xref: /inferno-os/os/boot/libflate/deflateblock.c (revision 74a4d8c26dd3c1e9febcb717cfd6cb6512991a7a)
1 #include "lib9.h"
2 #include <flate.h>
3 
4 typedef struct Block	Block;
5 
6 struct Block
7 {
8 	uchar	*pos;
9 	uchar	*limit;
10 };
11 
12 static int
blread(void * vb,void * buf,int n)13 blread(void *vb, void *buf, int n)
14 {
15 	Block *b;
16 
17 	b = vb;
18 	if(n > b->limit - b->pos)
19 		n = b->limit - b->pos;
20 	memmove(buf, b->pos, n);
21 	b->pos += n;
22 	return n;
23 }
24 
25 static int
blwrite(void * vb,void * buf,int n)26 blwrite(void *vb, void *buf, int n)
27 {
28 	Block *b;
29 
30 	b = vb;
31 
32 	if(n > b->limit - b->pos)
33 		n = b->limit - b->pos;
34 	memmove(b->pos, buf, n);
35 	b->pos += n;
36 	return n;
37 }
38 
39 int
deflateblock(uchar * dst,int dsize,uchar * src,int ssize,int level,int debug)40 deflateblock(uchar *dst, int dsize, uchar *src, int ssize, int level, int debug)
41 {
42 	Block bd, bs;
43 	int ok;
44 
45 	bs.pos = src;
46 	bs.limit = src + ssize;
47 
48 	bd.pos = dst;
49 	bd.limit = dst + dsize;
50 
51 	ok = deflate(&bd, blwrite, &bs, blread, level, debug);
52 	if(ok != FlateOk)
53 		return ok;
54 	return bd.pos - dst;
55 }
56