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1 /* inflate_util.c -- data and routines common to blocks and codes |
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2 * Copyright (C) 1995-2002 Mark Adler |
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3 * For conditions of distribution and use, see copyright notice in zlib.h |
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4 */ |
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5 |
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6 #include "zutil.h" |
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7 #include "infblock.h" |
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8 #include "inftrees.h" |
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9 #include "infcodes.h" |
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10 #include "infutil.h" |
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11 |
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12 |
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13 /* And'ing with mask[n] masks the lower n bits */ |
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14 local const uInt inflate_mask[17] = { |
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15 0x0000, |
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16 0x0001, 0x0003, 0x0007, 0x000f, 0x001f, 0x003f, 0x007f, 0x00ff, |
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17 0x01ff, 0x03ff, 0x07ff, 0x0fff, 0x1fff, 0x3fff, 0x7fff, 0xffff |
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18 }; |
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19 |
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20 |
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21 /* copy as much as possible from the sliding window to the output area */ |
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22 local int inflate_flush( /* s, z, r) */ |
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23 inflate_blocks_statef *s, |
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24 z_streamp z, |
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25 int r ) |
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26 { |
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27 uInt n; |
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28 Bytef *p; |
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29 Bytef *q; |
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30 |
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31 /* local copies of source and destination pointers */ |
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32 p = z->next_out; |
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33 q = s->read; |
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34 |
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35 /* compute number of bytes to copy as far as end of window */ |
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36 n = (uInt)((q <= s->write ? s->write : s->end) - q); |
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37 if (n > z->avail_out) n = z->avail_out; |
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38 if (n && r == Z_BUF_ERROR) r = Z_OK; |
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39 |
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40 /* update counters */ |
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41 z->avail_out -= n; |
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42 z->total_out += n; |
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43 |
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44 /* update check information */ |
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45 if (s->checkfn != Z_NULL) |
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46 z->adler = s->check = (*s->checkfn)(s->check, q, n); |
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47 |
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48 /* copy as far as end of window */ |
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49 zmemcpy(p, q, n); |
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50 p += n; |
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51 q += n; |
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52 |
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53 /* see if more to copy at beginning of window */ |
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54 if (q == s->end) |
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55 { |
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56 /* wrap pointers */ |
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57 q = s->window; |
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58 if (s->write == s->end) |
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59 s->write = s->window; |
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60 |
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61 /* compute bytes to copy */ |
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62 n = (uInt)(s->write - q); |
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63 if (n > z->avail_out) n = z->avail_out; |
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64 if (n && r == Z_BUF_ERROR) r = Z_OK; |
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65 |
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66 /* update counters */ |
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67 z->avail_out -= n; |
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68 z->total_out += n; |
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69 |
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70 /* update check information */ |
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71 if (s->checkfn != Z_NULL) |
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72 z->adler = s->check = (*s->checkfn)(s->check, q, n); |
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73 |
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74 /* copy */ |
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75 zmemcpy(p, q, n); |
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76 p += n; |
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77 q += n; |
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78 } |
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79 |
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80 /* update pointers */ |
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81 z->next_out = p; |
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82 s->read = q; |
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83 |
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84 /* done */ |
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85 return r; |
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86 } |