sys/src/cmd/hgfs/zip.c

   1 #include <u.h>
   2 #include <libc.h>
   3 #include <thread.h>
   4 #include "dat.h"
   5 #include "fns.h"
   6
   7 #include <flate.h>
   8
   9 struct zbuf {
  10         int     fd;
  11         int     len;
  12
  13         uchar   *b, *p, *e;
  14 };
  15
  16 static int
  17 zwrite(void *a, void *p, int n)
  18 {
  19         int *ofd = a;
  20
  21         if(write(*ofd, p, n) != n)
  22                 return -1;
  23         return n;
  24 }
  25
  26 static int
  27 zgetc(void *a)
  28 {
  29         struct zbuf *z = a;
  30         int n;
  31
  32         for(;;){
  33                 if(z->p < z->e)
  34                         return *z->p++;
  35                 if(z->len <= 0)
  36                         return -1;
  37                 if((n = BUFSZ) > z->len)
  38                         n = z->len;
  39                 if((n = read(z->fd, z->p = z->b, n)) <= 0)
  40                         return -1;
  41                 z->len -= n;
  42                 z->e = z->p + n;
  43         }
  44 }
  45
  46 int
  47 funzip(int ofd, int zfd, int len)
  48 {
  49         uchar buf[BUFSZ];
  50         struct zbuf z;
  51         int wlen, n;
  52         uchar *p;
  53
  54         if(len == 0)
  55                 return 0;
  56
  57         wlen = 0;
  58         if((n = BUFSZ) > len)
  59                 n = len;
  60         if((n = read(zfd, p = buf, n)) <= 0)
  61                 return -1;
  62         len -= n;
  63         switch(*p){
  64         default:
  65                 return -1;
  66         case 'u':
  67                 p++;
  68                 n--;
  69                 /* no break */
  70         case '\0':
  71                 while((n > 0) && (write(ofd, p, n) == n)){
  72                         wlen += n;
  73                         if(len <= 0)
  74                                 break;
  75                         if((n = BUFSZ) > len)
  76                                 n = len;
  77                         if((n = read(zfd, p = buf, n)) <= 0)
  78                                 break;
  79                         len -= n;
  80                 }
  81                 break;
  82         case 'x':
  83                 if(n < 2)
  84                         return -1;
  85                 z.fd = zfd;
  86                 z.len = len;
  87                 z.b = buf;
  88                 z.p = p + 2;
  89                 z.e = p + n;
  90                 if((wlen = inflate(&ofd, zwrite, &z, zgetc)) < 0){
  91                         werrstr("%s", flateerr(wlen));
  92                         return -1;
  93                 }
  94                 break;
  95         }
  96         return wlen;
  97 }