writefiles.c

   1 #include <stdio.h>
   2 #include <unistd.h>
   3 #include <stdlib.h>
   4 #include <fcntl.h>
   5 #include <errno.h>
   6 #include <time.h>
   7 #include <sys/time.h>
   8
   9
  10 static struct timeval tp1,tp2;
  11 static size_t block_size = 64 * 1024;
  12 static int osync;
  13
  14 static void start_timer()
  15 {
  16         gettimeofday(&tp1,NULL);
  17 }
  18
  19 static double end_timer()
  20 {
  21         gettimeofday(&tp2,NULL);
  22         return((tp2.tv_sec - tp1.tv_sec) +
  23                (tp2.tv_usec - tp1.tv_usec)*1.0e-6);
  24 }
  25
  26
  27 static void write_file(char *fname)
  28 {
  29         int fd;
  30         static double total, thisrun;
  31         int n;
  32         char *buf;
  33
  34         buf = malloc(block_size);
  35
  36         if (!buf) {
  37                 printf("Malloc of %d failed\n", (int)block_size);
  38                 exit(1);
  39         }
  40
  41         fd = open(fname, O_WRONLY|(osync?O_SYNC:0));
  42         if (fd == -1) {
  43                 perror(fname);
  44                 free(buf);
  45                 return;
  46         }
  47
  48         while ((n = write(fd, buf, block_size)) > 0) {
  49                 total += n;
  50                 thisrun += n;
  51                 if (end_timer() >= 1.0) {
  52                         time_t t = time(NULL);
  53                         printf("%6d MB    %.3f MB/sec  %s",
  54                                (int)(total/1.0e6),
  55                                (thisrun*1.0e-6)/end_timer(),
  56                                ctime(&t));
  57                         start_timer();
  58                         thisrun = 0;
  59                 }
  60         }
  61
  62         free(buf);
  63         close(fd);
  64 }
  65
  66
  67 static void usage(void)
  68 {
  69         printf("\n" \
  70 "writefiles - writes to a list of files, showing throughput\n" \
  71 "\n" \
  72 "Usage: writefiles [options] <files>\n" \
  73 "\n" \
  74 "Options:\n" \
  75 "    -B size        set the block size in bytes\n" \
  76 "    -s             sync open\n" \
  77 "\n" \
  78 "WARNING: writefiles is a destructive test!\n" \
  79 "\n" \
  80 "");
  81 }
  82
  83
  84 int main(int argc, char *argv[])
  85 {
  86         int i;
  87         extern char *optarg;
  88         extern int optind;
  89         int c;
  90
  91         while ((c = getopt(argc, argv, "B:hs")) != -1) {
  92                 switch (c) {
  93                 case 'B':
  94                         block_size = strtol(optarg, NULL, 0);
  95                         break;
  96                 case 's':
  97                         osync = 1;
  98                         break;
  99                 case 'h':
 100                 default:
 101                         usage();
 102                         exit(1);
 103                 }
 104         }
 105
 106         argc -= optind;
 107         argv += optind;
 108
 109         if (argc == 0) {
 110                 usage();
 111                 exit(1);
 112         }
 113
 114
 115         start_timer();
 116
 117         while (1) {
 118                 for (i=0; i<argc; i++) {
 119                         write_file(argv[i]);
 120                 }
 121         }
 122
 123         return 0;
 124 }
 125