78 lines
2.6 KiB
C++
78 lines
2.6 KiB
C++
#ifndef OSMIUM_OSM_CRC_ZLIB_HPP
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#define OSMIUM_OSM_CRC_ZLIB_HPP
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/*
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This file is part of Osmium (https://osmcode.org/libosmium).
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Copyright 2013-2023 Jochen Topf <jochen@topf.org> and others (see README).
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Boost Software License - Version 1.0 - August 17th, 2003
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Permission is hereby granted, free of charge, to any person or organization
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obtaining a copy of the software and accompanying documentation covered by
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this license (the "Software") to use, reproduce, display, distribute,
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execute, and transmit the Software, and to prepare derivative works of the
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Software, and to permit third-parties to whom the Software is furnished to
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do so, all subject to the following:
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The copyright notices in the Software and this entire statement, including
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the above license grant, this restriction and the following disclaimer,
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must be included in all copies of the Software, in whole or in part, and
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all derivative works of the Software, unless such copies or derivative
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works are solely in the form of machine-executable object code generated by
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a source language processor.
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THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
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SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
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FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
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ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
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DEALINGS IN THE SOFTWARE.
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*/
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#include <zlib.h>
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#include <cstddef>
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namespace osmium {
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/**
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* This class is used together with the CRC class to implement a CRC32
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* checksum based on the implementation from zlib.
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*
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* Usage:
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*
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* @code
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* osmium::CRC<osmium::CRC_zlib> crc32;
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* const osmium::Node& node = ...;
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* crc32.update(node);
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* std::cout << crc32.checksum() << '\n';
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* @endcode
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*/
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class CRC_zlib {
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unsigned long m_crc32 = ::crc32(0, nullptr, 0); // NOLINT(google-runtime-int)
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public:
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void process_byte(const unsigned char byte) noexcept {
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m_crc32 = ::crc32(m_crc32, &byte, 1U);
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}
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void process_bytes(const void* buffer, std::size_t byte_count) noexcept {
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m_crc32 = ::crc32(m_crc32, reinterpret_cast<const unsigned char*>(buffer), static_cast<unsigned int>(byte_count));
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}
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unsigned long checksum() const noexcept { // NOLINT(google-runtime-int)
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return m_crc32;
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}
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}; // class CRC_zlib
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} // namespace osmium
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#endif // OSMIUM_OSM_CRC_ZLIB_HPP
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