loadKernelMatrix.cpp

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#include <sys/types.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <limits.h>
#include <stdlib.h>
#include <fcntl.h>
#include <errno.h>
#include <fstream>
#include "Exception.h"
#include "Util.h"

using namespace std;
using namespace Util;

void getSize(istream& is, uint& nrows, uint& ncols)
{
  double dummy;
  ncols = 0;
  nrows = 0;
  string line;

  if(!getline(is,line))
    return;
  
  ++nrows;
  istringstream iss(line);
  while(iss >> dummy)
    ncols++;
   
  while( getline(is,line) ) {
    if( line == "")
      continue;
    ++nrows;
  }
}


int main(int argc, char *argv[]) {
  try {
    Exception::Assert( argc>=3, "Usage: %s <matrix file> <matrix id> [<symmetric=[0,1] (default=1)>]\n", argv[0]);
    char *in_file = argv[1];
    char *matrix_id = argv[2];
    bool symmetric = (argc>3) ? atoi(argv[3]) : true;

    // count lines
    ifstream ifs(in_file); Exception::Assert(ifs, "Error while opening file %s", in_file);
    
    cout << "Scan matrix: " << flush;
    uint nrows,ncols;
    getSize(ifs,nrows,ncols);
    cout << "found " << nrows << " rows and " << ncols << " cols" << endl;   
    ifs.close();

    // create shared memory
    int mdesc = shm_open(matrix_id,O_RDWR|O_CREAT|O_EXCL,0644);
    Exception::Assert(mdesc>=0, "Error while creating shared memory: %s", strerror(errno));

    // make space
    int tot_space = (symmetric) ? sizeof(float)*nrows*(nrows+1)/2 : sizeof(float)*nrows*ncols;
    int ret = ftruncate(mdesc,tot_space);
    Exception::Assert(ret==0, "Error while allocating shared memory: %s", strerror(errno));

    // map to memory
    float* matrix = (float*)mmap(NULL,tot_space,PROT_WRITE,MAP_SHARED,mdesc,0);
    Exception::Assert( matrix!=(float*)-1, "Error while mapping shared memory: %s", strerror(errno));
    
    // fill matrix

    ifstream ims(in_file); Exception::Assert(ims, "Error while opening file %s", in_file);
    string line;
    cout << "Read matrix: " << flush;
    if(symmetric){
      for(uint i=0; i<nrows; i++) {
        outProgress(i,100);

        getline(ims,line);
        istringstream ss(line);
        for(uint l=0; l<=i; l++ ) {
          matrix[l+i*(i+1)/2] = get<float>(ss);      
        }
      }
    }
    else{
      for(uint i=0; i<nrows; i++) {
        outProgress(i,100);

        getline(ims,line);
        istringstream ss(line);
        for(uint l=0; l< ncols; l++ ) {
          matrix[i*ncols+l] = get<float>(ss);      
        }
      }      
    }
    endProgress(nrows);

    ims.close();

    // unmap memory
    ret = munmap(matrix,tot_space);
    Exception::Assert( ret==0, "Error while unmapping shared memory: %s", strerror(errno));
  }
  catch(Exception *e) {
    cerr << e->GetMessage() << endl;
    return 1;
  }

  return 0;
}

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