chromium/third_party/abseil-cpp/absl/crc/internal/crc.h

// Copyright 2022 The Abseil 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.

#ifndef ABSL_CRC_INTERNAL_CRC_H_
#define ABSL_CRC_INTERNAL_CRC_H_

#include <cstdint>

#include "absl/base/config.h"

// This class implements CRCs (aka Rabin Fingerprints).
// Treats the input as a polynomial with coefficients in Z(2),
// and finds the remainder when divided by an primitive polynomial
// of the appropriate length.

// A polynomial is represented by the bit pattern formed by its coefficients,
// but with the highest order bit not stored.
// The highest degree coefficient is stored in the lowest numbered bit
// in the lowest addressed byte.   Thus, in what follows, the highest degree
// coefficient that is stored is in the low order bit of "lo" or "*lo".

// Hardware acceleration is used when available.

namespace absl {
ABSL_NAMESPACE_BEGIN
namespace crc_internal {

class CRC { … };

}  // namespace crc_internal
ABSL_NAMESPACE_END
}  // namespace absl

#endif  // ABSL_CRC_INTERNAL_CRC_H_