Wyatt Hepler | 92ccb66 | 2020-01-21 18:28:41 -0800 | [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 | |
| 15 | #include "pw_checksum/ccitt_crc16.h" |
| 16 | |
| 17 | #include <string_view> |
| 18 | |
| 19 | #include "gtest/gtest.h" |
| 20 | |
| 21 | namespace pw::checksum { |
| 22 | namespace { |
| 23 | |
| 24 | // The expected CRC16 values were calculated using |
| 25 | // |
| 26 | // http://www.sunshine2k.de/coding/javascript/crc/crc_js.html |
| 27 | // |
| 28 | // with polynomial 0x1021, initial value 0xFFFF. |
| 29 | constexpr uint8_t kBytes[] = {1, 2, 3, 4, 5, 6, 7, 8, 9}; |
| 30 | constexpr uint16_t kBufferCrc = 0x3B0A; |
| 31 | |
| 32 | constexpr std::string_view kString = |
| 33 | "In the beginning the Universe was created. This has made a lot of " |
| 34 | "people very angry and been widely regarded as a bad move."; |
| 35 | constexpr uint16_t kStringCrc = 0xC184; |
| 36 | |
| 37 | TEST(Crc16, Empty) { |
| 38 | EXPECT_EQ(CcittCrc16(span<std::byte>()), kCcittCrc16DefaultInitialValue); |
| 39 | } |
| 40 | |
| 41 | TEST(Crc16, ByteByByte) { |
| 42 | uint16_t crc = kCcittCrc16DefaultInitialValue; |
| 43 | for (size_t i = 0; i < sizeof(kBytes); i++) { |
| 44 | crc = CcittCrc16(std::byte{kBytes[i]}, crc); |
| 45 | } |
| 46 | EXPECT_EQ(crc, kBufferCrc); |
| 47 | } |
| 48 | |
| 49 | TEST(Crc16, Buffer) { |
| 50 | EXPECT_EQ(CcittCrc16(as_bytes(span(kBytes))), kBufferCrc); |
| 51 | } |
| 52 | |
| 53 | TEST(Crc16, String) { |
| 54 | EXPECT_EQ(CcittCrc16(as_bytes(span(kString))), kStringCrc); |
| 55 | } |
| 56 | |
| 57 | extern "C" uint16_t CallChecksumCcittCrc16(const void* data, size_t size_bytes); |
| 58 | |
| 59 | TEST(Crc16FromC, Buffer) { |
| 60 | EXPECT_EQ(CallChecksumCcittCrc16(kBytes, sizeof(kBytes)), kBufferCrc); |
| 61 | } |
| 62 | |
| 63 | TEST(Crc16FromC, String) { |
| 64 | EXPECT_EQ(CallChecksumCcittCrc16(kString.data(), kString.size()), kStringCrc); |
| 65 | } |
| 66 | |
| 67 | } // namespace |
| 68 | } // namespace pw::checksum |