crc_benchmark.cpp

#include <boost/crc_opt.hpp>
#include <iostream>

#include <algorithm>
#include <numeric>
#include <fstream>
#include <streambuf>

#include <cstring>
#include <string>
#include <chrono>
#include <math.h>
#define NUM_CRC 3000

int GetCrc32(const std::string& my_string) {
    boost::crc_32_type result;
    result.process_bytes(my_string.data(), my_string.length());
    return result.checksum();
}

void reportTime(long sum_ms) {
    printf("-| Average time taken is : %f ms\n", (sum_ms/NUM_CRC)*0.001);
    printf("-| Total time spent on CRC : %f ms\n", sum_ms*0.001);
}

int main(int argc, char** argv)
{

    namespace ch = std::chrono;
    bool printChecksums = false;

    if(argc <  2) {
    	std::cerr << "Need Filename as argument!" << std::endl;
    } 
    if (argc > 2) { printChecksums = std::string(argv[2]) == "checksums"; }
    
    // read file
    std::ifstream f(argv[1]);
    std::string str((std::istreambuf_iterator<char>(f)),
                 std::istreambuf_iterator<char>());

    ////////////////// CRC //////////////////

    int* checksums = (int*) malloc(NUM_CRC * sizeof(int));
    long* ms       = (long*) malloc(NUM_CRC * sizeof(long));
    ch::steady_clock::time_point ts, te;

    printf("Started calculating CRCs \n");
    for (int i=0; i<NUM_CRC; i++) {
        ts = ch::steady_clock::now();	    
    	checksums[i] = GetCrc32(str);
	te = ch::steady_clock::now();
	ms[i] = (ch::duration_cast<ch::microseconds>(te - ts)).count();

	// shuffle strings
	std::random_shuffle(str.begin(), str.end());
    }

    printf("Finished calculating CRCs \n");
    reportTime(std::accumulate(ms, ms+NUM_CRC,0));

    if (printChecksums) {
    	for (int i=0; i<NUM_CRC; i++) {
           printf("Crc #%d = %d\n",i, checksums[i]);
    	}
    }

    free(checksums);
    free(ms);    
}