5172
|
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 */
|
|
14 |
local 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 */
|
|
22 |
local int inflate_flush( /* s, z, r) */
|
|
23 |
inflate_blocks_statef *s,
|
|
24 |
z_streamp z,
|
|
25 |
int 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 |
}
|