File benchmark

filebench.c

#include "stdio.h"
#include "stdlib.h"


void initBuffer(char *buffer, int bufSize){
  if (buffer==NULL) exit (1);
  for (int n=0; n<bufSize; n++){
    buffer[n]=rand()%26+'a';
  }
}

int main(){

  char *buffer;
  int bufSize = 4096000;
  int bufStart = 0;

  int fileCount = 1000;
  int writeSize = 0; // size, in bytes, of each entry
  long maxFileSize = 2048000; // total file size
  int minFileSize = (int) (maxFileSize * .75);

  buffer = (char*) malloc(bufSize);
  initBuffer(buffer, bufSize);
  int maxStart = bufSize - maxFileSize;

  for(int fileIter = 0; fileIter < fileCount; fileIter++){
    FILE *wFile;  
    char fileName[30];
    sprintf(fileName, "myfile-%d.log", fileIter);
    wFile = fopen(fileName,"w");
    writeSize = minFileSize + (rand() % (maxFileSize - minFileSize));
    bufStart = rand() % maxStart;
    fwrite(buffer+bufStart, sizeof(char), writeSize, wFile);
    fclose (wFile);
  }

  free(buffer);
  return 0;
}

31 seconds on 2010 MBP (spinning disk).