sys/src/ape/lib/bsd/writev.c

   1 #include <sys/types.h>
   2 #include <unistd.h>
   3 #include <string.h>
   4
   5 /* bsd extensions */
   6 #include <sys/uio.h>
   7 #include <sys/socket.h>
   8
   9 #include "priv.h"
  10
  11 int
  12 writev(int fd, struct iovec *v, int ent)
  13 {
  14         int i, n, written;
  15         char *t, *e, *f;
  16         char buf[10*1024];
  17
  18         written = n = 0;
  19         t = buf;
  20         e = buf+sizeof(buf);
  21         for(;ent ; v++, ent--){
  22                 n = v->iov_len;
  23                 f = v->iov_base;
  24                 while(n > 0){
  25                         i = e-t;
  26                         if(n < i){
  27                                 memmove(t, f, n);
  28                                 t += n;
  29                                 break;
  30                         }
  31                         memmove(t, f, i);
  32                         n -= i;
  33                         f += i;
  34                         i = write(fd, buf, sizeof(buf));
  35                         if(i < 0){
  36                                 if(written > 0){
  37                                         return written;
  38                                 }else{
  39                                         _syserrno();
  40                                         return -1;
  41                                 }
  42                         }
  43                         written += i;
  44                         if(i != sizeof(buf)) {
  45                                 return written;
  46                         }
  47                         t = buf;
  48                 }
  49         }
  50         i = t - buf;
  51         if(i > 0){
  52                 n = write(fd, buf, i);
  53                 if(n < 0){
  54                         if(written == 0){
  55                                 _syserrno();
  56                                 return -1;
  57                         }
  58                 } else
  59                         written += n;
  60         }
  61         return written;
  62 }