1/*
2 * Copyright (C) 2017 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17package com.android.internal.util;
18
19import android.support.test.filters.SmallTest;
20import android.support.test.runner.AndroidJUnit4;
21import java.nio.ByteBuffer;
22import org.junit.Test;
23import org.junit.runner.RunWith;
24
25import static org.junit.Assert.assertEquals;
26import static com.android.internal.util.BitUtils.*;
27
28@SmallTest
29@RunWith(AndroidJUnit4.class)
30public class BitUtilsTest {
31
32    @Test
33    public void testUnsignedByteWideningConversions() {
34        byte b0 = 0;
35        byte b1 = 1;
36        byte bm1 = -1;
37        assertEquals(0, uint8(b0));
38        assertEquals(1, uint8(b1));
39        assertEquals(127, uint8(Byte.MAX_VALUE));
40        assertEquals(128, uint8(Byte.MIN_VALUE));
41        assertEquals(255, uint8(bm1));
42        assertEquals(255, uint8((byte)255));
43    }
44
45    @Test
46    public void testUnsignedShortWideningConversions() {
47        short s0 = 0;
48        short s1 = 1;
49        short sm1 = -1;
50        assertEquals(0, uint16(s0));
51        assertEquals(1, uint16(s1));
52        assertEquals(32767, uint16(Short.MAX_VALUE));
53        assertEquals(32768, uint16(Short.MIN_VALUE));
54        assertEquals(65535, uint16(sm1));
55        assertEquals(65535, uint16((short)65535));
56    }
57
58    @Test
59    public void testUnsignedShortComposition() {
60        byte b0 = 0;
61        byte b1 = 1;
62        byte b2 = 2;
63        byte b10 = 10;
64        byte b16 = 16;
65        byte b128 = -128;
66        byte b224 = -32;
67        byte b255 = -1;
68        assertEquals(0x0000, uint16(b0, b0));
69        assertEquals(0xffff, uint16(b255, b255));
70        assertEquals(0x0a01, uint16(b10, b1));
71        assertEquals(0x8002, uint16(b128, b2));
72        assertEquals(0x01ff, uint16(b1, b255));
73        assertEquals(0x80ff, uint16(b128, b255));
74        assertEquals(0xe010, uint16(b224, b16));
75    }
76
77    @Test
78    public void testUnsignedIntWideningConversions() {
79        assertEquals(0, uint32(0));
80        assertEquals(1, uint32(1));
81        assertEquals(2147483647L, uint32(Integer.MAX_VALUE));
82        assertEquals(2147483648L, uint32(Integer.MIN_VALUE));
83        assertEquals(4294967295L, uint32(-1));
84        assertEquals(4294967295L, uint32((int)4294967295L));
85    }
86
87    @Test
88    public void testBytesToInt() {
89        assertEquals(0x00000000, bytesToBEInt(bytes(0, 0, 0, 0)));
90        assertEquals(0xffffffff, bytesToBEInt(bytes(255, 255, 255, 255)));
91        assertEquals(0x0a000001, bytesToBEInt(bytes(10, 0, 0, 1)));
92        assertEquals(0x0a000002, bytesToBEInt(bytes(10, 0, 0, 2)));
93        assertEquals(0x0a001fff, bytesToBEInt(bytes(10, 0, 31, 255)));
94        assertEquals(0xe0000001, bytesToBEInt(bytes(224, 0, 0, 1)));
95
96        assertEquals(0x00000000, bytesToLEInt(bytes(0, 0, 0, 0)));
97        assertEquals(0x01020304, bytesToLEInt(bytes(4, 3, 2, 1)));
98        assertEquals(0xffff0000, bytesToLEInt(bytes(0, 0, 255, 255)));
99    }
100
101    @Test
102    public void testUnsignedGetters() {
103      ByteBuffer b = ByteBuffer.allocate(4);
104      b.putInt(0xffff);
105
106      assertEquals(0x0, getUint8(b, 0));
107      assertEquals(0x0, getUint8(b, 1));
108      assertEquals(0xff, getUint8(b, 2));
109      assertEquals(0xff, getUint8(b, 3));
110
111      assertEquals(0x0, getUint16(b, 0));
112      assertEquals(0xffff, getUint16(b, 2));
113
114      b.rewind();
115      b.putInt(0xffffffff);
116      assertEquals(0xffffffffL, getUint32(b, 0));
117    }
118
119    static byte[] bytes(int b1, int b2, int b3, int b4) {
120        return new byte[] {b(b1), b(b2), b(b3), b(b4)};
121    }
122
123    static byte b(int i) {
124        return (byte) i;
125    }
126}
127