comparison zlib/infutil.c @ 3:5a977ccbc7a9 default tip

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author darius
date Sat, 06 Dec 1997 05:41:29 +0000
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2:fba0b6e6cdc7 3:5a977ccbc7a9
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
10 struct inflate_codes_state {int dummy;}; /* for buggy compilers */
11
12 /* And'ing with mask[n] masks the lower n bits */
13 uInt 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 */
21 int inflate_flush(s, z, r)
22 struct inflate_blocks_state *s;
23 z_stream *z;
24 int 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 = (uInt)((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 if (s->checkfn != Z_NULL)
44 s->check = (*s->checkfn)(s->check, q, n);
45
46 /* copy as far as end of window */
47 zmemcpy(p, q, n);
48 p += n;
49 q += n;
50
51 /* see if more to copy at beginning of window */
52 if (q == s->end)
53 {
54 /* wrap pointers */
55 q = s->window;
56 if (s->write == s->end)
57 s->write = s->window;
58
59 /* compute bytes to copy */
60 n = (uInt)(s->write - q);
61 if (n > z->avail_out) n = z->avail_out;
62 if (n && r == Z_BUF_ERROR) r = Z_OK;
63
64 /* update counters */
65 z->avail_out -= n;
66 z->total_out += n;
67
68 /* update check information */
69 if (s->checkfn != Z_NULL)
70 s->check = (*s->checkfn)(s->check, q, n);
71
72 /* copy */
73 zmemcpy(p, q, n);
74 p += n;
75 q += n;
76 }
77
78 /* update pointers */
79 z->next_out = p;
80 s->read = q;
81
82 /* done */
83 return r;
84 }