splice/splice2.c

   1 #define _GNU_SOURCE
   2 #include <unistd.h>
   3 #include <fcntl.h>
   4 #include <sys/uio.h>
   5 #include <stdlib.h>
   6 #include <stdio.h>
   7 #include <errno.h>
   8 #include <string.h>
   9 #include <stdint.h>
  10 #include <sys/socket.h>
  11 #include <sys/sendfile.h>
  12
  13 int main(int argc, const char * const *argv)
  14 {
  15         int pfd[2];
  16         int zfd;
  17         int nfd;
  18         size_t i;
  19         size_t total_size;
  20         size_t current_size = 0;
  21         uint8_t *buffer = NULL;;
  22         size_t buffer_size;
  23
  24         if (argc != 4) {
  25                 printf("%s: usage %s <'splice'|'rw'> <total_size> <buffer_size>\n",
  26                         argv[0], argv[0]);
  27                 exit(1);
  28         }
  29
  30         total_size = strtoull(argv[2], NULL, 0);
  31         buffer_size = strtoull(argv[3], NULL, 0);
  32
  33         if (strcmp(argv[1], "splice") == 0) {
  34                 pipe(pfd);
  35         } else {
  36                 buffer = malloc(buffer_size);
  37         }
  38
  39         zfd = open("/dev/zero", O_RDONLY);
  40         nfd = open("/dev/null", O_WRONLY);
  41
  42         while (current_size < total_size) {
  43                 ssize_t zret;
  44                 ssize_t nret;
  45
  46                 errno = 0;
  47                 if (buffer) {
  48                         zret = read(zfd, buffer, buffer_size);
  49                 } else {
  50                         zret = splice(zfd, NULL, pfd[1], NULL,
  51                                       buffer_size, SPLICE_F_MOVE|SPLICE_F_NONBLOCK);
  52                 }
  53                 if (zret < 0) {
  54                         printf("%d: zret[%lld] errno[%d/%s]\n", __LINE__,
  55                                 (long long int)zret, errno, strerror(errno));
  56                         break;
  57                 }
  58
  59                 errno = 0;
  60                 if (buffer) {
  61                         nret = write(nfd, buffer, zret);
  62                 } else {
  63                         nret = splice(pfd[0], NULL, nfd, NULL,
  64                                       zret, SPLICE_F_MOVE|SPLICE_F_NONBLOCK);
  65                 }
  66                 if (nret < 0) {
  67                         printf("%d: nret[%lld] errno[%d/%s]\n", __LINE__,
  68                                 (long long int)nret, errno, strerror(errno));
  69                         break;
  70                 }
  71                 if (nret != zret) {
  72                         printf("%d: zret[%lld] nret[%lld]\n", __LINE__,
  73                                 (long long int)zret,
  74                                 (long long int)nret);
  75                         break;
  76                 }
  77
  78                 current_size += nret;
  79                 i++;
  80         }
  81
  82         printf("%s: i[%lld] total_size[%lld] buffer_size[%lld => %lld]\n",
  83                 argv[1],
  84                 (long long int)i,
  85                 (long long int)total_size,
  86                 (long long int)buffer_size,
  87                 (long long int)(total_size/i));
  88         return 0;
  89 }