1 // Copyright 2014 The Chromium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #include "base/hash.h" 6 7 #include <string> 8 #include <vector> 9 10 #include "testing/gtest/include/gtest/gtest.h" 11 12 namespace base { 13 14 TEST(HashTest, String) { 15 std::string str; 16 // Empty string (should hash to 0). 17 str = ""; 18 EXPECT_EQ(0u, Hash(str)); 19 20 // Simple test. 21 str = "hello world"; 22 EXPECT_EQ(2794219650u, Hash(str)); 23 24 // Change one bit. 25 str = "helmo world"; 26 EXPECT_EQ(1006697176u, Hash(str)); 27 28 // Insert a null byte. 29 str = "hello world"; 30 str[5] = '\0'; 31 EXPECT_EQ(2319902537u, Hash(str)); 32 33 // Test that the bytes after the null contribute to the hash. 34 str = "hello worle"; 35 str[5] = '\0'; 36 EXPECT_EQ(553904462u, Hash(str)); 37 38 // Extremely long string. 39 // Also tests strings with high bit set, and null byte. 40 std::vector<char> long_string_buffer; 41 for (int i = 0; i < 4096; ++i) 42 long_string_buffer.push_back((i % 256) - 128); 43 str.assign(&long_string_buffer.front(), long_string_buffer.size()); 44 EXPECT_EQ(2797962408u, Hash(str)); 45 46 // All possible lengths (mod 4). Tests separate code paths. Also test with 47 // final byte high bit set (regression test for http://crbug.com/90659). 48 // Note that the 1 and 3 cases have a weird bug where the final byte is 49 // treated as a signed char. It was decided on the above bug discussion to 50 // enshrine that behaviour as "correct" to avoid invalidating existing hashes. 51 52 // Length mod 4 == 0. 53 str = "hello w\xab"; 54 EXPECT_EQ(615571198u, Hash(str)); 55 // Length mod 4 == 1. 56 str = "hello wo\xab"; 57 EXPECT_EQ(623474296u, Hash(str)); 58 // Length mod 4 == 2. 59 str = "hello wor\xab"; 60 EXPECT_EQ(4278562408u, Hash(str)); 61 // Length mod 4 == 3. 62 str = "hello worl\xab"; 63 EXPECT_EQ(3224633008u, Hash(str)); 64 } 65 66 TEST(HashTest, CString) { 67 const char* str; 68 // Empty string (should hash to 0). 69 str = ""; 70 EXPECT_EQ(0u, Hash(str, strlen(str))); 71 72 // Simple test. 73 str = "hello world"; 74 EXPECT_EQ(2794219650u, Hash(str, strlen(str))); 75 76 // Ensure that it stops reading after the given length, and does not expect a 77 // null byte. 78 str = "hello world; don't read this part"; 79 EXPECT_EQ(2794219650u, Hash(str, strlen("hello world"))); 80 } 81 82 } // namespace base 83
