Performance: Identity conversion of primitive array could be more efficient about dozer HOT 4 CLOSED

Try to use copy-by-reference option not to create a separate array. As far as I know we do use System.arrayCopy in some places. If you could profile and see where it is missing would be great.

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Please, could you provide a code of concrete test case? Maybe, I will research it in the nearest future and try to fix.
BTW, feel free to submit patch :)

from dozer.

Hello, test case below.

In the head version of Dozer, the time is spent in MappingProcessor.addToPrimitiveArray .
It is much easier to fix than in previous release.

btw, my initial post was wrong concerning the immutables types. Maybe System.arrayCopy could also be used for types that are both "copy-by-reference" and final.
It could be useful for String[]

The following TC outputs ~1000 (ms) on my machine

public class DozerPerformanceTest extends TestCase {

public static class ByteTest {
    private byte[] data;

    public byte[] getData() {
        return data;
    }

    public void setData(byte[] data) {
        this.data = data;
    }
}

public void testByteCopy() {

    RootLogger.getRootLogger().setLevel(Level.WARN);

    ByteTest test = new ByteTest();
    test.setData(new byte[1024 * 1024]);
    DozerBeanMapper dozer = new DozerBeanMapper();
    ByteTest map = dozer.map(test, ByteTest.class);

    long start = System.currentTimeMillis();
    map = dozer.map(test, ByteTest.class);
    System.out.println(System.currentTimeMillis() - start);

}

}

from dozer.

This part of the code handles mixed element collections, but your final + copy-by-reference is a perfect solution how to distinguish the need for System.arrayCopy()!

So the solution should be - if it is a typed collection and type is final and copy-by-referenced, then do native array copy.

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