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/*
* Copyright (C) 2017 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.android.internal.util;
import static com.android.internal.util.BitUtils.bytesToBEInt;
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 android.os.Build;
import androidx.test.filters.SmallTest;
import com.android.testutils.DevSdkIgnoreRule;
import com.android.testutils.DevSdkIgnoreRunner;
import org.junit.Test;
import org.junit.runner.RunWith;
import java.nio.ByteBuffer;
import java.util.Arrays;
import java.util.Random;
@SmallTest
@RunWith(DevSdkIgnoreRunner.class)
@DevSdkIgnoreRule.IgnoreUpTo(Build.VERSION_CODES.R)
public class BitUtilsTest {
@Test
public void testUnsignedByteWideningConversions() {
byte b0 = 0;
byte b1 = 1;
byte bm1 = -1;
assertEquals(0, uint8(b0));
assertEquals(1, uint8(b1));
assertEquals(127, uint8(Byte.MAX_VALUE));
assertEquals(128, uint8(Byte.MIN_VALUE));
assertEquals(255, uint8(bm1));
assertEquals(255, uint8((byte)255));
}
@Test
public void testUnsignedShortWideningConversions() {
short s0 = 0;
short s1 = 1;
short sm1 = -1;
assertEquals(0, uint16(s0));
assertEquals(1, uint16(s1));
assertEquals(32767, uint16(Short.MAX_VALUE));
assertEquals(32768, uint16(Short.MIN_VALUE));
assertEquals(65535, uint16(sm1));
assertEquals(65535, uint16((short)65535));
}
@Test
public void testUnsignedShortComposition() {
byte b0 = 0;
byte b1 = 1;
byte b2 = 2;
byte b10 = 10;
byte b16 = 16;
byte b128 = -128;
byte b224 = -32;
byte b255 = -1;
assertEquals(0x0000, uint16(b0, b0));
assertEquals(0xffff, uint16(b255, b255));
assertEquals(0x0a01, uint16(b10, b1));
assertEquals(0x8002, uint16(b128, b2));
assertEquals(0x01ff, uint16(b1, b255));
assertEquals(0x80ff, uint16(b128, b255));
assertEquals(0xe010, uint16(b224, b16));
}
@Test
public void testUnsignedIntWideningConversions() {
assertEquals(0, uint32(0));
assertEquals(1, uint32(1));
assertEquals(2147483647L, uint32(Integer.MAX_VALUE));
assertEquals(2147483648L, uint32(Integer.MIN_VALUE));
assertEquals(4294967295L, uint32(-1));
assertEquals(4294967295L, uint32((int)4294967295L));
}
@Test
public void testBytesToInt() {
assertEquals(0x00000000, bytesToBEInt(bytes(0, 0, 0, 0)));
assertEquals(0xffffffff, bytesToBEInt(bytes(255, 255, 255, 255)));
assertEquals(0x0a000001, bytesToBEInt(bytes(10, 0, 0, 1)));
assertEquals(0x0a000002, bytesToBEInt(bytes(10, 0, 0, 2)));
assertEquals(0x0a001fff, bytesToBEInt(bytes(10, 0, 31, 255)));
assertEquals(0xe0000001, bytesToBEInt(bytes(224, 0, 0, 1)));
assertEquals(0x00000000, bytesToLEInt(bytes(0, 0, 0, 0)));
assertEquals(0x01020304, bytesToLEInt(bytes(4, 3, 2, 1)));
assertEquals(0xffff0000, bytesToLEInt(bytes(0, 0, 255, 255)));
}
@Test
public void testUnsignedGetters() {
ByteBuffer b = ByteBuffer.allocate(4);
b.putInt(0xffff);
assertEquals(0x0, getUint8(b, 0));
assertEquals(0x0, getUint8(b, 1));
assertEquals(0xff, getUint8(b, 2));
assertEquals(0xff, getUint8(b, 3));
assertEquals(0x0, getUint16(b, 0));
assertEquals(0xffff, getUint16(b, 2));
b.rewind();
b.putInt(0xffffffff);
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)};
}
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;
}
}
}
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