1 /* inflate_util.c -- data and routines common to blocks and codes
2 * Copyright (C) 1995-1998 Mark Adler
3 * For conditions of distribution and use, see copyright notice in zlib.h
4 */
5
6 #include <linux/zutil.h>
7 #include "infblock.h"
8 #include "inftrees.h"
9 #include "infcodes.h"
10 #include "infutil.h"
11
12 struct inflate_codes_state;
13
14 /* And'ing with mask[n] masks the lower n bits */
15 uInt zlib_inflate_mask[17] = {
16 0x0000,
17 0x0001, 0x0003, 0x0007, 0x000f, 0x001f, 0x003f, 0x007f, 0x00ff,
18 0x01ff, 0x03ff, 0x07ff, 0x0fff, 0x1fff, 0x3fff, 0x7fff, 0xffff
19 };
20
21
22 /* copy as much as possible from the sliding window to the output area */
zlib_inflate_flush(s,z,r)23 int zlib_inflate_flush(s, z, r)
24 inflate_blocks_statef *s;
25 z_streamp z;
26 int r;
27 {
28 uInt n;
29 Bytef *p;
30 Bytef *q;
31
32 /* local copies of source and destination pointers */
33 p = z->next_out;
34 q = s->read;
35
36 /* compute number of bytes to copy as far as end of window */
37 n = (uInt)((q <= s->write ? s->write : s->end) - q);
38 if (n > z->avail_out) n = z->avail_out;
39 if (n && r == Z_BUF_ERROR) r = Z_OK;
40
41 /* update counters */
42 z->avail_out -= n;
43 z->total_out += n;
44
45 /* update check information */
46 if (s->checkfn != Z_NULL)
47 z->adler = s->check = (*s->checkfn)(s->check, q, n);
48
49 /* copy as far as end of window */
50 memcpy(p, q, n);
51 p += n;
52 q += n;
53
54 /* see if more to copy at beginning of window */
55 if (q == s->end)
56 {
57 /* wrap pointers */
58 q = s->window;
59 if (s->write == s->end)
60 s->write = s->window;
61
62 /* compute bytes to copy */
63 n = (uInt)(s->write - q);
64 if (n > z->avail_out) n = z->avail_out;
65 if (n && r == Z_BUF_ERROR) r = Z_OK;
66
67 /* update counters */
68 z->avail_out -= n;
69 z->total_out += n;
70
71 /* update check information */
72 if (s->checkfn != Z_NULL)
73 z->adler = s->check = (*s->checkfn)(s->check, q, n);
74
75 /* copy */
76 memcpy(p, q, n);
77 p += n;
78 q += n;
79 }
80
81 /* update pointers */
82 z->next_out = p;
83 s->read = q;
84
85 /* done */
86 return r;
87 }
88