Adding upstream version 1:7.0.4.upstream/1%7.0.4upstream

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

6 files changed, 3184 insertions, 0 deletions

diff --git a/io/source/stm/odata.cxx b/io/source/stm/odata.cxx
new file mode 100644
index 000000000..3e802b2d3
--- /dev/null
+++ b/io/source/stm/odata.cxx
@@ -0,0 +1,1284 @@
+/* -*- 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 <string.h>
+#include <unordered_map>
+#include <vector>
+
+#include <cppuhelper/weak.hxx>
+#include <cppuhelper/implbase.hxx>
+#include <cppuhelper/supportsservice.hxx>
+#include <osl/endian.h>
+
+#include <com/sun/star/io/NotConnectedException.hpp>
+#include <com/sun/star/io/XObjectInputStream.hpp>
+#include <com/sun/star/io/XObjectOutputStream.hpp>
+#include <com/sun/star/io/XActiveDataSource.hpp>
+#include <com/sun/star/io/XActiveDataSink.hpp>
+#include <com/sun/star/io/XMarkableStream.hpp>
+#include <com/sun/star/io/XConnectable.hpp>
+#include <com/sun/star/io/UnexpectedEOFException.hpp>
+#include <com/sun/star/io/WrongFormatException.hpp>
+#include <com/sun/star/lang/XServiceInfo.hpp>
+#include <com/sun/star/uno/XComponentContext.hpp>
+
+using namespace ::cppu;
+using namespace ::osl;
+using namespace ::std;
+using namespace ::com::sun::star::io;
+using namespace ::com::sun::star::uno;
+using namespace ::com::sun::star::lang;
+
+#include <services.hxx>
+
+namespace io_stm {
+
+namespace {
+
+class ODataInputStream :
+    public WeakImplHelper <
+                              XDataInputStream,
+                              XActiveDataSink,
+                              XConnectable,
+                              XServiceInfo
+                           >
+{
+public:
+    ODataInputStream( )
+        : m_bValidStream( false )
+        {
+        }
+
+public: // XInputStream
+    virtual sal_Int32 SAL_CALL readBytes(Sequence< sal_Int8 >& aData, sal_Int32 nBytesToRead) override;
+    virtual sal_Int32 SAL_CALL readSomeBytes(Sequence< sal_Int8 >& aData, sal_Int32 nMaxBytesToRead) override;
+    virtual void SAL_CALL skipBytes(sal_Int32 nBytesToSkip) override;
+    virtual sal_Int32 SAL_CALL available() override;
+    virtual void SAL_CALL closeInput() override;
+
+public: // XDataInputStream
+    virtual sal_Int8 SAL_CALL readBoolean() override;
+    virtual sal_Int8 SAL_CALL readByte() override;
+    virtual sal_Unicode SAL_CALL readChar() override;
+    virtual sal_Int16 SAL_CALL readShort() override;
+    virtual sal_Int32 SAL_CALL readLong() override;
+    virtual sal_Int64 SAL_CALL readHyper() override;
+    virtual float SAL_CALL readFloat() override;
+    virtual double SAL_CALL readDouble() override;
+    virtual OUString SAL_CALL readUTF() override;
+
+
+public: // XActiveDataSink
+    virtual void SAL_CALL setInputStream(const Reference< XInputStream > & aStream) override;
+    virtual Reference< XInputStream > SAL_CALL getInputStream() override;
+
+public: // XConnectable
+    virtual void SAL_CALL setPredecessor(const Reference < XConnectable >& aPredecessor) override;
+    virtual Reference < XConnectable > SAL_CALL getPredecessor() override;
+    virtual void SAL_CALL setSuccessor(const Reference < XConnectable >& aSuccessor) override;
+    virtual Reference < XConnectable > SAL_CALL getSuccessor() override ;
+
+
+public: // XServiceInfo
+    OUString                     SAL_CALL getImplementationName() override;
+    Sequence< OUString >         SAL_CALL getSupportedServiceNames() override;
+    sal_Bool                        SAL_CALL supportsService(const OUString& ServiceName) override;
+
+protected:
+
+    Reference < XConnectable >  m_pred;
+    Reference < XConnectable >  m_succ;
+    Reference < XInputStream >  m_input;
+    bool m_bValidStream;
+};
+
+}
+
+// XInputStream
+sal_Int32 ODataInputStream::readBytes(Sequence< sal_Int8 >& aData, sal_Int32 nBytesToRead)
+{
+     if( !m_bValidStream )
+     {
+         throw NotConnectedException( );
+     }
+     sal_Int32 nRead = m_input->readBytes( aData , nBytesToRead );
+     return nRead;
+}
+
+sal_Int32 ODataInputStream::readSomeBytes(Sequence< sal_Int8 >& aData, sal_Int32 nMaxBytesToRead)
+{
+     if( !m_bValidStream )
+         throw NotConnectedException( );
+     sal_Int32 nRead = m_input->readSomeBytes( aData , nMaxBytesToRead );
+     return nRead;
+}
+void ODataInputStream::skipBytes(sal_Int32 nBytesToSkip)
+{
+     if( !m_bValidStream )
+         throw NotConnectedException( );
+     m_input->skipBytes( nBytesToSkip );
+}
+
+
+sal_Int32 ODataInputStream::available()
+{
+     if( !m_bValidStream )
+         throw NotConnectedException( );
+     sal_Int32 nAvail = m_input->available( );
+     return nAvail;
+}
+
+void ODataInputStream::closeInput()
+{
+     if( !m_bValidStream )
+         throw NotConnectedException( );
+     m_input->closeInput( );
+     setInputStream( Reference< XInputStream > () );
+     setPredecessor( Reference < XConnectable >() );
+     setSuccessor( Reference < XConnectable >() );
+     m_bValidStream = false;
+}
+
+
+//== XDataInputStream ===========================================
+
+// XDataInputStream
+sal_Int8 ODataInputStream::readBoolean()
+{
+    return readByte();
+}
+
+sal_Int8 ODataInputStream::readByte()
+{
+    Sequence<sal_Int8> aTmp(1);
+    if( 1 != readBytes( aTmp, 1 ) )
+    {
+        throw UnexpectedEOFException();
+    }
+    return aTmp.getConstArray()[0];
+}
+
+sal_Unicode ODataInputStream::readChar()
+{
+    Sequence<sal_Int8> aTmp(2);
+    if( 2 != readBytes( aTmp, 2 ) )
+    {
+        throw UnexpectedEOFException();
+    }
+
+    const sal_uInt8 * pBytes = reinterpret_cast<const sal_uInt8 *>(aTmp.getConstArray());
+    return (static_cast<sal_Unicode>(pBytes[0]) << 8) + pBytes[1];
+}
+
+sal_Int16 ODataInputStream::readShort()
+{
+    Sequence<sal_Int8> aTmp(2);
+    if( 2 != readBytes( aTmp, 2 ) )
+    {
+        throw UnexpectedEOFException();
+    }
+
+    const sal_uInt8 * pBytes = reinterpret_cast<const sal_uInt8 *>(aTmp.getConstArray());
+    return (static_cast<sal_Int16>(pBytes[0]) << 8) + pBytes[1];
+}
+
+
+sal_Int32 ODataInputStream::readLong()
+{
+    Sequence<sal_Int8> aTmp(4);
+    if( 4 != readBytes( aTmp, 4 ) )
+    {
+        throw UnexpectedEOFException( );
+    }
+
+    const sal_uInt8 * pBytes = reinterpret_cast<const sal_uInt8 *>(aTmp.getConstArray());
+    return (static_cast<sal_Int32>(pBytes[0]) << 24) + (static_cast<sal_Int32>(pBytes[1]) << 16) + (static_cast<sal_Int32>(pBytes[2]) << 8) + pBytes[3];
+}
+
+
+sal_Int64 ODataInputStream::readHyper()
+{
+    Sequence<sal_Int8> aTmp(8);
+    if( 8 != readBytes( aTmp, 8 ) )
+    {
+        throw UnexpectedEOFException( );
+    }
+
+    const sal_uInt8 * pBytes = reinterpret_cast<const sal_uInt8 *>(aTmp.getConstArray());
+    return
+        (static_cast<sal_Int64>(pBytes[0]) << 56) +
+        (static_cast<sal_Int64>(pBytes[1]) << 48) +
+        (static_cast<sal_Int64>(pBytes[2]) << 40) +
+        (static_cast<sal_Int64>(pBytes[3]) << 32) +
+        (static_cast<sal_Int64>(pBytes[4]) << 24) +
+        (static_cast<sal_Int64>(pBytes[5]) << 16) +
+        (static_cast<sal_Int64>(pBytes[6]) << 8) +
+        pBytes[7];
+}
+
+float ODataInputStream::readFloat()
+{
+    union { float f; sal_uInt32 n; } a;
+    a.n = readLong();
+    return a.f;
+}
+
+double ODataInputStream::readDouble()
+{
+    union { double d; struct { sal_uInt32 n1; sal_uInt32 n2; } ad; } a;
+#if defined OSL_LITENDIAN
+    a.ad.n2 = readLong();
+    a.ad.n1 = readLong();
+#else
+    a.ad.n1 = readLong();
+    a.ad.n2 = readLong();
+#endif
+    return a.d;
+}
+
+OUString ODataInputStream::readUTF()
+{
+    sal_uInt16              nShortLen = static_cast<sal_uInt16>(readShort());
+    sal_Int32               nUTFLen;
+
+    if( (sal_uInt16(0xffff)) == nShortLen )
+    {
+        // is interpreted as a sign, that string is longer than 64k
+        // incompatible to older XDataInputStream-routines, when strings are exactly 64k
+        nUTFLen = readLong();
+    }
+    else
+    {
+        nUTFLen = static_cast<sal_Int32>(nShortLen);
+    }
+
+    Sequence<sal_Unicode>   aBuffer( nUTFLen );
+    sal_Unicode *           pStr = aBuffer.getArray();
+
+    sal_Int32 nCount = 0;
+    sal_Int32 nStrLen = 0;
+    while( nCount < nUTFLen )
+    {
+        sal_uInt8 c = static_cast<sal_uInt8>(readByte());
+        sal_uInt8 char2, char3;
+        switch( c >> 4 )
+        {
+            case 0: case 1: case 2: case 3: case 4: case 5: case 6: case 7:
+                // 0xxxxxxx
+                nCount++;
+                pStr[nStrLen++] = c;
+                break;
+
+            case 12: case 13:
+                // 110x xxxx   10xx xxxx
+                nCount += 2;
+                if( nCount > nUTFLen )
+                {
+                    throw WrongFormatException( );
+                }
+
+                char2 = static_cast<sal_uInt8>(readByte());
+                if( (char2 & 0xC0) != 0x80 )
+                {
+                    throw WrongFormatException( );
+                }
+
+                pStr[nStrLen++] = (sal_Unicode(c & 0x1F) << 6) | (char2 & 0x3F);
+                break;
+
+            case 14:
+            // 1110 xxxx  10xx xxxx  10xx xxxx
+                nCount += 3;
+                if( nCount > nUTFLen )
+                {
+                    throw WrongFormatException( );
+                }
+
+                char2 = static_cast<sal_uInt8>(readByte());
+                char3 = static_cast<sal_uInt8>(readByte());
+
+                if( ((char2 & 0xC0) != 0x80) || ((char3 & 0xC0) != 0x80) ) {
+                    throw WrongFormatException( );
+                }
+                pStr[nStrLen++] = (sal_Unicode(c & 0x0F) << 12) |
+                                (sal_Unicode(char2 & 0x3F) << 6) |
+                                (char3 & 0x3F);
+                break;
+
+            default:
+                // 10xx xxxx,  1111 xxxx
+                throw WrongFormatException();
+                //throw new UTFDataFormatException();
+        }
+    }
+    return OUString( pStr, nStrLen );
+}
+
+
+// XActiveDataSource
+void ODataInputStream::setInputStream(const Reference< XInputStream > & aStream)
+{
+
+    if( m_input != aStream ) {
+        m_input = aStream;
+
+        Reference < XConnectable > pred( m_input , UNO_QUERY );
+        setPredecessor( pred );
+    }
+
+    m_bValidStream = m_input.is();
+}
+
+Reference< XInputStream > ODataInputStream::getInputStream()
+{
+    return m_input;
+}
+
+
+// XDataSink
+void ODataInputStream::setSuccessor( const Reference < XConnectable > &r )
+{
+     /// if the references match, nothing needs to be done
+     if( m_succ != r ) {
+         /// store the reference for later use
+         m_succ = r;
+
+         if( m_succ.is() ) {
+              /// set this instance as the sink !
+              m_succ->setPredecessor( Reference< XConnectable > (
+                  static_cast< XConnectable * >(this) ) );
+         }
+     }
+}
+
+Reference < XConnectable > ODataInputStream::getSuccessor()
+{
+    return m_succ;
+}
+
+
+// XDataSource
+void ODataInputStream::setPredecessor( const Reference < XConnectable > &r )
+{
+    if( r != m_pred ) {
+        m_pred = r;
+        if( m_pred.is() ) {
+            m_pred->setSuccessor( Reference< XConnectable > (
+                static_cast< XConnectable * >(this) ) );
+        }
+    }
+}
+Reference < XConnectable > ODataInputStream::getPredecessor()
+{
+    return m_pred;
+}
+
+// XServiceInfo
+OUString ODataInputStream::getImplementationName()
+{
+    return ODataInputStream_getImplementationName();
+}
+
+// XServiceInfo
+sal_Bool ODataInputStream::supportsService(const OUString& ServiceName)
+{
+    return cppu::supportsService(this, ServiceName);
+}
+
+// XServiceInfo
+Sequence< OUString > ODataInputStream::getSupportedServiceNames()
+{
+    return ODataInputStream_getSupportedServiceNames();
+}
+
+/***
+*
+* registration information
+*
+*
+****/
+
+Reference< XInterface > ODataInputStream_CreateInstance(
+    SAL_UNUSED_PARAMETER const Reference < XComponentContext > & )
+{
+    ODataInputStream *p = new ODataInputStream;
+    return Reference< XInterface > ( static_cast<OWeakObject *>(p) );
+}
+
+OUString ODataInputStream_getImplementationName()
+{
+    return "com.sun.star.comp.io.stm.DataInputStream";
+}
+
+Sequence<OUString> ODataInputStream_getSupportedServiceNames()
+{
+    Sequence<OUString> aRet { "com.sun.star.io.DataInputStream" };
+    return aRet;
+}
+
+namespace {
+
+class ODataOutputStream :
+    public WeakImplHelper <
+             XDataOutputStream,
+             XActiveDataSource,
+             XConnectable,
+              XServiceInfo >
+{
+public:
+    ODataOutputStream()
+        : m_bValidStream( false )
+        {
+        }
+
+public: // XOutputStream
+    virtual void SAL_CALL writeBytes(const Sequence< sal_Int8 >& aData) override;
+    virtual void SAL_CALL flush() override;
+    virtual void SAL_CALL closeOutput() override;
+
+public: // XDataOutputStream
+    virtual void SAL_CALL writeBoolean(sal_Bool Value) override;
+    virtual void SAL_CALL writeByte(sal_Int8 Value) override;
+    virtual void SAL_CALL writeChar(sal_Unicode Value) override;
+    virtual void SAL_CALL writeShort(sal_Int16 Value) override;
+    virtual void SAL_CALL writeLong(sal_Int32 Value) override;
+    virtual void SAL_CALL writeHyper(sal_Int64 Value) override;
+    virtual void SAL_CALL writeFloat(float Value) override;
+    virtual void SAL_CALL writeDouble(double Value) override;
+    virtual void SAL_CALL writeUTF(const OUString& Value) override;
+
+public: // XActiveDataSource
+    virtual void SAL_CALL setOutputStream(const Reference< XOutputStream > & aStream) override;
+    virtual Reference < XOutputStream > SAL_CALL getOutputStream() override;
+
+public: // XConnectable
+    virtual void SAL_CALL setPredecessor(const Reference < XConnectable >& aPredecessor) override;
+    virtual Reference < XConnectable > SAL_CALL getPredecessor() override;
+    virtual void SAL_CALL setSuccessor(const Reference < XConnectable >& aSuccessor) override;
+    virtual Reference < XConnectable > SAL_CALL getSuccessor() override;
+
+public: // XServiceInfo
+    OUString                     SAL_CALL getImplementationName() override;
+    Sequence< OUString >         SAL_CALL getSupportedServiceNames() override;
+    sal_Bool                     SAL_CALL supportsService(const OUString& ServiceName) override;
+
+protected:
+    Reference < XConnectable >  m_succ;
+    Reference < XConnectable >  m_pred;
+    Reference<  XOutputStream > m_output;
+    bool m_bValidStream;
+};
+
+}
+
+// XOutputStream
+void ODataOutputStream::writeBytes(const Sequence< sal_Int8 >& aData)
+{
+    if( !m_bValidStream )
+        throw NotConnectedException( );
+    m_output->writeBytes( aData );
+}
+
+void ODataOutputStream::flush()
+{
+    if( !m_bValidStream )
+        throw NotConnectedException();
+    m_output->flush();
+}
+
+
+void ODataOutputStream::closeOutput()
+{
+    if( !m_bValidStream )
+        throw NotConnectedException();
+    m_output->closeOutput();
+    setOutputStream( Reference< XOutputStream > () );
+    setPredecessor( Reference < XConnectable >() );
+    setSuccessor( Reference < XConnectable >() );
+}
+
+// XDataOutputStream
+void ODataOutputStream::writeBoolean(sal_Bool Value)
+{
+    if( Value )
+    {
+        writeByte( 1 );
+    }
+    else
+    {
+        writeByte( 0 );
+    }
+}
+
+
+void ODataOutputStream::writeByte(sal_Int8 Value)
+{
+    writeBytes( { Value } );
+}
+
+void ODataOutputStream::writeChar(sal_Unicode Value)
+{
+    writeBytes( { sal_Int8(Value >> 8),
+                  sal_Int8(Value) } );
+}
+
+
+void ODataOutputStream::writeShort(sal_Int16 Value)
+{
+    writeBytes( { sal_Int8(Value >> 8),
+                  sal_Int8(Value) } );
+}
+
+void ODataOutputStream::writeLong(sal_Int32 Value)
+{
+    writeBytes( { sal_Int8(Value >> 24),
+                  sal_Int8(Value >> 16),
+                  sal_Int8(Value >> 8),
+                  sal_Int8(Value) } );
+}
+
+void ODataOutputStream::writeHyper(sal_Int64 Value)
+{
+    writeBytes( { sal_Int8(Value >> 56),
+                  sal_Int8(Value >> 48),
+                  sal_Int8(Value >> 40),
+                  sal_Int8(Value >> 32),
+                  sal_Int8(Value >> 24),
+                  sal_Int8(Value >> 16),
+                  sal_Int8(Value >> 8),
+                  sal_Int8(Value) } );
+}
+
+
+void ODataOutputStream::writeFloat(float Value)
+{
+    union { float f; sal_uInt32 n; } a;
+    a.f = Value;
+    writeLong( a.n );
+}
+
+void ODataOutputStream::writeDouble(double Value)
+{
+    union { double d; struct { sal_uInt32 n1; sal_uInt32 n2; } ad; } a;
+    a.d = Value;
+#if defined OSL_LITENDIAN
+    writeLong( a.ad.n2 );
+    writeLong( a.ad.n1 );
+#else
+    writeLong( a.ad.n1 );
+    writeLong( a.ad.n2 );
+#endif
+}
+
+void ODataOutputStream::writeUTF(const OUString& Value)
+{
+    sal_Int32 nStrLen = Value.getLength();
+    const sal_Unicode * pStr = Value.getStr();
+    sal_Int32 nUTFLen = 0;
+    sal_Int32 i;
+
+    for( i = 0 ; i < nStrLen ; i++ )
+    {
+        sal_uInt16 c = pStr[i];
+        if( (c >= 0x0001) && (c <= 0x007F) )
+        {
+            nUTFLen++;
+        }
+        else if( c > 0x07FF )
+        {
+            nUTFLen += 3;
+        }
+        else
+        {
+            nUTFLen += 2;
+        }
+    }
+
+
+    // compatibility mode for older implementations, where it was not possible
+    // to write blocks bigger than 64 k. Note that there is a tradeoff. Blocks,
+    // that are exactly 64k long can not be read by older routines when written
+    // with these routines and the other way round !!!!!
+    if( nUTFLen >= 0xFFFF ) {
+        writeShort( sal_Int16(-1) );
+        writeLong( nUTFLen );
+    }
+    else {
+        writeShort( static_cast<sal_uInt16>(nUTFLen) );
+    }
+    for( i = 0 ; i < nStrLen ; i++ )
+    {
+        sal_uInt16 c = pStr[i];
+        if( (c >= 0x0001) && (c <= 0x007F) )
+        {
+            writeByte(sal_Int8(c));
+        }
+        else if( c > 0x07FF )
+        {
+            writeByte(sal_Int8(0xE0 | ((c >> 12) & 0x0F)));
+            writeByte(sal_Int8(0x80 | ((c >>  6) & 0x3F)));
+            writeByte(sal_Int8(0x80 | ((c >>  0) & 0x3F)));
+        }
+        else
+        {
+            writeByte(sal_Int8(0xC0 | ((c >>  6) & 0x1F)));
+            writeByte(sal_Int8(0x80 | ((c >>  0) & 0x3F)));
+        }
+    }
+}
+
+// XActiveDataSource
+void ODataOutputStream::setOutputStream(const Reference< XOutputStream > & aStream)
+{
+    if( m_output != aStream ) {
+        m_output = aStream;
+        m_bValidStream = m_output.is();
+
+        Reference < XConnectable > succ( m_output , UNO_QUERY );
+        setSuccessor( succ );
+    }
+}
+
+Reference< XOutputStream > ODataOutputStream::getOutputStream()
+{
+    return m_output;
+}
+
+
+// XDataSink
+void ODataOutputStream::setSuccessor( const Reference < XConnectable > &r )
+{
+     /// if the references match, nothing needs to be done
+     if( m_succ != r )
+     {
+         /// store the reference for later use
+         m_succ = r;
+
+         if( m_succ.is() )
+         {
+              /// set this instance as the sink !
+              m_succ->setPredecessor( Reference < XConnectable > (
+                  static_cast< XConnectable * >(this) ));
+         }
+     }
+}
+Reference < XConnectable > ODataOutputStream::getSuccessor()
+{
+    return m_succ;
+}
+
+
+// XDataSource
+void ODataOutputStream::setPredecessor( const Reference < XConnectable > &r )
+{
+    if( r != m_pred ) {
+        m_pred = r;
+        if( m_pred.is() ) {
+            m_pred->setSuccessor( Reference< XConnectable > (
+                static_cast< XConnectable * >(this) ));
+        }
+    }
+}
+Reference < XConnectable > ODataOutputStream::getPredecessor()
+{
+    return m_pred;
+}
+
+
+// XServiceInfo
+OUString ODataOutputStream::getImplementationName()
+{
+    return ODataOutputStream_getImplementationName();
+}
+
+// XServiceInfo
+sal_Bool ODataOutputStream::supportsService(const OUString& ServiceName)
+{
+    return cppu::supportsService(this, ServiceName);
+}
+
+// XServiceInfo
+Sequence< OUString > ODataOutputStream::getSupportedServiceNames()
+{
+    return ODataOutputStream_getSupportedServiceNames();
+}
+
+Reference< XInterface > ODataOutputStream_CreateInstance(
+    SAL_UNUSED_PARAMETER const Reference < XComponentContext > & )
+{
+    ODataOutputStream *p = new ODataOutputStream;
+    Reference< XInterface > xService = *p;
+    return xService;
+}
+
+
+OUString ODataOutputStream_getImplementationName()
+{
+    return "com.sun.star.comp.io.stm.DataOutputStream";
+}
+
+Sequence<OUString> ODataOutputStream_getSupportedServiceNames()
+{
+    Sequence<OUString> aRet { "com.sun.star.io.DataOutputStream" };
+    return aRet;
+}
+
+namespace {
+
+struct equalObjectContainer_Impl
+{
+    bool operator()(const Reference< XInterface > & s1,
+                         const Reference< XInterface > & s2) const
+      {
+        return s1 == s2;
+    }
+};
+
+
+struct hashObjectContainer_Impl
+{
+    size_t operator()(const Reference< XInterface > & xRef) const
+    {
+        return reinterpret_cast<size_t>(xRef.get());
+    }
+};
+
+}
+
+typedef std::unordered_map
+<
+    Reference< XInterface >,
+    sal_Int32,
+    hashObjectContainer_Impl,
+    equalObjectContainer_Impl
+> ObjectContainer_Impl;
+
+namespace {
+
+class OObjectOutputStream:
+    public ImplInheritanceHelper<
+            ODataOutputStream, /* parent */
+            XObjectOutputStream, XMarkableStream >
+{
+public:
+    OObjectOutputStream()
+        : m_nMaxId(0) ,
+          m_bValidMarkable(false)
+        {
+        }
+
+public:
+    // XOutputStream
+    virtual void SAL_CALL writeBytes(const Sequence< sal_Int8 >& aData) override
+        { ODataOutputStream::writeBytes( aData ); }
+
+    virtual void SAL_CALL flush() override
+        { ODataOutputStream::flush(); }
+
+    virtual void SAL_CALL closeOutput() override
+        { ODataOutputStream::closeOutput(); }
+
+public:
+    // XDataOutputStream
+    virtual void SAL_CALL writeBoolean(sal_Bool Value) override
+                { ODataOutputStream::writeBoolean( Value ); }
+    virtual void SAL_CALL writeByte(sal_Int8 Value) override
+                { ODataOutputStream::writeByte( Value ); }
+    virtual void SAL_CALL writeChar(sal_Unicode Value) override
+                { ODataOutputStream::writeChar( Value ); }
+    virtual void SAL_CALL writeShort(sal_Int16 Value) override
+                { ODataOutputStream::writeShort( Value ); }
+    virtual void SAL_CALL writeLong(sal_Int32 Value) override
+                { ODataOutputStream::writeLong( Value ); }
+    virtual void SAL_CALL writeHyper(sal_Int64 Value) override
+                { ODataOutputStream::writeHyper( Value ); }
+    virtual void SAL_CALL writeFloat(float Value) override
+                { ODataOutputStream::writeFloat( Value ); }
+    virtual void SAL_CALL writeDouble(double Value) override
+                { ODataOutputStream::writeDouble( Value ); }
+    virtual void SAL_CALL writeUTF(const OUString& Value) override
+                { ODataOutputStream::writeUTF( Value );}
+
+    // XObjectOutputStream
+        virtual void SAL_CALL writeObject( const Reference< XPersistObject > & r ) override;
+
+public: // XMarkableStream
+    virtual sal_Int32 SAL_CALL createMark() override;
+    virtual void SAL_CALL deleteMark(sal_Int32 Mark) override;
+    virtual void SAL_CALL jumpToMark(sal_Int32 nMark) override;
+    virtual void SAL_CALL jumpToFurthest() override;
+    virtual sal_Int32 SAL_CALL offsetToMark(sal_Int32 nMark) override;
+
+public: // XServiceInfo
+    OUString                   SAL_CALL   getImplementationName() override;
+    Sequence< OUString >       SAL_CALL   getSupportedServiceNames() override;
+    sal_Bool                   SAL_CALL   supportsService(const OUString& ServiceName) override;
+
+private:
+    void connectToMarkable();
+private:
+    ObjectContainer_Impl                m_mapObject;
+    sal_Int32                           m_nMaxId;
+    Reference< XMarkableStream >        m_rMarkable;
+    bool                            m_bValidMarkable;
+};
+
+}
+
+void OObjectOutputStream::writeObject( const Reference< XPersistObject > & xPObj )
+{
+
+    connectToMarkable();
+    bool bWriteObj = false;
+    // create Mark to write length of info
+    sal_uInt32 nInfoLenMark = m_rMarkable->createMark();
+
+    // length of the info data (is later rewritten)
+    OObjectOutputStream::writeShort( 0 );
+
+    // write the object identifier
+    if( xPObj.is() )
+    {
+        Reference< XInterface > rX( xPObj , UNO_QUERY );
+
+        ObjectContainer_Impl::const_iterator aIt
+            = m_mapObject.find( rX );
+        if( aIt == m_mapObject.end() )
+        {
+            // insert new object in hash table
+            m_mapObject[ rX ] = ++m_nMaxId;
+            ODataOutputStream::writeLong( m_nMaxId );
+            ODataOutputStream::writeUTF( xPObj->getServiceName() );
+            bWriteObj = true;
+        }
+        else
+        {
+            ODataOutputStream::writeLong( (*aIt).second );
+            ODataOutputStream::writeUTF( OUString() );
+        }
+    }
+    else
+    {
+        ODataOutputStream::writeLong( 0 );
+        ODataOutputStream::writeUTF( OUString() );
+    }
+
+    sal_uInt32 nObjLenMark = m_rMarkable->createMark();
+    ODataOutputStream::writeLong( 0 );
+
+    sal_Int32 nInfoLen = m_rMarkable->offsetToMark( nInfoLenMark );
+    m_rMarkable->jumpToMark( nInfoLenMark );
+    // write length of the info data
+    ODataOutputStream::writeShort( static_cast<sal_Int16>(nInfoLen) );
+    // jump to the end of the stream
+    m_rMarkable->jumpToFurthest();
+
+    if( bWriteObj )
+        xPObj->write( Reference< XObjectOutputStream > (
+            static_cast< XObjectOutputStream *  >(this) ) );
+
+    sal_Int32 nObjLen = m_rMarkable->offsetToMark( nObjLenMark ) -4;
+    m_rMarkable->jumpToMark( nObjLenMark );
+    // write length of the info data
+    ODataOutputStream::writeLong( nObjLen );
+    // jump to the end of the stream
+    m_rMarkable->jumpToFurthest();
+
+    m_rMarkable->deleteMark( nObjLenMark );
+    m_rMarkable->deleteMark( nInfoLenMark );
+}
+
+
+void OObjectOutputStream::connectToMarkable()
+{
+    if(  m_bValidMarkable )
+        return;
+
+    if( ! m_bValidStream )
+        throw NotConnectedException();
+
+    // find the markable stream !
+    Reference< XInterface > rTry(m_output);
+    while( true ) {
+        if( ! rTry.is() )
+        {
+            throw NotConnectedException();
+        }
+        Reference < XMarkableStream > markable( rTry , UNO_QUERY );
+        if( markable.is() )
+        {
+            m_rMarkable = markable;
+            break;
+        }
+        Reference < XActiveDataSource > source( rTry , UNO_QUERY );
+        rTry = source;
+    }
+    m_bValidMarkable = true;
+}
+
+
+sal_Int32 OObjectOutputStream::createMark()
+{
+    connectToMarkable();    // throws an exception, if a markable is not connected !
+
+    return m_rMarkable->createMark();
+}
+
+void OObjectOutputStream::deleteMark(sal_Int32 Mark)
+{
+    if( ! m_bValidMarkable )
+    {
+        throw NotConnectedException();
+    }
+    m_rMarkable->deleteMark( Mark );
+}
+
+void OObjectOutputStream::jumpToMark(sal_Int32 nMark)
+{
+    if( ! m_bValidMarkable )
+    {
+        throw NotConnectedException();
+    }
+    m_rMarkable->jumpToMark( nMark );
+}
+
+
+void OObjectOutputStream::jumpToFurthest()
+{
+    connectToMarkable();
+    m_rMarkable->jumpToFurthest();
+}
+
+sal_Int32 OObjectOutputStream::offsetToMark(sal_Int32 nMark)
+{
+    if( ! m_bValidMarkable )
+    {
+        throw NotConnectedException();
+    }
+    return m_rMarkable->offsetToMark( nMark );
+}
+
+
+Reference< XInterface > OObjectOutputStream_CreateInstance(
+    SAL_UNUSED_PARAMETER const Reference < XComponentContext > & )
+{
+    OObjectOutputStream *p = new OObjectOutputStream;
+    return  Reference< XInterface > ( static_cast< OWeakObject *  >(p) );
+}
+
+OUString OObjectOutputStream_getImplementationName()
+{
+    return "com.sun.star.comp.io.stm.ObjectOutputStream";
+}
+
+Sequence<OUString> OObjectOutputStream_getSupportedServiceNames()
+{
+    Sequence<OUString> aRet { "com.sun.star.io.ObjectOutputStream" };
+    return aRet;
+}
+
+// XServiceInfo
+OUString OObjectOutputStream::getImplementationName()
+{
+    return OObjectOutputStream_getImplementationName();
+}
+
+// XServiceInfo
+sal_Bool OObjectOutputStream::supportsService(const OUString& ServiceName)
+{
+    return cppu::supportsService(this, ServiceName);
+}
+
+// XServiceInfo
+Sequence< OUString > OObjectOutputStream::getSupportedServiceNames()
+{
+    return OObjectOutputStream_getSupportedServiceNames();
+}
+
+namespace {
+
+class OObjectInputStream:
+    public ImplInheritanceHelper<
+        ODataInputStream, /* parent */
+        XObjectInputStream, XMarkableStream >
+{
+public:
+    explicit OObjectInputStream( const Reference < XComponentContext > &r)
+        : m_rSMgr( r->getServiceManager() )
+        , m_rCxt( r )
+        , m_bValidMarkable(false)
+        {
+        }
+
+public: // XInputStream
+    virtual sal_Int32 SAL_CALL readBytes(Sequence< sal_Int8 >& aData, sal_Int32 nBytesToRead) override
+        { return ODataInputStream::readBytes( aData , nBytesToRead ); }
+
+    virtual sal_Int32 SAL_CALL readSomeBytes(Sequence< sal_Int8 >& aData, sal_Int32 nMaxBytesToRead) override
+        { return ODataInputStream::readSomeBytes( aData, nMaxBytesToRead ); }
+
+    virtual void SAL_CALL skipBytes(sal_Int32 nBytesToSkip) override
+        { ODataInputStream::skipBytes( nBytesToSkip ); }
+
+    virtual sal_Int32 SAL_CALL available() override
+        { return ODataInputStream::available(); }
+
+    virtual void SAL_CALL closeInput() override
+        { ODataInputStream::closeInput(); }
+
+public: // XDataInputStream
+    virtual sal_Int8 SAL_CALL readBoolean() override
+                { return ODataInputStream::readBoolean(); }
+    virtual sal_Int8 SAL_CALL readByte() override
+                { return ODataInputStream::readByte(); }
+    virtual sal_Unicode SAL_CALL readChar() override
+                { return ODataInputStream::readChar(); }
+    virtual sal_Int16 SAL_CALL readShort() override
+                { return ODataInputStream::readShort(); }
+    virtual sal_Int32 SAL_CALL readLong() override
+                { return ODataInputStream::readLong(); }
+    virtual sal_Int64 SAL_CALL readHyper() override
+                { return ODataInputStream::readHyper(); }
+    virtual float SAL_CALL readFloat() override
+                { return ODataInputStream::readFloat(); }
+    virtual double SAL_CALL readDouble() override
+        { return ODataInputStream::readDouble(); }
+    virtual OUString SAL_CALL readUTF() override
+                { return ODataInputStream::readUTF(); }
+
+public: // XObjectInputStream
+        virtual Reference< XPersistObject > SAL_CALL readObject( ) override;
+
+public: // XMarkableStream
+    virtual sal_Int32 SAL_CALL createMark() override;
+    virtual void SAL_CALL deleteMark(sal_Int32 Mark) override;
+    virtual void SAL_CALL jumpToMark(sal_Int32 nMark) override;
+    virtual void SAL_CALL jumpToFurthest() override;
+    virtual sal_Int32 SAL_CALL offsetToMark(sal_Int32 nMark) override;
+
+public: // XServiceInfo
+    OUString                     SAL_CALL getImplementationName() override;
+    Sequence< OUString >         SAL_CALL getSupportedServiceNames() override;
+    sal_Bool                     SAL_CALL supportsService(const OUString& ServiceName) override;
+
+private:
+    void connectToMarkable();
+private:
+    Reference < XMultiComponentFactory > m_rSMgr;
+    Reference < XComponentContext >     m_rCxt;
+    bool                m_bValidMarkable;
+    Reference < XMarkableStream > m_rMarkable;
+    vector < Reference<  XPersistObject > > m_aPersistVector;
+
+};
+
+}
+
+Reference< XPersistObject >  OObjectInputStream::readObject()
+{
+    // check if chain contains a XMarkableStream
+    connectToMarkable();
+
+    Reference< XPersistObject > xLoadedObj;
+
+    // create Mark to skip newer versions
+    sal_uInt32 nMark = m_rMarkable->createMark();
+    // length of the data
+    sal_Int32 nLen = static_cast<sal_uInt16>(ODataInputStream::readShort());
+    if( nLen < 0xc )
+    {
+        throw WrongFormatException();
+    }
+
+    // read the object identifier
+    sal_uInt32 nId = readLong();
+
+    // the name of the persist model
+    // MM ???
+    OUString aName = readUTF();
+
+    // Read the length of the object
+    sal_Int32 nObjLen = readLong();
+    if( 0 == nId && 0 != nObjLen )
+    {
+        throw WrongFormatException();
+    }
+
+    // skip data of new version
+    skipBytes( nLen - m_rMarkable->offsetToMark( nMark ) );
+
+    bool bLoadSuccessful = true;
+    if( nId )
+    {
+        if( !aName.isEmpty() )
+        {
+            // load the object
+            Reference< XInterface > x = m_rSMgr->createInstanceWithContext( aName, m_rCxt );
+            xLoadedObj.set( x, UNO_QUERY );
+            if( xLoadedObj.is() )
+            {
+                sal_uInt32 nSize = m_aPersistVector.size();
+                if( nSize <= nId )
+                {
+                    // grow to the right size
+                    Reference< XPersistObject > xEmpty;
+                    m_aPersistVector.insert( m_aPersistVector.end(), static_cast<long>(nId - nSize + 1), xEmpty );
+                }
+
+                m_aPersistVector[nId] = xLoadedObj;
+                xLoadedObj->read( Reference< XObjectInputStream >(
+                    static_cast< XObjectInputStream * >(this) ) );
+            }
+            else
+            {
+                // no service with this name could be instantiated
+                bLoadSuccessful = false;
+            }
+        }
+        else {
+            if (nId >= m_aPersistVector.size())
+            {
+                // id unknown, load failure !
+                bLoadSuccessful = false;
+            }
+            else
+            {
+                // Object has already been read,
+                xLoadedObj = m_aPersistVector[nId];
+            }
+        }
+    }
+
+    // skip to the position behind the object
+    skipBytes( nObjLen + nLen - m_rMarkable->offsetToMark( nMark ) );
+    m_rMarkable->deleteMark( nMark );
+
+    if( ! bLoadSuccessful )
+    {
+        throw WrongFormatException();
+    }
+    return xLoadedObj;
+}
+
+
+void OObjectInputStream::connectToMarkable()
+{
+    if(  m_bValidMarkable )        return;
+
+    if( ! m_bValidStream )
+    {
+        throw NotConnectedException( );
+    }
+
+    // find the markable stream !
+    Reference< XInterface > rTry(m_input);
+    while( true ) {
+        if( ! rTry.is() )
+        {
+            throw NotConnectedException( );
+        }
+        Reference<  XMarkableStream > markable( rTry , UNO_QUERY );
+        if( markable.is() )
+        {
+            m_rMarkable = markable;
+            break;
+        }
+        Reference < XActiveDataSink > sink( rTry , UNO_QUERY );
+        rTry = sink;
+    }
+    m_bValidMarkable = true;
+}
+
+sal_Int32 OObjectInputStream::createMark()
+{
+    connectToMarkable();    // throws an exception, if a markable is not connected !
+
+    return m_rMarkable->createMark();
+}
+
+void OObjectInputStream::deleteMark(sal_Int32 Mark)
+{
+    if( ! m_bValidMarkable )
+    {
+        throw NotConnectedException();
+    }
+    m_rMarkable->deleteMark( Mark );
+}
+
+void OObjectInputStream::jumpToMark(sal_Int32 nMark)
+{
+    if( ! m_bValidMarkable )
+    {
+        throw NotConnectedException();
+    }
+    m_rMarkable->jumpToMark( nMark );
+}
+void OObjectInputStream::jumpToFurthest()
+{
+    connectToMarkable();
+    m_rMarkable->jumpToFurthest();
+}
+
+sal_Int32 OObjectInputStream::offsetToMark(sal_Int32 nMark)
+{
+    if( ! m_bValidMarkable )
+    {
+        throw NotConnectedException();
+    }
+    return m_rMarkable->offsetToMark( nMark );
+}
+
+// XServiceInfo
+OUString OObjectInputStream::getImplementationName()
+{
+    return OObjectInputStream_getImplementationName();
+}
+
+// XServiceInfo
+sal_Bool OObjectInputStream::supportsService(const OUString& ServiceName)
+{
+    return cppu::supportsService(this, ServiceName);
+}
+
+// XServiceInfo
+Sequence< OUString > OObjectInputStream::getSupportedServiceNames()
+{
+    return OObjectInputStream_getSupportedServiceNames();
+}
+
+Reference< XInterface > OObjectInputStream_CreateInstance( const Reference < XComponentContext > & rCtx )
+{
+    OObjectInputStream *p = new OObjectInputStream( rCtx );
+    return Reference< XInterface> ( static_cast< OWeakObject * >(p) );
+}
+
+OUString OObjectInputStream_getImplementationName()
+{
+    return "com.sun.star.comp.io.stm.ObjectInputStream";
+}
+
+Sequence<OUString> OObjectInputStream_getSupportedServiceNames()
+{
+    Sequence<OUString> aRet { "com.sun.star.io.ObjectInputStream" };
+    return aRet;
+}
+
+}
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */
diff --git a/io/source/stm/omark.cxx b/io/source/stm/omark.cxx
new file mode 100644
index 000000000..0c7a82142
--- /dev/null
+++ b/io/source/stm/omark.cxx
@@ -0,0 +1,801 @@
+/* -*- 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 <map>
+#include <memory>
+
+#include <com/sun/star/io/BufferSizeExceededException.hpp>
+#include <com/sun/star/io/NotConnectedException.hpp>
+#include <com/sun/star/io/XMarkableStream.hpp>
+#include <com/sun/star/io/XOutputStream.hpp>
+#include <com/sun/star/io/XInputStream.hpp>
+#include <com/sun/star/io/XActiveDataSource.hpp>
+#include <com/sun/star/io/XActiveDataSink.hpp>
+#include <com/sun/star/io/XConnectable.hpp>
+#include <com/sun/star/lang/IllegalArgumentException.hpp>
+#include <com/sun/star/lang/XServiceInfo.hpp>
+
+#include <cppuhelper/weak.hxx>
+#include <cppuhelper/implbase.hxx>
+#include <cppuhelper/supportsservice.hxx>
+
+#include <osl/mutex.hxx>
+#include <osl/diagnose.h>
+
+
+using namespace ::std;
+using namespace ::cppu;
+using namespace ::osl;
+using namespace ::com::sun::star::io;
+using namespace ::com::sun::star::uno;
+using namespace ::com::sun::star::lang;
+
+#include <services.hxx>
+#include "streamhelper.hxx"
+
+namespace io_stm {
+
+namespace {
+
+/***********************
+*
+* OMarkableOutputStream.
+*
+* This object allows to set marks in an outputstream. It is allowed to jump back to the marks and
+* rewrite the same bytes.
+*
+*         The object must buffer the data since the last mark set. Flush will not
+*         have any effect. As soon as the last mark has been removed, the object may write the data
+*         through to the chained object.
+*
+**********************/
+class OMarkableOutputStream :
+    public WeakImplHelper< XOutputStream ,
+                            XActiveDataSource ,
+                            XMarkableStream ,
+                            XConnectable,
+                            XServiceInfo
+                          >
+{
+public:
+    OMarkableOutputStream(  );
+
+public: // XOutputStream
+    virtual void SAL_CALL writeBytes(const Sequence< sal_Int8 >& aData) override;
+    virtual void SAL_CALL flush() override;
+    virtual void SAL_CALL closeOutput() override;
+
+public: // XMarkable
+    virtual sal_Int32 SAL_CALL createMark() override;
+    virtual void SAL_CALL deleteMark(sal_Int32 Mark) override;
+    virtual void SAL_CALL jumpToMark(sal_Int32 nMark) override;
+    virtual void SAL_CALL jumpToFurthest() override;
+    virtual sal_Int32 SAL_CALL offsetToMark(sal_Int32 nMark) override;
+
+public: // XActiveDataSource
+    virtual void SAL_CALL setOutputStream(const Reference < XOutputStream > & aStream) override;
+    virtual Reference < XOutputStream > SAL_CALL getOutputStream() override;
+
+public: // XConnectable
+    virtual void SAL_CALL setPredecessor(const Reference < XConnectable > & aPredecessor) override;
+    virtual Reference < XConnectable > SAL_CALL getPredecessor() override;
+    virtual void SAL_CALL setSuccessor(const Reference < XConnectable >& aSuccessor) override;
+    virtual Reference<  XConnectable >  SAL_CALL getSuccessor() override;
+
+public: // XServiceInfo
+    OUString                     SAL_CALL getImplementationName() override;
+    Sequence< OUString >         SAL_CALL getSupportedServiceNames() override;
+    sal_Bool                        SAL_CALL supportsService(const OUString& ServiceName) override;
+
+private:
+    // helper methods
+    /// @throws NotConnectedException
+    /// @throws BufferSizeExceededException
+    void checkMarksAndFlush();
+
+    Reference< XConnectable > m_succ;
+    Reference< XConnectable > m_pred;
+
+    Reference< XOutputStream >  m_output;
+    bool m_bValidStream;
+
+    std::unique_ptr<MemRingBuffer> m_pBuffer;
+    map<sal_Int32,sal_Int32,less< sal_Int32 > > m_mapMarks;
+    sal_Int32 m_nCurrentPos;
+    sal_Int32 m_nCurrentMark;
+
+    Mutex m_mutex;
+};
+
+}
+
+OMarkableOutputStream::OMarkableOutputStream( )
+    : m_bValidStream(false)
+    , m_pBuffer( new MemRingBuffer )
+    , m_nCurrentPos(0)
+    , m_nCurrentMark(0)
+{
+}
+
+// XOutputStream
+void OMarkableOutputStream::writeBytes(const Sequence< sal_Int8 >& aData)
+{
+    if( !m_bValidStream ) {
+        throw NotConnectedException();
+    }
+    if( m_mapMarks.empty() && ( m_pBuffer->getSize() == 0 ) ) {
+        // no mark and  buffer active, simple write through
+        m_output->writeBytes( aData );
+    }
+    else {
+        MutexGuard guard( m_mutex );
+        // new data must be buffered
+        m_pBuffer->writeAt( m_nCurrentPos , aData );
+        m_nCurrentPos += aData.getLength();
+        checkMarksAndFlush();
+    }
+
+}
+
+void OMarkableOutputStream::flush()
+{
+    Reference< XOutputStream > output;
+    {
+        MutexGuard guard( m_mutex );
+        output = m_output;
+    }
+
+    // Markable cannot flush buffered data, because the data may get rewritten,
+    // however one can forward the flush to the chained stream to give it
+    // a chance to write data buffered in the chained stream.
+    if( output.is() )
+    {
+        output->flush();
+    }
+}
+
+void OMarkableOutputStream::closeOutput()
+{
+    if( !m_bValidStream ) {
+        throw NotConnectedException();
+    }
+    MutexGuard guard( m_mutex );
+    // all marks must be cleared and all
+
+    m_mapMarks.clear();
+    m_nCurrentPos = m_pBuffer->getSize();
+    checkMarksAndFlush();
+
+    m_output->closeOutput();
+
+    setOutputStream( Reference< XOutputStream > () );
+    setPredecessor( Reference < XConnectable >() );
+    setSuccessor( Reference< XConnectable > () );
+
+}
+
+
+sal_Int32 OMarkableOutputStream::createMark()
+{
+    MutexGuard guard( m_mutex );
+    sal_Int32 nMark = m_nCurrentMark;
+
+    m_mapMarks[nMark] = m_nCurrentPos;
+
+    m_nCurrentMark ++;
+    return nMark;
+}
+
+void OMarkableOutputStream::deleteMark(sal_Int32 Mark)
+{
+    MutexGuard guard( m_mutex );
+    map<sal_Int32,sal_Int32,less<sal_Int32> >::iterator ii = m_mapMarks.find( Mark );
+
+    if( ii == m_mapMarks.end() ) {
+        throw IllegalArgumentException(
+            "MarkableOutputStream::deleteMark unknown mark (" + OUString::number(Mark) + ")",
+            *this, 0);
+    }
+    m_mapMarks.erase( ii );
+    checkMarksAndFlush();
+}
+
+void OMarkableOutputStream::jumpToMark(sal_Int32 nMark)
+{
+    MutexGuard guard( m_mutex );
+    map<sal_Int32,sal_Int32,less<sal_Int32> >::iterator ii = m_mapMarks.find( nMark );
+
+    if( ii == m_mapMarks.end() ) {
+        throw IllegalArgumentException(
+            "MarkableOutputStream::jumpToMark unknown mark (" + OUString::number(nMark) + ")",
+            *this, 0);
+    }
+    m_nCurrentPos = (*ii).second;
+}
+
+void OMarkableOutputStream::jumpToFurthest()
+{
+    MutexGuard guard( m_mutex );
+    m_nCurrentPos = m_pBuffer->getSize();
+    checkMarksAndFlush();
+}
+
+sal_Int32 OMarkableOutputStream::offsetToMark(sal_Int32 nMark)
+{
+
+    MutexGuard guard( m_mutex );
+    map<sal_Int32,sal_Int32,less<sal_Int32> >::const_iterator ii = m_mapMarks.find( nMark );
+
+    if( ii == m_mapMarks.end() )
+    {
+        throw IllegalArgumentException(
+            "MarkableOutputStream::offsetToMark unknown mark (" + OUString::number(nMark) + ")",
+            *this, 0);
+    }
+    return m_nCurrentPos - (*ii).second;
+}
+
+
+// XActiveDataSource2
+void OMarkableOutputStream::setOutputStream(const Reference < XOutputStream >& aStream)
+{
+    if( m_output != aStream ) {
+        m_output = aStream;
+
+        Reference < XConnectable > succ( m_output , UNO_QUERY );
+        setSuccessor( succ );
+    }
+    m_bValidStream = m_output.is();
+}
+
+Reference< XOutputStream > OMarkableOutputStream::getOutputStream()
+{
+    return m_output;
+}
+
+
+void OMarkableOutputStream::setSuccessor( const Reference< XConnectable > &r )
+{
+     /// if the references match, nothing needs to be done
+     if( m_succ != r ) {
+         /// store the reference for later use
+         m_succ = r;
+
+         if( m_succ.is() ) {
+              m_succ->setPredecessor( Reference < XConnectable > (
+                  static_cast< XConnectable *  >(this) ) );
+         }
+     }
+}
+Reference <XConnectable > OMarkableOutputStream::getSuccessor()
+{
+    return m_succ;
+}
+
+
+// XDataSource
+void OMarkableOutputStream::setPredecessor( const Reference< XConnectable > &r )
+{
+    if( r != m_pred ) {
+        m_pred = r;
+        if( m_pred.is() ) {
+            m_pred->setSuccessor( Reference < XConnectable > (
+                static_cast< XConnectable *  >(this ) ) );
+        }
+    }
+}
+Reference < XConnectable > OMarkableOutputStream::getPredecessor()
+{
+    return m_pred;
+}
+
+
+// private methods
+
+void OMarkableOutputStream::checkMarksAndFlush()
+{
+    // find the smallest mark
+    sal_Int32 nNextFound = m_nCurrentPos;
+    for (auto const& mark : m_mapMarks)
+    {
+        if( mark.second <= nNextFound )  {
+            nNextFound = mark.second;
+        }
+    }
+
+    if( nNextFound ) {
+        // some data must be released !
+        m_nCurrentPos -= nNextFound;
+        for (auto & mark : m_mapMarks)
+        {
+            mark.second -= nNextFound;
+        }
+
+        Sequence<sal_Int8> seq(nNextFound);
+        m_pBuffer->readAt( 0 , seq , nNextFound );
+        m_pBuffer->forgetFromStart( nNextFound );
+
+        // now write data through to streams
+        m_output->writeBytes( seq );
+    }
+    else {
+        // nothing to do. There is a mark or the current cursor position, that prevents
+        // releasing data !
+    }
+}
+
+
+// XServiceInfo
+OUString OMarkableOutputStream::getImplementationName()
+{
+    return OMarkableOutputStream_getImplementationName();
+}
+
+// XServiceInfo
+sal_Bool OMarkableOutputStream::supportsService(const OUString& ServiceName)
+{
+    return cppu::supportsService(this, ServiceName);
+}
+
+// XServiceInfo
+Sequence< OUString > OMarkableOutputStream::getSupportedServiceNames()
+{
+    return OMarkableOutputStream_getSupportedServiceNames();
+}
+
+/*------------------------
+*
+* external binding
+*
+*------------------------*/
+Reference< XInterface > OMarkableOutputStream_CreateInstance(
+    SAL_UNUSED_PARAMETER const Reference < XComponentContext > & )
+{
+    OMarkableOutputStream *p = new OMarkableOutputStream( );
+
+    return Reference < XInterface > ( static_cast<OWeakObject *>(p) );
+}
+
+OUString    OMarkableOutputStream_getImplementationName()
+{
+    return "com.sun.star.comp.io.stm.MarkableOutputStream";
+}
+
+Sequence<OUString> OMarkableOutputStream_getSupportedServiceNames()
+{
+    Sequence<OUString> aRet { "com.sun.star.io.MarkableOutputStream" };
+
+    return aRet;
+}
+
+
+// XMarkableInputStream
+
+namespace {
+
+class OMarkableInputStream :
+    public WeakImplHelper
+    <
+             XInputStream,
+             XActiveDataSink,
+             XMarkableStream,
+             XConnectable,
+             XServiceInfo
+    >
+{
+public:
+    OMarkableInputStream(  );
+
+
+public: // XInputStream
+    virtual sal_Int32 SAL_CALL readBytes(Sequence< sal_Int8 >& aData, sal_Int32 nBytesToRead) override ;
+    virtual sal_Int32 SAL_CALL readSomeBytes(Sequence< sal_Int8 >& aData, sal_Int32 nMaxBytesToRead) override;
+    virtual void SAL_CALL skipBytes(sal_Int32 nBytesToSkip) override;
+
+    virtual sal_Int32 SAL_CALL available() override;
+    virtual void SAL_CALL closeInput() override;
+
+public: // XMarkable
+    virtual sal_Int32 SAL_CALL createMark() override;
+    virtual void SAL_CALL deleteMark(sal_Int32 Mark) override;
+    virtual void SAL_CALL jumpToMark(sal_Int32 nMark) override;
+    virtual void SAL_CALL jumpToFurthest() override;
+    virtual sal_Int32 SAL_CALL offsetToMark(sal_Int32 nMark) override;
+
+public: // XActiveDataSink
+    virtual void SAL_CALL setInputStream(const Reference < XInputStream > & aStream) override;
+    virtual Reference < XInputStream > SAL_CALL getInputStream() override;
+
+public: // XConnectable
+    virtual void SAL_CALL setPredecessor(const Reference < XConnectable > & aPredecessor) override;
+    virtual Reference < XConnectable > SAL_CALL getPredecessor() override;
+    virtual void SAL_CALL setSuccessor(const Reference < XConnectable > & aSuccessor) override;
+    virtual Reference < XConnectable > SAL_CALL getSuccessor() override;
+
+public: // XServiceInfo
+    OUString                     SAL_CALL getImplementationName() override;
+    Sequence< OUString >         SAL_CALL getSupportedServiceNames() override;
+    sal_Bool                         SAL_CALL  supportsService(const OUString& ServiceName) override;
+
+private:
+    void checkMarksAndFlush();
+
+    Reference < XConnectable >  m_succ;
+    Reference < XConnectable >  m_pred;
+
+    Reference< XInputStream > m_input;
+    bool m_bValidStream;
+
+    std::unique_ptr<MemRingBuffer> m_pBuffer;
+    map<sal_Int32,sal_Int32,less< sal_Int32 > > m_mapMarks;
+    sal_Int32 m_nCurrentPos;
+    sal_Int32 m_nCurrentMark;
+
+    Mutex m_mutex;
+};
+
+}
+
+OMarkableInputStream::OMarkableInputStream()
+    : m_bValidStream(false)
+    , m_nCurrentPos(0)
+    , m_nCurrentMark(0)
+{
+    m_pBuffer.reset( new MemRingBuffer );
+}
+
+
+// XInputStream
+
+sal_Int32 OMarkableInputStream::readBytes(Sequence< sal_Int8 >& aData, sal_Int32 nBytesToRead)
+{
+    sal_Int32 nBytesRead;
+
+    if( !m_bValidStream ) {
+        throw NotConnectedException(
+            "MarkableInputStream::readBytes NotConnectedException",
+            *this );
+    }
+    MutexGuard guard( m_mutex );
+    if( m_mapMarks.empty() && ! m_pBuffer->getSize() ) {
+        // normal read !
+        nBytesRead = m_input->readBytes( aData, nBytesToRead );
+    }
+    else {
+        // read from buffer
+        sal_Int32 nRead;
+
+        // read enough bytes into buffer
+        if( m_pBuffer->getSize() - m_nCurrentPos < nBytesToRead  ) {
+            sal_Int32 nToRead = nBytesToRead - ( m_pBuffer->getSize() - m_nCurrentPos );
+            nRead = m_input->readBytes( aData , nToRead );
+
+            OSL_ASSERT( aData.getLength() == nRead );
+
+            m_pBuffer->writeAt( m_pBuffer->getSize() , aData );
+
+            if( nRead < nToRead ) {
+                nBytesToRead = nBytesToRead - (nToRead-nRead);
+            }
+        }
+
+        OSL_ASSERT( m_pBuffer->getSize() - m_nCurrentPos >= nBytesToRead  );
+
+        m_pBuffer->readAt( m_nCurrentPos , aData , nBytesToRead );
+
+        m_nCurrentPos += nBytesToRead;
+        nBytesRead = nBytesToRead;
+    }
+
+    return nBytesRead;
+}
+
+
+sal_Int32 OMarkableInputStream::readSomeBytes(Sequence< sal_Int8 >& aData, sal_Int32 nMaxBytesToRead)
+{
+
+    sal_Int32 nBytesRead;
+    if( !m_bValidStream )    {
+        throw NotConnectedException(
+            "MarkableInputStream::readSomeBytes NotConnectedException",
+            *this );
+    }
+
+    MutexGuard guard( m_mutex );
+    if( m_mapMarks.empty() && ! m_pBuffer->getSize() ) {
+        // normal read !
+        nBytesRead = m_input->readSomeBytes( aData, nMaxBytesToRead );
+    }
+    else {
+        // read from buffer
+        sal_Int32 nRead = 0;
+        sal_Int32 nInBuffer = m_pBuffer->getSize() - m_nCurrentPos;
+        sal_Int32 nAdditionalBytesToRead = std::min<sal_Int32>(nMaxBytesToRead-nInBuffer,m_input->available());
+        nAdditionalBytesToRead = std::max<sal_Int32>(0 , nAdditionalBytesToRead );
+
+        // read enough bytes into buffer
+        if( 0 == nInBuffer ) {
+            nRead = m_input->readSomeBytes( aData , nMaxBytesToRead );
+        }
+        else if( nAdditionalBytesToRead ) {
+            nRead = m_input->readBytes( aData , nAdditionalBytesToRead );
+        }
+
+        if( nRead ) {
+            aData.realloc( nRead );
+            m_pBuffer->writeAt( m_pBuffer->getSize() , aData );
+        }
+
+        nBytesRead = std::min( nMaxBytesToRead , nInBuffer + nRead );
+
+        // now take everything from buffer !
+        m_pBuffer->readAt( m_nCurrentPos , aData , nBytesRead );
+
+        m_nCurrentPos += nBytesRead;
+    }
+
+    return nBytesRead;
+
+
+}
+
+
+void OMarkableInputStream::skipBytes(sal_Int32 nBytesToSkip)
+{
+    if ( nBytesToSkip < 0 )
+        throw BufferSizeExceededException(
+            "precondition not met: XInputStream::skipBytes: non-negative integer required!",
+            *this
+        );
+
+    // this method is blocking
+    Sequence<sal_Int8> seqDummy( nBytesToSkip );
+    readBytes( seqDummy , nBytesToSkip );
+}
+
+sal_Int32 OMarkableInputStream::available()
+{
+    if( !m_bValidStream )    {
+        throw NotConnectedException(
+            "MarkableInputStream::available NotConnectedException",
+            *this );
+    }
+
+    MutexGuard guard( m_mutex );
+    sal_Int32 nAvail = m_input->available() + ( m_pBuffer->getSize() - m_nCurrentPos );
+    return nAvail;
+}
+
+
+void OMarkableInputStream::closeInput()
+{
+    if( !m_bValidStream ) {
+        throw NotConnectedException(
+            "MarkableInputStream::closeInput NotConnectedException",
+            *this );
+    }
+    MutexGuard guard( m_mutex );
+
+    m_input->closeInput();
+
+    setInputStream( Reference< XInputStream > () );
+    setPredecessor( Reference< XConnectable > () );
+    setSuccessor( Reference< XConnectable >() );
+
+    m_pBuffer.reset();
+    m_nCurrentPos = 0;
+    m_nCurrentMark = 0;
+}
+
+// XMarkable
+
+sal_Int32 OMarkableInputStream::createMark()
+{
+    MutexGuard guard( m_mutex );
+    sal_Int32 nMark = m_nCurrentMark;
+
+    m_mapMarks[nMark] = m_nCurrentPos;
+
+    m_nCurrentMark ++;
+    return nMark;
+}
+
+void OMarkableInputStream::deleteMark(sal_Int32 Mark)
+{
+    MutexGuard guard( m_mutex );
+    map<sal_Int32,sal_Int32,less<sal_Int32> >::iterator ii = m_mapMarks.find( Mark );
+
+    if( ii == m_mapMarks.end() ) {
+        throw IllegalArgumentException(
+            "MarkableInputStream::deleteMark unknown mark (" + OUString::number(Mark) + ")",
+            *this , 0 );
+    }
+    m_mapMarks.erase( ii );
+    checkMarksAndFlush();
+}
+
+void OMarkableInputStream::jumpToMark(sal_Int32 nMark)
+{
+    MutexGuard guard( m_mutex );
+    map<sal_Int32,sal_Int32,less<sal_Int32> >::iterator ii = m_mapMarks.find( nMark );
+
+    if( ii == m_mapMarks.end() )
+    {
+        throw IllegalArgumentException(
+            "MarkableInputStream::jumpToMark unknown mark (" + OUString::number(nMark) + ")",
+            *this , 0 );
+    }
+    m_nCurrentPos = (*ii).second;
+}
+
+void OMarkableInputStream::jumpToFurthest()
+{
+    MutexGuard guard( m_mutex );
+    m_nCurrentPos = m_pBuffer->getSize();
+    checkMarksAndFlush();
+}
+
+sal_Int32 OMarkableInputStream::offsetToMark(sal_Int32 nMark)
+{
+    MutexGuard guard( m_mutex );
+    map<sal_Int32,sal_Int32,less<sal_Int32> >::const_iterator ii = m_mapMarks.find( nMark );
+
+    if( ii == m_mapMarks.end() )
+    {
+        throw IllegalArgumentException(
+            "MarkableInputStream::offsetToMark unknown mark (" + OUString::number(nMark) + ")",
+            *this, 0 );
+    }
+    return m_nCurrentPos - (*ii).second;
+}
+
+
+// XActiveDataSource
+void OMarkableInputStream::setInputStream(const Reference< XInputStream > & aStream)
+{
+
+    if( m_input != aStream ) {
+        m_input = aStream;
+
+        Reference < XConnectable >  pred( m_input , UNO_QUERY );
+        setPredecessor( pred );
+    }
+
+    m_bValidStream = m_input.is();
+
+}
+
+Reference< XInputStream > OMarkableInputStream::getInputStream()
+{
+    return m_input;
+}
+
+
+// XDataSink
+void OMarkableInputStream::setSuccessor( const Reference< XConnectable > &r )
+{
+     /// if the references match, nothing needs to be done
+     if( m_succ != r ) {
+         /// store the reference for later use
+         m_succ = r;
+
+         if( m_succ.is() ) {
+              /// set this instance as the sink !
+              m_succ->setPredecessor( Reference< XConnectable > (
+                  static_cast< XConnectable * >(this) ) );
+         }
+     }
+}
+
+Reference < XConnectable >  OMarkableInputStream::getSuccessor()
+{
+    return m_succ;
+}
+
+
+// XDataSource
+void OMarkableInputStream::setPredecessor( const Reference < XConnectable >  &r )
+{
+    if( r != m_pred ) {
+        m_pred = r;
+        if( m_pred.is() ) {
+            m_pred->setSuccessor( Reference< XConnectable > (
+                static_cast< XConnectable * >(this) ) );
+        }
+    }
+}
+Reference< XConnectable >  OMarkableInputStream::getPredecessor()
+{
+    return m_pred;
+}
+
+
+void OMarkableInputStream::checkMarksAndFlush()
+{
+    // find the smallest mark
+    sal_Int32 nNextFound = m_nCurrentPos;
+    for (auto const& mark : m_mapMarks)
+    {
+        if( mark.second <= nNextFound )  {
+            nNextFound = mark.second;
+        }
+    }
+
+    if( nNextFound ) {
+        // some data must be released !
+        m_nCurrentPos -= nNextFound;
+        for (auto & mark : m_mapMarks)
+        {
+            mark.second -= nNextFound;
+        }
+
+        m_pBuffer->forgetFromStart( nNextFound );
+
+    }
+    else {
+        // nothing to do. There is a mark or the current cursor position, that prevents
+        // releasing data !
+    }
+}
+
+// XServiceInfo
+OUString OMarkableInputStream::getImplementationName()
+{
+    return OMarkableInputStream_getImplementationName();
+}
+
+// XServiceInfo
+sal_Bool OMarkableInputStream::supportsService(const OUString& ServiceName)
+{
+    return cppu::supportsService(this, ServiceName);
+}
+
+// XServiceInfo
+Sequence< OUString > OMarkableInputStream::getSupportedServiceNames()
+{
+    return OMarkableInputStream_getSupportedServiceNames();
+}
+
+/*------------------------
+*
+* external binding
+*
+*------------------------*/
+Reference < XInterface > OMarkableInputStream_CreateInstance(
+    SAL_UNUSED_PARAMETER const Reference < XComponentContext > & )
+{
+    OMarkableInputStream *p = new OMarkableInputStream( );
+    return Reference< XInterface > ( static_cast<OWeakObject *>(p) );
+}
+
+OUString    OMarkableInputStream_getImplementationName()
+{
+    return "com.sun.star.comp.io.stm.MarkableInputStream";
+}
+
+Sequence<OUString> OMarkableInputStream_getSupportedServiceNames()
+{
+    Sequence<OUString> aRet { "com.sun.star.io.MarkableInputStream" };
+    return aRet;
+}
+
+}
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */
diff --git a/io/source/stm/opipe.cxx b/io/source/stm/opipe.cxx
new file mode 100644
index 000000000..07331472d
--- /dev/null
+++ b/io/source/stm/opipe.cxx
@@ -0,0 +1,380 @@
+/* -*- 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 <sal/config.h>
+
+#include <com/sun/star/io/BufferSizeExceededException.hpp>
+#include <com/sun/star/io/NotConnectedException.hpp>
+#include <com/sun/star/io/XPipe.hpp>
+#include <com/sun/star/io/XConnectable.hpp>
+
+#include <com/sun/star/lang/XServiceInfo.hpp>
+
+#include <cppuhelper/implbase.hxx>
+#include <cppuhelper/supportsservice.hxx>
+
+#include <osl/conditn.hxx>
+#include <osl/mutex.hxx>
+
+#include <limits>
+#include <memory>
+#include <string.h>
+
+using namespace ::osl;
+using namespace ::cppu;
+using namespace ::com::sun::star::uno;
+using namespace ::com::sun::star::io;
+using namespace ::com::sun::star::lang;
+
+#include <services.hxx>
+#include "streamhelper.hxx"
+
+namespace com::sun::star::uno { class XComponentContext; }
+
+// Implementation and service names
+#define IMPLEMENTATION_NAME "com.sun.star.comp.io.stm.Pipe"
+
+namespace io_stm{
+
+namespace {
+
+class OPipeImpl :
+    public WeakImplHelper< XPipe , XConnectable , XServiceInfo >
+{
+public:
+    OPipeImpl( );
+
+public: // XInputStream
+    virtual sal_Int32 SAL_CALL readBytes(Sequence< sal_Int8 >& aData, sal_Int32 nBytesToRead) override;
+    virtual sal_Int32 SAL_CALL readSomeBytes(Sequence< sal_Int8 >& aData, sal_Int32 nMaxBytesToRead) override;
+    virtual void SAL_CALL skipBytes(sal_Int32 nBytesToSkip) override;
+    virtual sal_Int32 SAL_CALL available() override;
+    virtual void SAL_CALL closeInput() override;
+
+public: // XOutputStream
+
+    virtual void SAL_CALL writeBytes(const Sequence< sal_Int8 >& aData) override;
+    virtual void SAL_CALL flush() override;
+    virtual void SAL_CALL closeOutput() override;
+
+public: // XConnectable
+    virtual void SAL_CALL setPredecessor(const Reference< XConnectable >& aPredecessor) override;
+    virtual Reference< XConnectable > SAL_CALL getPredecessor() override;
+    virtual void SAL_CALL setSuccessor(const Reference < XConnectable > & aSuccessor) override;
+    virtual Reference < XConnectable > SAL_CALL getSuccessor() override ;
+
+
+public: // XServiceInfo
+    OUString                    SAL_CALL getImplementationName() override;
+    Sequence< OUString >         SAL_CALL getSupportedServiceNames() override;
+    sal_Bool                        SAL_CALL supportsService(const OUString& ServiceName) override;
+
+private:
+
+    Reference < XConnectable >  m_succ;
+    Reference < XConnectable >  m_pred;
+
+    sal_Int32 m_nBytesToSkip;
+
+    bool m_bOutputStreamClosed;
+    bool m_bInputStreamClosed;
+
+    osl::Condition m_conditionBytesAvail;
+    Mutex          m_mutexAccess;
+    std::unique_ptr<MemFIFO> m_pFIFO;
+};
+
+}
+
+OPipeImpl::OPipeImpl()
+    : m_nBytesToSkip(0 )
+    , m_bOutputStreamClosed(false )
+    , m_bInputStreamClosed( false )
+    , m_pFIFO( new MemFIFO )
+{
+}
+
+
+
+sal_Int32 OPipeImpl::readBytes(Sequence< sal_Int8 >& aData, sal_Int32 nBytesToRead)
+{
+    while( true )
+    {
+        { // start guarded section
+            MutexGuard guard( m_mutexAccess );
+            if( m_bInputStreamClosed )
+            {
+                throw NotConnectedException(
+                    "Pipe::readBytes NotConnectedException",
+                    *this );
+            }
+            sal_Int32 nOccupiedBufferLen = m_pFIFO->getSize();
+
+            if( m_bOutputStreamClosed && nBytesToRead > nOccupiedBufferLen )
+            {
+                nBytesToRead = nOccupiedBufferLen;
+            }
+
+            if( nOccupiedBufferLen < nBytesToRead )
+            {
+                // wait outside guarded section
+                m_conditionBytesAvail.reset();
+            }
+            else {
+                // necessary bytes are available
+                m_pFIFO->read( aData , nBytesToRead );
+                return nBytesToRead;
+            }
+        } // end guarded section
+
+        // wait for new data outside guarded section!
+        m_conditionBytesAvail.wait();
+    }
+}
+
+
+sal_Int32 OPipeImpl::readSomeBytes(Sequence< sal_Int8 >& aData, sal_Int32 nMaxBytesToRead)
+{
+    while( true ) {
+        {
+            MutexGuard guard( m_mutexAccess );
+            if( m_bInputStreamClosed )
+            {
+                throw NotConnectedException(
+                    "Pipe::readSomeBytes NotConnectedException",
+                    *this );
+            }
+            if( m_pFIFO->getSize() )
+            {
+                sal_Int32 nSize = std::min( nMaxBytesToRead , m_pFIFO->getSize() );
+                aData.realloc( nSize );
+                m_pFIFO->read( aData , nSize );
+                return nSize;
+            }
+
+            if( m_bOutputStreamClosed )
+            {
+                // no bytes in buffer anymore
+                return 0;
+            }
+        }
+
+        m_conditionBytesAvail.wait();
+    }
+}
+
+
+void OPipeImpl::skipBytes(sal_Int32 nBytesToSkip)
+{
+    MutexGuard guard( m_mutexAccess );
+    if( m_bInputStreamClosed )
+    {
+        throw NotConnectedException(
+            "Pipe::skipBytes NotConnectedException",
+            *this );
+    }
+
+    if( nBytesToSkip < 0
+        || (nBytesToSkip
+            > std::numeric_limits< sal_Int32 >::max() - m_nBytesToSkip) )
+    {
+        throw BufferSizeExceededException(
+            "Pipe::skipBytes BufferSizeExceededException",
+            *this );
+    }
+    m_nBytesToSkip += nBytesToSkip;
+
+    nBytesToSkip = std::min( m_pFIFO->getSize() , m_nBytesToSkip );
+    m_pFIFO->skip( nBytesToSkip );
+    m_nBytesToSkip -= nBytesToSkip;
+}
+
+
+sal_Int32 OPipeImpl::available()
+ {
+    MutexGuard guard( m_mutexAccess );
+    if( m_bInputStreamClosed )
+    {
+        throw NotConnectedException(
+            "Pipe::available NotConnectedException",
+            *this );
+    }
+    return m_pFIFO->getSize();
+}
+
+void OPipeImpl::closeInput()
+{
+    MutexGuard guard( m_mutexAccess );
+
+    m_bInputStreamClosed = true;
+
+    m_pFIFO.reset();
+
+    // readBytes may throw an exception
+    m_conditionBytesAvail.set();
+
+    setSuccessor( Reference< XConnectable > () );
+}
+
+
+void OPipeImpl::writeBytes(const Sequence< sal_Int8 >& aData)
+{
+    MutexGuard guard( m_mutexAccess );
+
+    if( m_bOutputStreamClosed )
+    {
+        throw NotConnectedException(
+            "Pipe::writeBytes NotConnectedException (outputstream)",
+            *this );
+    }
+
+    if( m_bInputStreamClosed )
+    {
+        throw NotConnectedException(
+            "Pipe::writeBytes NotConnectedException (inputstream)",
+            *this );
+    }
+
+    // check skipping
+    sal_Int32 nLen = aData.getLength();
+    if( m_nBytesToSkip  && m_nBytesToSkip >= nLen  ) {
+        // all must be skipped - forget whole call
+        m_nBytesToSkip -= nLen;
+        return;
+    }
+
+    // adjust buffersize if necessary
+    if( m_nBytesToSkip )
+    {
+        Sequence< sal_Int8 > seqCopy( nLen - m_nBytesToSkip );
+        memcpy( seqCopy.getArray() , &( aData.getConstArray()[m_nBytesToSkip] ) , nLen-m_nBytesToSkip );
+        m_pFIFO->write( seqCopy );
+    }
+    else
+    {
+        m_pFIFO->write( aData );
+    }
+    m_nBytesToSkip = 0;
+
+    // readBytes may check again if enough bytes are available
+    m_conditionBytesAvail.set();
+}
+
+
+void OPipeImpl::flush()
+{
+    // nothing to do for a pipe
+}
+
+void OPipeImpl::closeOutput()
+{
+    MutexGuard guard( m_mutexAccess );
+
+    m_bOutputStreamClosed = true;
+    m_conditionBytesAvail.set();
+    setPredecessor( Reference < XConnectable > () );
+}
+
+
+void OPipeImpl::setSuccessor( const Reference < XConnectable >  &r )
+{
+     /// if the references match, nothing needs to be done
+     if( m_succ != r ) {
+         /// store the reference for later use
+         m_succ = r;
+
+         if( m_succ.is() )
+         {
+              m_succ->setPredecessor(
+                  Reference< XConnectable > ( static_cast< XConnectable * >(this) ) );
+         }
+     }
+}
+
+Reference < XConnectable > OPipeImpl::getSuccessor()
+{
+    return m_succ;
+}
+
+
+// XDataSource
+void OPipeImpl::setPredecessor( const Reference < XConnectable > &r )
+{
+    if( r != m_pred ) {
+        m_pred = r;
+        if( m_pred.is() ) {
+            m_pred->setSuccessor(
+                Reference < XConnectable > ( static_cast< XConnectable * >(this) ) );
+        }
+    }
+}
+
+Reference < XConnectable > OPipeImpl::getPredecessor()
+{
+    return m_pred;
+}
+
+
+// XServiceInfo
+OUString OPipeImpl::getImplementationName()
+{
+    return OPipeImpl_getImplementationName();
+}
+
+// XServiceInfo
+sal_Bool OPipeImpl::supportsService(const OUString& ServiceName)
+{
+    return cppu::supportsService(this, ServiceName);
+}
+
+// XServiceInfo
+Sequence< OUString > OPipeImpl::getSupportedServiceNames()
+{
+    return OPipeImpl_getSupportedServiceNames();
+}
+
+/* implementation functions
+*
+*
+*/
+
+
+Reference < XInterface > OPipeImpl_CreateInstance(
+    SAL_UNUSED_PARAMETER const Reference < XComponentContext > & )
+{
+    OPipeImpl *p = new OPipeImpl;
+
+    return Reference < XInterface > ( static_cast< OWeakObject * >(p) );
+}
+
+
+OUString    OPipeImpl_getImplementationName()
+{
+    return IMPLEMENTATION_NAME;
+}
+
+Sequence<OUString> OPipeImpl_getSupportedServiceNames()
+{
+    Sequence<OUString> aRet { "com.sun.star.io.Pipe" };
+    return aRet;
+}
+}
+
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */
diff --git a/io/source/stm/opump.cxx b/io/source/stm/opump.cxx
new file mode 100644
index 000000000..cba66d3c5
--- /dev/null
+++ b/io/source/stm/opump.cxx
@@ -0,0 +1,458 @@
+/* -*- 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 <sal/log.hxx>
+
+#include <com/sun/star/io/IOException.hpp>
+#include <com/sun/star/io/NotConnectedException.hpp>
+#include <com/sun/star/io/XActiveDataSource.hpp>
+#include <com/sun/star/io/XActiveDataSink.hpp>
+#include <com/sun/star/io/XActiveDataControl.hpp>
+#include <com/sun/star/io/XConnectable.hpp>
+#include <com/sun/star/lang/XServiceInfo.hpp>
+
+#include <cppuhelper/implbase.hxx>
+#include <cppuhelper/interfacecontainer.hxx>
+#include <cppuhelper/supportsservice.hxx>
+#include <osl/mutex.hxx>
+#include <osl/thread.h>
+#include <tools/diagnose_ex.h>
+
+using namespace osl;
+using namespace std;
+using namespace cppu;
+using namespace com::sun::star::uno;
+using namespace com::sun::star::lang;
+using namespace com::sun::star::io;
+
+#include <services.hxx>
+
+namespace io_stm {
+
+    namespace {
+
+    class Pump : public WeakImplHelper<
+          XActiveDataSource, XActiveDataSink, XActiveDataControl, XConnectable, XServiceInfo >
+    {
+        Mutex                                   m_aMutex;
+        oslThread                               m_aThread;
+
+        Reference< XConnectable >               m_xPred;
+        Reference< XConnectable >               m_xSucc;
+        Reference< XInputStream >               m_xInput;
+        Reference< XOutputStream >              m_xOutput;
+        OInterfaceContainerHelper               m_cnt;
+        bool                                m_closeFired;
+
+        void run();
+        static void static_run( void* pObject );
+
+        void close();
+        void fireClose();
+        void fireStarted();
+        void fireTerminated();
+        void fireError( const Any &a );
+
+    public:
+        Pump();
+        virtual ~Pump() override;
+
+        // XActiveDataSource
+        virtual void SAL_CALL setOutputStream( const Reference< css::io::XOutputStream >& xOutput ) override;
+        virtual Reference< css::io::XOutputStream > SAL_CALL getOutputStream() override;
+
+        // XActiveDataSink
+        virtual void SAL_CALL setInputStream( const Reference< css::io::XInputStream >& xStream ) override;
+        virtual Reference< css::io::XInputStream > SAL_CALL getInputStream() override;
+
+        // XActiveDataControl
+        virtual void SAL_CALL addListener( const Reference< css::io::XStreamListener >& xListener ) override;
+        virtual void SAL_CALL removeListener( const Reference< css::io::XStreamListener >& xListener ) override;
+        virtual void SAL_CALL start() override;
+        virtual void SAL_CALL terminate() override;
+
+        // XConnectable
+        virtual void SAL_CALL setPredecessor( const Reference< css::io::XConnectable >& xPred ) override;
+        virtual Reference< css::io::XConnectable > SAL_CALL getPredecessor() override;
+        virtual void SAL_CALL setSuccessor( const Reference< css::io::XConnectable >& xSucc ) override;
+        virtual Reference< css::io::XConnectable > SAL_CALL getSuccessor() override;
+
+    public: // XServiceInfo
+        virtual OUString    SAL_CALL getImplementationName() override;
+        virtual Sequence< OUString > SAL_CALL getSupportedServiceNames() override;
+        virtual sal_Bool     SAL_CALL supportsService(const OUString& ServiceName) override;
+    };
+
+    }
+
+Pump::Pump() : m_aThread( nullptr ),
+               m_cnt( m_aMutex ),
+               m_closeFired( false )
+{
+}
+
+Pump::~Pump()
+{
+    // exit gracefully
+    if( m_aThread )
+    {
+        osl_joinWithThread( m_aThread );
+        osl_destroyThread( m_aThread );
+    }
+}
+
+void Pump::fireError( const  Any & exception )
+{
+    OInterfaceIteratorHelper iter( m_cnt );
+    while( iter.hasMoreElements() )
+    {
+        try
+        {
+            static_cast< XStreamListener * > ( iter.next() )->error( exception );
+        }
+        catch ( const RuntimeException & )
+        {
+            TOOLS_WARN_EXCEPTION("io.streams","com.sun.star.comp.stoc.Pump: unexpected exception during calling listeners");
+        }
+    }
+}
+
+void Pump::fireClose()
+{
+    bool bFire = false;
+    {
+        MutexGuard guard( m_aMutex );
+        if( ! m_closeFired  )
+        {
+            m_closeFired = true;
+            bFire = true;
+        }
+    }
+
+    if( !bFire )
+        return;
+
+    OInterfaceIteratorHelper iter( m_cnt );
+    while( iter.hasMoreElements() )
+    {
+        try
+        {
+            static_cast< XStreamListener * > ( iter.next() )->closed( );
+        }
+        catch ( const RuntimeException & )
+        {
+            TOOLS_WARN_EXCEPTION("io.streams","com.sun.star.comp.stoc.Pump: unexpected exception during calling listeners");
+        }
+    }
+}
+
+void Pump::fireStarted()
+{
+    OInterfaceIteratorHelper iter( m_cnt );
+    while( iter.hasMoreElements() )
+    {
+        try
+        {
+            static_cast< XStreamListener * > ( iter.next() )->started( );
+        }
+        catch ( const RuntimeException & )
+        {
+            TOOLS_WARN_EXCEPTION("io.streams","com.sun.star.comp.stoc.Pump: unexpected exception during calling listeners");
+        }
+    }
+}
+
+void Pump::fireTerminated()
+{
+    OInterfaceIteratorHelper iter( m_cnt );
+    while( iter.hasMoreElements() )
+    {
+        try
+        {
+            static_cast< XStreamListener * > ( iter.next() )->terminated();
+        }
+        catch ( const RuntimeException & )
+        {
+            TOOLS_WARN_EXCEPTION("io.streams","com.sun.star.comp.stoc.Pump: unexpected exception during calling listeners");
+        }
+    }
+}
+
+
+void Pump::close()
+{
+    // close streams and release references
+    Reference< XInputStream > rInput;
+    Reference< XOutputStream > rOutput;
+    {
+        MutexGuard guard( m_aMutex );
+        rInput = m_xInput;
+        m_xInput.clear();
+
+        rOutput = m_xOutput;
+        m_xOutput.clear();
+        m_xSucc.clear();
+        m_xPred.clear();
+    }
+    if( rInput.is() )
+    {
+        try
+        {
+            rInput->closeInput();
+        }
+        catch( Exception & )
+        {
+            // go down calm
+        }
+    }
+    if( rOutput.is() )
+    {
+        try
+        {
+            rOutput->closeOutput();
+        }
+        catch( Exception & )
+        {
+            // go down calm
+        }
+    }
+}
+
+void Pump::static_run( void* pObject )
+{
+    osl_setThreadName("io_stm::Pump::run()");
+    static_cast<Pump*>(pObject)->run();
+    static_cast<Pump*>(pObject)->release();
+}
+
+void Pump::run()
+{
+    try
+    {
+        fireStarted();
+        try
+        {
+            Reference< XInputStream > rInput;
+            Reference< XOutputStream > rOutput;
+            {
+                Guard< Mutex > aGuard( m_aMutex );
+                rInput = m_xInput;
+                rOutput = m_xOutput;
+            }
+
+            if( ! rInput.is() )
+            {
+                throw NotConnectedException( "no input stream set", static_cast<OWeakObject*>(this) );
+            }
+            Sequence< sal_Int8 > aData;
+            while( rInput->readSomeBytes( aData, 65536 ) )
+            {
+                if( ! rOutput.is() )
+                {
+                    throw NotConnectedException( "no output stream set", static_cast<OWeakObject*>(this) );
+                }
+                rOutput->writeBytes( aData );
+                osl_yieldThread();
+            }
+        }
+        catch ( const IOException & e )
+        {
+            fireError( makeAny( e ) );
+        }
+        catch ( const RuntimeException & e )
+        {
+            fireError( makeAny( e ) );
+        }
+        catch ( const Exception & e )
+        {
+            fireError( makeAny( e ) );
+        }
+
+        close();
+        fireClose();
+    }
+    catch ( const css::uno::Exception & )
+    {
+        // we are the last on the stack.
+        // this is to avoid crashing the program, when e.g. a bridge crashes
+        TOOLS_WARN_EXCEPTION("io.streams","com.sun.star.comp.stoc.Pump: unexpected exception during calling listeners");
+    }
+}
+
+
+/*
+ * XConnectable
+ */
+
+void Pump::setPredecessor( const Reference< XConnectable >& xPred )
+{
+    Guard< Mutex > aGuard( m_aMutex );
+    m_xPred = xPred;
+}
+
+
+Reference< XConnectable > Pump::getPredecessor()
+{
+    Guard< Mutex > aGuard( m_aMutex );
+    return m_xPred;
+}
+
+
+void Pump::setSuccessor( const Reference< XConnectable >& xSucc )
+{
+    Guard< Mutex > aGuard( m_aMutex );
+    m_xSucc = xSucc;
+}
+
+
+Reference< XConnectable > Pump::getSuccessor()
+{
+    Guard< Mutex > aGuard( m_aMutex );
+    return m_xSucc;
+}
+
+
+/*
+ * XActiveDataControl
+ */
+
+void Pump::addListener( const Reference< XStreamListener >& xListener )
+{
+    m_cnt.addInterface( xListener );
+}
+
+
+void Pump::removeListener( const Reference< XStreamListener >& xListener )
+{
+    m_cnt.removeInterface( xListener );
+}
+
+
+void Pump::start()
+{
+    Guard< Mutex > aGuard( m_aMutex );
+    m_aThread = osl_createSuspendedThread(Pump::static_run,this);
+    if( !m_aThread )
+    {
+        throw RuntimeException(
+            "Pump::start Couldn't create worker thread",
+            *this);
+    }
+
+    // will be released by OPump::static_run
+    acquire();
+    osl_resumeThread( m_aThread );
+
+}
+
+
+void Pump::terminate()
+{
+    close();
+
+    // wait for the worker to die
+    if( m_aThread )
+        osl_joinWithThread( m_aThread );
+
+    fireTerminated();
+    fireClose();
+}
+
+
+/*
+ * XActiveDataSink
+ */
+
+void Pump::setInputStream( const Reference< XInputStream >& xStream )
+{
+    Guard< Mutex > aGuard( m_aMutex );
+    m_xInput = xStream;
+    Reference< XConnectable > xConnect( xStream, UNO_QUERY );
+    if( xConnect.is() )
+        xConnect->setSuccessor( this );
+    // data transfer starts in XActiveDataControl::start
+}
+
+
+Reference< XInputStream > Pump::getInputStream()
+{
+    Guard< Mutex > aGuard( m_aMutex );
+    return m_xInput;
+}
+
+
+/*
+ * XActiveDataSource
+ */
+
+void Pump::setOutputStream( const Reference< XOutputStream >& xOut )
+{
+    Guard< Mutex > aGuard( m_aMutex );
+    m_xOutput = xOut;
+    Reference< XConnectable > xConnect( xOut, UNO_QUERY );
+    if( xConnect.is() )
+        xConnect->setPredecessor( this );
+    // data transfer starts in XActiveDataControl::start
+}
+
+Reference< XOutputStream > Pump::getOutputStream()
+{
+    Guard< Mutex > aGuard( m_aMutex );
+    return m_xOutput;
+}
+
+// XServiceInfo
+OUString Pump::getImplementationName()
+{
+    return OPumpImpl_getImplementationName();
+}
+
+// XServiceInfo
+sal_Bool Pump::supportsService(const OUString& ServiceName)
+{
+    return cppu::supportsService(this, ServiceName);
+}
+
+// XServiceInfo
+Sequence< OUString > Pump::getSupportedServiceNames()
+{
+    return OPumpImpl_getSupportedServiceNames();
+}
+
+
+Reference< XInterface > OPumpImpl_CreateInstance(
+    SAL_UNUSED_PARAMETER const Reference< XComponentContext > & )
+{
+    return Reference< XInterface >( *new Pump );
+}
+
+OUString OPumpImpl_getImplementationName()
+{
+    return "com.sun.star.comp.io.Pump";
+}
+
+Sequence<OUString> OPumpImpl_getSupportedServiceNames()
+{
+    return Sequence< OUString > { "com.sun.star.io.Pump" };
+}
+
+}
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */
diff --git a/io/source/stm/streamhelper.cxx b/io/source/stm/streamhelper.cxx
new file mode 100644
index 000000000..4a2df5891
--- /dev/null
+++ b/io/source/stm/streamhelper.cxx
@@ -0,0 +1,173 @@
+/* -*- 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 <limits>
+#include <string.h>
+
+#include <com/sun/star/uno/Sequence.hxx>
+
+#include <com/sun/star/io/BufferSizeExceededException.hpp>
+
+using namespace ::com::sun::star::uno;
+
+#include "streamhelper.hxx"
+
+namespace io_stm {
+
+void MemFIFO::write( const Sequence< sal_Int8 > &seq )
+{
+    writeAt(getSize(), seq);
+}
+
+void MemFIFO::read( Sequence<sal_Int8> &seq , sal_Int32 nBufferLen )
+{
+    readAt(0, seq , nBufferLen);
+    forgetFromStart( nBufferLen );
+}
+
+void MemFIFO::skip( sal_Int32 nBytesToSkip )
+{
+    forgetFromStart( nBytesToSkip );
+}
+
+MemRingBuffer::MemRingBuffer() : m_p(nullptr), m_nBufferLen(0), m_nStart(0), m_nOccupiedBuffer(0)
+{
+}
+
+MemRingBuffer::~MemRingBuffer()
+{
+    std::free( m_p );
+}
+
+void MemRingBuffer::resizeBuffer( sal_Int32 nMinSize )
+{
+    sal_Int32 nNewLen = 1;
+
+    while( nMinSize > nNewLen ) {
+        nNewLen = nNewLen << 1;
+    }
+
+    // buffer never shrinks !
+    if( nNewLen < m_nBufferLen ) {
+        nNewLen = m_nBufferLen;
+    }
+
+    if( nNewLen == m_nBufferLen )
+        return;
+
+    auto p = static_cast<sal_Int8*>(std::realloc(m_p, nNewLen));
+    if (!p)
+        throw css::io::BufferSizeExceededException(
+            "MemRingBuffer::resizeBuffer BufferSizeExceededException");
+
+    m_p = p;
+
+
+    if( m_nStart + m_nOccupiedBuffer > m_nBufferLen ) {
+        memmove( &( m_p[m_nStart+(nNewLen-m_nBufferLen)]) , &(m_p[m_nStart]) , m_nBufferLen - m_nStart );
+        m_nStart += nNewLen - m_nBufferLen;
+    }
+    m_nBufferLen = nNewLen;
+}
+
+
+void MemRingBuffer::readAt( sal_Int32 nPos, Sequence<sal_Int8> &seq , sal_Int32 nBytesToRead ) const
+{
+    if( nPos + nBytesToRead > m_nOccupiedBuffer ) {
+        throw css::io::BufferSizeExceededException(
+            "MemRingBuffer::readAt BufferSizeExceededException");
+    }
+
+    sal_Int32 nStartReadingPos = nPos + m_nStart;
+    if( nStartReadingPos >= m_nBufferLen ) {
+        nStartReadingPos -= m_nBufferLen;
+    }
+
+    seq.realloc( nBytesToRead );
+
+    if( nStartReadingPos + nBytesToRead > m_nBufferLen ) {
+        sal_Int32 nDeltaLen = m_nBufferLen - nStartReadingPos;
+        memcpy( seq.getArray() , &(m_p[nStartReadingPos]) , nDeltaLen );
+        memcpy( &(seq.getArray()[nDeltaLen]), m_p , nBytesToRead - nDeltaLen );
+    }
+    else {
+        memcpy( seq.getArray() , &(m_p[nStartReadingPos]) , nBytesToRead );
+    }
+}
+
+
+void MemRingBuffer::writeAt( sal_Int32 nPos, const Sequence<sal_Int8> &seq )
+{
+    checkInvariants();
+    const sal_Int32 nLen = seq.getLength();
+
+    if( nPos < 0 || nPos > std::numeric_limits< sal_Int32 >::max() - nLen )
+    {
+        throw css::io::BufferSizeExceededException(
+            "MemRingBuffer::writeAt BufferSizeExceededException");
+    }
+
+    if( nPos + nLen - m_nOccupiedBuffer > 0 ) {
+        resizeBuffer( nPos + nLen );
+        m_nOccupiedBuffer = nPos + nLen;
+    }
+
+    sal_Int32 nStartWritingIndex = m_nStart + nPos;
+    if( nStartWritingIndex >= m_nBufferLen ) {
+        nStartWritingIndex -= m_nBufferLen;
+    }
+
+    if( const sal_Int32 nBufferRestLen = m_nBufferLen-nStartWritingIndex; nLen > nBufferRestLen ) {
+        // two area copy
+        memcpy( &(m_p[nStartWritingIndex]) , seq.getConstArray(), nBufferRestLen );
+        memcpy( m_p , &( seq.getConstArray()[nBufferRestLen] ), nLen - nBufferRestLen );
+
+    }
+    else {
+        // one area copy
+        memcpy( &( m_p[nStartWritingIndex]), seq.getConstArray() , nLen );
+    }
+    checkInvariants();
+}
+
+
+sal_Int32 MemRingBuffer::getSize()  const throw()
+{
+    return m_nOccupiedBuffer;
+}
+
+void MemRingBuffer::forgetFromStart( sal_Int32 nBytesToForget )
+{
+    checkInvariants();
+    if( nBytesToForget > m_nOccupiedBuffer ) {
+        throw css::io::BufferSizeExceededException(
+            "MemRingBuffer::forgetFromStart BufferSizeExceededException");
+    }
+    m_nStart += nBytesToForget;
+    if( m_nStart >= m_nBufferLen ) {
+        m_nStart = m_nStart - m_nBufferLen;
+    }
+    m_nOccupiedBuffer -= nBytesToForget;
+    checkInvariants();
+}
+
+
+}
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */
diff --git a/io/source/stm/streamhelper.hxx b/io/source/stm/streamhelper.hxx
new file mode 100644
index 000000000..c1bb1b7db
--- /dev/null
+++ b/io/source/stm/streamhelper.hxx
@@ -0,0 +1,88 @@
+/* -*- 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 .
+ */
+
+#ifndef INCLUDED_IO_SOURCE_STM_STREAMHELPER_HXX
+#define INCLUDED_IO_SOURCE_STM_STREAMHELPER_HXX
+
+#include <com/sun/star/uno/Sequence.hxx>
+
+#include <assert.h>
+
+using namespace com::sun::star::uno;
+
+namespace io_stm
+{
+
+class MemRingBuffer
+{
+public:
+    MemRingBuffer();
+    virtual ~MemRingBuffer();
+
+    /***
+    * overwrites data at given position. Size is automatically extended, when
+    * data is written beyond end.
+    ***/
+    /// @throws css::io::BufferSizeExceededException
+    void    writeAt( sal_Int32 nPos, const Sequence<sal_Int8> &);
+    /// @throws css::io::BufferSizeExceededException
+    void    readAt( sal_Int32 nPos, Sequence<sal_Int8> & , sal_Int32 nBytesToRead ) const;
+    sal_Int32   getSize() const throw();
+    /// @throws css::io::BufferSizeExceededException
+    void    forgetFromStart(sal_Int32 nBytesToForget);
+
+private:
+    /// @throws css::io::BufferSizeExceededException
+    void resizeBuffer(sal_Int32 nMinSize);
+    void checkInvariants() const {
+        assert( m_nBufferLen >= 0 );
+        assert( m_nOccupiedBuffer >= 0 );
+        assert( m_nOccupiedBuffer <= m_nBufferLen );
+        assert( m_nStart >= 0 );
+        assert( 0 == m_nStart || m_nStart < m_nBufferLen );
+        (void) this; // avoid loplugin:staticmethods
+    }
+
+    sal_Int8    *m_p;
+    sal_Int32   m_nBufferLen;
+    sal_Int32   m_nStart;
+    sal_Int32   m_nOccupiedBuffer;
+};
+
+
+class MemFIFO :
+    private MemRingBuffer
+{
+public:
+    /// @throws css::io::BufferSizeExceededException
+    void          write( const Sequence<sal_Int8> &);
+    /// @throws css::io::BufferSizeExceededException
+    void          read( Sequence<sal_Int8> & , sal_Int32 nBytesToRead );
+    /// @throws css::io::BufferSizeExceededException
+    void          skip( sal_Int32 nBytesToSkip );
+    sal_Int32     getSize() const throw()
+                  { return MemRingBuffer::getSize(); }
+
+};
+
+}
+
+#endif // INCLUDED_IO_SOURCE_STM_STREAMHELPER_HXX
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */