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Diffstat (limited to 'infutil.c')
-rw-r--r-- | infutil.c | 76 |
1 files changed, 76 insertions, 0 deletions
diff --git a/infutil.c b/infutil.c new file mode 100644 index 0000000..92d115f --- /dev/null +++ b/infutil.c | |||
@@ -0,0 +1,76 @@ | |||
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 = (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 | } | ||