Reading Cell Values in Multiple Threads Simultaneously

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To read cell values in more than one thread simultaneously, set Cells.multiThreadReading(boolean) to true. If you do not, you might get the wrong cell values.

The following code:

  1. Creates a workbook.
  2. Adds a worksheet.
  3. Populates the worksheet with string values.
  4. It then creates two threads that simultaneously read values from random cells. If the values read are correct, nothing happens. If the values read are incorrect, then a message is displayed.

If you comment this line:

testWorkbook.worksheets.get(0).cells.multiThreadReading(true);

then the following message is displayed:

if (s !== "R" + row + "C" + col)
{
    console.log("This message box will show up when cells read values are incorrect.");
}

Otherwise, the program runs without showing any message which means all values read from cells are correct.

<!DOCTYPE html>
<html>
    <head>
        <title>Aspose.Cells Example</title>
    </head>
    <body>
        <h1>Multi-Threading Read Example</h1>
        <input type="file" id="fileInput" accept=".xls,.xlsx,.csv" />
        <button id="runExample">Run Example</button>
        <a id="downloadLink" style="display: none;">Download Result</a>
        <div id="result"></div>
    </body>

    <script src="aspose.cells.js.min.js"></script>
    <script type="text/javascript">
        const { Workbook, SaveFormat } = AsposeCells;
        
        const readyPromise = AsposeCells.onReady({
            license: "/lic/aspose.cells.enc",
            fontPath: "/fonts/",
            fontList: [
                "arial.ttf",
                "NotoSansSC-Regular.ttf"
            ]
        }).then(() => {
            console.log("Aspose.Cells initialized");
        });

        let testWorkbook;

        const threadLoop = () => {
            const random = Math.random;
            while (true) {
                const row = Math.floor(random() * 10000);
                const col = Math.floor(random() * 100);
                const s = testWorkbook.worksheets.get(0).cells.get(row, col).stringValue;
                if (s !== "R" + row + "C" + col) {
                    console.log("This message will show up when cells read values are incorrect.");
                }
            }
        };

        const testMultiThreadingRead = () => {
            testWorkbook = new Workbook();
            testWorkbook.worksheets.clear();
            testWorkbook.worksheets.add("Sheet1");

            for (let row = 0; row < 10000; row++) {
                for (let col = 0; col < 100; col++) {
                    testWorkbook.worksheets.get(0).cells.get(row, col).value = "R" + row + "C" + col;
                }
            }

            // Uncommenting this line will enable multi-threaded reading    
            //testWorkbook.worksheets.get(0).cells.setMultiThreadReading(true);

            const myThread1 = setInterval(threadLoop, 0);
            const myThread2 = setInterval(threadLoop, 0);

            setTimeout(() => {
                clearInterval(myThread1);
                clearInterval(myThread2);
                document.getElementById('result').innerHTML = '<p style="color: green;">Multi-threading read test completed.</p>';
            }, 5 * 1000);
        };

        document.getElementById('runExample').addEventListener('click', async () => {
            await readyPromise;
            document.getElementById('result').innerHTML = '<p style="color: green;">Starting multi-threading read test. This will run for 5 seconds.</p>';
            testMultiThreadingRead();
        });
    </script>
</html>
Populate Data First by Row then by Column