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107 lines
2.2 KiB
C++
107 lines
2.2 KiB
C++
//
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// Checksum64.h
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//
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// Library: Foundation
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// Package: Core
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// Module: Checksum64
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//
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// Definition of the Checksum64 class.
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//
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// Copyright (c) 2007, Applied Informatics Software Engineering GmbH.
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// and Contributors.
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//
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// SPDX-License-Identifier: BSL-1.0
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//
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#ifndef Foundation_Checksum64_INCLUDED
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#define Foundation_Checksum64_INCLUDED
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#include "Poco/Foundation.h"
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#include "Poco/ChecksumImpl.h"
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namespace Poco {
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class Foundation_API Checksum64 : public ChecksumImpl
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/// This class calculates CRC-64 checksums for arbitrary data.
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///
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/// The algorithm and table are based on the polynomial
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///
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/// x^64 + x^62 + x^57 + x^55 + x^54 + x^53 + x^52 + x^47 + x^46 + x^45 +
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/// x^40 + x^39 + x^38 + x^37 + x^35 + x^33 + x^32 + x^31 + x^29 + x^27 +
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/// x^24 + x^23 + x^22 + x^21 + x^19 + x^17 + x^13 + x^12 + x^10 + x^9 +
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/// x^7 + x^4 + x + 1
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///
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/// Implementation is adapted from the DLT1 spec:
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/// ECMA - 182, http://www.ecma-international.org/publications/standards/Ecma-182.htm
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///
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{
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public:
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Checksum64();
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/// Creates a CRC-64 checksum initialized to 0.
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Checksum64(Type t);
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/// Creates the Checksum64, using the given type.
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~Checksum64();
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/// Destroys the Checksum64.
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void update(const char* data, unsigned length);
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/// Updates the checksum with the given data.
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void update(const std::string& data);
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/// Updates the checksum with the given data.
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void update(char data);
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/// Updates the checksum with the given data.
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Poco::UInt64 checksum() const;
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/// Returns the calculated checksum.
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ChecksumImpl::Type type() const;
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/// Which type of checksum are we calculating.
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private:
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static Poco::UInt64 _initCRC64Val;
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static Poco::UInt64 _finXORVal;
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static const unsigned _tableSize = 256;
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static Poco::UInt64 _crcTable[_tableSize];
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Poco::UInt64 _value;
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};
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//
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// inlines
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//
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inline void Checksum64::update(const std::string& data)
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{
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update(data.c_str(), static_cast<unsigned int>(data.size()));
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}
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inline void Checksum64::update(char c)
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{
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update(&c, 1);
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}
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inline Poco::UInt64 Checksum64::checksum() const
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{
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return _value;
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}
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inline ChecksumImpl::Type Checksum64::type() const
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{
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return TYPE_CRC64_IMPL;
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}
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} // namespace Poco
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#endif // Foundation_Checksum64_INCLUDED
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