1 b6afd33e 2003-11-23 devnull #include <u.h>
 2 b6afd33e 2003-11-23 devnull #include <libc.h>
 3 b6afd33e 2003-11-23 devnull #include <flate.h>
 4 b6afd33e 2003-11-23 devnull #include "zlib.h"
 5 b6afd33e 2003-11-23 devnull 
 6 b6afd33e 2003-11-23 devnull typedef struct ZRead	ZRead;
 7 b6afd33e 2003-11-23 devnull 
 8 b6afd33e 2003-11-23 devnull struct ZRead
 9 b6afd33e 2003-11-23 devnull {
10 b6afd33e 2003-11-23 devnull 	ulong	adler;
11 b6afd33e 2003-11-23 devnull 	void	*rr;
12 b6afd33e 2003-11-23 devnull 	int	(*r)(void*, void*, int);
13 b6afd33e 2003-11-23 devnull };
14 b6afd33e 2003-11-23 devnull 
15 b6afd33e 2003-11-23 devnull static int
16 b6afd33e 2003-11-23 devnull zlread(void *vzr, void *buf, int n)
17 b6afd33e 2003-11-23 devnull {
18 b6afd33e 2003-11-23 devnull 	ZRead *zr;
19 b6afd33e 2003-11-23 devnull 
20 b6afd33e 2003-11-23 devnull 	zr = vzr;
21 b6afd33e 2003-11-23 devnull 	n = (*zr->r)(zr->rr, buf, n);
22 b6afd33e 2003-11-23 devnull 	if(n <= 0)
23 b6afd33e 2003-11-23 devnull 		return n;
24 b6afd33e 2003-11-23 devnull 	zr->adler = adler32(zr->adler, buf, n);
25 b6afd33e 2003-11-23 devnull 	return n;
26 b6afd33e 2003-11-23 devnull }
27 b6afd33e 2003-11-23 devnull 
28 b6afd33e 2003-11-23 devnull int
29 b6afd33e 2003-11-23 devnull deflatezlib(void *wr, int (*w)(void*, void*, int), void *rr, int (*r)(void*, void*, int), int level, int debug)
30 b6afd33e 2003-11-23 devnull {
31 b6afd33e 2003-11-23 devnull 	ZRead zr;
32 b6afd33e 2003-11-23 devnull 	uchar buf[4];
33 b6afd33e 2003-11-23 devnull 	int ok;
34 b6afd33e 2003-11-23 devnull 
35 b6afd33e 2003-11-23 devnull 	buf[0] = ZlibDeflate | ZlibWin32k;
36 b6afd33e 2003-11-23 devnull 
37 b6afd33e 2003-11-23 devnull 	/* bogus zlib encoding of compression level */
38 b6afd33e 2003-11-23 devnull 	buf[1] = ((level > 2) + (level > 5) + (level > 8)) << 6;
39 b6afd33e 2003-11-23 devnull 
40 b6afd33e 2003-11-23 devnull 	/* header check field */
41 b6afd33e 2003-11-23 devnull 	buf[1] |= 31 - ((buf[0] << 8) | buf[1]) % 31;
42 b6afd33e 2003-11-23 devnull 	if((*w)(wr, buf, 2) != 2)
43 b6afd33e 2003-11-23 devnull 		return FlateOutputFail;
44 b6afd33e 2003-11-23 devnull 
45 b6afd33e 2003-11-23 devnull 	zr.rr = rr;
46 b6afd33e 2003-11-23 devnull 	zr.r = r;
47 b6afd33e 2003-11-23 devnull 	zr.adler = 1;
48 b6afd33e 2003-11-23 devnull 	ok = deflate(wr, w, &zr, zlread, level, debug);
49 b6afd33e 2003-11-23 devnull 	if(ok != FlateOk)
50 b6afd33e 2003-11-23 devnull 		return ok;
51 b6afd33e 2003-11-23 devnull 
52 b6afd33e 2003-11-23 devnull 	buf[0] = zr.adler >> 24;
53 b6afd33e 2003-11-23 devnull 	buf[1] = zr.adler >> 16;
54 b6afd33e 2003-11-23 devnull 	buf[2] = zr.adler >> 8;
55 b6afd33e 2003-11-23 devnull 	buf[3] = zr.adler;
56 b6afd33e 2003-11-23 devnull 	if((*w)(wr, buf, 4) != 4)
57 b6afd33e 2003-11-23 devnull 		return FlateOutputFail;
58 b6afd33e 2003-11-23 devnull 
59 b6afd33e 2003-11-23 devnull 	return FlateOk;
60 b6afd33e 2003-11-23 devnull }