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Libreoffice custom import - getCellByPosition bottleneck

asked 2018-08-30 14:45:45 +0100

jeremy gravatar image

I am currently creating a custom importer/exporter for my own file type with java using XFilter.

I now have a serious bottleneck when importing. Here is my code for inserting my content into a spreadsheet:

XSpreadsheetDocument document = UnoRuntime.queryInterface(
XMultiServiceFactory serviceFactory = UnoRuntime.queryInterface(,

for (int i = 0; i < numberOfSpreadsheets; i++) {
    Object spreadsheetObject = serviceFactory.createInstance("");
    XSpreadsheet spreadsheet = UnoRuntime.queryInterface(
    document.getSheets().insertByName(spreadsheetNames.get(i), spreadsheet);

    // Not sure about this part
    spreadsheet = UnoRuntime.queryInterface(

    for (int rowIndex = 0; rowIndex < numberOfRows; rowIndex++) {
        for (int columnIndex = 0; columnIndex < numberOfCellsInRow; columnIndex++) {
            // This call to getCellByPosition seems to be the bottleneck
            XCell cell = spreadsheet.getCellByPosition(columnIndex, rowIndex);

            XText text = UnoRuntime.queryInterface(XText.class, cell);

Is there any way I can omit all these calls to getCellByPosition?
Is there some sort of bulk API available?

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answered 2018-08-30 15:01:44 +0100

Look at XCellRangeData's setDataArray.

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The issue with this is that I have to be able to format the cells. The setDataArray function is fast, but formatting the cells afterwards is slow.

jeremy gravatar imagejeremy ( 2018-09-11 13:24:33 +0100 )edit

Heh, good to hear about additional important requirements not mentioned in the initial post (only telling about data)...

Well - I suppose that unless you apply formatting to big ranges at once (like to columns), there's no way to improve speed if you want to handle cells one-by-one. I would be glad to be proven wrong.

Mike Kaganski gravatar imageMike Kaganski ( 2018-09-11 13:31:28 +0100 )edit

Sorry about that. So then the problem really is the link between my extension and LO? Because native importers are very fast by comparison.

jeremy gravatar imagejeremy ( 2018-09-11 13:34:34 +0100 )edit

I tried implementing XExportFilter and XDocumentHandler for the export, but it is also very slow. So it seems to be the link between my extension and LO.

jeremy gravatar imagejeremy ( 2018-09-11 13:40:09 +0100 )edit

Well - UNO is rather slow. "Native" importers are fast because they work with internal structures... Some of built-in importers for XML types are (were? they are being converted to use orcus) using XSLT - and they are also very slow.

Mike Kaganski gravatar imageMike Kaganski ( 2018-09-11 13:43:37 +0100 )edit
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Asked: 2018-08-30 14:45:45 +0100

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Last updated: Aug 30 '18