mdw@git.distorted.org.uk Git - qmail/blob - substdi.c

   1 #include "substdio.h"
   2 #include "byte.h"
   3 #include "error.h"
   4
   5 static int oneread(op,fd,buf,len)
   6 register int (*op)();
   7 register int fd;
   8 register char *buf;
   9 register int len;
  10 {
  11   register int r;
  12
  13   for (;;) {
  14     r = op(fd,buf,len);
  15     if (r == -1) if (errno == error_intr) continue;
  16     return r;
  17   }
  18 }
  19
  20 static int getthis(s,buf,len)
  21 register substdio *s;
  22 register char *buf;
  23 register int len;
  24 {
  25   register int r;
  26   register int q;
  27
  28   r = s->p;
  29   q = r - len;
  30   if (q > 0) { r = len; s->p = q; } else s->p = 0;
  31   byte_copy(buf,r,s->x + s->n);
  32   s->n += r;
  33   return r;
  34 }
  35
  36 int substdio_feed(s)
  37 register substdio *s;
  38 {
  39   register int r;
  40   register int q;
  41
  42   if (s->p) return s->p;
  43   q = s->n;
  44   r = oneread(s->op,s->fd,s->x,q);
  45   if (r <= 0) return r;
  46   s->p = r;
  47   q -= r;
  48   s->n = q;
  49   if (q > 0) /* damn, gotta shift */ byte_copyr(s->x + q,r,s->x);
  50   return r;
  51 }
  52
  53 int substdio_bget(s,buf,len)
  54 register substdio *s;
  55 register char *buf;
  56 register int len;
  57 {
  58   register int r;
  59
  60   if (s->p > 0) return getthis(s,buf,len);
  61   r = s->n; if (r <= len) return oneread(s->op,s->fd,buf,r);
  62   r = substdio_feed(s); if (r <= 0) return r;
  63   return getthis(s,buf,len);
  64 }
  65
  66 int substdio_get(s,buf,len)
  67 register substdio *s;
  68 register char *buf;
  69 register int len;
  70 {
  71   register int r;
  72
  73   if (s->p > 0) return getthis(s,buf,len);
  74   if (s->n <= len) return oneread(s->op,s->fd,buf,len);
  75   r = substdio_feed(s); if (r <= 0) return r;
  76   return getthis(s,buf,len);
  77 }
  78
  79 char *substdio_peek(s)
  80 register substdio *s;
  81 {
  82   return s->x + s->n;
  83 }
  84
  85 void substdio_seek(s,len)
  86 register substdio *s;
  87 register int len;
  88 {
  89   s->n += len;
  90   s->p -= len;
  91 }