1 // Copyright (c) 2012 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/metrics/bucket_ranges.h" 6 7 #include <stdint.h> 8 9 #include "testing/gtest/include/gtest/gtest.h" 10 11 namespace base { 12 namespace { 13 14 TEST(BucketRangesTest, NormalSetup) { 15 BucketRanges ranges(5); 16 ASSERT_EQ(5u, ranges.size()); 17 ASSERT_EQ(4u, ranges.bucket_count()); 18 19 for (int i = 0; i < 5; ++i) { 20 EXPECT_EQ(0, ranges.range(i)); 21 } 22 EXPECT_EQ(0u, ranges.checksum()); 23 24 ranges.set_range(3, 100); 25 EXPECT_EQ(100, ranges.range(3)); 26 } 27 28 TEST(BucketRangesTest, Equals) { 29 // Compare empty ranges. 30 BucketRanges ranges1(3); 31 BucketRanges ranges2(3); 32 BucketRanges ranges3(5); 33 34 EXPECT_TRUE(ranges1.Equals(&ranges2)); 35 EXPECT_FALSE(ranges1.Equals(&ranges3)); 36 EXPECT_FALSE(ranges2.Equals(&ranges3)); 37 38 // Compare full filled ranges. 39 ranges1.set_range(0, 0); 40 ranges1.set_range(1, 1); 41 ranges1.set_range(2, 2); 42 ranges1.set_checksum(100); 43 ranges2.set_range(0, 0); 44 ranges2.set_range(1, 1); 45 ranges2.set_range(2, 2); 46 ranges2.set_checksum(100); 47 48 EXPECT_TRUE(ranges1.Equals(&ranges2)); 49 50 // Checksum does not match. 51 ranges1.set_checksum(99); 52 EXPECT_FALSE(ranges1.Equals(&ranges2)); 53 ranges1.set_checksum(100); 54 55 // Range does not match. 56 ranges1.set_range(1, 3); 57 EXPECT_FALSE(ranges1.Equals(&ranges2)); 58 } 59 60 TEST(BucketRangesTest, Checksum) { 61 BucketRanges ranges(3); 62 ranges.set_range(0, 0); 63 ranges.set_range(1, 1); 64 ranges.set_range(2, 2); 65 66 ranges.ResetChecksum(); 67 EXPECT_EQ(289217253u, ranges.checksum()); 68 69 ranges.set_range(2, 3); 70 EXPECT_FALSE(ranges.HasValidChecksum()); 71 72 ranges.ResetChecksum(); 73 EXPECT_EQ(2843835776u, ranges.checksum()); 74 EXPECT_TRUE(ranges.HasValidChecksum()); 75 } 76 77 // Table was generated similarly to sample code for CRC-32 given on: 78 // http://www.w3.org/TR/PNG/#D-CRCAppendix. 79 TEST(BucketRangesTest, Crc32TableTest) { 80 for (int i = 0; i < 256; ++i) { 81 uint32_t checksum = i; 82 for (int j = 0; j < 8; ++j) { 83 const uint32_t kReversedPolynomial = 0xedb88320L; 84 if (checksum & 1) 85 checksum = kReversedPolynomial ^ (checksum >> 1); 86 else 87 checksum >>= 1; 88 } 89 EXPECT_EQ(kCrcTable[i], checksum); 90 } 91 } 92 93 } // namespace 94 } // namespace base 95
