pw_checksum: Rename CRC-16-CCITT files
Change-Id: I34c60c32a1e3ce7d4e1c0fd2314ea967e4dc1118
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/17404
Reviewed-by: Keir Mierle <keir@google.com>
diff --git a/pw_checksum/crc16_ccitt_test.cc b/pw_checksum/crc16_ccitt_test.cc
new file mode 100644
index 0000000..3ac9c78
--- /dev/null
+++ b/pw_checksum/crc16_ccitt_test.cc
@@ -0,0 +1,83 @@
+// 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/crc16_ccitt.h"
+
+#include <string_view>
+
+#include "gtest/gtest.h"
+
+namespace pw::checksum {
+namespace {
+
+// The expected CRC16 values were calculated using
+//
+// http://www.sunshine2k.de/coding/javascript/crc/crc_js.html
+//
+// with polynomial 0x1021, initial value 0xFFFF.
+constexpr uint8_t kBytes[] = {1, 2, 3, 4, 5, 6, 7, 8, 9};
+constexpr uint16_t kBufferCrc = 0x3B0A;
+
+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 uint16_t kStringCrc = 0xC184;
+
+TEST(Crc16, Empty) {
+ EXPECT_EQ(Crc16Ccitt::Calculate(std::span<std::byte>()),
+ Crc16Ccitt::kInitialValue);
+}
+
+TEST(Crc16, ByteByByte) {
+ uint16_t crc = Crc16Ccitt::kInitialValue;
+ for (size_t i = 0; i < sizeof(kBytes); i++) {
+ crc = Crc16Ccitt::Calculate(std::byte{kBytes[i]}, crc);
+ }
+ EXPECT_EQ(crc, kBufferCrc);
+}
+
+TEST(Crc16, Buffer) {
+ EXPECT_EQ(Crc16Ccitt::Calculate(std::as_bytes(std::span(kBytes))),
+ kBufferCrc);
+}
+
+TEST(Crc16, String) {
+ EXPECT_EQ(Crc16Ccitt::Calculate(std::as_bytes(std::span(kString))),
+ kStringCrc);
+}
+
+TEST(Crc16Class, Buffer) {
+ Crc16Ccitt crc16;
+ crc16.Update(std::as_bytes(std::span(kBytes)));
+ EXPECT_EQ(crc16.value(), kBufferCrc);
+}
+
+TEST(Crc16Class, String) {
+ Crc16Ccitt crc16;
+ crc16.Update(std::as_bytes(std::span(kString)));
+ EXPECT_EQ(crc16.value(), kStringCrc);
+}
+
+extern "C" uint16_t CallChecksumCrc16Ccitt(const void* data, size_t size_bytes);
+
+TEST(Crc16FromC, Buffer) {
+ EXPECT_EQ(CallChecksumCrc16Ccitt(kBytes, sizeof(kBytes)), kBufferCrc);
+}
+
+TEST(Crc16FromC, String) {
+ EXPECT_EQ(CallChecksumCrc16Ccitt(kString.data(), kString.size()), kStringCrc);
+}
+
+} // namespace
+} // namespace pw::checksum