src/stdio/fread.c

   1 #include "stdio_impl.h"
   2 #include <string.h>
   3
   4 #define MIN(a,b) ((a)<(b) ? (a) : (b))
   5
   6 size_t fread(void *restrict destv, size_t size, size_t nmemb, FILE *restrict f)
   7 {
   8         unsigned char *dest = destv;
   9         size_t len = size*nmemb, l = len, k;
  10         if (!size) nmemb = 0;
  11
  12         FLOCK(f);
  13
  14         f->mode |= f->mode-1;
  15
  16         if (f->rpos != f->rend) {
  17                 /* First exhaust the buffer. */
  18                 k = MIN(f->rend - f->rpos, l);
  19                 memcpy(dest, f->rpos, k);
  20                 f->rpos += k;
  21                 dest += k;
  22                 l -= k;
  23         }
  24
  25         /* Read the remainder directly */
  26         for (; l; l-=k, dest+=k) {
  27                 k = __toread(f) ? 0 : f->read(f, dest, l);
  28                 if (!k) {
  29                         FUNLOCK(f);
  30                         return (len-l)/size;
  31                 }
  32         }
  33
  34         FUNLOCK(f);
  35         return nmemb;
  36 }
  37
  38 weak_alias(fread, fread_unlocked);