speedtesting.cpp

#include <fstream>
#include "cyclichash.h"
#include "rabinkarphash.h"
#include "generalhash.h"
#include "threewisehash.h"
#include "ztimer.h"

using namespace std;


template<class hashfunction>
double hashALot( int n, int L, uint ttimes,uint sizeoftest , vector<uint32> & recorder) {
    ZTimer t;
    for(uint times = 0; times<ttimes; ++times) {
        hashfunction hf(n,L);
        for(uint k = 0; k<static_cast<uint>(n); ++k) {
            hf.eat(static_cast<unsigned char>(k));
        }
        for(uint k = n; k<sizeoftest; ++k) {
            hf.update(static_cast<unsigned char>(k-n),static_cast<unsigned char>(k));
        }
        /* The goal of the recorder is to prevent
        the compiler from deciding that this whole computation
        is not required!
        */
        recorder.push_back(hf.hashvalue);
    }
    return t.split()/(1000.0*ttimes);
}


template<class hashfunction>
double hashALot( int n, int L, uint ttimes , vector<uint32> & recorder, vector<unsigned char> & data) {
    ZTimer t;
    for(uint times = 0; times<ttimes; ++times) {
        hashfunction hf(n,L);
        for(uint k = 0; k<static_cast<uint>(n); ++k) {
            hf.eat(data[k]);
        }
        for(uint k = n; k<data.size(); ++k) {
            hf.update(data[k-n],data[k]);
        }
        /* The goal of the recorder is to prevent
        the compiler from deciding that this whole computation
        is not required!
        */
        recorder.push_back(hf.hashvalue);
    }
    return t.split()/1000.0;
}

void synthetic() {
    int L = 19;
    vector<uint32> recorder;
    uint sizeoftest = 100000000;
    cout<<"#n three-wise General BufferedGeneral Cyclic Karp-Rabin "<<endl;
    for(uint n = 1; n+L<=32; ++n) {
        cout<<n<<" "<<hashALot<ThreeWiseHash<> >(n,L,1,sizeoftest,recorder)<<" ";
        cout<<hashALot<GeneralHash<NOPRECOMP> >(n,L,1,sizeoftest,recorder)<<" ";
        cout<<hashALot<GeneralHash<FULLPRECOMP> >(n,L,1,sizeoftest,recorder)<<" ";
        cout<<hashALot<CyclicHash<> >(n,L+n,1,sizeoftest,recorder)<< " ";
        cout<<hashALot<KarpRabinHash<> >(n,L,1,sizeoftest,recorder)<<endl;
    }
    cout <<"# L= "<<L<<" char-length= "<<sizeoftest<<endl;
}

void grabFileContent(vector<unsigned char> & data, string filename) {
    string line;
    ifstream file(filename.c_str());
    getline(file, line);
    while ( file.good() ) {
        getline(file, line);
        for(uint k = 0; k<line.size(); ++k)
            data.push_back(line[k]);//presumably not very fast to do it char by char
    }
    file.close();
}
void realdata(string filename) {
    int L = 19;
    vector<uint32> recorder;
    uint repeats=1;
    vector<unsigned char>  data;
    grabFileContent(data, filename);
    cout<<"#n three-wise General BufferedGeneral Cyclic Karp-Rabin "<<endl;
    for(uint n = 1; n+L<=32; ++n) {
        cout<<n<<" "<<hashALot<ThreeWiseHash<> >(n,L,repeats,recorder,data)<<" ";
        cout<<hashALot<GeneralHash<NOPRECOMP> >(n,L,repeats,recorder,data)<<" ";
        cout<<hashALot<GeneralHash<FULLPRECOMP> >(n,L,repeats,recorder,data)<<" ";
        cout<<hashALot<CyclicHash<> >(n,L+n,repeats,recorder,data)<< " ";
        cout<<hashALot<KarpRabinHash<> >(n,L,repeats,recorder,data)<<endl;
    }
    cout <<"# L= "<<L<<" char-length= "<<data.size()<< " repeats="<<repeats<<endl;

}

int main(int params, char ** args) {
    if (params == 1)
        synthetic();
    else
        realdata(args[1]);

    return 0;
}