Class ZstdTest

core/src/test/java/io/questdb/test/std/ZstdTest.java:36–264

import org.junit.Test;

public class ZstdTest {

    static {
        Os.init();
    }

    @Test
    public void testCompressThenDecompressHighlyCompressibleRuns() throws Exception {
        TestUtils.assertMemoryLeak(() -> {
            // Runs of repeated bytes should compress dramatically.
            int len = 256 * 1024;
            long src = Unsafe.malloc(len, MemoryTag.NATIVE_DEFAULT);
            try {
                for (int i = 0; i < len; i++) {
                    Unsafe.putByte(src + i, (byte) (i / 1024));
                }
                roundTrip(src, len);
            } finally {
                Unsafe.free(src, len, MemoryTag.NATIVE_DEFAULT);
            }
        });
    }

    @Test
    public void testCompressThenDecompressRandom() throws Exception {
        TestUtils.assertMemoryLeak(() -> {
            int len = 64 * 1024;
            long src = Unsafe.malloc(len, MemoryTag.NATIVE_DEFAULT);
            try {
                Rnd rnd = new Rnd();
                for (int i = 0; i < len; i++) {
                    Unsafe.putByte(src + i, (byte) rnd.nextInt());
                }
                roundTrip(src, len);
            } finally {
                Unsafe.free(src, len, MemoryTag.NATIVE_DEFAULT);
            }
        });
    }

    @Test
    public void testCompressTooSmallDestinationReturnsError() throws Exception {
        TestUtils.assertMemoryLeak(() -> {
            // A realistic payload compressed into a destination one byte wide cannot fit
            // even the zstd frame header. The native side must return a negative error
            // code, not silently truncate.
            int len = 4096;
            long src = Unsafe.malloc(len, MemoryTag.NATIVE_DEFAULT);
            long dst = Unsafe.malloc(1, MemoryTag.NATIVE_DEFAULT);
            long cctx = Zstd.createCCtx(3);
            try {
                for (int i = 0; i < len; i++) {
                    Unsafe.putByte(src + i, (byte) i);
                }
                long result = Zstd.compress(cctx, src, len, dst, 1);
                Assert.assertTrue("expected negative error, got " + result, result < 0);
            } finally {
                Zstd.freeCCtx(cctx);