Library: Foundation
Package: Core
Header: Poco/Checksum.h
Description
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.
Member Summary
Member Functions: checksum, type, update
Enumerations
Type
TYPE_ADLER32 = 0
Constructors
Checksum
Checksum();
Creates a CRC-32 checksum initialized to 0.
Checksum
Creates the Checksum, using the given type.
Destructor
~Checksum
~Checksum();
Destroys the Checksum.
Member Functions
checksum
Poco::UInt32 checksum() const;
Returns the calculated checksum.
type
Type type() const;
Which type of checksum are we calulcating
update
void update(
const char * data,
unsigned length
);
Updates the checksum with the given data.
update
void update(
const std::string & data
);
Updates the checksum with the given data.
update
void update(
char data
);
Updates the checksum with the given data.