Adding upstream version 4:7.4.7.upstream/4%7.4.7upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

2 files changed, 2068 insertions, 0 deletions

diff --git a/sax/source/fastparser/fastparser.cxx b/sax/source/fastparser/fastparser.cxx
new file mode 100644
index 000000000..250078bc5
--- /dev/null
+++ b/sax/source/fastparser/fastparser.cxx
@@ -0,0 +1,1693 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ *
+ * This file incorporates work covered by the following license notice:
+ *
+ *   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 .
+ */
+
+#include <sax/fastparser.hxx>
+#include <sax/fastattribs.hxx>
+#include <utility>
+#include <xml2utf.hxx>
+
+#include <com/sun/star/io/XSeekable.hpp>
+#include <com/sun/star/lang/DisposedException.hpp>
+#include <com/sun/star/lang/IllegalArgumentException.hpp>
+#include <com/sun/star/uno/XComponentContext.hpp>
+#include <com/sun/star/xml/sax/FastToken.hpp>
+#include <com/sun/star/xml/sax/SAXParseException.hpp>
+#include <com/sun/star/xml/sax/XFastContextHandler.hpp>
+#include <cppuhelper/implbase.hxx>
+#include <cppuhelper/supportsservice.hxx>
+#include <cppuhelper/exc_hlp.hxx>
+#include <osl/conditn.hxx>
+#include <rtl/ref.hxx>
+#include <rtl/ustrbuf.hxx>
+#include <sal/log.hxx>
+#include <salhelper/thread.hxx>
+#include <tools/diagnose_ex.h>
+#include <o3tl/string_view.hxx>
+
+#include <queue>
+#include <memory>
+#include <mutex>
+#include <optional>
+#include <stack>
+#include <string_view>
+#include <unordered_map>
+#include <vector>
+#include <cassert>
+#include <cstring>
+#include <libxml/parser.h>
+
+// Inverse of libxml's BAD_CAST.
+#define XML_CAST( str ) reinterpret_cast< const char* >( str )
+
+using namespace ::osl;
+using namespace ::cppu;
+using namespace ::com::sun::star::uno;
+using namespace ::com::sun::star::lang;
+using namespace ::com::sun::star::xml::sax;
+using namespace ::com::sun::star::io;
+using namespace com::sun::star;
+using namespace sax_fastparser;
+
+static void NormalizeURI( OUString& rName );
+
+namespace {
+
+struct Event;
+class FastLocatorImpl;
+struct NamespaceDefine;
+struct Entity;
+
+typedef std::unordered_map< OUString, sal_Int32 > NamespaceMap;
+
+struct EventList
+{
+    std::vector<Event> maEvents;
+    bool mbIsAttributesEmpty;
+};
+
+enum class CallbackType { START_ELEMENT, END_ELEMENT, CHARACTERS, PROCESSING_INSTRUCTION, DONE, EXCEPTION };
+
+struct Event
+{
+    CallbackType maType;
+    sal_Int32 mnElementToken;
+    OUString msNamespace;
+    OUString msElementName;
+    rtl::Reference< FastAttributeList > mxAttributes;
+    rtl::Reference< FastAttributeList > mxDeclAttributes;
+    OUString msChars;
+};
+
+struct NameWithToken
+{
+    OUString msName;
+    sal_Int32 mnToken;
+
+    NameWithToken(OUString sName, sal_Int32 nToken) :
+        msName(std::move(sName)), mnToken(nToken) {}
+};
+
+struct SaxContext
+{
+    Reference< XFastContextHandler > mxContext;
+    sal_Int32 mnElementToken;
+    OUString  maNamespace;
+    OUString  maElementName;
+
+    SaxContext( sal_Int32 nElementToken, const OUString& aNamespace, const OUString& aElementName ):
+            mnElementToken(nElementToken)
+    {
+        if (nElementToken == FastToken::DONTKNOW)
+        {
+            maNamespace = aNamespace;
+            maElementName = aElementName;
+        }
+    }
+};
+
+struct ParserData
+{
+    css::uno::Reference< css::xml::sax::XFastDocumentHandler > mxDocumentHandler;
+    rtl::Reference<FastTokenHandlerBase>                       mxTokenHandler;
+    css::uno::Reference< css::xml::sax::XErrorHandler >        mxErrorHandler;
+    css::uno::Reference< css::xml::sax::XFastNamespaceHandler >mxNamespaceHandler;
+
+    ParserData();
+};
+
+struct NamespaceDefine
+{
+    OString     maPrefix;
+    sal_Int32   mnToken;
+    OUString    maNamespaceURL;
+
+    NamespaceDefine( OString aPrefix, sal_Int32 nToken, OUString aNamespaceURL )
+        : maPrefix(std::move( aPrefix )), mnToken( nToken ), maNamespaceURL(std::move( aNamespaceURL )) {}
+    NamespaceDefine() : mnToken(-1) {}
+};
+
+// Entity binds all information needed for a single file | single call of parseStream
+struct Entity : public ParserData
+{
+    // Amount of work producer sends to consumer in one iteration:
+    static const size_t mnEventListSize = 1000;
+
+    // unique for each Entity instance:
+
+    // Number of valid events in mxProducedEvents:
+    size_t mnProducedEventsSize;
+    std::optional<EventList> mxProducedEvents;
+    std::queue<EventList> maPendingEvents;
+    std::queue<EventList> maUsedEvents;
+    std::mutex maEventProtector;
+
+    static const size_t mnEventLowWater = 4;
+    static const size_t mnEventHighWater = 8;
+    osl::Condition maConsumeResume;
+    osl::Condition maProduceResume;
+    // Event we use to store data if threading is disabled:
+    Event maSharedEvent;
+
+    // copied in copy constructor:
+
+    // Allow to disable threading for small documents:
+    bool                                    mbEnableThreads;
+    css::xml::sax::InputSource              maStructSource;
+    xmlParserCtxtPtr                        mpParser;
+    ::sax_expatwrap::XMLFile2UTFConverter   maConverter;
+
+    // Exceptions cannot be thrown through the C-XmlParser (possible
+    // resource leaks), therefore any exception thrown by a UNO callback
+    // must be saved somewhere until the C-XmlParser is stopped.
+    css::uno::Any                           maSavedException;
+    std::mutex                              maSavedExceptionMutex;
+    void saveException( const Any & e );
+    // Thread-safe check if maSavedException has value
+    bool hasException();
+    void throwException( const ::rtl::Reference< FastLocatorImpl > &xDocumentLocator,
+                         bool mbDuringParse );
+
+    std::stack< NameWithToken, std::vector<NameWithToken> > maNamespaceStack;
+    /* Context for main thread consuming events.
+     * startElement() stores the data, which characters() and endElement() uses
+     */
+    std::stack< SaxContext, std::vector<SaxContext> >  maContextStack;
+    // Determines which elements of maNamespaceDefines are valid in current context
+    std::stack< sal_uInt32, std::vector<sal_uInt32> >  maNamespaceCount;
+    std::vector< NamespaceDefine >                     maNamespaceDefines;
+
+    explicit Entity( const ParserData& rData );
+    Entity( const Entity& rEntity ) = delete;
+    Entity& operator=( const Entity& rEntity ) = delete;
+    void startElement( Event const *pEvent );
+    void characters( const OUString& sChars );
+    void endElement();
+    void processingInstruction( const OUString& rTarget, const OUString& rData );
+    EventList& getEventList();
+    Event& getEvent( CallbackType aType );
+};
+
+// Stuff for custom entity names
+struct ReplacementPair
+{
+    OUString name;
+    OUString replacement;
+};
+inline bool operator<(const ReplacementPair& lhs, const ReplacementPair& rhs)
+{
+    return lhs.name < rhs.name;
+}
+inline bool operator<(const ReplacementPair& lhs, const char* rhs)
+{
+    return lhs.name.compareToAscii(rhs) < 0;
+}
+
+} // namespace
+
+namespace sax_fastparser {
+
+class FastSaxParserImpl
+{
+public:
+    explicit FastSaxParserImpl();
+    ~FastSaxParserImpl();
+
+private:
+    std::vector<ReplacementPair> m_Replacements;
+    std::vector<xmlEntityPtr> m_TemporalEntities;
+
+public:
+    // XFastParser
+    /// @throws css::xml::sax::SAXException
+    /// @throws css::io::IOException
+    /// @throws css::uno::RuntimeException
+    void parseStream( const css::xml::sax::InputSource& aInputSource );
+    /// @throws css::uno::RuntimeException
+    void setFastDocumentHandler( const css::uno::Reference< css::xml::sax::XFastDocumentHandler >& Handler );
+    /// @throws css::uno::RuntimeException
+    void setTokenHandler( const css::uno::Reference< css::xml::sax::XFastTokenHandler >& Handler );
+    /// @throws css::lang::IllegalArgumentException
+    /// @throws css::uno::RuntimeException
+    void registerNamespace( const OUString& NamespaceURL, sal_Int32 NamespaceToken );
+    /// @throws css::lang::IllegalArgumentException
+    /// @throws css::uno::RuntimeException
+    OUString const & getNamespaceURL( std::u16string_view rPrefix );
+    /// @throws css::uno::RuntimeException
+    void setErrorHandler( const css::uno::Reference< css::xml::sax::XErrorHandler >& Handler );
+    /// @throws css::uno::RuntimeException
+    void setNamespaceHandler( const css::uno::Reference< css::xml::sax::XFastNamespaceHandler >& Handler);
+    // Fake DTD file
+    void setCustomEntityNames(
+       const ::css::uno::Sequence<::css::beans::Pair<::rtl::OUString, ::rtl::OUString>>& replacements);
+
+    // called by the C callbacks of the expat parser
+    void callbackStartElement( const xmlChar *localName , const xmlChar* prefix, const xmlChar* URI,
+        int numNamespaces, const xmlChar** namespaces, int numAttributes, const xmlChar **attributes );
+    void callbackEndElement();
+    void callbackCharacters( const xmlChar* s, int nLen );
+    void callbackProcessingInstruction( const xmlChar *target, const xmlChar *data );
+    xmlEntityPtr callbackGetEntity( const xmlChar *name );
+
+    void pushEntity(const ParserData&, xml::sax::InputSource const&);
+    void popEntity();
+    Entity& getEntity()             { return *mpTop; }
+    void parse();
+    void produce( bool bForceFlush = false );
+    bool m_bIgnoreMissingNSDecl;
+    bool m_bDisableThreadedParser;
+
+private:
+    bool consume(EventList&);
+    void deleteUsedEvents();
+    void sendPendingCharacters();
+    void addUnknownElementWithPrefix(const xmlChar **attributes, int i, rtl::Reference< FastAttributeList > const & xAttributes);
+
+    sal_Int32 GetToken( const xmlChar* pName, sal_Int32 nameLen );
+    /// @throws css::xml::sax::SAXException
+    sal_Int32 GetTokenWithPrefix( const xmlChar* pPrefix, int prefixLen, const xmlChar* pName, int nameLen );
+    /// @throws css::xml::sax::SAXException
+    OUString const & GetNamespaceURL( std::string_view rPrefix );
+    sal_Int32 GetNamespaceToken( const OUString& rNamespaceURL );
+    sal_Int32 GetTokenWithContextNamespace( sal_Int32 nNamespaceToken, const xmlChar* pName, int nNameLen );
+    void DefineNamespace( const OString& rPrefix, const OUString& namespaceURL );
+
+private:
+    std::mutex maMutex; ///< Protecting whole parseStream() execution
+    ::rtl::Reference< FastLocatorImpl >     mxDocumentLocator;
+    NamespaceMap                            maNamespaceMap;
+
+    ParserData maData;                      /// Cached parser configuration for next call of parseStream().
+
+    Entity *mpTop;                          /// std::stack::top() is amazingly slow => cache this.
+    std::stack< Entity > maEntities;        /// Entity stack for each call of parseStream().
+    std::vector<char> pendingCharacters;    /// Data from characters() callback that needs to be sent.
+};
+
+} // namespace sax_fastparser
+
+namespace {
+
+class ParserThread: public salhelper::Thread
+{
+    FastSaxParserImpl *mpParser;
+public:
+    explicit ParserThread(FastSaxParserImpl *pParser): Thread("Parser"), mpParser(pParser) {}
+private:
+    virtual void execute() override
+    {
+        try
+        {
+            mpParser->parse();
+        }
+        catch (...)
+        {
+            Entity &rEntity = mpParser->getEntity();
+            rEntity.getEvent( CallbackType::EXCEPTION );
+            mpParser->produce( true );
+        }
+    }
+};
+
+extern "C" {
+
+static void call_callbackStartElement(void *userData, const xmlChar *localName , const xmlChar* prefix, const xmlChar* URI,
+    int numNamespaces, const xmlChar** namespaces, int numAttributes, int /*defaultedAttributes*/, const xmlChar **attributes)
+{
+    FastSaxParserImpl* pFastParser = static_cast<FastSaxParserImpl*>( userData );
+    pFastParser->callbackStartElement( localName, prefix, URI, numNamespaces, namespaces, numAttributes, attributes );
+}
+
+static void call_callbackEndElement(void *userData, const xmlChar* /*localName*/, const xmlChar* /*prefix*/, const xmlChar* /*URI*/)
+{
+    FastSaxParserImpl* pFastParser = static_cast<FastSaxParserImpl*>( userData );
+    pFastParser->callbackEndElement();
+}
+
+static void call_callbackCharacters( void *userData , const xmlChar *s , int nLen )
+{
+    FastSaxParserImpl* pFastParser = static_cast<FastSaxParserImpl*>( userData );
+    pFastParser->callbackCharacters( s, nLen );
+}
+
+static void call_callbackProcessingInstruction( void *userData, const xmlChar *target, const xmlChar *data )
+{
+    FastSaxParserImpl* pFastParser = static_cast<FastSaxParserImpl*>( userData );
+    pFastParser->callbackProcessingInstruction( target, data );
+}
+
+static xmlEntityPtr call_callbackGetEntity( void *userData, const xmlChar *name)
+{
+    FastSaxParserImpl* pFastParser = static_cast<FastSaxParserImpl*>( userData );
+    return pFastParser->callbackGetEntity( name );
+}
+
+}
+
+class FastLocatorImpl : public WeakImplHelper< XLocator >
+{
+public:
+    explicit FastLocatorImpl(FastSaxParserImpl *p) : mpParser(p) {}
+
+    void dispose() { mpParser = nullptr; }
+    /// @throws RuntimeException
+    void checkDispose() const { if( !mpParser ) throw DisposedException(); }
+
+    //XLocator
+    virtual sal_Int32 SAL_CALL getColumnNumber() override;
+    virtual sal_Int32 SAL_CALL getLineNumber() override;
+    virtual OUString SAL_CALL getPublicId() override;
+    virtual OUString SAL_CALL getSystemId() override;
+
+private:
+    FastSaxParserImpl *mpParser;
+};
+
+sal_Int32 SAL_CALL FastLocatorImpl::getColumnNumber()
+{
+    checkDispose();
+    return xmlSAX2GetColumnNumber( mpParser->getEntity().mpParser );
+}
+
+sal_Int32 SAL_CALL FastLocatorImpl::getLineNumber()
+{
+    checkDispose();
+    return xmlSAX2GetLineNumber( mpParser->getEntity().mpParser );
+}
+
+OUString SAL_CALL FastLocatorImpl::getPublicId()
+{
+    checkDispose();
+    return mpParser->getEntity().maStructSource.sPublicId;
+}
+
+OUString SAL_CALL FastLocatorImpl::getSystemId()
+{
+    checkDispose();
+    return mpParser->getEntity().maStructSource.sSystemId;
+}
+
+ParserData::ParserData()
+{}
+
+Entity::Entity(const ParserData& rData)
+    : ParserData(rData)
+    , mnProducedEventsSize(0)
+    , mbEnableThreads(false)
+    , mpParser(nullptr)
+{
+}
+
+void Entity::startElement( Event const *pEvent )
+{
+    const sal_Int32& nElementToken = pEvent->mnElementToken;
+    const OUString& aNamespace = pEvent->msNamespace;
+    const OUString& aElementName = pEvent->msElementName;
+
+    // Use un-wrapped pointers to avoid significant acquire/release overhead
+    XFastContextHandler *pParentContext = nullptr;
+    if( !maContextStack.empty() )
+    {
+        pParentContext = maContextStack.top().mxContext.get();
+        if( !pParentContext )
+        {
+            maContextStack.push( SaxContext(nElementToken, aNamespace, aElementName) );
+            return;
+        }
+    }
+
+    maContextStack.push( SaxContext( nElementToken, aNamespace, aElementName ) );
+
+    try
+    {
+        Reference< XFastAttributeList > xAttr( pEvent->mxAttributes );
+        Reference< XFastContextHandler > xContext;
+
+        if ( mxNamespaceHandler.is() )
+        {
+            const Sequence< xml::Attribute > NSDeclAttribs = pEvent->mxDeclAttributes->getUnknownAttributes();
+            for (const auto& rNSDeclAttrib : NSDeclAttribs)
+            {
+                mxNamespaceHandler->registerNamespace( rNSDeclAttrib.Name, rNSDeclAttrib.Value );
+            }
+        }
+
+        if( nElementToken == FastToken::DONTKNOW )
+        {
+            if( pParentContext )
+                xContext = pParentContext->createUnknownChildContext( aNamespace, aElementName, xAttr );
+            else if( mxDocumentHandler.is() )
+                xContext = mxDocumentHandler->createUnknownChildContext( aNamespace, aElementName, xAttr );
+
+            if( xContext.is() )
+            {
+                xContext->startUnknownElement( aNamespace, aElementName, xAttr );
+            }
+        }
+        else
+        {
+            if( pParentContext )
+                xContext = pParentContext->createFastChildContext( nElementToken, xAttr );
+            else if( mxDocumentHandler.is() )
+                xContext = mxDocumentHandler->createFastChildContext( nElementToken, xAttr );
+
+            if( xContext.is() )
+                xContext->startFastElement( nElementToken, xAttr );
+        }
+        // swap the reference we own in to avoid referencing thrash.
+        maContextStack.top().mxContext = std::move( xContext );
+    }
+    catch (...)
+    {
+        saveException( ::cppu::getCaughtException() );
+    }
+}
+
+void Entity::characters( const OUString& sChars )
+{
+    if (maContextStack.empty())
+    {
+        // Malformed XML stream !?
+        return;
+    }
+
+    XFastContextHandler * pContext( maContextStack.top().mxContext.get() );
+    if( pContext ) try
+    {
+        pContext->characters( sChars );
+    }
+    catch (...)
+    {
+        saveException( ::cppu::getCaughtException() );
+    }
+}
+
+void Entity::endElement()
+{
+    if (maContextStack.empty())
+    {
+        // Malformed XML stream !?
+        return;
+    }
+
+    const SaxContext& aContext = maContextStack.top();
+    XFastContextHandler* pContext( aContext.mxContext.get() );
+    if( pContext )
+        try
+        {
+            sal_Int32 nElementToken = aContext.mnElementToken;
+            if( nElementToken != FastToken::DONTKNOW )
+                pContext->endFastElement( nElementToken );
+            else
+                pContext->endUnknownElement( aContext.maNamespace, aContext.maElementName );
+        }
+        catch (...)
+        {
+            saveException( ::cppu::getCaughtException() );
+        }
+    maContextStack.pop();
+}
+
+void Entity::processingInstruction( const OUString& rTarget, const OUString& rData )
+{
+    if( mxDocumentHandler.is() ) try
+    {
+        mxDocumentHandler->processingInstruction( rTarget, rData );
+    }
+    catch (...)
+    {
+        saveException( ::cppu::getCaughtException() );
+    }
+}
+
+EventList& Entity::getEventList()
+{
+    if (!mxProducedEvents)
+    {
+        std::unique_lock aGuard(maEventProtector);
+        if (!maUsedEvents.empty())
+        {
+            mxProducedEvents = std::move(maUsedEvents.front());
+            maUsedEvents.pop();
+            aGuard.unlock(); // unlock
+            mnProducedEventsSize = 0;
+        }
+        if (!mxProducedEvents)
+        {
+            mxProducedEvents.emplace();
+            mxProducedEvents->maEvents.resize(mnEventListSize);
+            mxProducedEvents->mbIsAttributesEmpty = false;
+            mnProducedEventsSize = 0;
+        }
+    }
+    return *mxProducedEvents;
+}
+
+Event& Entity::getEvent( CallbackType aType )
+{
+    if (!mbEnableThreads)
+        return maSharedEvent;
+
+    EventList& rEventList = getEventList();
+    if (mnProducedEventsSize == rEventList.maEvents.size())
+    {
+        SAL_WARN_IF(!maSavedException.hasValue(), "sax",
+            "Event vector should only exceed " << mnEventListSize <<
+            " temporarily while an exception is pending");
+        rEventList.maEvents.resize(mnProducedEventsSize + 1);
+    }
+    Event& rEvent = rEventList.maEvents[mnProducedEventsSize++];
+    rEvent.maType = aType;
+    return rEvent;
+}
+
+OUString lclGetErrorMessage( xmlParserCtxtPtr ctxt, std::u16string_view sSystemId, sal_Int32 nLine )
+{
+    const char* pMessage;
+    xmlErrorPtr error = xmlCtxtGetLastError( ctxt );
+    if( error && error->message )
+        pMessage = error->message;
+    else
+        pMessage = "unknown error";
+    return OUString::Concat("[") + sSystemId + " line " + OUString::number(nLine) + "]: " +
+           OUString(pMessage, strlen(pMessage), RTL_TEXTENCODING_ASCII_US);
+}
+
+// throw an exception, but avoid callback if
+// during a threaded produce
+void Entity::throwException( const ::rtl::Reference< FastLocatorImpl > &xDocumentLocator,
+                             bool mbDuringParse )
+{
+    // Error during parsing !
+    Any savedException;
+    {
+        std::scoped_lock g(maSavedExceptionMutex);
+        if (maSavedException.hasValue())
+        {
+            savedException.setValue(&maSavedException, cppu::UnoType<decltype(maSavedException)>::get());
+        }
+    }
+    SAXParseException aExcept(
+        lclGetErrorMessage( mpParser,
+                            xDocumentLocator->getSystemId(),
+                            xDocumentLocator->getLineNumber() ),
+        Reference< XInterface >(),
+        savedException,
+        xDocumentLocator->getPublicId(),
+        xDocumentLocator->getSystemId(),
+        xDocumentLocator->getLineNumber(),
+        xDocumentLocator->getColumnNumber()
+    );
+
+    // error handler is set, it may throw the exception
+    if( !mbDuringParse || !mbEnableThreads )
+    {
+        if (mxErrorHandler.is() )
+            mxErrorHandler->fatalError( Any( aExcept ) );
+    }
+
+    // error handler has not thrown, but parsing must stop => throw ourselves
+    throw aExcept;
+}
+
+// In the single threaded case we emit events via our C
+// callbacks, so any exception caught must be queued up until
+// we can safely re-throw it from our C++ parent of parse()
+
+// If multi-threaded, we need to push an EXCEPTION event, at
+// which point we transfer ownership of maSavedException to
+// the consuming thread.
+void Entity::saveException( const Any & e )
+{
+    // fdo#81214 - allow the parser to run on after an exception,
+    // unexpectedly some 'startElements' produce a UNO_QUERY_THROW
+    // for XComponent; and yet expect to continue parsing.
+    SAL_WARN("sax", "Unexpected exception from XML parser " << exceptionToString(e));
+    std::scoped_lock g(maSavedExceptionMutex);
+    if (maSavedException.hasValue())
+    {
+        SAL_INFO("sax.fastparser", "discarding exception, already have one");
+    }
+    else
+    {
+        maSavedException = e;
+    }
+}
+
+bool Entity::hasException()
+{
+    std::scoped_lock g(maSavedExceptionMutex);
+    return maSavedException.hasValue();
+}
+
+} // namespace
+
+namespace sax_fastparser {
+
+FastSaxParserImpl::FastSaxParserImpl() :
+    m_bIgnoreMissingNSDecl(false),
+    m_bDisableThreadedParser(false),
+    mpTop(nullptr)
+{
+    mxDocumentLocator.set( new FastLocatorImpl( this ) );
+}
+
+FastSaxParserImpl::~FastSaxParserImpl()
+{
+    if( mxDocumentLocator.is() )
+        mxDocumentLocator->dispose();
+    for (auto& entity : m_TemporalEntities)
+    {
+        if (!entity)
+            continue;
+        xmlNodePtr pPtr = reinterpret_cast<xmlNodePtr>(entity);
+        xmlUnlinkNode(pPtr);
+        xmlFreeNode(pPtr);
+    }
+}
+
+void FastSaxParserImpl::DefineNamespace( const OString& rPrefix, const OUString& namespaceURL )
+{
+    Entity& rEntity = getEntity();
+    assert(!rEntity.maNamespaceCount.empty()); // need a context!
+
+    sal_uInt32 nOffset = rEntity.maNamespaceCount.top()++;
+    if( rEntity.maNamespaceDefines.size() <= nOffset )
+        rEntity.maNamespaceDefines.resize( rEntity.maNamespaceDefines.size() + 64 );
+
+    rEntity.maNamespaceDefines[nOffset] = NamespaceDefine( rPrefix, GetNamespaceToken( namespaceURL ), namespaceURL );
+}
+
+sal_Int32 FastSaxParserImpl::GetToken( const xmlChar* pName, sal_Int32 nameLen /* = 0 */ )
+{
+    return FastTokenHandlerBase::getTokenFromChars( getEntity(). mxTokenHandler.get(),
+                                                    XML_CAST( pName ), nameLen ); // uses utf-8
+}
+
+sal_Int32 FastSaxParserImpl::GetTokenWithPrefix( const xmlChar* pPrefix, int nPrefixLen, const xmlChar* pName, int nNameLen )
+{
+    sal_Int32 nNamespaceToken = FastToken::DONTKNOW;
+
+    Entity& rEntity = getEntity();
+    if (rEntity.maNamespaceCount.empty())
+        return nNamespaceToken;
+
+    sal_uInt32 nNamespace = rEntity.maNamespaceCount.top();
+    while( nNamespace-- )
+    {
+        const auto & rNamespaceDefine = rEntity.maNamespaceDefines[nNamespace];
+        const OString& rPrefix( rNamespaceDefine.maPrefix );
+        if( (rPrefix.getLength() == nPrefixLen) &&
+            rtl_str_reverseCompare_WithLength(rPrefix.pData->buffer, rPrefix.pData->length, XML_CAST( pPrefix ), nPrefixLen ) == 0 )
+        {
+            nNamespaceToken = rNamespaceDefine.mnToken;
+            break;
+        }
+
+        if( !nNamespace && !m_bIgnoreMissingNSDecl )
+            throw SAXException("No namespace defined for " + OUString(XML_CAST(pPrefix),
+                    nPrefixLen, RTL_TEXTENCODING_UTF8), Reference< XInterface >(), Any());
+    }
+
+    if( nNamespaceToken != FastToken::DONTKNOW )
+    {
+        sal_Int32 nNameToken = GetToken( pName, nNameLen );
+        if( nNameToken != FastToken::DONTKNOW )
+            return nNamespaceToken | nNameToken;
+    }
+
+    return FastToken::DONTKNOW;
+}
+
+sal_Int32 FastSaxParserImpl::GetNamespaceToken( const OUString& rNamespaceURL )
+{
+    NamespaceMap::iterator aIter( maNamespaceMap.find( rNamespaceURL ) );
+    if( aIter != maNamespaceMap.end() )
+        return (*aIter).second;
+    else
+        return FastToken::DONTKNOW;
+}
+
+OUString const & FastSaxParserImpl::GetNamespaceURL( std::string_view rPrefix )
+{
+    Entity& rEntity = getEntity();
+    if( !rEntity.maNamespaceCount.empty() )
+    {
+        sal_uInt32 nNamespace = rEntity.maNamespaceCount.top();
+        while( nNamespace-- )
+            if( rEntity.maNamespaceDefines[nNamespace].maPrefix == rPrefix )
+                return rEntity.maNamespaceDefines[nNamespace].maNamespaceURL;
+    }
+
+    throw SAXException("No namespace defined for " + OUString::fromUtf8(rPrefix),
+            Reference< XInterface >(), Any());
+}
+
+sal_Int32 FastSaxParserImpl::GetTokenWithContextNamespace( sal_Int32 nNamespaceToken, const xmlChar* pName, int nNameLen )
+{
+    if( nNamespaceToken != FastToken::DONTKNOW )
+    {
+        sal_Int32 nNameToken = GetToken( pName, nNameLen );
+        if( nNameToken != FastToken::DONTKNOW )
+            return nNamespaceToken | nNameToken;
+    }
+
+    return FastToken::DONTKNOW;
+}
+
+namespace
+{
+    class ParserCleanup
+    {
+    private:
+        FastSaxParserImpl& m_rParser;
+        Entity& m_rEntity;
+        rtl::Reference<ParserThread> m_xParser;
+    public:
+        ParserCleanup(FastSaxParserImpl& rParser, Entity& rEntity)
+            : m_rParser(rParser)
+            , m_rEntity(rEntity)
+        {
+        }
+        ~ParserCleanup()
+        {
+            if (m_rEntity.mpParser)
+            {
+                if (m_rEntity.mpParser->myDoc)
+                    xmlFreeDoc(m_rEntity.mpParser->myDoc);
+                xmlFreeParserCtxt(m_rEntity.mpParser);
+            }
+            joinThread();
+            m_rParser.popEntity();
+        }
+        void setThread(const rtl::Reference<ParserThread> &xParser)
+        {
+            m_xParser = xParser;
+        }
+        void joinThread()
+        {
+            if (m_xParser.is())
+            {
+                rtl::Reference<ParserThread> xToJoin = m_xParser;
+                m_xParser.clear();
+                xToJoin->join();
+            }
+        }
+    };
+}
+/***************
+*
+* parseStream does Parser-startup initializations. The FastSaxParser::parse() method does
+* the file-specific initialization work. (During a parser run, external files may be opened)
+*
+****************/
+void FastSaxParserImpl::parseStream(const InputSource& rStructSource)
+{
+    xmlInitParser();
+
+    // Only one text at one time
+    std::unique_lock guard( maMutex );
+
+    pushEntity(maData, rStructSource);
+    Entity& rEntity = getEntity();
+    ParserCleanup aEnsureFree(*this, rEntity);
+
+    // start the document
+    if( rEntity.mxDocumentHandler.is() )
+    {
+        rEntity.mxDocumentHandler->setDocumentLocator( mxDocumentLocator );
+        rEntity.mxDocumentHandler->startDocument();
+    }
+
+#ifdef EMSCRIPTEN
+    rEntity.mbEnableThreads = false;
+#else
+    if (!getenv("SAX_DISABLE_THREADS") && !m_bDisableThreadedParser)
+    {
+        Reference<css::io::XSeekable> xSeekable(rEntity.maStructSource.aInputStream, UNO_QUERY);
+        // available() is not __really__ relevant here, but leave it in as a heuristic for non-seekable streams
+        rEntity.mbEnableThreads = (xSeekable.is() && xSeekable->getLength() > 10000)
+                || (rEntity.maStructSource.aInputStream->available() > 10000);
+    }
+#endif
+
+    if (rEntity.mbEnableThreads)
+    {
+        rtl::Reference<ParserThread> xParser = new ParserThread(this);
+        xParser->launch();
+        aEnsureFree.setThread(xParser);
+        bool done = false;
+        do {
+            rEntity.maConsumeResume.wait();
+            rEntity.maConsumeResume.reset();
+
+            std::unique_lock aGuard(rEntity.maEventProtector);
+            while (!rEntity.maPendingEvents.empty())
+            {
+                if (rEntity.maPendingEvents.size() <= Entity::mnEventLowWater)
+                    rEntity.maProduceResume.set(); // start producer again
+
+                EventList aEventList = std::move(rEntity.maPendingEvents.front());
+                rEntity.maPendingEvents.pop();
+                aGuard.unlock(); // unlock
+
+                if (!consume(aEventList))
+                    done = true;
+
+                aGuard.lock(); // lock
+
+                if ( rEntity.maPendingEvents.size() <= Entity::mnEventLowWater )
+                {
+                    aGuard.unlock();
+                    for (auto& rEvent : aEventList.maEvents)
+                    {
+                        if (rEvent.mxAttributes.is())
+                        {
+                            rEvent.mxAttributes->clear();
+                            if( rEntity.mxNamespaceHandler.is() )
+                                rEvent.mxDeclAttributes->clear();
+                        }
+                        aEventList.mbIsAttributesEmpty = true;
+                    }
+                    aGuard.lock();
+                }
+
+                rEntity.maUsedEvents.push(std::move(aEventList));
+            }
+        } while (!done);
+        aEnsureFree.joinThread();
+        deleteUsedEvents();
+
+        // callbacks used inside XML_Parse may have caught an exception
+        // No need to lock maSavedExceptionMutex here because parser
+        // thread is joined.
+        if( rEntity.maSavedException.hasValue() )
+            rEntity.throwException( mxDocumentLocator, true );
+    }
+    else
+    {
+        parse();
+    }
+
+    // finish document
+    if( rEntity.mxDocumentHandler.is() )
+    {
+        rEntity.mxDocumentHandler->endDocument();
+    }
+}
+
+void FastSaxParserImpl::setFastDocumentHandler( const Reference< XFastDocumentHandler >& Handler )
+{
+    maData.mxDocumentHandler = Handler;
+}
+
+void FastSaxParserImpl::setTokenHandler( const Reference< XFastTokenHandler >& xHandler )
+{
+    assert( dynamic_cast< FastTokenHandlerBase *>( xHandler.get() ) && "we expect this handler to be a subclass of FastTokenHandlerBase" );
+    maData.mxTokenHandler = dynamic_cast< FastTokenHandlerBase *>( xHandler.get() );
+}
+
+void FastSaxParserImpl::registerNamespace( const OUString& NamespaceURL, sal_Int32 NamespaceToken )
+{
+    if( NamespaceToken < FastToken::NAMESPACE )
+        throw IllegalArgumentException("Invalid namespace token " + OUString::number(NamespaceToken), css::uno::Reference<css::uno::XInterface >(), 0);
+
+    if( GetNamespaceToken( NamespaceURL ) == FastToken::DONTKNOW )
+    {
+        maNamespaceMap[ NamespaceURL ] = NamespaceToken;
+        return;
+    }
+    throw IllegalArgumentException("namespace URL is already registered: " + NamespaceURL, css::uno::Reference<css::uno::XInterface >(), 0);
+}
+
+OUString const & FastSaxParserImpl::getNamespaceURL( std::u16string_view rPrefix )
+{
+    try
+    {
+        return GetNamespaceURL( OUStringToOString( rPrefix, RTL_TEXTENCODING_UTF8 ) );
+    }
+    catch (const Exception&)
+    {
+    }
+    throw IllegalArgumentException();
+}
+
+void FastSaxParserImpl::setErrorHandler(const Reference< XErrorHandler > & Handler)
+{
+    maData.mxErrorHandler = Handler;
+}
+
+void FastSaxParserImpl::setNamespaceHandler( const Reference< XFastNamespaceHandler >& Handler )
+{
+    maData.mxNamespaceHandler = Handler;
+}
+
+void FastSaxParserImpl::setCustomEntityNames(
+    const ::css::uno::Sequence<::css::beans::Pair<::rtl::OUString, ::rtl::OUString>>& replacements)
+{
+    m_Replacements.resize(replacements.size());
+    for (size_t i = 0; i < replacements.size(); ++i)
+    {
+        m_Replacements[i].name = replacements[i].First;
+        m_Replacements[i].replacement = replacements[i].Second;
+    }
+    if (m_Replacements.size() > 1)
+        std::sort(m_Replacements.begin(), m_Replacements.end());
+}
+
+void FastSaxParserImpl::deleteUsedEvents()
+{
+    Entity& rEntity = getEntity();
+    std::unique_lock aGuard(rEntity.maEventProtector);
+
+    while (!rEntity.maUsedEvents.empty())
+    {
+        { // the block makes sure that aEventList is destructed outside the lock
+            EventList aEventList = std::move(rEntity.maUsedEvents.front());
+            rEntity.maUsedEvents.pop();
+
+            aGuard.unlock(); // unlock
+        }
+
+        aGuard.lock(); // lock
+    }
+}
+
+void FastSaxParserImpl::produce( bool bForceFlush )
+{
+    Entity& rEntity = getEntity();
+    if (!(bForceFlush ||
+        rEntity.mnProducedEventsSize >= Entity::mnEventListSize))
+        return;
+
+    std::unique_lock aGuard(rEntity.maEventProtector);
+
+    while (rEntity.maPendingEvents.size() >= Entity::mnEventHighWater)
+    { // pause parsing for a bit
+        aGuard.unlock(); // unlock
+        rEntity.maProduceResume.wait();
+        rEntity.maProduceResume.reset();
+        aGuard.lock(); // lock
+    }
+
+    rEntity.maPendingEvents.push(std::move(*rEntity.mxProducedEvents));
+    rEntity.mxProducedEvents.reset();
+    assert(!rEntity.mxProducedEvents);
+
+    aGuard.unlock(); // unlock
+
+    rEntity.maConsumeResume.set();
+}
+
+bool FastSaxParserImpl::consume(EventList& rEventList)
+{
+    Entity& rEntity = getEntity();
+    rEventList.mbIsAttributesEmpty = false;
+    for (auto& rEvent : rEventList.maEvents)
+    {
+        switch (rEvent.maType)
+        {
+            case CallbackType::START_ELEMENT:
+                rEntity.startElement( &rEvent );
+                break;
+            case CallbackType::END_ELEMENT:
+                rEntity.endElement();
+                break;
+            case CallbackType::CHARACTERS:
+                rEntity.characters( rEvent.msChars );
+                break;
+            case CallbackType::PROCESSING_INSTRUCTION:
+                rEntity.processingInstruction(
+                    rEvent.msNamespace, rEvent.msElementName ); // ( target, data )
+                break;
+            case CallbackType::DONE:
+                return false;
+            case CallbackType::EXCEPTION:
+                rEntity.throwException( mxDocumentLocator, false );
+                [[fallthrough]]; // avoid unreachable code warning with some compilers
+            default:
+                assert(false);
+                return false;
+        }
+    }
+    return true;
+}
+
+void FastSaxParserImpl::pushEntity(const ParserData& rEntityData,
+        xml::sax::InputSource const& rSource)
+{
+    if (!rSource.aInputStream.is())
+        throw SAXException("No input source", Reference<XInterface>(), Any());
+
+    maEntities.emplace(rEntityData);
+    mpTop = &maEntities.top();
+
+    mpTop->maStructSource = rSource;
+
+    mpTop->maConverter.setInputStream(mpTop->maStructSource.aInputStream);
+    if (!mpTop->maStructSource.sEncoding.isEmpty())
+    {
+        mpTop->maConverter.setEncoding(OUStringToOString(mpTop->maStructSource.sEncoding, RTL_TEXTENCODING_ASCII_US));
+    }
+}
+
+void FastSaxParserImpl::popEntity()
+{
+    maEntities.pop();
+    mpTop = !maEntities.empty() ? &maEntities.top() : nullptr;
+}
+
+// starts parsing with actual parser !
+void FastSaxParserImpl::parse()
+{
+    const int BUFFER_SIZE = 16 * 1024;
+    Sequence< sal_Int8 > seqOut( BUFFER_SIZE );
+
+    Entity& rEntity = getEntity();
+
+    // set all necessary C-Callbacks
+    static xmlSAXHandler callbacks;
+    callbacks.startElementNs = call_callbackStartElement;
+    callbacks.endElementNs = call_callbackEndElement;
+    callbacks.characters = call_callbackCharacters;
+    callbacks.processingInstruction = call_callbackProcessingInstruction;
+    callbacks.getEntity = call_callbackGetEntity;
+    callbacks.initialized = XML_SAX2_MAGIC;
+    int nRead = 0;
+    do
+    {
+        nRead = rEntity.maConverter.readAndConvert( seqOut, BUFFER_SIZE );
+        if( nRead <= 0 )
+        {
+            if( rEntity.mpParser != nullptr )
+            {
+                if( xmlParseChunk( rEntity.mpParser, reinterpret_cast<const char*>(seqOut.getConstArray()), 0, 1 ) != XML_ERR_OK )
+                    rEntity.throwException( mxDocumentLocator, true );
+                if (rEntity.hasException())
+                    rEntity.throwException(mxDocumentLocator, true);
+            }
+            break;
+        }
+
+        bool bContinue = true;
+        if( rEntity.mpParser == nullptr )
+        {
+            // create parser with proper encoding (needs the first chunk of data)
+            rEntity.mpParser = xmlCreatePushParserCtxt( &callbacks, this,
+                reinterpret_cast<const char*>(seqOut.getConstArray()), nRead, nullptr );
+            if( !rEntity.mpParser )
+                throw SAXException("Couldn't create parser", Reference< XInterface >(), Any() );
+
+            // Tell libxml2 parser to decode entities in attribute values.
+            // Also allow XML attribute values which are larger than 10MB, because this used to work
+            // with expat.
+            // coverity[unsafe_xml_parse_config] - entity support is required
+            xmlCtxtUseOptions(rEntity.mpParser, XML_PARSE_NOENT | XML_PARSE_HUGE);
+        }
+        else
+        {
+            bContinue = xmlParseChunk( rEntity.mpParser, reinterpret_cast<const char*>(seqOut.getConstArray()), nRead, 0 )
+                            == XML_ERR_OK;
+        }
+
+        // callbacks used inside XML_Parse may have caught an exception
+        if (!bContinue)
+        {
+            rEntity.throwException( mxDocumentLocator, true );
+        }
+        if (rEntity.hasException())
+        {
+            rEntity.throwException( mxDocumentLocator, true );
+        }
+    } while( nRead > 0 );
+    rEntity.getEvent( CallbackType::DONE );
+    if( rEntity.mbEnableThreads )
+        produce( true );
+}
+
+// The C-Callbacks
+void FastSaxParserImpl::callbackStartElement(const xmlChar *localName , const xmlChar* prefix, const xmlChar* URI,
+    int numNamespaces, const xmlChar** namespaces, int numAttributes, const xmlChar **attributes)
+{
+    if (!pendingCharacters.empty())
+        sendPendingCharacters();
+    Entity& rEntity = getEntity();
+    if( rEntity.maNamespaceCount.empty() )
+    {
+        rEntity.maNamespaceCount.push(0);
+        DefineNamespace( "xml", "http://www.w3.org/XML/1998/namespace");
+    }
+    else
+    {
+        rEntity.maNamespaceCount.push( rEntity.maNamespaceCount.top() );
+    }
+
+    // create attribute map and process namespace instructions
+    Event& rEvent = rEntity.getEvent( CallbackType::START_ELEMENT );
+    bool bIsAttributesEmpty = false;
+    if ( rEntity.mbEnableThreads )
+        bIsAttributesEmpty = rEntity.getEventList().mbIsAttributesEmpty;
+
+    if (rEvent.mxAttributes.is())
+    {
+        if( !bIsAttributesEmpty )
+            rEvent.mxAttributes->clear();
+    }
+    else
+        rEvent.mxAttributes.set(
+                new FastAttributeList( rEntity.mxTokenHandler.get() ) );
+
+    if( rEntity.mxNamespaceHandler.is() )
+    {
+        if (rEvent.mxDeclAttributes.is())
+        {
+            if( !bIsAttributesEmpty )
+                rEvent.mxDeclAttributes->clear();
+        }
+        else
+            rEvent.mxDeclAttributes.set(
+                new FastAttributeList( rEntity.mxTokenHandler.get() ) );
+    }
+
+    OUString sNamespace;
+    sal_Int32 nNamespaceToken = FastToken::DONTKNOW;
+    if (!rEntity.maNamespaceStack.empty())
+    {
+        sNamespace = rEntity.maNamespaceStack.top().msName;
+        nNamespaceToken = rEntity.maNamespaceStack.top().mnToken;
+    }
+
+    try
+    {
+        /*  #158414# Each element may define new namespaces, also for attributes.
+            First, process all namespaces, second, process the attributes after namespaces
+            have been initialized. */
+
+        // #158414# first: get namespaces
+        for (int i = 0; i < numNamespaces * 2; i += 2)
+        {
+            // namespaces[] is (prefix/URI)
+            if( namespaces[ i ] != nullptr )
+            {
+                OString aPrefix( XML_CAST( namespaces[ i ] ));
+                OUString namespaceURL( XML_CAST( namespaces[ i + 1 ] ), strlen( XML_CAST( namespaces[ i + 1 ] )), RTL_TEXTENCODING_UTF8 );
+                NormalizeURI( namespaceURL );
+                DefineNamespace(aPrefix, namespaceURL);
+                if( rEntity.mxNamespaceHandler.is() )
+                    rEvent.mxDeclAttributes->addUnknown( OString( XML_CAST( namespaces[ i ] ) ), OString( XML_CAST( namespaces[ i + 1 ] ) ) );
+            }
+            else
+            {
+                // default namespace
+                sNamespace = OUString( XML_CAST( namespaces[ i + 1 ] ), strlen( XML_CAST( namespaces[ i + 1 ] )), RTL_TEXTENCODING_UTF8 );
+                NormalizeURI( sNamespace );
+                nNamespaceToken = GetNamespaceToken( sNamespace );
+                if( rEntity.mxNamespaceHandler.is() )
+                    rEvent.mxDeclAttributes->addUnknown( "", OString( XML_CAST( namespaces[ i + 1 ] ) ) );
+            }
+        }
+
+        if ( rEntity.mxTokenHandler.is() )
+        {
+            // #158414# second: fill attribute list with other attributes
+            rEvent.mxAttributes->reserve( numAttributes );
+            for (int i = 0; i < numAttributes * 5; i += 5)
+            {
+                // attributes[] is ( localname / prefix / nsURI / valueBegin / valueEnd )
+                if( attributes[ i + 1 ] != nullptr )
+                {
+                    sal_Int32 nAttributeToken = GetTokenWithPrefix( attributes[ i + 1 ], strlen( XML_CAST( attributes[ i + 1 ] )), attributes[ i ], strlen( XML_CAST( attributes[ i ] )));
+                    if( nAttributeToken != FastToken::DONTKNOW )
+                        rEvent.mxAttributes->add( nAttributeToken, XML_CAST( attributes[ i + 3 ] ), attributes[ i + 4 ] - attributes[ i + 3 ] );
+                    else
+                        addUnknownElementWithPrefix(attributes, i, rEvent.mxAttributes);
+                }
+                else
+                {
+                    sal_Int32 nAttributeToken = GetToken( attributes[ i ], strlen( XML_CAST( attributes[ i ] )));
+                    if( nAttributeToken != FastToken::DONTKNOW )
+                        rEvent.mxAttributes->add( nAttributeToken, XML_CAST( attributes[ i + 3 ] ), attributes[ i + 4 ] - attributes[ i + 3 ] );
+                    else
+                    {
+                        SAL_WARN("xmloff", "unknown attribute " << XML_CAST( attributes[ i ] ) << "=" <<
+                            OString( XML_CAST( attributes[ i + 3 ] ), attributes[ i + 4 ] - attributes[ i + 3 ] ));
+                        rEvent.mxAttributes->addUnknown( XML_CAST( attributes[ i ] ),
+                            OString( XML_CAST( attributes[ i + 3 ] ), attributes[ i + 4 ] - attributes[ i + 3 ] ));
+                    }
+                }
+            }
+
+            if( prefix != nullptr )
+                rEvent.mnElementToken = GetTokenWithPrefix( prefix, strlen( XML_CAST( prefix )), localName, strlen( XML_CAST( localName )));
+            else if( !sNamespace.isEmpty() )
+                rEvent.mnElementToken = GetTokenWithContextNamespace( nNamespaceToken, localName, strlen( XML_CAST( localName )));
+            else
+                rEvent.mnElementToken = GetToken( localName, strlen( XML_CAST( localName )));
+        }
+        else
+        {
+            for (int i = 0; i < numAttributes * 5; i += 5)
+            {
+                if( attributes[ i + 1 ] != nullptr )
+                    addUnknownElementWithPrefix(attributes, i, rEvent.mxAttributes);
+                else
+                    rEvent.mxAttributes->addUnknown( XML_CAST( attributes[ i ] ),
+                            OString( XML_CAST( attributes[ i + 3 ] ), attributes[ i + 4 ] - attributes[ i + 3 ] ));
+            }
+
+            rEvent.mnElementToken = FastToken::DONTKNOW;
+        }
+
+        if( rEvent.mnElementToken == FastToken::DONTKNOW )
+        {
+            OUString aElementPrefix;
+            if( prefix != nullptr )
+            {
+                if ( !m_bIgnoreMissingNSDecl || URI != nullptr )
+                    sNamespace = OUString( XML_CAST( URI ), strlen( XML_CAST( URI )), RTL_TEXTENCODING_UTF8 );
+                else
+                    sNamespace.clear();
+                nNamespaceToken = GetNamespaceToken( sNamespace );
+                aElementPrefix = OUString( XML_CAST( prefix ), strlen( XML_CAST( prefix )), RTL_TEXTENCODING_UTF8 );
+            }
+            OUString aElementLocalName( XML_CAST( localName ), strlen( XML_CAST( localName )), RTL_TEXTENCODING_UTF8 );
+            rEvent.msNamespace = sNamespace;
+            if( aElementPrefix.isEmpty() )
+                rEvent.msElementName = std::move(aElementLocalName);
+            else
+                rEvent.msElementName = aElementPrefix + ":" + aElementLocalName;
+        }
+        else // token is always preferred.
+            rEvent.msElementName.clear();
+
+        rEntity.maNamespaceStack.push( NameWithToken(sNamespace, nNamespaceToken) );
+        if (rEntity.mbEnableThreads)
+            produce();
+        else
+        {
+            SAL_INFO("sax.fastparser", " startElement line " << mxDocumentLocator->getLineNumber() << " column " << mxDocumentLocator->getColumnNumber() << " " << ( prefix ? XML_CAST(prefix) : "(null)" ) << ":" << localName);
+            rEntity.startElement( &rEvent );
+        }
+    }
+    catch (...)
+    {
+        rEntity.saveException( ::cppu::getCaughtException() );
+    }
+}
+
+void FastSaxParserImpl::addUnknownElementWithPrefix(const xmlChar **attributes, int i, rtl::Reference< FastAttributeList > const & xAttributes)
+{
+    OUString aNamespaceURI;
+    if ( !m_bIgnoreMissingNSDecl || attributes[i + 2] != nullptr )
+        aNamespaceURI = OUString( XML_CAST( attributes[ i + 2 ] ), strlen( XML_CAST( attributes[ i + 2 ] )), RTL_TEXTENCODING_UTF8 );
+    const OString& rPrefix = OString( XML_CAST( attributes[ i + 1 ] ));
+    const OString& rLocalName = OString( XML_CAST( attributes[ i ] ));
+    OString aQualifiedName = (rPrefix.isEmpty())? rLocalName : rPrefix + ":" + rLocalName;
+    xAttributes->addUnknown( aNamespaceURI, aQualifiedName,
+        OString( XML_CAST( attributes[ i + 3 ] ), attributes[ i + 4 ] - attributes[ i + 3 ] ));
+    // ignore an element that otherwise generates a lot of noise in the logs
+    SAL_WARN_IF(aQualifiedName != "x14ac:dyDescent", "xmloff", "unknown element " << aQualifiedName << " " << aNamespaceURI);
+}
+
+void FastSaxParserImpl::callbackEndElement()
+{
+    if (!pendingCharacters.empty())
+        sendPendingCharacters();
+    Entity& rEntity = getEntity();
+    SAL_WARN_IF(rEntity.maNamespaceCount.empty(), "sax", "Empty NamespaceCount");
+    if( !rEntity.maNamespaceCount.empty() )
+        rEntity.maNamespaceCount.pop();
+
+    SAL_WARN_IF(rEntity.maNamespaceStack.empty(), "sax", "Empty NamespaceStack");
+    if( !rEntity.maNamespaceStack.empty() )
+        rEntity.maNamespaceStack.pop();
+
+    rEntity.getEvent( CallbackType::END_ELEMENT );
+    if (rEntity.mbEnableThreads)
+        produce();
+    else
+        rEntity.endElement();
+}
+
+void FastSaxParserImpl::callbackCharacters( const xmlChar* s, int nLen )
+{
+    // SAX interface allows that the characters callback splits content of one XML node
+    // (e.g. because there's an entity that needs decoding), however for consumers it's
+    // simpler FastSaxParser's character callback provides the whole string at once,
+    // so merge data from possible multiple calls and send them at once (before the element
+    // ends or another one starts).
+    //
+    // We use a std::vector<char> to avoid calling into the OUString constructor more than once when
+    // we have multiple callbackCharacters() calls that we have to merge, which happens surprisingly
+    // often in writer documents.
+    int nOriginalLen = pendingCharacters.size();
+    pendingCharacters.resize(nOriginalLen + nLen);
+    memcpy(pendingCharacters.data() + nOriginalLen, s, nLen);
+}
+
+void FastSaxParserImpl::sendPendingCharacters()
+{
+    Entity& rEntity = getEntity();
+    OUString sChars( pendingCharacters.data(), pendingCharacters.size(), RTL_TEXTENCODING_UTF8 );
+    if (rEntity.mbEnableThreads)
+    {
+        Event& rEvent = rEntity.getEvent( CallbackType::CHARACTERS );
+        rEvent.msChars = std::move(sChars);
+        produce();
+    }
+    else
+        rEntity.characters( sChars );
+    pendingCharacters.resize(0);
+}
+
+void FastSaxParserImpl::callbackProcessingInstruction( const xmlChar *target, const xmlChar *data )
+{
+    if (!pendingCharacters.empty())
+        sendPendingCharacters();
+    Entity& rEntity = getEntity();
+    Event& rEvent = rEntity.getEvent( CallbackType::PROCESSING_INSTRUCTION );
+
+    // This event is very rare, so no need to waste extra space for this
+    // Using namespace and element strings to be target and data in that order.
+    rEvent.msNamespace = OUString( XML_CAST( target ), strlen( XML_CAST( target ) ), RTL_TEXTENCODING_UTF8 );
+    if ( data != nullptr )
+        rEvent.msElementName = OUString( XML_CAST( data ), strlen( XML_CAST( data ) ), RTL_TEXTENCODING_UTF8 );
+    else
+        rEvent.msElementName.clear();
+
+    if (rEntity.mbEnableThreads)
+        produce();
+    else
+        rEntity.processingInstruction( rEvent.msNamespace, rEvent.msElementName );
+}
+
+xmlEntityPtr FastSaxParserImpl::callbackGetEntity( const xmlChar *name )
+{
+    if( !name )
+        return xmlGetPredefinedEntity(name);
+    const char* dname = XML_CAST(name);
+    int lname = strlen(dname);
+    if( lname == 0 )
+        return xmlGetPredefinedEntity(name);
+    if (m_Replacements.size() > 0)
+    {
+        auto it = std::lower_bound(m_Replacements.begin(), m_Replacements.end(), dname);
+        if (it != m_Replacements.end() && it->name.compareToAscii(dname) == 0)
+        {
+            xmlEntityPtr entpt = xmlNewEntity(
+                nullptr, name, XML_INTERNAL_GENERAL_ENTITY, nullptr, nullptr,
+                BAD_CAST(OUStringToOString(it->replacement, RTL_TEXTENCODING_UTF8).getStr()));
+            m_TemporalEntities.push_back(entpt);
+            return entpt;
+        }
+    }
+    if( lname < 2 )
+        return xmlGetPredefinedEntity(name);
+    if ( dname[0] == '#' )
+    {
+        sal_uInt32 cval = 0;
+        if( dname[1] == 'x' ||  dname[1] == 'X' )
+        {
+            if( lname < 3 )
+                return xmlGetPredefinedEntity(name);
+            cval = static_cast<sal_uInt32>( strtoul( dname + 2, nullptr, 16 ) );
+            if( cval == 0 )
+                return xmlGetPredefinedEntity(name);
+            OUString vname( &cval, 1 );
+            xmlEntityPtr entpt
+                = xmlNewEntity(nullptr, name, XML_INTERNAL_GENERAL_ENTITY, nullptr, nullptr,
+                               BAD_CAST(OUStringToOString(vname, RTL_TEXTENCODING_UTF8).getStr()));
+            m_TemporalEntities.push_back(entpt);
+            return entpt;
+        }
+        else
+        {
+            cval = static_cast<sal_uInt32>( strtoul( dname + 2, nullptr, 10 ) );
+            if( cval == 0 )
+                return xmlGetPredefinedEntity(name);
+            OUString vname(&cval, 1);
+            xmlEntityPtr entpt
+                = xmlNewEntity(nullptr, name, XML_INTERNAL_GENERAL_ENTITY, nullptr, nullptr,
+                               BAD_CAST(OUStringToOString(vname, RTL_TEXTENCODING_UTF8).getStr()));
+            m_TemporalEntities.push_back(entpt);
+            return entpt;
+        }
+    }
+    return xmlGetPredefinedEntity(name);
+}
+
+FastSaxParser::FastSaxParser() : mpImpl(new FastSaxParserImpl) {}
+
+FastSaxParser::~FastSaxParser()
+{
+}
+
+void SAL_CALL
+FastSaxParser::initialize(css::uno::Sequence< css::uno::Any > const& rArguments)
+{
+    if (!rArguments.hasElements())
+        return;
+
+    OUString str;
+    if ( !(rArguments[0] >>= str) )
+        throw IllegalArgumentException();
+
+    if ( str == "IgnoreMissingNSDecl" )
+        mpImpl->m_bIgnoreMissingNSDecl = true;
+    else if ( str == "DoSmeplease" )
+        ; //just ignore as this is already immune to billion laughs
+    else if ( str == "DisableThreadedParser" )
+        mpImpl->m_bDisableThreadedParser = true;
+    else
+        throw IllegalArgumentException();
+
+}
+
+void FastSaxParser::parseStream( const xml::sax::InputSource& aInputSource )
+{
+    mpImpl->parseStream(aInputSource);
+}
+
+void FastSaxParser::setFastDocumentHandler( const uno::Reference<xml::sax::XFastDocumentHandler>& Handler )
+{
+    mpImpl->setFastDocumentHandler(Handler);
+}
+
+void FastSaxParser::setTokenHandler( const uno::Reference<xml::sax::XFastTokenHandler>& Handler )
+{
+    mpImpl->setTokenHandler(Handler);
+}
+
+void FastSaxParser::registerNamespace( const OUString& NamespaceURL, sal_Int32 NamespaceToken )
+{
+    mpImpl->registerNamespace(NamespaceURL, NamespaceToken);
+}
+
+OUString FastSaxParser::getNamespaceURL( const OUString& rPrefix )
+{
+    return mpImpl->getNamespaceURL(rPrefix);
+}
+
+void FastSaxParser::setErrorHandler( const uno::Reference< xml::sax::XErrorHandler >& Handler )
+{
+    mpImpl->setErrorHandler(Handler);
+}
+
+void FastSaxParser::setEntityResolver( const uno::Reference< xml::sax::XEntityResolver >& )
+{
+    // not implemented
+}
+
+void FastSaxParser::setLocale( const lang::Locale& )
+{
+    // not implemented
+}
+
+void FastSaxParser::setNamespaceHandler( const uno::Reference< css::xml::sax::XFastNamespaceHandler >& Handler)
+{
+    mpImpl->setNamespaceHandler(Handler);
+}
+
+OUString FastSaxParser::getImplementationName()
+{
+    return "com.sun.star.comp.extensions.xml.sax.FastParser";
+}
+
+void FastSaxParser::setCustomEntityNames(
+    const ::css::uno::Sequence<::css::beans::Pair<::rtl::OUString, ::rtl::OUString>>& replacements)
+{
+    mpImpl->setCustomEntityNames(replacements);
+}
+
+sal_Bool FastSaxParser::supportsService( const OUString& ServiceName )
+{
+    return cppu::supportsService(this, ServiceName);
+}
+
+uno::Sequence<OUString> FastSaxParser::getSupportedServiceNames()
+{
+    return { "com.sun.star.xml.sax.FastParser" };
+}
+
+} // namespace sax_fastparser
+
+extern "C" SAL_DLLPUBLIC_EXPORT css::uno::XInterface *
+com_sun_star_comp_extensions_xml_sax_FastParser_get_implementation(
+    css::uno::XComponentContext *,
+    css::uno::Sequence<css::uno::Any> const &)
+{
+    return cppu::acquire(new FastSaxParser);
+}
+
+// ----------------------------------------------------------
+// copy of the code in xmloff/source/core/namespace.cxx, which adds namespace aliases
+// for various dodgy namespace decls in the wild.
+
+static bool NormalizeW3URI( OUString& rName );
+static bool NormalizeOasisURN( OUString& rName );
+
+static void NormalizeURI( OUString& rName )
+{
+    // try OASIS + W3 URI normalization
+    bool bSuccess = NormalizeOasisURN( rName );
+    if( ! bSuccess )
+        bSuccess = NormalizeW3URI( rName );
+}
+
+constexpr OUStringLiteral XML_URI_W3_PREFIX(u"http://www.w3.org/");
+constexpr OUStringLiteral XML_URI_XFORMS_SUFFIX(u"/xforms");
+constexpr OUStringLiteral XML_N_XFORMS_1_0(u"http://www.w3.org/2002/xforms");
+constexpr OUStringLiteral XML_N_SVG(u"http://www.w3.org/2000/svg");
+constexpr OUStringLiteral XML_N_SVG_COMPAT(u"urn:oasis:names:tc:opendocument:xmlns:svg-compatible:1.0");
+constexpr OUStringLiteral XML_N_FO(u"http://www.w3.org/1999/XSL/Format");
+constexpr OUStringLiteral XML_N_FO_COMPAT(u"urn:oasis:names:tc:opendocument:xmlns:xsl-fo-compatible:1.0");
+constexpr OUStringLiteral XML_N_SMIL(u"http://www.w3.org/2001/SMIL20/");
+constexpr OUStringLiteral XML_N_SMIL_OLD(u"http://www.w3.org/2001/SMIL20");
+constexpr OUStringLiteral XML_N_SMIL_COMPAT(u"urn:oasis:names:tc:opendocument:xmlns:smil-compatible:1.0");
+constexpr OUStringLiteral XML_URN_OASIS_NAMES_TC(u"urn:oasis:names:tc");
+constexpr OUStringLiteral XML_XMLNS(u"xmlns");
+constexpr OUStringLiteral XML_OPENDOCUMENT(u"opendocument");
+constexpr OUStringLiteral XML_1_0(u"1.0");
+
+static bool NormalizeW3URI( OUString& rName )
+{
+    // check if URI matches:
+    // http://www.w3.org/[0-9]*/[:letter:]*
+    //                   (year)/(WG name)
+    // For the following WG/standards names:
+    // - xforms
+
+    bool bSuccess = false;
+    const OUString& sURIPrefix = XML_URI_W3_PREFIX;
+    if( rName.startsWith( sURIPrefix ) )
+    {
+        const OUString& sURISuffix = XML_URI_XFORMS_SUFFIX ;
+        sal_Int32 nCompareFrom = rName.getLength() - sURISuffix.getLength();
+        if( rName.subView( nCompareFrom ) == sURISuffix )
+        {
+            // found W3 prefix, and xforms suffix
+            rName = XML_N_XFORMS_1_0;
+            bSuccess = true;
+        }
+    }
+    return bSuccess;
+}
+
+static bool NormalizeOasisURN( OUString& rName )
+{
+    // #i38644#
+    // we exported the wrong namespace for smil, so we correct this here on load
+    // for older documents
+    if( rName == XML_N_SVG )
+    {
+        rName = XML_N_SVG_COMPAT;
+        return true;
+    }
+    else if( rName == XML_N_FO )
+    {
+        rName = XML_N_FO_COMPAT;
+        return true;
+    }
+    else if( rName == XML_N_SMIL || rName == XML_N_SMIL_OLD  )
+    {
+        rName = XML_N_SMIL_COMPAT;
+        return true;
+    }
+
+
+    // Check if URN matches
+    // :urn:oasis:names:tc:[^:]*:xmlns:[^:]*:1.[^:]*
+    //                     |---|       |---| |-----|
+    //                     TC-Id      Sub-Id Version
+
+    sal_Int32 nNameLen = rName.getLength();
+    // :urn:oasis:names:tc.*
+    const OUString& rOasisURN = XML_URN_OASIS_NAMES_TC;
+    if( !rName.startsWith( rOasisURN ) )
+        return false;
+
+    // :urn:oasis:names:tc:.*
+    sal_Int32 nPos = rOasisURN.getLength();
+    if( nPos >= nNameLen || rName[nPos] != ':' )
+        return false;
+
+    // :urn:oasis:names:tc:[^:]:.*
+    sal_Int32 nTCIdStart = nPos+1;
+    sal_Int32 nTCIdEnd = rName.indexOf( ':', nTCIdStart );
+    if( -1 == nTCIdEnd )
+        return false;
+
+    // :urn:oasis:names:tc:[^:]:xmlns.*
+    nPos = nTCIdEnd + 1;
+    std::u16string_view sTmp( rName.subView( nPos ) );
+    const OUString& rXMLNS = XML_XMLNS;
+    if( !o3tl::starts_with(sTmp, rXMLNS ) )
+        return false;
+
+    // :urn:oasis:names:tc:[^:]:xmlns:.*
+    nPos += rXMLNS.getLength();
+    if( nPos >= nNameLen || rName[nPos] != ':' )
+        return false;
+
+    // :urn:oasis:names:tc:[^:]:xmlns:[^:]*:.*
+    nPos = rName.indexOf( ':', nPos+1 );
+    if( -1 == nPos )
+        return false;
+
+    // :urn:oasis:names:tc:[^:]:xmlns:[^:]*:[^:][^:][^:][^:]*
+    sal_Int32 nVersionStart = nPos+1;
+    if( nVersionStart+2 >= nNameLen ||
+        -1 != rName.indexOf( ':', nVersionStart ) )
+        return false;
+
+    // :urn:oasis:names:tc:[^:]:xmlns:[^:]*:1\.[^:][^:]*
+    if( rName[nVersionStart] != '1' || rName[nVersionStart+1] != '.' )
+        return false;
+
+    // replace [tcid] with current TCID and version with current version.
+
+    rName = rName.subView( 0, nTCIdStart ) +
+            XML_OPENDOCUMENT +
+            rName.subView( nTCIdEnd, nVersionStart-nTCIdEnd ) +
+            XML_1_0;
+
+    return true;
+}
+
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */
diff --git a/sax/source/fastparser/legacyfastparser.cxx b/sax/source/fastparser/legacyfastparser.cxx
new file mode 100644
index 000000000..e4c425bd0
--- /dev/null
+++ b/sax/source/fastparser/legacyfastparser.cxx
@@ -0,0 +1,375 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ *
+ * This file incorporates work covered by the following license notice:
+ *
+ *   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 .
+ */
+
+#include <com/sun/star/lang/XServiceInfo.hpp>
+#include <com/sun/star/xml/sax/XParser.hpp>
+#include <com/sun/star/xml/sax/FastParser.hpp>
+#include <com/sun/star/lang/XInitialization.hpp>
+#include <com/sun/star/beans/Pair.hpp>
+#include <comphelper/attributelist.hxx>
+#include <cppuhelper/supportsservice.hxx>
+#include <comphelper/processfactory.hxx>
+#include <rtl/ref.hxx>
+#include <memory>
+#include <utility>
+#include <vector>
+
+using namespace ::cppu;
+using namespace css;
+using namespace uno;
+using namespace lang;
+using namespace xml::sax;
+using namespace io;
+
+namespace {
+
+class NamespaceHandler : public WeakImplHelper< XFastNamespaceHandler >
+{
+private:
+    struct NamespaceDefine
+    {
+        OUString    m_aPrefix;
+        OUString    m_aNamespaceURI;
+
+        NamespaceDefine( OUString aPrefix, OUString aNamespaceURI ) : m_aPrefix(std::move( aPrefix )), m_aNamespaceURI(std::move( aNamespaceURI )) {}
+    };
+    std::vector< std::unique_ptr< NamespaceDefine > > m_aNamespaceDefines;
+
+public:
+    NamespaceHandler();
+    void addNSDeclAttributes( rtl::Reference < comphelper::AttributeList > const & rAttrList );
+
+    //XFastNamespaceHandler
+    virtual void SAL_CALL registerNamespace( const OUString& rNamespacePrefix, const OUString& rNamespaceURI ) override;
+    virtual OUString SAL_CALL getNamespaceURI( const OUString& rNamespacePrefix ) override;
+};
+
+NamespaceHandler::NamespaceHandler()
+{
+}
+
+void NamespaceHandler::addNSDeclAttributes( rtl::Reference < comphelper::AttributeList > const & rAttrList )
+{
+    for(const auto& aNamespaceDefine : m_aNamespaceDefines)
+    {
+        OUString& rPrefix = aNamespaceDefine->m_aPrefix;
+        OUString& rNamespaceURI = aNamespaceDefine->m_aNamespaceURI;
+        OUString sDecl;
+        if ( rPrefix.isEmpty() )
+            sDecl = "xmlns";
+        else
+            sDecl = "xmlns:" + rPrefix;
+        rAttrList->AddAttribute( sDecl, "CDATA", rNamespaceURI );
+    }
+    m_aNamespaceDefines.clear();
+}
+
+void NamespaceHandler::registerNamespace( const OUString& rNamespacePrefix, const OUString& rNamespaceURI )
+{
+    m_aNamespaceDefines.push_back( std::make_unique<NamespaceDefine>(
+                                    rNamespacePrefix, rNamespaceURI) );
+}
+
+OUString NamespaceHandler::getNamespaceURI( const OUString&/* rNamespacePrefix */ )
+{
+    return OUString();
+}
+
+class SaxLegacyFastParser : public WeakImplHelper< XInitialization, XServiceInfo, XParser >
+{
+private:
+    rtl::Reference< NamespaceHandler > m_aNamespaceHandler;
+public:
+    SaxLegacyFastParser();
+
+// css::lang::XInitialization:
+    virtual void SAL_CALL initialize(css::uno::Sequence<css::uno::Any> const& rArguments) override;
+
+// The SAX-Parser-Interface
+    virtual void SAL_CALL parseStream(  const InputSource& structSource) override;
+    virtual void SAL_CALL setDocumentHandler(const Reference< XDocumentHandler > & xHandler) override;
+    virtual void SAL_CALL setErrorHandler(const Reference< XErrorHandler > & xHandler) override;
+    virtual void SAL_CALL setDTDHandler(const Reference < XDTDHandler > & xHandler) override;
+    virtual void SAL_CALL setEntityResolver(const Reference<  XEntityResolver >& xResolver) override;
+    virtual void SAL_CALL setLocale( const Locale &locale ) override;
+
+// XServiceInfo
+    OUString SAL_CALL getImplementationName() override;
+    Sequence< OUString > SAL_CALL getSupportedServiceNames() override;
+    sal_Bool SAL_CALL supportsService(const OUString& ServiceName) override;
+
+private:
+    Reference< XFastParser > m_xParser;
+    Reference< XDocumentHandler > m_xDocumentHandler;
+    Reference< XFastTokenHandler > m_xTokenHandler;
+
+};
+
+
+class CallbackDocumentHandler : public WeakImplHelper< XFastDocumentHandler >
+{
+private:
+    Reference< XDocumentHandler > m_xDocumentHandler;
+    Reference< XFastTokenHandler > m_xTokenHandler;
+    rtl::Reference< NamespaceHandler > m_aNamespaceHandler;
+    OUString getNamespacePrefixFromToken( sal_Int32 nToken );
+    OUString getNameFromToken( sal_Int32 nToken );
+
+    static constexpr OUStringLiteral aDefaultNamespace = u"";
+    static constexpr OUStringLiteral aNamespaceSeparator = u":";
+
+public:
+    CallbackDocumentHandler( Reference< XDocumentHandler > const & xDocumentHandler,
+                             rtl::Reference< NamespaceHandler > const & rNamespaceHandler,
+                             Reference< XFastTokenHandler > const & xTokenHandler);
+
+    // XFastDocumentHandler
+    virtual void SAL_CALL startDocument() override;
+    virtual void SAL_CALL endDocument() override;
+    virtual void SAL_CALL processingInstruction( const OUString& rTarget, const OUString& rData ) override;
+    virtual void SAL_CALL setDocumentLocator( const Reference< XLocator >& xLocator ) override;
+
+    // XFastContextHandler
+    virtual void SAL_CALL startFastElement( sal_Int32 nElement, const Reference< XFastAttributeList >& Attribs ) override;
+    virtual void SAL_CALL startUnknownElement( const OUString& Namespace, const OUString& Name, const Reference< XFastAttributeList >& Attribs ) override;
+    virtual void SAL_CALL endFastElement( sal_Int32 Element ) override;
+    virtual void SAL_CALL endUnknownElement( const OUString& Namespace, const OUString& Name ) override;
+    virtual Reference< XFastContextHandler > SAL_CALL createFastChildContext( sal_Int32 nElement, const Reference< XFastAttributeList >& Attribs ) override;
+    virtual Reference< XFastContextHandler > SAL_CALL createUnknownChildContext( const OUString& Namespace, const OUString& Name, const Reference< XFastAttributeList >& Attribs ) override;
+    virtual void SAL_CALL characters( const OUString& aChars ) override;
+
+};
+
+OUString CallbackDocumentHandler::getNamespacePrefixFromToken( sal_Int32 nToken )
+{
+    if ( ( nToken & 0xffff0000 ) != 0 )
+    {
+        Sequence< sal_Int8 > aSeq = m_xTokenHandler->getUTF8Identifier( nToken & 0xffff0000 );
+        return OUString( reinterpret_cast< const char* >(
+                        aSeq.getConstArray() ), aSeq.getLength(), RTL_TEXTENCODING_UTF8 );
+    }
+    else
+        return OUString();
+}
+
+OUString CallbackDocumentHandler::getNameFromToken( sal_Int32 nToken )
+{
+    Sequence< sal_Int8 > aSeq = m_xTokenHandler->getUTF8Identifier( nToken & 0xffff );
+    return OUString( reinterpret_cast< const char* >(
+                    aSeq.getConstArray() ), aSeq.getLength(), RTL_TEXTENCODING_UTF8 );
+}
+
+CallbackDocumentHandler::CallbackDocumentHandler( Reference< XDocumentHandler > const & xDocumentHandler,
+                                                  rtl::Reference< NamespaceHandler > const & rNamespaceHandler,
+                                                  Reference< XFastTokenHandler > const & xTokenHandler)
+{
+   m_xDocumentHandler.set( xDocumentHandler );
+   m_aNamespaceHandler = rNamespaceHandler;
+   m_xTokenHandler.set( xTokenHandler );
+}
+
+void SAL_CALL CallbackDocumentHandler::startDocument()
+{
+    if ( m_xDocumentHandler.is() )
+        m_xDocumentHandler->startDocument();
+}
+
+void SAL_CALL CallbackDocumentHandler::endDocument()
+{
+    if ( m_xDocumentHandler.is() )
+        m_xDocumentHandler->endDocument();
+}
+
+void SAL_CALL CallbackDocumentHandler::processingInstruction( const OUString& rTarget, const OUString& rData )
+{
+    if ( m_xDocumentHandler.is() )
+        m_xDocumentHandler->processingInstruction( rTarget, rData );
+}
+
+void SAL_CALL CallbackDocumentHandler::setDocumentLocator( const Reference< XLocator >& xLocator )
+{
+    if ( m_xDocumentHandler.is() )
+        m_xDocumentHandler->setDocumentLocator( xLocator );
+}
+
+void SAL_CALL CallbackDocumentHandler::startFastElement( sal_Int32 nElement , const Reference< XFastAttributeList >& Attribs  )
+{
+    const OUString& rPrefix = CallbackDocumentHandler::getNamespacePrefixFromToken( nElement );
+    const OUString& rLocalName = CallbackDocumentHandler::getNameFromToken( nElement );
+    startUnknownElement( aDefaultNamespace, (rPrefix.isEmpty())? rLocalName : rPrefix + aNamespaceSeparator + rLocalName, Attribs );
+}
+
+void SAL_CALL CallbackDocumentHandler::startUnknownElement( const OUString& /*Namespace*/, const OUString& Name, const Reference< XFastAttributeList >& Attribs  )
+{
+    if ( !m_xDocumentHandler.is() )
+        return;
+
+    rtl::Reference < comphelper::AttributeList > rAttrList = new comphelper::AttributeList;
+    m_aNamespaceHandler->addNSDeclAttributes( rAttrList );
+
+    const Sequence< xml::FastAttribute > fastAttribs = Attribs->getFastAttributes();
+    for (const auto& rAttr : fastAttribs)
+    {
+        const OUString& rAttrValue = rAttr.Value;
+        sal_Int32 nToken = rAttr.Token;
+        const OUString& rAttrNamespacePrefix = CallbackDocumentHandler::getNamespacePrefixFromToken( nToken );
+        OUString sAttrName = CallbackDocumentHandler::getNameFromToken( nToken );
+        if ( !rAttrNamespacePrefix.isEmpty() )
+            sAttrName = rAttrNamespacePrefix + aNamespaceSeparator + sAttrName;
+
+        rAttrList->AddAttribute( sAttrName, "CDATA", rAttrValue );
+    }
+
+    const Sequence< xml::Attribute > unknownAttribs = Attribs->getUnknownAttributes();
+    for (const auto& rAttr : unknownAttribs)
+    {
+        const OUString& rAttrValue = rAttr.Value;
+        const OUString& rAttrName = rAttr.Name;
+
+        rAttrList->AddAttribute( rAttrName, "CDATA", rAttrValue );
+    }
+    m_xDocumentHandler->startElement( Name, rAttrList );
+}
+
+void SAL_CALL CallbackDocumentHandler::endFastElement( sal_Int32 nElement )
+{
+    const OUString& rPrefix = CallbackDocumentHandler::getNamespacePrefixFromToken( nElement );
+    const OUString& rLocalName = CallbackDocumentHandler::getNameFromToken( nElement );
+    endUnknownElement( aDefaultNamespace, (rPrefix.isEmpty())? rLocalName : rPrefix + aNamespaceSeparator + rLocalName );
+}
+
+
+void SAL_CALL CallbackDocumentHandler::endUnknownElement( const OUString& /*Namespace*/, const OUString& Name )
+{
+    if ( m_xDocumentHandler.is() )
+    {
+        m_xDocumentHandler->endElement( Name );
+    }
+}
+
+Reference< XFastContextHandler > SAL_CALL CallbackDocumentHandler::createFastChildContext( sal_Int32/* nElement */, const Reference< XFastAttributeList >&/* Attribs */ )
+{
+    return this;
+}
+
+
+Reference< XFastContextHandler > SAL_CALL CallbackDocumentHandler::createUnknownChildContext( const OUString&/* Namespace */, const OUString&/* Name */, const Reference< XFastAttributeList >&/* Attribs */ )
+{
+    return this;
+}
+
+void SAL_CALL CallbackDocumentHandler::characters( const OUString& aChars )
+{
+    if ( m_xDocumentHandler.is() )
+        m_xDocumentHandler->characters( aChars );
+}
+
+SaxLegacyFastParser::SaxLegacyFastParser( ) : m_aNamespaceHandler( new NamespaceHandler ),
+  m_xParser(FastParser::create(::comphelper::getProcessComponentContext() ))
+{
+    m_xParser->setNamespaceHandler( m_aNamespaceHandler );
+}
+
+void SAL_CALL SaxLegacyFastParser::initialize(Sequence< Any > const& rArguments )
+{
+    if (!rArguments.hasElements())
+        return;
+
+    Reference< XFastTokenHandler > xTokenHandler;
+    OUString str;
+    if ( ( rArguments[0] >>= xTokenHandler ) && xTokenHandler.is() )
+    {
+        m_xTokenHandler.set( xTokenHandler );
+    }
+    else if ( ( rArguments[0] >>= str ) && "registerNamespaces" == str )
+    {
+        css::beans::Pair< OUString, sal_Int32 > rPair;
+        for (sal_Int32 i = 1; i < rArguments.getLength(); i++ )
+        {
+            rArguments[i] >>= rPair;
+            m_xParser->registerNamespace( rPair.First, rPair.Second );
+        }
+    }
+    else
+    {
+        uno::Reference<lang::XInitialization> const xInit(m_xParser,
+                        uno::UNO_QUERY_THROW);
+        xInit->initialize( rArguments );
+    }
+}
+
+void SaxLegacyFastParser::parseStream( const InputSource& structSource )
+{
+    m_xParser->setFastDocumentHandler( new CallbackDocumentHandler( m_xDocumentHandler,
+                                       m_aNamespaceHandler, m_xTokenHandler ) );
+    m_xParser->setTokenHandler( m_xTokenHandler );
+    m_xParser->parseStream( structSource );
+}
+
+void SaxLegacyFastParser::setDocumentHandler( const Reference< XDocumentHandler > & xHandler )
+{
+    m_xDocumentHandler = xHandler;
+}
+
+void SaxLegacyFastParser::setErrorHandler( const Reference< XErrorHandler > & xHandler )
+{
+    m_xParser->setErrorHandler( xHandler );
+}
+
+void SaxLegacyFastParser::setDTDHandler( const Reference < XDTDHandler > &/* xHandler */ )
+{
+
+}
+
+void SaxLegacyFastParser::setEntityResolver( const Reference<  XEntityResolver >& xResolver )
+{
+    m_xParser->setEntityResolver( xResolver );
+}
+
+void SaxLegacyFastParser::setLocale( const Locale &locale )
+{
+    m_xParser->setLocale( locale );
+}
+
+OUString SaxLegacyFastParser::getImplementationName()
+{
+    return "com.sun.star.comp.extensions.xml.sax.LegacyFastParser";
+}
+
+sal_Bool SaxLegacyFastParser::supportsService(const OUString& ServiceName)
+{
+    return cppu::supportsService(this, ServiceName);
+}
+
+Sequence< OUString > SaxLegacyFastParser::getSupportedServiceNames()
+{
+    return { "com.sun.star.xml.sax.LegacyFastParser" };
+}
+
+} //namespace
+
+extern "C" SAL_DLLPUBLIC_EXPORT css::uno::XInterface *
+com_sun_star_comp_extensions_xml_sax_LegacyFastParser_get_implementation(
+    css::uno::XComponentContext *,
+    css::uno::Sequence<css::uno::Any> const &)
+{
+    return cppu::acquire(new SaxLegacyFastParser);
+}
+
+ /* vim:set shiftwidth=4 softtabstop=4 expandtab: */