poco/Foundation/include/Poco/Checksum32.h
2017-10-11 19:03:20 -05:00

104 lines
2.2 KiB
C++

//
// Checksum32.h
//
// Library: Foundation
// Package: Core
// Module: Checksum32
//
// Definition of the Checksum32 class.
//
// Copyright (c) 2007, Applied Informatics Software Engineering GmbH.
// and Contributors.
//
// SPDX-License-Identifier: BSL-1.0
//
#ifndef Foundation_Checksum32_INCLUDED
#define Foundation_Checksum32_INCLUDED
#include "Poco/Foundation.h"
#include "Poco/ChecksumImpl.h"
namespace Poco {
class Foundation_API Checksum32 : public ChecksumImpl
/// This class calculates CRC-32 or Adler-32 checksums
/// for arbitrary data.
///
/// A cyclic redundancy check (CRC) is a type of hash function, which is used to produce a
/// small, fixed-size checksum of a larger block of data, such as a packet of network
/// traffic or a computer file. CRC-32 is one of the most commonly used CRC algorithms.
///
/// Adler-32 is a checksum algorithm which was invented by Mark Adler.
/// It is almost as reliable as a 32-bit cyclic redundancy check for protecting against
/// accidental modification of data, such as distortions occurring during a transmission,
/// but is significantly faster to calculate in software.
{
public:
Checksum32();
/// Creates a CRC-32 checksum initialized to 0.
Checksum32(ChecksumImpl::Type t);
/// Creates the Checksum32, using the given type.
~Checksum32();
/// Destroys the Checksum32.
void update(const char* data, unsigned length);
/// Updates the checksum with the given data.
void update(const std::string& data);
/// Updates the checksum with the given data.
void update(char data);
/// Updates the checksum with the given data.
Poco::UInt64 checksum() const;
/// Returns the calculated checksum.
ChecksumImpl::Type type() const;
/// Which type of checksum are we calculating.
private:
Type _type;
Poco::UInt32 _value;
};
//
// inlines
//
inline void Checksum32::update(const std::string& data)
{
update(data.c_str(), static_cast<unsigned int>(data.size()));
}
inline void Checksum32::update(char c)
{
update(&c, 1);
}
inline Poco::UInt64 Checksum32::checksum() const
{
return _value;
}
inline ChecksumImpl::Type Checksum32::type() const
{
return _type;
}
} // namespace Poco
#endif // Foundation_Checksum32_INCLUDED