Home | History | Annotate | Download | only in util 
      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 
     17 package com.android.internal.util;
     18 
     19 import static com.android.internal.util.BitUtils.bytesToBEInt;
     20 import static com.android.internal.util.BitUtils.bytesToLEInt;
     21 import static com.android.internal.util.BitUtils.getUint16;
     22 import static com.android.internal.util.BitUtils.getUint32;
     23 import static com.android.internal.util.BitUtils.getUint8;
     24 import static com.android.internal.util.BitUtils.uint16;
     25 import static com.android.internal.util.BitUtils.uint32;
     26 import static com.android.internal.util.BitUtils.uint8;
     27 
     28 import static org.junit.Assert.assertEquals;
     29 
     30 import androidx.test.filters.SmallTest;
     31 import androidx.test.runner.AndroidJUnit4;
     32 
     33 import org.junit.Test;
     34 import org.junit.runner.RunWith;
     35 
     36 import java.nio.ByteBuffer;
     37 
     38 @SmallTest
     39 @RunWith(AndroidJUnit4.class)
     40 public class BitUtilsTest {
     41 
     42     @Test
     43     public void testUnsignedByteWideningConversions() {
     44         byte b0 = 0;
     45         byte b1 = 1;
     46         byte bm1 = -1;
     47         assertEquals(0, uint8(b0));
     48         assertEquals(1, uint8(b1));
     49         assertEquals(127, uint8(Byte.MAX_VALUE));
     50         assertEquals(128, uint8(Byte.MIN_VALUE));
     51         assertEquals(255, uint8(bm1));
     52         assertEquals(255, uint8((byte)255));
     53     }
     54 
     55     @Test
     56     public void testUnsignedShortWideningConversions() {
     57         short s0 = 0;
     58         short s1 = 1;
     59         short sm1 = -1;
     60         assertEquals(0, uint16(s0));
     61         assertEquals(1, uint16(s1));
     62         assertEquals(32767, uint16(Short.MAX_VALUE));
     63         assertEquals(32768, uint16(Short.MIN_VALUE));
     64         assertEquals(65535, uint16(sm1));
     65         assertEquals(65535, uint16((short)65535));
     66     }
     67 
     68     @Test
     69     public void testUnsignedShortComposition() {
     70         byte b0 = 0;
     71         byte b1 = 1;
     72         byte b2 = 2;
     73         byte b10 = 10;
     74         byte b16 = 16;
     75         byte b128 = -128;
     76         byte b224 = -32;
     77         byte b255 = -1;
     78         assertEquals(0x0000, uint16(b0, b0));
     79         assertEquals(0xffff, uint16(b255, b255));
     80         assertEquals(0x0a01, uint16(b10, b1));
     81         assertEquals(0x8002, uint16(b128, b2));
     82         assertEquals(0x01ff, uint16(b1, b255));
     83         assertEquals(0x80ff, uint16(b128, b255));
     84         assertEquals(0xe010, uint16(b224, b16));
     85     }
     86 
     87     @Test
     88     public void testUnsignedIntWideningConversions() {
     89         assertEquals(0, uint32(0));
     90         assertEquals(1, uint32(1));
     91         assertEquals(2147483647L, uint32(Integer.MAX_VALUE));
     92         assertEquals(2147483648L, uint32(Integer.MIN_VALUE));
     93         assertEquals(4294967295L, uint32(-1));
     94         assertEquals(4294967295L, uint32((int)4294967295L));
     95     }
     96 
     97     @Test
     98     public void testBytesToInt() {
     99         assertEquals(0x00000000, bytesToBEInt(bytes(0, 0, 0, 0)));
    100         assertEquals(0xffffffff, bytesToBEInt(bytes(255, 255, 255, 255)));
    101         assertEquals(0x0a000001, bytesToBEInt(bytes(10, 0, 0, 1)));
    102         assertEquals(0x0a000002, bytesToBEInt(bytes(10, 0, 0, 2)));
    103         assertEquals(0x0a001fff, bytesToBEInt(bytes(10, 0, 31, 255)));
    104         assertEquals(0xe0000001, bytesToBEInt(bytes(224, 0, 0, 1)));
    105 
    106         assertEquals(0x00000000, bytesToLEInt(bytes(0, 0, 0, 0)));
    107         assertEquals(0x01020304, bytesToLEInt(bytes(4, 3, 2, 1)));
    108         assertEquals(0xffff0000, bytesToLEInt(bytes(0, 0, 255, 255)));
    109     }
    110 
    111     @Test
    112     public void testUnsignedGetters() {
    113       ByteBuffer b = ByteBuffer.allocate(4);
    114       b.putInt(0xffff);
    115 
    116       assertEquals(0x0, getUint8(b, 0));
    117       assertEquals(0x0, getUint8(b, 1));
    118       assertEquals(0xff, getUint8(b, 2));
    119       assertEquals(0xff, getUint8(b, 3));
    120 
    121       assertEquals(0x0, getUint16(b, 0));
    122       assertEquals(0xffff, getUint16(b, 2));
    123 
    124       b.rewind();
    125       b.putInt(0xffffffff);
    126       assertEquals(0xffffffffL, getUint32(b, 0));
    127     }
    128 
    129     static byte[] bytes(int b1, int b2, int b3, int b4) {
    130         return new byte[] {b(b1), b(b2), b(b3), b(b4)};
    131     }
    132 
    133     static byte b(int i) {
    134         return (byte) i;
    135     }
    136 }
    137