buffer_get.c

   1 #include "buffer.h"
   2 #include "byte.h"
   3 #include "error.h"
   4
   5 static int oneread(int (*op)(),int fd,char *buf,unsigned int len)
   6 {
   7   int r;
   8
   9   for (;;) {
  10     r = op(fd,buf,len);
  11     if (r == -1) if (errno == error_intr) continue;
  12     return r;
  13   }
  14 }
  15
  16 static int getthis(buffer *s,char *buf,unsigned int len)
  17 {
  18   if (len > s->p) len = s->p;
  19   s->p -= len;
  20   byte_copy(buf,len,s->x + s->n);
  21   s->n += len;
  22   return len;
  23 }
  24
  25 int buffer_feed(buffer *s)
  26 {
  27   int r;
  28
  29   if (s->p) return s->p;
  30   r = oneread(s->op,s->fd,s->x,s->n);
  31   if (r <= 0) return r;
  32   s->p = r;
  33   s->n -= r;
  34   if (s->n > 0) byte_copyr(s->x + s->n,r,s->x);
  35   return r;
  36 }
  37
  38 int buffer_bget(buffer *s,char *buf,unsigned int len)
  39 {
  40   int r;
  41
  42   if (s->p > 0) return getthis(s,buf,len);
  43   if (s->n <= len) return oneread(s->op,s->fd,buf,s->n);
  44   r = buffer_feed(s); if (r <= 0) return r;
  45   return getthis(s,buf,len);
  46 }
  47
  48 int buffer_get(buffer *s,char *buf,unsigned int len)
  49 {
  50   int r;
  51
  52   if (s->p > 0) return getthis(s,buf,len);
  53   if (s->n <= len) return oneread(s->op,s->fd,buf,len);
  54   r = buffer_feed(s); if (r <= 0) return r;
  55   return getthis(s,buf,len);
  56 }
  57
  58 char *buffer_peek(buffer *s)
  59 {
  60   return s->x + s->n;
  61 }
  62
  63 void buffer_seek(buffer *s,unsigned int len)
  64 {
  65   s->n += len;
  66   s->p -= len;
  67 }