Merge "BitUtils: support packing/unpacking negative long values" (9e5de85e) · Commits · e / os / android_frameworks_base

core/java/com/android/internal/util/BitUtils.java

+3 −3

Original line number	Diff line number	Diff line
		@@ -68,9 +68,9 @@ public final class BitUtils {
		int[] result = new int[size];
		int index = 0;
		int bitPos = 0;
		while (val > 0) {
		while (val != 0) {
		if ((val & 1) == 1) result[index++] = bitPos;
		val = val >> 1;
		val = val >>> 1;
		bitPos++;
		}
		return result;
		@@ -79,7 +79,7 @@ public final class BitUtils {
		public static long packBits(int[] bits) {
		long packed = 0;
		for (int b : bits) {
		packed \|= (1 << b);
		packed \|= (1L << b);
		}
		return packed;
		}

tests/net/java/com/android/internal/util/BitUtilsTest.java

+76 −11

Original line number	Diff line number	Diff line
		@@ -21,11 +21,14 @@ import static com.android.internal.util.BitUtils.bytesToLEInt;
		import static com.android.internal.util.BitUtils.getUint16;
		import static com.android.internal.util.BitUtils.getUint32;
		import static com.android.internal.util.BitUtils.getUint8;
		import static com.android.internal.util.BitUtils.packBits;
		import static com.android.internal.util.BitUtils.uint16;
		import static com.android.internal.util.BitUtils.uint32;
		import static com.android.internal.util.BitUtils.uint8;
		import static com.android.internal.util.BitUtils.unpackBits;

		import static org.junit.Assert.assertEquals;
		import static org.junit.Assert.assertTrue;

		import androidx.test.filters.SmallTest;
		import androidx.test.runner.AndroidJUnit4;
		@@ -34,6 +37,8 @@ import org.junit.Test;
		import org.junit.runner.RunWith;

		import java.nio.ByteBuffer;
		import java.util.Arrays;
		import java.util.Random;

		@SmallTest
		@RunWith(AndroidJUnit4.class)
		@@ -126,6 +131,52 @@ public class BitUtilsTest {
		assertEquals(0xffffffffL, getUint32(b, 0));
		}

		@Test
		public void testBitsPacking() {
		BitPackingTestCase[] testCases = {
		new BitPackingTestCase(0, ints()),
		new BitPackingTestCase(1, ints(0)),
		new BitPackingTestCase(2, ints(1)),
		new BitPackingTestCase(3, ints(0, 1)),
		new BitPackingTestCase(4, ints(2)),
		new BitPackingTestCase(6, ints(1, 2)),
		new BitPackingTestCase(9, ints(0, 3)),
		new BitPackingTestCase(~Long.MAX_VALUE, ints(63)),
		new BitPackingTestCase(~Long.MAX_VALUE + 1, ints(0, 63)),
		new BitPackingTestCase(~Long.MAX_VALUE + 2, ints(1, 63)),
		};
		for (BitPackingTestCase tc : testCases) {
		int[] got = unpackBits(tc.packedBits);
		assertTrue(
		"unpackBits("
		+ tc.packedBits
		+ "): expected "
		+ Arrays.toString(tc.bits)
		+ " but got "
		+ Arrays.toString(got),
		Arrays.equals(tc.bits, got));
		}
		for (BitPackingTestCase tc : testCases) {
		long got = packBits(tc.bits);
		assertEquals(
		"packBits("
		+ Arrays.toString(tc.bits)
		+ "): expected "
		+ tc.packedBits
		+ " but got "
		+ got,
		tc.packedBits,
		got);
		}

		long[] moreTestCases = {
		0, 1, -1, 23895, -908235, Long.MAX_VALUE, Long.MIN_VALUE, new Random().nextLong(),
		};
		for (long l : moreTestCases) {
		assertEquals(l, packBits(unpackBits(l)));
		}
		}

		static byte[] bytes(int b1, int b2, int b3, int b4) {
		return new byte[] {b(b1), b(b2), b(b3), b(b4)};
		}
		@@ -133,4 +184,18 @@ public class BitUtilsTest {
		static byte b(int i) {
		return (byte) i;
		}

		static int[] ints(int... array) {
		return array;
		}

		static class BitPackingTestCase {
		final int[] bits;
		final long packedBits;

		BitPackingTestCase(long packedBits, int[] bits) {
		this.bits = bits;
		this.packedBits = packedBits;
		}
		}
		}