1 /* 2 * Copyright (C) 2008 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 android.core; 18 19 import junit.framework.TestCase; 20 21 import java.util.zip.Adler32; 22 import java.util.zip.CRC32; 23 import android.test.suitebuilder.annotation.SmallTest; 24 25 /** 26 * tests for CRC32 and Adler32 checksum algorithms. 27 */ 28 public class ChecksumTest extends TestCase { 29 30 @SmallTest testChecksum()31 public void testChecksum() throws Exception { 32 /* 33 * Values computed experimentally, using C interfaces. 34 */ 35 adler32Test(mTestString, 0x9de210dbL); 36 cRC32Test(mTestString, 0x939f04afL); 37 38 // Test for issue 1016037 39 wrongChecksumWithAdler32Test(); 40 } 41 adler32Test(byte[] values, long expected)42 private void adler32Test(byte[] values, long expected) { 43 Adler32 adler = new Adler32(); 44 45 // try it all at once 46 adler.update(values); 47 assertEquals(adler.getValue(), expected); 48 49 // try resetting and computing one byte at a time 50 adler.reset(); 51 for (int i = 0; i < values.length; i++) { 52 adler.update(values[i]); 53 } 54 assertEquals(adler.getValue(), expected); 55 } 56 cRC32Test(byte[] values, long expected)57 private void cRC32Test(byte[] values, long expected) { 58 CRC32 crc = new CRC32(); 59 60 // try it all at once 61 crc.update(values); 62 assertEquals(crc.getValue(), expected); 63 64 // try resetting and computing one byte at a time 65 crc.reset(); 66 for (int i = 0; i < values.length; i++) { 67 crc.update(values[i]); 68 } 69 assertEquals(crc.getValue(), expected); 70 } 71 72 // "The quick brown fox jumped over the lazy dogs\n" 73 private static byte[] mTestString = { 74 0x54, 0x68, 0x65, 0x20, 0x71, 0x75, 0x69, 0x63, 75 0x6b, 0x20, 0x62, 0x72, 0x6f, 0x77, 0x6e, 0x20, 76 0x66, 0x6f, 0x78, 0x20, 0x6a, 0x75, 0x6d, 0x70, 77 0x65, 0x64, 0x20, 0x6f, 0x76, 0x65, 0x72, 0x20, 78 0x74, 0x68, 0x65, 0x20, 0x6c, 0x61, 0x7a, 0x79, 79 0x20, 0x64, 0x6f, 0x67, 0x73, 0x2e, 0x0a 80 }; 81 82 83 // Test for issue 1016037 wrongChecksumWithAdler32Test()84 private void wrongChecksumWithAdler32Test() { 85 byte[] bytes = {1, 0, 5, 0, 15, 0, 1, 11, 0, 1}; 86 Adler32 adler = new Adler32(); 87 adler.update(bytes); 88 long arrayChecksum = adler.getValue(); 89 adler.reset(); 90 for (int i = 0; i < bytes.length; i++) { 91 adler.update(bytes[i]); 92 } 93 assertEquals("Checksums not equal: expected: " + arrayChecksum + 94 " actual: " + adler.getValue(), arrayChecksum, adler.getValue()); 95 } 96 } 97 98