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1 /* inflate_util.c -- data and routines common to blocks and codes
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2 * Copyright (C) 1995-1998 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 struct inflate_codes_state {int dummy;}; /* for buggy compilers */
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13
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14 /* And'ing with mask[n] masks the lower n bits */
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15 uInt inflate_mask[17] = {
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16 0x0000,
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17 0x0001, 0x0003, 0x0007, 0x000f, 0x001f, 0x003f, 0x007f, 0x00ff,
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18 0x01ff, 0x03ff, 0x07ff, 0x0fff, 0x1fff, 0x3fff, 0x7fff, 0xffff
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19 };
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20
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21
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22 /* copy as much as possible from the sliding window to the output area */
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23 int inflate_flush(s, z, r)
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24 inflate_blocks_statef *s;
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25 z_streamp z;
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26 int r;
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27 {
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28 uInt n;
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29 Bytef *p;
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30 Bytef *q;
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31
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32 /* local copies of source and destination pointers */
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33 p = z->next_out;
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34 q = s->read;
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35
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36 /* compute number of bytes to copy as far as end of window */
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37 n = (uInt)((q <= s->write ? s->write : s->end) - q);
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38 if (n > z->avail_out) n = z->avail_out;
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39 if (n && r == Z_BUF_ERROR) r = Z_OK;
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40
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41 /* update counters */
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42 z->avail_out -= n;
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43 z->total_out += n;
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44
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45 /* update check information */
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46 if (s->checkfn != Z_NULL)
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47 z->adler = s->check = (*s->checkfn)(s->check, q, n);
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48
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49 /* copy as far as end of window */
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50 zmemcpy(p, q, n);
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51 p += n;
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52 q += n;
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53
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54 /* see if more to copy at beginning of window */
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55 if (q == s->end)
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56 {
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57 /* wrap pointers */
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58 q = s->window;
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59 if (s->write == s->end)
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60 s->write = s->window;
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61
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62 /* compute bytes to copy */
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63 n = (uInt)(s->write - q);
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64 if (n > z->avail_out) n = z->avail_out;
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65 if (n && r == Z_BUF_ERROR) r = Z_OK;
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66
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67 /* update counters */
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68 z->avail_out -= n;
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69 z->total_out += n;
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70
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71 /* update check information */
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72 if (s->checkfn != Z_NULL)
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73 z->adler = s->check = (*s->checkfn)(s->check, q, n);
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74
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75 /* copy */
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76 zmemcpy(p, q, n);
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77 p += n;
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78 q += n;
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79 }
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80
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81 /* update pointers */
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82 z->next_out = p;
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83 s->read = q;
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84
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85 /* done */
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86 return r;
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87 }
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