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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 "zutil.h" | |
7 | #include "infblock.h" | |
8 | #include "inftrees.h" | |
9 | #include "infcodes.h" | |
10 | #include "infutil.h" | |
11 | ||
12 | struct inflate_codes_state {int dummy;}; /* for buggy compilers */ | |
13 | ||
14 | /* And'ing with mask[n] masks the lower n bits */ | |
15 | uInt 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 */ | |
23 | int 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 | zmemcpy(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 | zmemcpy(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 | } |