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// Copyright 2020 The Pigweed Authors
//
// Licensed under the Apache License, Version 2.0 (the "License"); you may not
// use this file except in compliance with the License. You may obtain a copy of
// the License at
//
// https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
// License for the specific language governing permissions and limitations under
// the License.
#include "pw_checksum/crc32.h"
#include <span>
#include <string_view>
#include "gtest/gtest.h"
#include "pw_bytes/array.h"
namespace pw::checksum {
namespace {
// The expected CRC32 values were calculated using
//
// http://www.sunshine2k.de/coding/javascript/crc/crc_js.html
//
// with polynomial 0x4C11DB7, initial value 0xFFFFFFFF.
constexpr auto kBytes = bytes::Array<1, 2, 3, 4, 5, 6, 7, 8, 9>();
constexpr auto kBytesPart0 = bytes::Array<1, 2, 3, 4, 5>();
constexpr auto kBytesPart1 = bytes::Array<6, 7, 8, 9>();
constexpr uint32_t kBufferCrc = 0x40EFAB9E;
constexpr std::string_view kString =
"In the beginning the Universe was created. This has made a lot of "
"people very angry and been widely regarded as a bad move.";
constexpr uint32_t kStringCrc = 0x9EC87F88;
TEST(Crc32, Empty) {
EXPECT_EQ(Crc32::Calculate(std::span<std::byte>()), PW_CHECKSUM_EMPTY_CRC32);
}
TEST(Crc32, Buffer) {
EXPECT_EQ(Crc32::Calculate(std::as_bytes(std::span(kBytes))), kBufferCrc);
}
TEST(Crc32, String) {
EXPECT_EQ(Crc32::Calculate(std::as_bytes(std::span(kString))), kStringCrc);
}
TEST(Crc32Class, ByteByByte) {
Crc32 crc;
for (std::byte b : kBytes) {
crc.Update(b);
}
EXPECT_EQ(crc.value(), kBufferCrc);
}
TEST(Crc32Class, Buffer) {
Crc32 crc32;
crc32.Update(std::as_bytes(std::span(kBytes)));
EXPECT_EQ(crc32.value(), kBufferCrc);
}
TEST(Crc32Class, BufferAppend) {
Crc32 crc32;
crc32.Update(kBytesPart0);
crc32.Update(kBytesPart1);
EXPECT_EQ(crc32.value(), kBufferCrc);
}
TEST(Crc32Class, String) {
Crc32 crc32;
crc32.Update(std::as_bytes(std::span(kString)));
EXPECT_EQ(crc32.value(), kStringCrc);
}
extern "C" uint32_t CallChecksumCrc32(const void* data, size_t size_bytes);
extern "C" uint32_t CallChecksumCrc32Append(const void* data,
size_t size_bytes,
uint32_t value);
TEST(Crc32FromC, Buffer) {
EXPECT_EQ(CallChecksumCrc32(kBytes.data(), kBytes.size()), kBufferCrc);
}
TEST(Crc32FromC, String) {
EXPECT_EQ(CallChecksumCrc32(kString.data(), kString.size()), kStringCrc);
}
TEST(Crc32AppendFromC, Buffer) {
uint32_t crc = PW_CHECKSUM_EMPTY_CRC32;
for (std::byte b : kBytes) {
crc = CallChecksumCrc32Append(&b, 1, crc);
}
EXPECT_EQ(crc, kBufferCrc);
}
TEST(Crc32AppendFromC, String) {
EXPECT_EQ(CallChecksumCrc32Append(
kString.data(), kString.size(), PW_CHECKSUM_EMPTY_CRC32),
kStringCrc);
}
} // namespace
} // namespace pw::checksum