Zihan Chen | 0a7db3e | 2020-06-23 16:36:06 -0700 | [diff] [blame^] | 1 | // Copyright 2020 The Pigweed Authors |
| 2 | // |
| 3 | // Licensed under the Apache License, Version 2.0 (the "License"); you may not |
| 4 | // use this file except in compliance with the License. You may obtain a copy of |
| 5 | // the License at |
| 6 | // |
| 7 | // https://www.apache.org/licenses/LICENSE-2.0 |
| 8 | // |
| 9 | // Unless required by applicable law or agreed to in writing, software |
| 10 | // distributed under the License is distributed on an "AS IS" BASIS, WITHOUT |
| 11 | // WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the |
| 12 | // License for the specific language governing permissions and limitations under |
| 13 | // the License. |
| 14 | #include "pw_checksum/crc32.h" |
| 15 | |
| 16 | #include <span> |
| 17 | #include <string_view> |
| 18 | |
| 19 | #include "gtest/gtest.h" |
| 20 | |
| 21 | namespace pw::checksum { |
| 22 | namespace { |
| 23 | |
| 24 | // The expected CRC32 values were calculated using |
| 25 | // |
| 26 | // http://www.sunshine2k.de/coding/javascript/crc/crc_js.html |
| 27 | // |
| 28 | // with polynomial 0x4C11DB7, initial value 0xFFFFFFFF. |
| 29 | |
| 30 | constexpr uint8_t kBytes[] = {1, 2, 3, 4, 5, 6, 7, 8, 9}; |
| 31 | constexpr uint8_t kBytesPart0[] = {1, 2, 3, 4, 5}; |
| 32 | constexpr uint8_t kBytesPart1[] = {6, 7, 8, 9}; |
| 33 | constexpr uint32_t kBufferCrc = 0x40EFAB9E; |
| 34 | |
| 35 | constexpr std::string_view kString = |
| 36 | "In the beginning the Universe was created. This has made a lot of " |
| 37 | "people very angry and been widely regarded as a bad move."; |
| 38 | constexpr uint32_t kStringCrc = 0x9EC87F88; |
| 39 | |
| 40 | TEST(Crc32, Empty) { |
| 41 | EXPECT_EQ(Crc32(std::span<std::byte>()), ~kCrc32InitialValue); |
| 42 | } |
| 43 | |
| 44 | TEST(Crc32, ByteByByte) { |
| 45 | uint32_t crc; |
| 46 | crc = Crc32(std::byte{kBytes[0]}); |
| 47 | for (size_t i = 1; i < sizeof(kBytes); i++) { |
| 48 | crc = Crc32(std::byte{kBytes[i]}, crc); |
| 49 | } |
| 50 | EXPECT_EQ(crc, kBufferCrc); |
| 51 | } |
| 52 | |
| 53 | TEST(Crc32, Buffer) { |
| 54 | EXPECT_EQ(Crc32(as_bytes(std::span(kBytes))), kBufferCrc); |
| 55 | } |
| 56 | |
| 57 | TEST(Crc32, BufferAppend) { |
| 58 | uint32_t crc = Crc32(as_bytes(std::span(kBytesPart0))); |
| 59 | EXPECT_EQ(Crc32(as_bytes(std::span(kBytesPart1)), crc), kBufferCrc); |
| 60 | } |
| 61 | |
| 62 | TEST(Crc32, String) { |
| 63 | EXPECT_EQ(Crc32(as_bytes(std::span(kString))), kStringCrc); |
| 64 | } |
| 65 | |
| 66 | extern "C" uint32_t CallChecksumCrc32(const void* data, size_t size_bytes); |
| 67 | extern "C" uint32_t CallChecksumCrc32Append(const void* data, |
| 68 | size_t size_bytes); |
| 69 | |
| 70 | TEST(Crc32FromC, Buffer) { |
| 71 | EXPECT_EQ(CallChecksumCrc32(kBytes, sizeof(kBytes)), kBufferCrc); |
| 72 | } |
| 73 | |
| 74 | TEST(Crc32FromC, String) { |
| 75 | EXPECT_EQ(CallChecksumCrc32(kString.data(), kString.size()), kStringCrc); |
| 76 | } |
| 77 | |
| 78 | TEST(Crc32AppendFromC, Buffer) { |
| 79 | EXPECT_EQ(CallChecksumCrc32(kBytes, sizeof(kBytes)), kBufferCrc); |
| 80 | } |
| 81 | |
| 82 | TEST(Crc32AppendFromC, String) { |
| 83 | EXPECT_EQ(CallChecksumCrc32Append(kString.data(), kString.size()), |
| 84 | kStringCrc); |
| 85 | } |
| 86 | |
| 87 | } // namespace |
| 88 | } // namespace pw::checksum |