CRC32 Class Reference

compute CRC32 hash, based on Intel's Slicing-by-8 algorithm More...

#include <crc32.h>

Public Types
enum	{ HashBytes = 4 }
	hash is 4 bytes long More...

Public Member Functions
	CRC32 ()
	same as reset()
std::string	operator() (const void *data, size_t numBytes)
	compute CRC32 of a memory block
std::string	operator() (const std::string &text)
	compute CRC32 of a string, excluding final zero
void	add (const void *data, size_t numBytes)
	add arbitrary number of bytes
std::string	getHash ()
	return latest hash as 8 hex characters
void	getHash (unsigned char buffer[HashBytes])
	return latest hash as bytes
void	reset ()
	restart

Detailed Description

compute CRC32 hash, based on Intel's Slicing-by-8 algorithm

Usage: CRC32 crc32; std::string myHash = crc32("Hello World"); // std::string std::string myHash2 = crc32("How are you", 11); // arbitrary data, 11 bytes

or in a streaming fashion:

CRC32 crc32;
while (more data available)
  crc32.add(pointer to fresh data, number of new bytes);
std::string myHash3 = crc32.getHash();

Note:
You can find code for the faster Slicing-by-16 algorithm on my website, too:
http://create.stephan-brumme.com/crc32/
Its unrolled version is about twice as fast but its look-up table doubled in size as well.

Definition at line 45 of file crc32.h.

Member Enumeration Documentation

anonymous enum

anonymous enum

hash is 4 bytes long

Definition at line 49 of file crc32.h.

Constructor & Destructor Documentation

CRC32()

CRC32::CRC32

(

)

same as reset()

Definition at line 18 of file crc32.cpp.

Member Function Documentation

add()

void CRC32::add	(	const void *	data,
		size_t	numBytes )

add arbitrary number of bytes

Definition at line 341 of file crc32.cpp.

getHash()

std::string CRC32::getHash

(

)

return latest hash as 8 hex characters

Definition at line 385 of file crc32.cpp.

operator()() [1/2]

std::string CRC32::operator()

(

const std::string &

text

)

compute CRC32 of a string, excluding final zero

Definition at line 428 of file crc32.cpp.

operator()() [2/2]

std::string CRC32::operator()	(	const void *	data,
		size_t	numBytes )

compute CRC32 of a memory block

Definition at line 419 of file crc32.cpp.

reset()

void CRC32::reset

(

)

restart

Definition at line 25 of file crc32.cpp.

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The documentation for this class was generated from the following files:

• hash/include/crc32.h
• hash/src/crc32.cpp