| 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 | 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 | #if defined(__VISAGECPP__) /* Visualage can't handle this antiquated interface */ |
| 24 | int inflate_flush(inflate_blocks_statef* s, z_streamp z, int r) |
| 25 | #else |
| 26 | int inflate_flush(s, z, r) |
| 27 | inflate_blocks_statef *s; |
| 28 | z_streamp z; |
| 29 | int r; |
| 30 | #endif |
| 31 | { |
| 32 | uInt n; |
| 33 | Bytef *p; |
| 34 | Bytef *q; |
| 35 | |
| 36 | /* local copies of source and destination pointers */ |
| 37 | p = z->next_out; |
| 38 | q = s->read; |
| 39 | |
| 40 | /* compute number of bytes to copy as far as end of window */ |
| 41 | n = (uInt)((q <= s->write ? s->write : s->end) - q); |
| 42 | if (n > z->avail_out) n = z->avail_out; |
| 43 | if (n && r == Z_BUF_ERROR) r = Z_OK; |
| 44 | |
| 45 | /* update counters */ |
| 46 | z->avail_out -= n; |
| 47 | z->total_out += n; |
| 48 | |
| 49 | /* update check information */ |
| 50 | if (s->checkfn != Z_NULL) |
| 51 | z->adler = s->check = (*s->checkfn)(s->check, q, n); |
| 52 | |
| 53 | /* copy as far as end of window */ |
| 54 | zmemcpy(p, q, n); |
| 55 | p += n; |
| 56 | q += n; |
| 57 | |
| 58 | /* see if more to copy at beginning of window */ |
| 59 | if (q == s->end) |
| 60 | { |
| 61 | /* wrap pointers */ |
| 62 | q = s->window; |
| 63 | if (s->write == s->end) |
| 64 | s->write = s->window; |
| 65 | |
| 66 | /* compute bytes to copy */ |
| 67 | n = (uInt)(s->write - q); |
| 68 | if (n > z->avail_out) n = z->avail_out; |
| 69 | if (n && r == Z_BUF_ERROR) r = Z_OK; |
| 70 | |
| 71 | /* update counters */ |
| 72 | z->avail_out -= n; |
| 73 | z->total_out += n; |
| 74 | |
| 75 | /* update check information */ |
| 76 | if (s->checkfn != Z_NULL) |
| 77 | z->adler = s->check = (*s->checkfn)(s->check, q, n); |
| 78 | |
| 79 | /* copy */ |
| 80 | zmemcpy(p, q, n); |
| 81 | p += n; |
| 82 | q += n; |
| 83 | } |
| 84 | |
| 85 | /* update pointers */ |
| 86 | z->next_out = p; |
| 87 | s->read = q; |
| 88 | |
| 89 | /* done */ |
| 90 | return r; |
| 91 | } |