyClass)ruby.getClassFromPath("Nokogiri::XML::RelaxNG"));
        nokogiriClassCache.put("Nokogiri::XML::Schema", (RubyClass)ruby.getClassFromPath("Nokogiri::XML::Schema"));
        nokogiriClassCache.put("Nokogiri::XML::XPathContext", (RubyClass)ruby.getClassFromPath("Nokogiri::XML::XPathContext"));
        nokogiriClassCache.put("Nokogiri::XML::AttributeDecl", (RubyClass)ruby.getClassFromPath("Nokogiri::XML::AttributeDecl"));
        nokogiriClassCache.put("Nokogiri::XML::SAX::ParserContext", (RubyClass)ruby.getClassFromPath("Nokogiri::XML::SAX::ParserContext"));
    }

    private void init(Ruby ruby) {
        RubyModule nokogiri = ruby.defineModule("Nokogiri");
        RubyModule xmlModule = nokogiri.defineModuleUnder("XML");
        RubyModule xmlSaxModule = xmlModule.defineModuleUnder("SAX");
        RubyModule htmlModule = nokogiri.defineModuleUnder("HTML");
        RubyModule htmlSaxModule = htmlModule.defineModuleUnder("SAX");
        RubyModule xsltModule = nokogiri.defineModuleUnder("XSLT");

        createNokogiriModule(ruby, nokogiri);
        createSyntaxErrors(ruby, nokogiri, xmlModule);
        RubyClass xmlNode = createXmlModule(ruby, xmlModule);
        createHtmlModule(ruby, htmlModule);
        createDocuments(ruby, xmlModule, htmlModule, xmlNode);
        createSaxModule(ruby, xmlSaxModule, htmlSaxModule);
        createXsltModule(ruby, xsltModule);
    }
    
    private void createNokogiriModule(Ruby ruby, RubyModule nokogiri) {;
        RubyClass encHandler = nokogiri.defineClassUnder("EncodingHandler", ruby.getObject(), ENCODING_HANDLER_ALLOCATOR);
        encHandler.defineAnnotatedMethods(EncodingHandler.class);
    }
    
    private void createSyntaxErrors(Ruby ruby, RubyModule nokogiri, RubyModule xmlModule) {
        RubyClass syntaxError = nokogiri.defineClassUnder("SyntaxError", ruby.getStandardError(), ruby.getStandardError().getAllocator());
        RubyClass xmlSyntaxError = xmlModule.defineClassUnder("SyntaxError", syntaxError, XML_SYNTAXERROR_ALLOCATOR);
        xmlSyntaxError.defineAnnotatedMethods(XmlSyntaxError.class);
    }
    
    private RubyClass createXmlModule(Ruby ruby, RubyModule xmlModule) {
        RubyClass node = xmlModule.defineClassUnder("Node", ruby.getObject(), XML_NODE_ALLOCATOR);
        node.defineAnnotatedMethods(XmlNode.class);
        
        RubyClass attr = xmlModule.defineClassUnder("Attr", node, XML_ATTR_ALLOCATOR);
        attr.defineAnnotatedMethods(XmlAttr.class);
        
        RubyClass attrDecl = xmlModule.defineClassUnder("AttributeDecl", node, XML_ATTRIBUTE_DECL_ALLOCATOR);
        attrDecl.defineAnnotatedMethods(XmlAttributeDecl.class);
        
        RubyClass characterData = xmlModule.defineClassUnder("CharacterData", node, null);
        
        RubyClass comment = xmlModule.defineClassUnder("Comment", characterData, XML_COMMENT_ALLOCATOR);
        comment.defineAnnotatedMethods(XmlComment.class);
        
        RubyClass text = xmlModule.defineClassUnder("Text", characterData, XML_TEXT_ALLOCATOR);
        text.defineAnnotatedMethods(XmlText.class);
        
        RubyModule cdata = xmlModule.defineClassUnder("CDATA", text, XML_CDATA_ALLOCATOR);
        cdata.defineAnnotatedMethods(XmlCdata.class);
        
        RubyClass dtd = xmlModule.defineClassUnder("DTD", node, XML_DTD_ALLOCATOR);
        dtd.defineAnnotatedMethods(XmlDtd.class);

        RubyClass documentFragment = xmlModule.defineClassUnder("DocumentFragment", node, XML_DOCUMENT_FRAGMENT_ALLOCATOR);
        documentFragment.defineAnnotatedMethods(XmlDocumentFragment.class);
        
        RubyClass element = xmlModule.defineClassUnder("Element", node, XML_ELEMENT_ALLOCATOR);
        element.defineAnnotatedMethods(XmlElement.class);
        
        RubyClass elementContent = xmlModule.defineClassUnder("ElementContent", ruby.getObject(), XML_ELEMENT_CONTENT_ALLOCATOR);
        elementContent.defineAnnotatedMethods(XmlElementContent.class);
        
        RubyClass elementDecl = xmlModule.defineClassUnder("ElementDecl", node, XML_ELEMENT_DECL_ALLOCATOR);
        elementDecl.defineAnnotatedMethods(XmlElementDecl.class);
        
        RubyClass entityDecl = xmlModule.defineClassUnder("EntityDecl", node, XML_ENTITY_DECL_ALLOCATOR);
        entityDecl.defineAnnotatedMethods(XmlEntityDecl.class);
        
        entityDecl.defineConstant("INTERNAL_GENERAL", RubyFixnum.newFixnum(ruby, XmlEntityDecl.INTERNAL_GENERAL));
        entityDecl.defineConstant("EXTERNAL_GENERAL_PARSED", RubyFixnum.newFixnum(ruby, XmlEntityDecl.EXTERNAL_GENERAL_PARSED));
        entityDecl.defineConstant("EXTERNAL_GENERAL_UNPARSED", RubyFixnum.newFixnum(ruby, XmlEntityDecl.EXTERNAL_GENERAL_UNPARSED));
        entityDecl.defineConstant("INTERNAL_PARAMETER", RubyFixnum.newFixnum(ruby, XmlEntityDecl.INTERNAL_PARAMETER));
        entityDecl.defineConstant("EXTERNAL_PARAMETER", RubyFixnum.newFixnum(ruby, XmlEntityDecl.EXTERNAL_PARAMETER));
        entityDecl.defineConstant("INTERNAL_PREDEFINED", RubyFixnum.newFixnum(ruby, XmlEntityDecl.INTERNAL_PREDEFINED));
        
        RubyClass entref = xmlModule.defineClassUnder("EntityReference", node, XML_ENTITY_REFERENCE_ALLOCATOR);
        entref.defineAnnotatedMethods(XmlEntityReference.class);
        
        RubyClass namespace = xmlModule.defineClassUnder("Namespace", ruby.getObject(), XML_NAMESPACE_ALLOCATOR);
        namespace.defineAnnotatedMethods(XmlNamespace.class);
        
        RubyClass nodeSet = xmlModule.defineClassUnder("NodeSet", ruby.getObject(), XML_NODESET_ALLOCATOR);
        nodeSet.defineAnnotatedMethods(XmlNodeSet.class);
        
        RubyClass pi = xmlModule.defineClassUnder("ProcessingInstruction", node, XML_PROCESSING_INSTRUCTION_ALLOCATOR);
        pi.defineAnnotatedMethods(XmlProcessingInstruction.class);
        
        RubyClass reader = xmlModule.defineClassUnder("Reader", ruby.getObject(), XML_READER_ALLOCATOR);
        reader.defineAnnotatedMethods(XmlReader.class);
        
        RubyClass schema = xmlModule.defineClassUnder("Schema", ruby.getObject(), XML_SCHEMA_ALLOCATOR);
        schema.defineAnnotatedMethods(XmlSchema.class);

        RubyClass relaxng = xmlModule.defineClassUnder("RelaxNG", schema, XML_RELAXNG_ALLOCATOR);
        relaxng.defineAnnotatedMethods(XmlRelaxng.class);
        
        RubyClass xpathContext = xmlModule.defineClassUnder("XPathContext", ruby.getObject(), XML_XPATHCONTEXT_ALLOCATOR);
        xpathContext.defineAnnotatedMethods(XmlXpathContext.class);
        
        return node;
    }

    private void createHtmlModule(Ruby ruby, RubyModule htmlModule) {
        RubyClass htmlElemDesc = htmlModule.defineClassUnder("ElementDescription", ruby.getObject(), HTML_ELEMENT_DESCRIPTION_ALLOCATOR);
        htmlElemDesc.defineAnnotatedMethods(HtmlElementDescription.class);
        
        RubyClass htmlEntityLookup = htmlModule.defineClassUnder("EntityLookup", ruby.getObject(), HTML_ENTITY_LOOKUP_ALLOCATOR);
        htmlEntityLookup.defineAnnotatedMethods(HtmlEntityLookup.class);
    }
    
    private void createDocuments(Ruby ruby, RubyModule xmlModule, RubyModule htmlModule, RubyClass node) {
        RubyClass xmlDocument = xmlModule.defineClassUnder("Document", node, XML_DOCUMENT_ALLOCATOR);
        xmlDocument.defineAnnotatedMethods(XmlDocument.class);
        
        //RubyModule htmlDoc = html.defineOrGetClassUnder("Document", document);
        RubyModule htmlDocument = htmlModule.defineClassUnder("Document", xmlDocument, HTML_DOCUMENT_ALLOCATOR);
        htmlDocument.defineAnnotatedMethods(HtmlDocument.class);
    }
    
    private void createSaxModule(Ruby ruby, RubyModule xmlSaxModule, RubyModule htmlSaxModule) {
        RubyClass xmlSaxParserContext = xmlSaxModule.defineClassUnder("ParserContext", ruby.getObject(), XML_SAXPARSER_CONTEXT_ALLOCATOR);
        xmlSaxParserContext.defineAnnotatedMethods(XmlSaxParserContext.class);
        
        RubyClass xmlSaxPushParser = xmlSaxModule.defineClassUnder("PushParser", ruby.getObject(), XML_SAXPUSHPARSER_ALLOCATOR);
        xmlSaxPushParser.defineAnnotatedMethods(XmlSaxPushParser.class);
        
        RubyClass htmlSaxParserContext = htmlSaxModule.defineClassUnder("ParserContext", xmlSaxParserContext, HTML_SAXPARSER_CONTEXT_ALLOCATOR);
        htmlSaxParserContext.defineAnnotatedMethods(HtmlSaxParserContext.class);
    }
    
    private void createXsltModule(Ruby ruby, RubyModule xsltModule) {
        RubyClass stylesheet = xsltModule.defineClassUnder("Stylesheet", ruby.getObject(), XSLT_STYLESHEET_ALLOCATOR);
        stylesheet.defineAnnotatedMethods(XsltStylesheet.class);
        xsltModule.defineAnnotatedMethod(XsltStylesheet.class, "register");
    }

    private static ObjectAllocator ENCODING_HANDLER_ALLOCATOR = new ObjectAllocator() {
        public IRubyObject allocate(Ruby runtime, RubyClass klazz) {
            return new EncodingHandler(runtime, klazz, "");
        }
    };

    public static final ObjectAllocator HTML_DOCUMENT_ALLOCATOR = new ObjectAllocator() {
        private HtmlDocument htmlDocument = null;
        public IRubyObject allocate(Ruby runtime, RubyClass klazz) {
            if (htmlDocument == null) htmlDocument = new HtmlDocument(runtime, klazz);
            try {
                HtmlDocument clone = (HtmlDocument) htmlDocument.clone();
                clone.setMetaClass(klazz);
                return clone;
            } catch (CloneNotSupportedException e) {
                return new HtmlDocument(runtime, klazz);
            }
        }
    };

    public static final ObjectAllocator HTML_SAXPARSER_CONTEXT_ALLOCATOR = new ObjectAllocator() {
        private HtmlSaxParserContext htmlSaxParserContext = null;
        public IRubyObject allocate(Ruby runtime, RubyClass klazz) {
            if (htmlSaxParserContext == null) htmlSaxParserContext = new HtmlSaxParserContext(runtime, klazz);
            try {
                HtmlSaxParserContext clone = (HtmlSaxParserContext) htmlSaxParserContext.clone();
                clone.setMetaClass(klazz);
                return clone;
            } catch (CloneNotSupportedException e) {
                return new HtmlSaxParserContext(runtime, klazz);
            }
        }
    };

    private static ObjectAllocator HTML_ELEMENT_DESCRIPTION_ALLOCATOR =
        new ObjectAllocator() {
            public IRubyObject allocate(Ruby runtime, RubyClass klazz) {
                return new HtmlElementDescription(runtime, klazz);
            }
        };

    private static ObjectAllocator HTML_ENTITY_LOOKUP_ALLOCATOR =
        new ObjectAllocator() {
            public IRubyObject allocate(Ruby runtime, RubyClass klazz) {
                return new HtmlEntityLookup(runtime, klazz);
            }
        };

    public static final ObjectAllocator XML_ATTR_ALLOCATOR = new ObjectAllocator() {
        private XmlAttr xmlAttr = null;
        public IRubyObject allocate(Ruby runtime, RubyClass klazz) {
            if (xmlAttr == null) xmlAttr = new XmlAttr(runtime, klazz);
            try {
                XmlAttr clone = (XmlAttr) xmlAttr.clone();
                clone.setMetaClass(klazz);
                return clone;
            } catch (CloneNotSupportedException e) {
                return new XmlAttr(runtime, klazz);
            }
        }
    };

    public static final ObjectAllocator XML_CDATA_ALLOCATOR = new ObjectAllocator() {
        private XmlCdata xmlCdata = null;
        public IRubyObject allocate(Ruby runtime, RubyClass klazz) {
            if (xmlCdata == null) xmlCdata = new XmlCdata(runtime, klazz);
            try {
                XmlCdata clone = (XmlCdata) xmlCdata.clone();
                clone.setMetaClass(klazz);
                return clone;
            } catch (CloneNotSupportedException e) {
                return new XmlCdata(runtime, klazz);
            }
        }
    };

    public static final ObjectAllocator XML_COMMENT_ALLOCATOR = new ObjectAllocator() {
        private XmlComment xmlComment = null;
        public IRubyObject allocate(Ruby runtime, RubyClass klazz) {
            if (xmlComment == null) xmlComment = new XmlComment(runtime, klazz);
            try {
                XmlComment clone = (XmlComment) xmlComment.clone();
                clone.setMetaClass(klazz);
                return clone;
            } catch (CloneNotSupportedException e) {
                return new XmlComment(runtime, klazz);
            }
        }
    };

    public static final ObjectAllocator XML_DOCUMENT_ALLOCATOR = new ObjectAllocator() {
        private XmlDocument xmlDocument = null;
        public IRubyObject allocate(Ruby runtime, RubyClass klazz) {
            if (xmlDocument == null) xmlDocument = new XmlDocument(runtime, klazz);
            try {
                XmlDocument clone = (XmlDocument) xmlDocument.clone();
                clone.setMetaClass(klazz);
                return clone;
            } catch (CloneNotSupportedException e) {
                return new XmlDocument(runtime, klazz);
            }
        }
    };

    public static final ObjectAllocator XML_DOCUMENT_FRAGMENT_ALLOCATOR = new ObjectAllocator() {
        private XmlDocumentFragment xmlDocumentFragment = null;
        public IRubyObject allocate(Ruby runtime, RubyClass klazz) {
            if (xmlDocumentFragment == null) xmlDocumentFragment = new XmlDocumentFragment(runtime, klazz);
            try {
                XmlDocumentFragment clone = (XmlDocumentFragment)xmlDocumentFragment.clone();
                clone.setMetaClass(klazz);
                return clone;
            } catch (CloneNotSupportedException e) {
                return new XmlDocumentFragment(runtime, klazz);
            }
        }
    };

    public static final ObjectAllocator XML_DTD_ALLOCATOR = new ObjectAllocator() {
        private XmlDtd xmlDtd = null;
        public IRubyObject allocate(Ruby runtime, RubyClass klazz) {
            if (xmlDtd == null) xmlDtd = new XmlDtd(runtime, klazz);
            try {
                XmlDtd clone = (XmlDtd)xmlDtd.clone();
                clone.setMetaClass(klazz);
                return clone;
            } catch (CloneNotSupportedException e) {
                return new XmlDtd(runtime, klazz);
            }
        }
    };

    public static final ObjectAllocator XML_ELEMENT_ALLOCATOR = new ObjectAllocator() {
        private XmlElement xmlElement = null;
        public IRubyObject allocate(Ruby runtime, RubyClass klazz) {
            if (xmlElement == null) xmlElement = new XmlElement(runtime, klazz);
            try {
                XmlElement clone = (XmlElement)xmlElement.clone();
                clone.setMetaClass(klazz);
                return clone;
            } catch (CloneNotSupportedException e) {
                return new XmlElement(runtime, klazz);
            }
        }
    };
    
    public static ObjectAllocator XML_ELEMENT_DECL_ALLOCATOR = new ObjectAllocator() {
        private XmlElementDecl xmlElementDecl = null;
        public IRubyObject allocate(Ruby runtime, RubyClass klazz) {
            if (xmlElementDecl == null) xmlElementDecl = new XmlElementDecl(runtime, klazz);
            try {
                XmlElementDecl clone = (XmlElementDecl)xmlElementDecl.clone();
                clone.setMetaClass(klazz);
                return clone;
            } catch (CloneNotSupportedException e) {
                return new XmlElementDecl(runtime, klazz);
            }
        }
    };

    public static ObjectAllocator XML_ENTITY_REFERENCE_ALLOCATOR = new ObjectAllocator() {
        private XmlEntityReference xmlEntityRef = null;
        public IRubyObject allocate(Ruby runtime, RubyClass klazz) {
            if (xmlEntityRef == null) xmlEntityRef = new XmlEntityReference(runtime, klazz);
            try {
                XmlEntityReference clone = (XmlEntityReference)xmlEntityRef.clone();
                clone.setMetaClass(klazz);
                return clone;
            } catch (CloneNotSupportedException e) {
                return new XmlEntityReference(runtime, klazz);
            }
        }
    };
    
    public static final ObjectAllocator XML_NAMESPACE_ALLOCATOR = new ObjectAllocator() {
        private XmlNamespace xmlNamespace = null;
        public IRubyObject allocate(Ruby runtime, RubyClass klazz) {
            if (xmlNamespace == null) xmlNamespace = new XmlNamespace(runtime, klazz);
            try {
                XmlNamespace clone = (XmlNamespace) xmlNamespace.clone();
                clone.setMetaClass(klazz);
                return clone;
            } catch (CloneNotSupportedException e) {
                return new XmlNamespace(runtime, klazz);
            }
        }
    };

    public static final ObjectAllocator XML_NODE_ALLOCATOR = new ObjectAllocator() {
        private XmlNode xmlNode = null;
        public IRubyObject allocate(Ruby runtime, RubyClass klazz) {
            if (xmlNode == null) xmlNode = new XmlNode(runtime, klazz);
            try {
                XmlNode clone  = (XmlNode) xmlNode.clone();
                clone.setMetaClass(klazz);
                return clone;
            } catch (CloneNotSupportedException e) {
                return new XmlNode(runtime, klazz);
            }
        }
    };

    public static final ObjectAllocator XML_NODESET_ALLOCATOR = new ObjectAllocator() {
        private XmlNodeSet xmlNodeSet = null;
        public IRubyObject allocate(Ruby runtime, RubyClass klazz) {
            if (xmlNodeSet == null) xmlNodeSet = new XmlNodeSet(runtime, klazz);
            try {
                XmlNodeSet clone  = (XmlNodeSet) xmlNodeSet.clone();
                clone.setMetaClass(klazz);
                return clone;
            } catch (CloneNotSupportedException e) {
                xmlNodeSet = new XmlNodeSet(runtime, klazz);
                xmlNodeSet.setNodes(RubyArray.newEmptyArray(runtime));
                return xmlNodeSet;
            }
        }
    };
    
    public static ObjectAllocator XML_PROCESSING_INSTRUCTION_ALLOCATOR = new ObjectAllocator() {
        private XmlProcessingInstruction xmlProcessingInstruction = null;
        public IRubyObject allocate(Ruby runtime, RubyClass klazz) {
            if (xmlProcessingInstruction == null) xmlProcessingInstruction = new XmlProcessingInstruction(runtime, klazz);
            try {
                XmlProcessingInstruction clone = (XmlProcessingInstruction)xmlProcessingInstruction.clone();
                clone.setMetaClass(klazz);
                return clone;
            } catch (CloneNotSupportedException e) {
                return new XmlProcessingInstruction(runtime, klazz);
            }
        }
    };

    public static ObjectAllocator XML_READER_ALLOCATOR = new ObjectAllocator() {
        private XmlReader xmlReader = null;
        public IRubyObject allocate(Ruby runtime, RubyClass klazz) {
            if (xmlReader == null) xmlReader = new XmlReader(runtime, klazz);
            try {
                XmlReader clone  = (XmlReader) xmlReader.clone();
                clone.setMetaClass(klazz);
                return clone;
            } catch (CloneNotSupportedException e) {
                xmlReader = new XmlReader(runtime, klazz);
                return xmlReader;
            }
        }
    };

    private static ObjectAllocator XML_ATTRIBUTE_DECL_ALLOCATOR = new ObjectAllocator() {
        public IRubyObject allocate(Ruby runtime, RubyClass klazz) {
            return new XmlAttributeDecl(runtime, klazz);
        }
    };

    private static ObjectAllocator XML_ENTITY_DECL_ALLOCATOR = new ObjectAllocator() {
        public IRubyObject allocate(Ruby runtime, RubyClass klazz) {
            return new XmlEntityDecl(runtime, klazz);
        }
    };

    private static ObjectAllocator XML_ELEMENT_CONTENT_ALLOCATOR = new ObjectAllocator() {
        public IRubyObject allocate(Ruby runtime, RubyClass klazz) {
            throw runtime.newNotImplementedError("not implemented");
        }
    };

    public static final ObjectAllocator XML_RELAXNG_ALLOCATOR = new ObjectAllocator() {
        private XmlRelaxng xmlRelaxng = null;
        public IRubyObject allocate(Ruby runtime, RubyClass klazz) {
            if (xmlRelaxng == null) xmlRelaxng = new XmlRelaxng(runtime, klazz);
            try {
                XmlRelaxng clone  = (XmlRelaxng) xmlRelaxng.clone();
                clone.setMetaClass(klazz);
                return clone;
            } catch (CloneNotSupportedException e) {
                return new XmlRelaxng(runtime, klazz);
            }
        }
    };

    public static final ObjectAllocator XML_SAXPARSER_CONTEXT_ALLOCATOR = new ObjectAllocator() {
        private XmlSaxParserContext xmlSaxParserContext = null;
        public IRubyObject allocate(Ruby runtime, RubyClass klazz) {
            if (xmlSaxParserContext == null) xmlSaxParserContext = new XmlSaxParserContext(runtime, klazz);
            try {
                XmlSaxParserContext clone = (XmlSaxParserContext) xmlSaxParserContext.clone();
                clone.setMetaClass(klazz);
                return clone;
            } catch (CloneNotSupportedException e) {
                return new XmlSaxParserContext(runtime, klazz);
            }
        }
    };

    private static ObjectAllocator XML_SAXPUSHPARSER_ALLOCATOR = new ObjectAllocator() {
        public IRubyObject allocate(Ruby runtime, RubyClass klazz) {
            return new XmlSaxPushParser(runtime, klazz);
        }
    };

    public static final ObjectAllocator XML_SCHEMA_ALLOCATOR = new ObjectAllocator() {
        private XmlSchema xmlSchema = null;
        public IRubyObject allocate(Ruby runtime, RubyClass klazz) {
            if (xmlSchema == null) xmlSchema = new XmlSchema(runtime, klazz);
            try {
                XmlSchema clone  = (XmlSchema) xmlSchema.clone();
                clone.setMetaClass(klazz);
                return clone;
            } catch (CloneNotSupportedException e) {
                return new XmlSchema(runtime, klazz);
            }
        }
    };

    public static final ObjectAllocator XML_SYNTAXERROR_ALLOCATOR = new ObjectAllocator() {
        private XmlSyntaxError xmlSyntaxError = null;
        public IRubyObject allocate(Ruby runtime, RubyClass klazz) {
            if (xmlSyntaxError == null) xmlSyntaxError = new XmlSyntaxError(runtime, klazz);
            try {
                XmlSyntaxError clone  = (XmlSyntaxError) xmlSyntaxError.clone();
                clone.setMetaClass(klazz);
                return clone;
            } catch (CloneNotSupportedException e) {
                return new XmlSyntaxError(runtime, klazz);
            }
        }
    };

    public static final ObjectAllocator XML_TEXT_ALLOCATOR = new ObjectAllocator() {
        private XmlText xmlText = null;
        public IRubyObject allocate(Ruby runtime, RubyClass klazz) {
            if (xmlText == null) xmlText = new XmlText(runtime, klazz);
            try {
                XmlText clone  = (XmlText) xmlText.clone();
                clone.setMetaClass(klazz);
                return clone;
            } catch (CloneNotSupportedException e) {
                return new XmlText(runtime, klazz);
            }
        }
    };

    public static ObjectAllocator XML_XPATHCONTEXT_ALLOCATOR = new ObjectAllocator() {
        private XmlXpathContext xmlXpathContext = null;
        public IRubyObject allocate(Ruby runtime, RubyClass klazz) {
            if (xmlXpathContext == null) xmlXpathContext = new XmlXpathContext(runtime, klazz);
            try {
                XmlXpathContext clone  = (XmlXpathContext) xmlXpathContext.clone();
                clone.setMetaClass(klazz);
                return clone;
            } catch (CloneNotSupportedException e) {
                return new XmlXpathContext(runtime, klazz);
            }
        }
    };

    public static ObjectAllocator XSLT_STYLESHEET_ALLOCATOR = new ObjectAllocator() {
        private XsltStylesheet xsltStylesheet = null;
        public IRubyObject allocate(Ruby runtime, RubyClass klazz) {
            if (xsltStylesheet == null) xsltStylesheet = new XsltStylesheet(runtime, klazz);
            try {
                XsltStylesheet clone  = (XsltStylesheet) xsltStylesheet.clone();
                clone.setMetaClass(klazz);
                return clone;
            } catch (CloneNotSupportedException e) {
                return new XmlText(runtime, klazz);
            }
        }
    };
}
