1 /* 2 * Copyright (C) 2012 The Guava Authors 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except 5 * in compliance with the License. You may obtain a copy of the License at 6 * 7 * http://www.apache.org/licenses/LICENSE-2.0 8 * 9 * Unless required by applicable law or agreed to in writing, software distributed under the License 10 * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express 11 * or implied. See the License for the specific language governing permissions and limitations under 12 * the License. 13 */ 14 15 package com.google.common.hash; 16 17 import static com.google.common.hash.Hashing.ChecksumType.ADLER_32; 18 import static com.google.common.hash.Hashing.ChecksumType.CRC_32; 19 20 import com.google.common.base.Supplier; 21 22 import junit.framework.TestCase; 23 24 import java.util.zip.Checksum; 25 26 /** 27 * Tests for ChecksumHashFunction. 28 * 29 * @author Colin Decker 30 */ 31 public class ChecksumHashFunctionTest extends TestCase { 32 33 public void testCrc32_equalsChecksumValue() throws Exception { 34 assertChecksum(CRC_32, ""); 35 assertChecksum(CRC_32, "Z"); 36 assertChecksum(CRC_32, "foobar"); 37 } 38 39 public void testAdler32_equalsChecksumValue() throws Exception { 40 assertChecksum(ADLER_32, ""); 41 assertChecksum(ADLER_32, "Z"); 42 assertChecksum(ADLER_32, "foobar"); 43 } 44 45 public void testCrc32_knownValues() throws Exception { 46 assertHash32(0x1C8600E3, CRC_32, "hell"); 47 assertHash32(0x3610A686, CRC_32, "hello"); 48 assertHash32(0xED81F9F6, CRC_32, "hello "); 49 assertHash32(0x4850DDC2, CRC_32, "hello w"); 50 assertHash32(0x7A2D6005, CRC_32, "hello wo"); 51 assertHash32(0x1C192672, CRC_32, "hello wor"); 52 assertHash32(0x414FA339, CRC_32, "The quick brown fox jumps over the lazy dog"); 53 assertHash32(0x4400B5BC, CRC_32, "The quick brown fox jumps over the lazy cog"); 54 } 55 56 public void testAdler32_knownValues() throws Exception { 57 assertHash32(0x041701A6, ADLER_32, "hell"); 58 assertHash32(0x062C0215, ADLER_32, "hello"); 59 assertHash32(0x08610235, ADLER_32, "hello "); 60 assertHash32(0x0B0D02AC, ADLER_32, "hello w"); 61 assertHash32(0x0E28031B, ADLER_32, "hello wo"); 62 assertHash32(0x11B5038D, ADLER_32, "hello wor"); 63 assertHash32(0x5BDC0FDA, ADLER_32, "The quick brown fox jumps over the lazy dog"); 64 assertHash32(0x5BD90FD9, ADLER_32, "The quick brown fox jumps over the lazy cog"); 65 } 66 67 private static void assertChecksum(Supplier<Checksum> supplier, String input) { 68 byte[] bytes = HashTestUtils.ascii(input); 69 70 Checksum checksum = supplier.get(); 71 checksum.update(bytes, 0, bytes.length); 72 long value = checksum.getValue(); 73 74 String toString = "name"; 75 HashFunction func = new ChecksumHashFunction(supplier, 32, toString); 76 assertEquals(toString, func.toString()); 77 assertEquals(value, func.hashBytes(bytes).padToLong()); 78 } 79 80 private static void assertHash32(int expected, Supplier<Checksum> supplier, String input) { 81 byte[] bytes = HashTestUtils.ascii(input); 82 String toString = "name"; 83 HashFunction func = new ChecksumHashFunction(supplier, 32, toString); 84 assertEquals(expected, func.hashBytes(bytes).asInt()); 85 assertEquals(toString, func.toString()); 86 } 87 } 88
