static HRESULT WINAPI PersistHistory_SaveHistory(IPersistHistory *iface, IStream *pStream)
{
    HTMLDocument *This = impl_from_IPersistHistory(iface);
    ULONG len, written;
    BSTR display_uri;
    HRESULT hres;

    TRACE("(%p)->(%p)\n", This, pStream);

    if(!This->window || !This->window->uri) {
        FIXME("No current URI\n");
        return E_FAIL;
    }

    /* NOTE: The format we store is *not* compatible with native MSHTML. We currently
     * store only URI of the page (as a length followed by a string) */
    hres = IUri_GetDisplayUri(This->window->uri, &display_uri);
    if(FAILED(hres))
        return hres;

    len = SysStringLen(display_uri);
    hres = IStream_Write(pStream, &len, sizeof(len), &written);
    if(SUCCEEDED(hres))
        hres = IStream_Write(pStream, display_uri, len*sizeof(WCHAR), &written);
    SysFreeString(display_uri);
    return hres;
}

/******************************************************************************
 *        ItemMoniker_Save
 ******************************************************************************/
static HRESULT WINAPI ItemMonikerImpl_Save(IMoniker* iface, IStream* pStm, BOOL fClearDirty)
{
    ItemMonikerImpl *This = impl_from_IMoniker(iface);
    HRESULT res;
    CHAR *itemNameA,*itemDelimiterA;

    /* data written by this function are : 1) DWORD : size of item delimiter string ('\0' included ) */
    /*                                    2) String (type A): item delimiter string ('\0' included)          */
    /*                                    3) DWORD : size of item name string ('\0' included)       */
    /*                                    4) String (type A): item name string ('\0' included)               */

    DWORD nameLength = WideCharToMultiByte( CP_ACP, 0, This->itemName, -1, NULL, 0, NULL, NULL);
    DWORD delimiterLength = WideCharToMultiByte( CP_ACP, 0, This->itemDelimiter, -1, NULL, 0, NULL, NULL);
    itemNameA=HeapAlloc(GetProcessHeap(),0,nameLength);
    itemDelimiterA=HeapAlloc(GetProcessHeap(),0,delimiterLength);
    WideCharToMultiByte( CP_ACP, 0, This->itemName, -1, itemNameA, nameLength, NULL, NULL);
    WideCharToMultiByte( CP_ACP, 0, This->itemDelimiter, -1, itemDelimiterA, delimiterLength, NULL, NULL);

    TRACE("%p, %s\n", pStm, fClearDirty ? "TRUE" : "FALSE");

    res=IStream_Write(pStm,&delimiterLength,sizeof(DWORD),NULL);
    res=IStream_Write(pStm,itemDelimiterA,delimiterLength * sizeof(CHAR),NULL);
    res=IStream_Write(pStm,&nameLength,sizeof(DWORD),NULL);
    res=IStream_Write(pStm,itemNameA,nameLength * sizeof(CHAR),NULL);

    HeapFree(GetProcessHeap(), 0, itemNameA);
    HeapFree(GetProcessHeap(), 0, itemDelimiterA);

    return res;
}

static HRESULT CALLBACK CB_Save(LPITEMDATA pInfo, IStream *pStm, LPARAM lp)
{
    HRESULT hRes;
    
    ok(lp == 0xdeadbeef, "lp=%ld\n", lp);
    hRes = IStream_Write(pStm, &pInfo->iPos, sizeof(INT), NULL);
    ok(hRes == S_OK, "hRes=0x%x\n", hRes);
    hRes = IStream_Write(pStm, &pInfo->pvData, sizeof(PVOID), NULL);
    ok(hRes == S_OK, "hRes=0x%x\n", hRes);
    return S_OK;
}

static HRESULT CALLBACK CB_Save(DPASTREAMINFO *pInfo, IStream *pStm, LPVOID lp)
{
    HRESULT hRes;

    ok(lp == (LPVOID)0xdeadbeef, "lp=%p\n", lp);
    hRes = IStream_Write(pStm, &pInfo->iPos, sizeof(INT), NULL);
    expect(S_OK, hRes);
    hRes = IStream_Write(pStm, &pInfo->pvItem, sizeof(PVOID), NULL);
    expect(S_OK, hRes);
    return S_OK;
}

/******************************************************************************
 *        ClassMoniker_Save
 ******************************************************************************/
static HRESULT WINAPI ClassMoniker_Save(IMoniker* iface, IStream* pStm, BOOL fClearDirty)
{
    ClassMoniker *This = impl_from_IMoniker(iface);
    HRESULT hr;
    DWORD zero = 0;

    TRACE("(%p, %s)\n", pStm, fClearDirty ? "TRUE" : "FALSE");

    hr = IStream_Write(pStm, &This->clsid, sizeof(This->clsid), NULL);
    if (FAILED(hr)) return hr;

    return IStream_Write(pStm, &zero, sizeof(zero), NULL);
}

static HRESULT WINAPI
FTMarshalImpl_MarshalInterface (LPMARSHAL iface, IStream * pStm, REFIID riid, void *pv,
			       DWORD dwDestContext, void *pvDestContext, DWORD mshlflags)
{

    IMarshal *pMarshal = NULL;
    HRESULT hres;

    TRACE("(%p, %s, %p, 0x%x, %p, 0x%x)\n", pStm, debugstr_guid(riid), pv,
        dwDestContext, pvDestContext, mshlflags);

    /* if the marshalling happens inside the same process the interface pointer is
       copied between the apartments */
    if (dwDestContext == MSHCTX_INPROC || dwDestContext == MSHCTX_CROSSCTX) {
        void *object;
        DWORD constant = 0;
        GUID unknown_guid = { 0 };

        hres = IUnknown_QueryInterface((IUnknown *)pv, riid, &object);
        if (FAILED(hres))
            return hres;

        /* don't hold a reference to table-weak marshaled interfaces */
        if (mshlflags & MSHLFLAGS_TABLEWEAK)
            IUnknown_Release((IUnknown *)object);

        hres = IStream_Write (pStm, &mshlflags, sizeof (mshlflags), NULL);
        if (hres != S_OK) return STG_E_MEDIUMFULL;

        hres = IStream_Write (pStm, &object, sizeof (object), NULL);
        if (hres != S_OK) return STG_E_MEDIUMFULL;

        if (sizeof(object) == sizeof(DWORD))
        {
            hres = IStream_Write (pStm, &constant, sizeof (constant), NULL);
            if (hres != S_OK) return STG_E_MEDIUMFULL;
        }

        hres = IStream_Write (pStm, &unknown_guid, sizeof (unknown_guid), NULL);
        if (hres != S_OK) return STG_E_MEDIUMFULL;

        return S_OK;
    }

    /* use the standard marshaler to handle all other cases */
    CoGetStandardMarshal (riid, pv, dwDestContext, pvDestContext, mshlflags, &pMarshal);
    hres = IMarshal_MarshalInterface (pMarshal, pStm, riid, pv, dwDestContext, pvDestContext, mshlflags);
    IMarshal_Release (pMarshal);
    return hres;
}

/******************************************************************************
 *        AntiMoniker_Save
 ******************************************************************************/
static HRESULT WINAPI
AntiMonikerImpl_Save(IMoniker* iface,IStream* pStm,BOOL fClearDirty)
{
    static const DWORD constant = 1;
    /* data written by this function is only a DWORD constant set to 1 ! */
    return IStream_Write(pStm,&constant,sizeof(constant),NULL);
}

// Creates a set of sample files in the current user's Documents directory to use as items in the
// custom category inserted into the Jump List.
HRESULT CreateSampleFiles()
{
    PWSTR pszPathDocuments;
    HRESULT hr = SHGetKnownFolderPath(FOLDERID_Documents, KF_FLAG_CREATE, NULL, &pszPathDocuments);
    if (SUCCEEDED(hr))
    {
        for (UINT i = 0; SUCCEEDED(hr) && i < ARRAYSIZE(c_rgpszFiles); i++)
        {
            WCHAR szPathSample[MAX_PATH];
            hr = PathCombine(szPathSample, pszPathDocuments, c_rgpszFiles[i]) ? S_OK : E_FAIL;
            if (SUCCEEDED(hr))
            {
                IStream *pstm;
                hr = SHCreateStreamOnFileEx(szPathSample, (STGM_WRITE | STGM_FAILIFTHERE), FILE_ATTRIBUTE_NORMAL, TRUE, NULL, &pstm);
                if (SUCCEEDED(hr))
                {
                    PCWSTR pszText = L"This is a sample file for the CustomJumpListSample.\r\n";
                    ULONG cb = (sizeof(pszText[0]) * (lstrlen(pszText) + 1));
                    hr = IStream_Write(pstm, pszText, cb);
                    pstm->Release();
                }
                else if (HRESULT_FROM_WIN32(ERROR_FILE_EXISTS) == hr)
                {
                    // If the file exists, we're ok, we'll just reuse it
                    hr = S_OK;
                }
            }
        }
        CoTaskMemFree(pszPathDocuments);
    }
    return hr;
}

static HRESULT WINAPI XMLView_BindStatusCallback_OnDataAvailable(
        IBindStatusCallback *iface, DWORD grfBSCF, DWORD dwSize,
        FORMATETC *pformatetc, STGMEDIUM *pstgmed)
{
    BindStatusCallback *This = impl_from_IBindStatusCallback(iface);
    char buf[1024];
    DWORD size;
    HRESULT hres;

    TRACE("(%p)->(%x %d %p %p)\n", This, grfBSCF, dwSize, pformatetc, pstgmed);

    if(!This->stream)
        return E_FAIL;

    do {
        hres = IStream_Read(pstgmed->u.pstm, buf, sizeof(buf), &size);
        IStream_Write(This->stream, buf, size, &size);
    } while(hres==S_OK && size);

    if(FAILED(hres) && hres!=E_PENDING)
        return hres;
    if(hres != S_FALSE)
        return S_OK;

    return handle_xml_load(This);
}

static HRESULT WINAPI mxwriter_saxcontent_startDocument(ISAXContentHandler *iface)
{
    mxwriter *This = impl_from_ISAXContentHandler( iface );

    TRACE("(%p)\n", This);

    /* If properties have been changed since the last "endDocument" call
     * we need to reset the output buffer. If we don't the output buffer
     * could end up with multiple XML documents in it, plus this seems to
     * be how Windows works.
     */
    if (This->prop_changed) {
        reset_output_buffer(This);
        This->prop_changed = FALSE;
    }

    if (This->props[MXWriter_OmitXmlDecl] == VARIANT_TRUE) return S_OK;

    write_prolog_buffer(This);

    if (This->dest && This->xml_enc == XmlEncoding_UTF16) {
        static const char utf16BOM[] = {0xff,0xfe};

        if (This->props[MXWriter_BOM] == VARIANT_TRUE)
            /* Windows passes a NULL pointer as the pcbWritten parameter and
             * ignores any error codes returned from this Write call.
             */
            IStream_Write(This->dest, utf16BOM, sizeof(utf16BOM), NULL);
    }

    return S_OK;
}

static HRESULT WINAPI IcnsEncoder_Commit(IWICBitmapEncoder *iface)
{
    IcnsEncoder *This = impl_from_IWICBitmapEncoder(iface);
    size_t buffer_size;
    HRESULT hr = S_OK;
    ULONG byteswritten;

    TRACE("(%p)\n", iface);

    EnterCriticalSection(&This->lock);

    if (!This->any_frame_committed || This->outstanding_commits > 0 || This->committed)
    {
        hr = WINCODEC_ERR_WRONGSTATE;
        goto end;
    }

    buffer_size = GetHandleSize((Handle)This->icns_family);
    hr = IStream_Write(This->stream, *This->icns_family, buffer_size, &byteswritten);
    if (FAILED(hr) || byteswritten != buffer_size)
    {
        WARN("writing file failed, hr = 0x%08X\n", hr);
        hr = E_FAIL;
        goto end;
    }

    This->committed = TRUE;

end:
    LeaveCriticalSection(&This->lock);
    return hr;
}

static HRESULT WINAPI PersistStreamInit_Save(IPersistStreamInit *iface, LPSTREAM pStm,
                                             BOOL fClearDirty)
{
    HTMLDocument *This = impl_from_IPersistStreamInit(iface);
    char *str;
    DWORD written=0;
    HRESULT hres;

    TRACE("(%p)->(%p %x)\n", This, pStm, fClearDirty);

    hres = get_doc_string(This->doc_node, &str);
    if(FAILED(hres))
        return hres;

    hres = IStream_Write(pStm, str, strlen(str), &written);
    if(FAILED(hres))
        FIXME("Write failed: %08x\n", hres);

    heap_free(str);

    if(fClearDirty)
        set_dirty(This, VARIANT_FALSE);

    return S_OK;
}

static HRESULT WINAPI IDirectMusicLoaderGenericStream_IStream_Write (LPSTREAM iface, const void* pv, ULONG cb, ULONG* pcbWritten) {
	ICOM_THIS_MULTI(IDirectMusicLoaderGenericStream, StreamVtbl, iface);	
	TRACE_(dmfileraw)("(%p, %p, 0x%08lX, %p): redirecting to low-level stream\n", This, pv, cb, pcbWritten);
	if (!This->pStream)
		return E_FAIL;

	return IStream_Write (This->pStream, pv, cb, pcbWritten);
}

static HRESULT write_hlink_string(IStream *pStm, LPCWSTR str)
{
    DWORD len;
    HRESULT hr;

    TRACE("(%p, %s)\n", pStm, debugstr_w(str));

    len = strlenW(str) + 1;

    hr = IStream_Write(pStm, &len, sizeof(len), NULL);
    if (FAILED(hr)) return hr;

    hr = IStream_Write(pStm, str, len * sizeof(WCHAR), NULL);
    if (FAILED(hr)) return hr;

    return S_OK;
}

static HRESULT WINAPI IWICStreamImpl_Write(IWICStream *iface,
    void const *pv, ULONG cb, ULONG *pcbWritten)
{
    IWICStreamImpl *This = impl_from_IWICStream(iface);
    TRACE("(%p): relay\n", This);

    if (!This->pStream) return WINCODEC_ERR_NOTINITIALIZED;
    return IStream_Write(This->pStream, pv, cb, pcbWritten);
}

static HRESULT WINAPI URLMoniker_Save(IMoniker *iface, IStream* pStm, BOOL fClearDirty)
{
    URLMoniker *This = impl_from_IMoniker(iface);
    HRESULT res;
    ULONG size;

    TRACE("(%p,%p,%d)\n", This, pStm, fClearDirty);

    if(!pStm)
        return E_INVALIDARG;

    size = (SysStringLen(This->URLName) + 1)*sizeof(WCHAR);
    res=IStream_Write(pStm,&size,sizeof(ULONG),NULL);
    if(SUCCEEDED(res))
        res=IStream_Write(pStm,This->URLName,size,NULL);

    return res;

}

/***
 * This method is part of the IStream interface.
 *
 * It will copy the 'cb' Bytes to 'pstm' IStream.
 *
 * See the documentation of IStream for more info.
 */
static HRESULT WINAPI HGLOBALStreamImpl_CopyTo(
				    IStream*      iface,
				    IStream*      pstm,         /* [unique][in] */
				    ULARGE_INTEGER  cb,           /* [in] */
				    ULARGE_INTEGER* pcbRead,      /* [out] */
				    ULARGE_INTEGER* pcbWritten)   /* [out] */
{
  HRESULT        hr = S_OK;
  BYTE           tmpBuffer[128];
  ULONG          bytesRead, bytesWritten, copySize;
  ULARGE_INTEGER totalBytesRead;
  ULARGE_INTEGER totalBytesWritten;

  TRACE("(%p, %p, %d, %p, %p)\n", iface, pstm,
	cb.u.LowPart, pcbRead, pcbWritten);

  if ( pstm == 0 )
    return STG_E_INVALIDPOINTER;

  totalBytesRead.QuadPart = 0;
  totalBytesWritten.QuadPart = 0;

  while ( cb.QuadPart > 0 )
  {
    if ( cb.QuadPart >= sizeof(tmpBuffer) )
      copySize = sizeof(tmpBuffer);
    else
      copySize = cb.u.LowPart;

    hr = IStream_Read(iface, tmpBuffer, copySize, &bytesRead);
    if (FAILED(hr))
        break;

    totalBytesRead.QuadPart += bytesRead;

    if (bytesRead)
    {
        hr = IStream_Write(pstm, tmpBuffer, bytesRead, &bytesWritten);
        if (FAILED(hr))
            break;

        totalBytesWritten.QuadPart += bytesWritten;
    }

    if (bytesRead!=copySize)
      cb.QuadPart = 0;
    else
      cb.QuadPart -= bytesRead;
  }

  if (pcbRead) pcbRead->QuadPart = totalBytesRead.QuadPart;
  if (pcbWritten) pcbWritten->QuadPart = totalBytesWritten.QuadPart;

  return hr;
}

static void test_copyto(void)
{
    IStream *pStream, *pStream2;
    HRESULT hr = CreateStreamOnHGlobal(NULL, TRUE, &pStream);
    static const char szHello[] = "Hello";
    ULARGE_INTEGER cb;
    static const char *methods_copyto[] =
    {
        "TestStream_Write",
        NULL
    };
    ULONG written;
    ULARGE_INTEGER ullRead;
    ULARGE_INTEGER ullWritten;
    ULARGE_INTEGER libNewPosition;
    static const LARGE_INTEGER llZero;
    char buffer[15];

    ok_ole_success(hr, "CreateStreamOnHGlobal");

    expected_method_list = methods_copyto;

    hr = IStream_Write(pStream, szHello, sizeof(szHello), &written);
    ok_ole_success(hr, "IStream_Write");
    ok(written == sizeof(szHello), "only %d bytes written\n", written);

    hr = IStream_Seek(pStream, llZero, STREAM_SEEK_SET, NULL);
    ok_ole_success(hr, "IStream_Seek");

    cb.QuadPart = sizeof(szHello);
    hr = IStream_CopyTo(pStream, &Test_Stream, cb, &ullRead, &ullWritten);
    ok(ullWritten.QuadPart == 5, "ullWritten was %d instead\n", (ULONG)ullWritten.QuadPart);
    ok(ullRead.QuadPart == sizeof(szHello), "only %d bytes read\n", (ULONG)ullRead.QuadPart);
    ok_ole_success(hr, "IStream_CopyTo");

    ok(!*expected_method_list, "Method sequence starting from %s not called\n", *expected_method_list);

    hr = IStream_Clone(pStream, &pStream2);
    ok_ole_success(hr, "IStream_Clone");

    hr = IStream_Seek(pStream2, llZero, STREAM_SEEK_CUR, &libNewPosition);
    ok_ole_success(hr, "IStream_Seek");
    ok(libNewPosition.QuadPart == sizeof(szHello), "libNewPosition wasn't set correctly for the cloned stream\n");

    hr = IStream_Seek(pStream2, llZero, STREAM_SEEK_SET, NULL);
    ok_ole_success(hr, "IStream_Seek");

    hr = IStream_Read(pStream2, buffer, sizeof(buffer), NULL);
    ok_ole_success(hr, "IStream_Read");
    ok(!strcmp(buffer, szHello), "read data \"%s\" didn't match originally written data\n", buffer);

    IStream_Release(pStream2);
    IStream_Release(pStream);
}

static HRESULT WINAPI xmldoc_IPersistStreamInit_Load(
    IPersistStreamInit *iface, LPSTREAM pStm)
{
    xmldoc *This = impl_from_IPersistStreamInit(iface);
    HRESULT hr;
    HGLOBAL hglobal;
    DWORD read, written, len;
    BYTE buf[4096];
    char *ptr;

    TRACE("(%p, %p)\n", iface, pStm);

    if (!pStm)
        return E_INVALIDARG;

    /* release previously allocated stream */
    if (This->stream) IStream_Release(This->stream);
    hr = CreateStreamOnHGlobal(NULL, TRUE, &This->stream);
    if (FAILED(hr))
        return hr;

    do
    {
        IStream_Read(pStm, buf, sizeof(buf), &read);
        hr = IStream_Write(This->stream, buf, read, &written);
    } while(SUCCEEDED(hr) && written != 0 && read != 0);

    if (FAILED(hr))
    {
        ERR("Failed to copy stream\n");
        return hr;
    }

    hr = GetHGlobalFromStream(This->stream, &hglobal);
    if (FAILED(hr))
        return hr;

    len = GlobalSize(hglobal);
    ptr = GlobalLock(hglobal);
    if (len != 0)
    {
        xmlFreeDoc(This->xmldoc);
        This->xmldoc = parse_xml(ptr, len);
    }
    GlobalUnlock(hglobal);

    if (!This->xmldoc)
    {
        ERR("Failed to parse xml\n");
        return E_FAIL;
    }

    return S_OK;
}

static void user_write_data(png_structp png_ptr, png_bytep data, png_size_t length)
{
    PngEncoder *This = ppng_get_io_ptr(png_ptr);
    HRESULT hr;
    ULONG byteswritten;

    hr = IStream_Write(This->stream, data, length, &byteswritten);
    if (FAILED(hr) || byteswritten != length)
    {
        ppng_error(png_ptr, "failed writing data");
    }
}