CMSDK  2.0.1
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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
 

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.

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