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