1/* inflate_util.c -- data and routines common to blocks and codes
2 * Copyright (C) 1995-2002 Mark Adler
3 * For conditions of distribution and use, see copyright notice in zlib.h
4 */
5
6#include "zutil.h"
7#include "infblock.h"
8#include "inftrees.h"
9#include "infcodes.h"
10#include "infutil.h"
11
12
13/* And'ing with mask[n] masks the lower n bits */
14local const uInt inflate_mask[17] = {
15 0x0000,
16 0x0001, 0x0003, 0x0007, 0x000f, 0x001f, 0x003f, 0x007f, 0x00ff,
17 0x01ff, 0x03ff, 0x07ff, 0x0fff, 0x1fff, 0x3fff, 0x7fff, 0xffff
18};
19
20
21/* copy as much as possible from the sliding window to the output area */
22local int inflate_flush( /* s, z, r) */
23inflate_blocks_statef *s,
24z_streamp z,
25int r )
26{
27 uInt n;
28 Bytef *p;
29 Bytef *q;
30
31 /* local copies of source and destination pointers */
32 p = z->next_out;
33 q = s->read;
34
35 /* compute number of bytes to copy as far as end of window */
36 n = (uInt)((q <= s->write ? s->write : s->end) - q);
37 if (n > z->avail_out) n = z->avail_out;
38 if (n && r == Z_BUF_ERROR) r = Z_OK;
39
40 /* update counters */
41 z->avail_out -= n;
42 z->total_out += n;
43
44 /* update check information */
45 if (s->checkfn != Z_NULL)
46 z->adler = s->check = (*s->checkfn)(s->check, q, n);
47
48 /* copy as far as end of window */
49 zmemcpy(p, q, n);
50 p += n;
51 q += n;
52
53 /* see if more to copy at beginning of window */
54 if (q == s->end)
55 {
56 /* wrap pointers */
57 q = s->window;
58 if (s->write == s->end)
59 s->write = s->window;
60
61 /* compute bytes to copy */
62 n = (uInt)(s->write - q);
63 if (n > z->avail_out) n = z->avail_out;
64 if (n && r == Z_BUF_ERROR) r = Z_OK;
65
66 /* update counters */
67 z->avail_out -= n;
68 z->total_out += n;
69
70 /* update check information */
71 if (s->checkfn != Z_NULL)
72 z->adler = s->check = (*s->checkfn)(s->check, q, n);
73
74 /* copy */
75 zmemcpy(p, q, n);
76 p += n;
77 q += n;
78 }
79
80 /* update pointers */
81 z->next_out = p;
82 s->read = q;
83
84 /* done */
85 return r;
86}
87