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1/* inflate_util.c -- data and routines common to blocks and codes
2 * Copyright (C) 1995 Mark Adler
3 * For conditions of distribution and use, see copyright notice in zlib.h
4 */
5
6#include "zutil.h"
7#include "inftrees.h"
8#include "infutil.h"
9
10struct inflate_codes_state {int dummy;}; /* for buggy compilers */
11
12/* And'ing with mask[n] masks the lower n bits */
13uInt inflate_mask[] = {
14 0x0000,
15 0x0001, 0x0003, 0x0007, 0x000f, 0x001f, 0x003f, 0x007f, 0x00ff,
16 0x01ff, 0x03ff, 0x07ff, 0x0fff, 0x1fff, 0x3fff, 0x7fff, 0xffff
17};
18
19
20/* copy as much as possible from the sliding window to the output area */
21int inflate_flush(s, z, r)
22struct inflate_blocks_state *s;
23z_stream *z;
24int r;
25{
26 uInt n;
27 Byte *p, *q;
28
29 /* local copies of source and destination pointers */
30 p = z->next_out;
31 q = s->read;
32
33 /* compute number of bytes to copy as far as end of window */
34 n = (q <= s->write ? s->write : s->end) - q;
35 if (n > z->avail_out) n = z->avail_out;
36 if (n && r == Z_BUF_ERROR) r = Z_OK;
37
38 /* update counters */
39 z->avail_out -= n;
40 z->total_out += n;
41
42 /* update check information */
43 s->check = adler32(s->check, q, n);
44
45 /* copy as far as end of window */
46 while (n--) *p++ = *q++;
47
48 /* see if more to copy at beginning of window */
49 if (q == s->end)
50 {
51 /* wrap source pointer */
52 q = s->window;
53
54 /* compute bytes to copy */
55 n = s->write - q;
56 if (n > z->avail_out) n = z->avail_out;
57 if (n && r == Z_BUF_ERROR) r = Z_OK;
58
59 /* update counters */
60 z->avail_out -= n;
61 z->total_out += n;
62
63 /* update check information */
64 s->check = adler32(s->check, q, n);
65
66 /* copy */
67 while (n--) *p++ = *q++;
68 }
69
70 /* update pointers */
71 z->next_out = p;
72 s->read = q;
73
74 /* done */
75 return r;
76}